- Email: [email protected]
Surgical Alternatives for the Palliation of Heart Failure: A Prospectus
Journal of Cardiac Failure Vol. 11 No. 9 2005
Perspective
Surgical Alternatives for the Palliation of Heart Failure: A Prospectus THOMAS S. MAXEY, MD, W. BRENT KEELING, MD, AND K. ERIC SOMMERS, MD Tampa, Florida
ABSTRACT Background: Congestive heart failure (CHF) is the leading cause of hospital admissions in the United States. Methods and Results: CHF has a variety of palliative options for treatment and 1 curative one: cardiac transplantation. Palliative medical therapies are often limited in effectiveness by progression of the disease or patient intolerance. Because of limited donor availability, alternative surgical strategies are now being relied on for palliation of patients in end-stage CHF. Conclusion: In this manuscript, we review the principles, outcomes, and practices of some of these surgical strategies often used in the palliation of end-stage CHF. Key Words: Heart failure, Surgery, Coronary artery bypass, Mitral valve, Ventricular restoration.
coronary revascularization, mitral valve reconstruction, and endoventricular circular patch plasty. This article will review the concepts, techniques, and outcomes of these restorative procedures.
Heart transplantation is an established and effective therapy for patients with end-stage congestive heart failure (CHF). However, limits in available donor organs severely restrict transplantation for CHF. Effective medical therapy for heart failure is limited in many cases by disease progression. Therefore, a need for innovative surgical approaches aimed at palliation of heart failure exists. The aim of surgical palliation of dilated cardiomyopathy is to restore normal anatomic relationships of the left ventricle and mitral apparatus. Procedures designed to restore ventricular shape and subsequently improve left ventricular function are based on the specific etiologies of cardiomyopathy. Contributing factors include: (1) infarcted or ischemic muscle (regional ischemia), (2) secondary dilation after valvular insufficiency, and (3) intrinsic myocyte dysfunction as in idiopathic dilated cardiomyopathy, Chagas disease, and other direct muscle disorders. Several surgical procedures are under evaluation for palliation of heart failure including
Coronary Revascularization Patients with coronary artery disease and decreased left ventricular function have a poor outlook despite maximum medical therapy with a two year survival rate of only 20% to 30%. Coronary artery bypass grafting (CABG) for ischemic cardiomyopathy has been shown to be a reasonable alternative to transplantation and medical treatment of patients with advanced ventricular dysfunction.1,2 Given the shortage of organs for transplantation, high-risk CABG is an increasingly appealing option for patients with endstage heart failure and operable coronary disease. Although patients with ischemic cardiomyopathy may have coronary revascularization as an option, it can be difficult to predict outcome. In analyzing 143 patients with an ejection fraction less than 30%, Luciani and associates suggested that perioperative angina may be a predictor of a good result.3 Twenty patients underwent myocardial revascularization and showed no difference in actuarial survival when compared with the 51 patients who underwent transplantation. Angina was the most common presenting symptom of the patients undergoing CABG. The University of Virginia experience has shown
From the Department of Surgery, University of South Florida, Tampa, Florida. Manuscript received April 5, 2005; revised manuscript received July 11, 2005; revised manuscript accepted July 14, 2005. Reprint requests: K. Eric Sommers, MD, Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive Tampa, FL 33612. 1071-9164/$ - see front matter Ó 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.cardfail.2005.07.004
670
Surgical Alternatives for the Palliation of Heart Failure
that although this may be true, the lack of angina did not predict a worse outcome.2 96 patients in this study underwent CABG with an ejection fraction (EF) !25%. All patients were either New York Heart Association (NYHA) class III or IV. The only independent predictors of poor outcome in this cohort were age (O68.8) and poor target vessel quality. Interestingly, the presence or absence of angina, preoperative EF, preoperative arrhythmias, aortic crossclamp time, and the number of grafts had no significant effect on outcome. Results from the same center evaluated the outcomes of 39 patients with a mean preoperative EF was 18.3% who underwent CABG for ischemic cardiomyopathy. There was 1 operative mortality, 8 late deaths (7 of which were due to dysrhythmia), and 3-year survival was 83%.4 The AWESOME study (Angina With Extremely Serious Operative Mortality Evaluation) included 446 patients with a left ventricular ejection fraction less than 35%.5 Survival in this large group of patients ranged from 59% to 72% at 36 months after CABG. Given the power of this study, the outcomes are encouraging. Results from the CABG Patch Trial further elucidated the role of primary coronary bypass in patients with low ejection fractions. This randomized multicenter trial evaluated 1429 patients who underwent either primary or repeat CABG. All patients had an ejection fraction less than 36%. Operative mortality was significantly higher in patients who underwent repeat CABG (12.0% versus 4.6%).6 Table 1 summarizes the results of these studies. The lower limit of left ventricular (LV) function that will allow for a safe operation is not known. Selection of patients for high-risk CABG involves multiple considerations. It is important to determine first if any conditions exist that may preclude intervention or that could raise the risk of revascularization above any potential benefit. These include patients who have severe comorbid diseases including renal failure, pulmonary disease, or cerebral vascular disease. Furthermore, patients with other longevity limiting illnesses should be excluded (ie, cancer, severe lung or liver disease, advanced diabetes, collagen vascular disease). Finally, technical factors including previous myocardial revascularization or a history of chest radiation should alert the cardiac surgeon that the risk of revascularization may be too high. Perhaps the most important discriminator in preoperative patient selection, however, should be myocardial viability and the presence of ischemia in the viable myocardium. Patients with evidence of flow metabolism mismatches
Maxey et al
671
are much more likely to have a subsequent myocardial infarction as opposed to patients that do not. Myocardial viability has been assessed using a number of methods including positron emission testing, cardiac magnetic resonance imaging, and nuclear medicine studies. Although the best test for myocardial viability remains debatable, the need for preoperative myocardial viability testing is unquestioned in the setting of ischemic cardiomyopathy. The concept of reversible hibernating myocardium is also clinically important because ischemic ventricular functional abnormalities have been shown to ameliorate by favorably altering myocardial supply/demand imbalance. Preoperative tests are important not only in determining the presence of ischemia (which may not be well correlated with angina in many patients) but also in determining the absolute amount of myocardium that could be revascularized. In general, if left ventricular volumes are large (greater than 250 mL), meaningful improvement of ejection fraction is unlikely with CABG alone. If the ventricle is not greatly enlarged and there is extensive jeopardized viable myocardium corresponding to greater than 20% of LV mass, functional improvement is likely, and these patients should be selected for surgical revascularization regardless of ejection fraction. Finally, any test for myocardial viability and ischemia must be correlated with cardiac catheterization findings to determine the technical suitability of coronary artery bypass grafting in each particular patient. Technical considerations include the quality of distal vessels for bypass targets. Operative time spent grafting very small or diseased vessels is counterproductive, and additional techniques such as endarterectomy may not be helpful and may increase surgical risk. The use of internal mammary arteries is clearly beneficial if the conduit is of good caliber. Absolute attention to myocardial protection, and the careful use of antegrade and retrograde blood cardioplegia should be encouraged.7 Transesophageal echocardiography used in the operating room to assess regional myocardial contractility before and after revascularization is helpful. The use of the intra-aortic balloon pump and non–b receptor agonist inotropes such as phosodiesterase inhibitors have further increased the likelihood of a good outcome in these patients from an operative standpoint.8 There are many reports of off-pump CABG being used in this subset of patients and if expertise and experience with the technique is available, it may provide satisfactory outcomes.
Table 1. Chart Comparing Recent Outcomes of CABG Performed in the Setting of Low EF Number of Patients Elefteriades et al (1993) Langenburg et al (1989) Kron et al (1989) Lucciani et al (1993) AWESOME trial (2004) a
83 96 39 20 140
Mean Preoperative EF 24.6% 20.0% 18.3% 22% 25%–30%
Mean EF at Follow-up
Hospital Mortality
Survival
33.2% d
8.4% 8.0% 2.6% 14.3% d
80% (3 year) d 83% (3 year) 80% (5 year) 59–72% (3 year)
42%a d
EF determined by echocardiography; remaining EFs determined by angiography. CABG, coronary artery bypass graft; EF, ejection fraction; AWESOME, Angina With Extremely Serious Operative Mortality Evaluation.
672 Journal of Cardiac Failure Vol. 11 No. 9 December 2005 Mitral Valve Repair/Replacement Functional mitral regurgitation (MR) of varying severity accompanies many patients with end-stage cardiomyopathy. Normal mitral valve competence results from the interaction between the annulus, leaflets, chordae tendinae, papillary muscles, and the ventricular free wall. In dilated cardiomyopathy, MR usually results from an alteration in the annular-ventricular apparatus and altered ventricular geometry.9 In the healthy state, mitral leaflet area is 2.5 times the area of the mitral orifice. As ventricular and annular enlargement occurs, this ratio is diminished such that coaptation of the mitral leaflets becomes ineffective and functional regurgitation develops.9 The diameter of the mitral annulus is therefore the most important factor in mitral valve competence. Evolution of mitral valve surgery in patients with LV dysfunction has been greatly advanced by the observation that preservation of annulo-papillary continuity and preservation of subvalvular structures leads to improved outcomes. The additional experience with mitral valve repair versus replacement provided the rationale for the series of mitral valve repairs in patients with depressed LV function described by Bolling et al.10 In this series, 48 patients underwent mitral annuloplasty. All patients were NYHA Class III or IV. Actuarial survival was 82% at 1 year and 71% at 2 years. Only 1 patient progressed to transplantation. More recent investigations from the University of Virginia have clearly demonstrated that mitral repair is superior to mitral replacement when associated with coronary artery disease in terms of perioperative morbidity and hospital mortality.11 This study consisted of 100 patients who underwent CABG in conjunction with their respective mitral valve procedure. Interestingly, the in-hospital mortality of patients undergoing mitral valve replacement was 10.7%, whereas the mortality for those patients undergoing repair was 1.9% (P ! .05). The conclusion of the authors was that mitral valve repair was clearly the preferred procedure when performed in conjunction with coronary revascularization. Results of either mitral valve replacement or repair are less favorable in patients with ischemic cardiomyopathy secondary to the progression of coronary artery disease and continued loss of LV function.10,12 In spite of the optimism engendered by prior studies, recent information from the University of Michigan indicates that mortality rates in patients with MR and LV dysfunction is not improved.13 All patients in this study had an EF of less than 30%. Because this study contained excellent statistical analysis, the investigators first established end points (death, ventricular device insertion, transplantation) and then delineated risk factors leading to the prescribed end points. Of the patients deemed to be candidates for surgery, mortality was 38% for those not undergoing mitral valve annuloplasty versus 48% for those who underwent mitral valve annuloplasty (P 5 NS). Mitral valve annuloplasty, therefore, had no bearing on clinical outcome.
Patients with ischemic MR are a heterogeneous group which explains the wide range of outcomes after surgery in these patients. Observational studies in both experimental animals and clinical subjects demonstrate varied mechanisms. Carpentier’s functional classification of leaflet motion describes two plausible mechanisms. In patients with Carpentier type I dysfunction, leaflet motion is unrestricted and ischemic mitral regurgitation occurs on the basis of posterior annular dilatation; this process is ordinarily corrected by ring annuloplasty. Type IIIb leaflet motion is caused by tethering of the anterior and posterior leaflets to the posterior papillary muscle and subjacent left ventricle. Annuloplasty alone is occasionally inadequate in type IIIb disease as residual leaflet tethering after annuloplasty results in mitral regurgitation despite adequate annular area reduction. This mechanism leads to progressive mitral regurgitation and has been observed in 20% of patients after mitral annuloplasty as reported by investigators from the University of Virginia and confirmed by Grossi and associates.14 Carpentier recommends further downsizing of the ring to treat residual mitral regurgitation after annuloplasty for type IIIb ischemic mitral regurgitation. Although this may be effective, it fails to identify and specifically address the mechanism of residual mitral regurgitation, leaving the pathophysiologic process of leaflet tethering uncorrected. Liel-Cohen and associates, using 3-dimensional echocardiography, showed that apical displacement of the posterior papillary muscle tip after posterolateral ischemia is a prevalent mechanism of ischemic MR.15 Through a series of provocative experimental studies, that group developed 2 experimental surgical strategies for treatment of ischemic MR from this mechanism. The first procedure sought to reposition the posterior papillary muscle tip through plication of the infarcted posterolateral epicardial left ventricular surface. By relocating the posterior papillary muscle tip, apical tethering of the posterior leaflet was reduced, resulting in less mitral regurgitation. In a more recent publication from that group, cutting second-order chordae tendinae to the anterior leaflet of was shown to improve coaptation and decrease MR.16 Using a porcine model of MR, these investigators cut 2 central basal chordae without subsequent prolapse. All 8 pigs showed a dramatic improvement in MR from 7.1 mL per beat before cutting to 0.9 mL per beat after. This procedure prevents tethering of the leaflet by uncoupling a segment of the subvalvular apparatus. The tip of the posterior papillary muscle could therefore remain abnormally positioned without regional leaflet restriction. Building on these data, surgeons at the University of Virginia have adopted a policy of surgical relocation of the subvalvular apparatus in all cases of chronic ischemic mitral regurgitation with previous transmural inferior wall infarctions. In patients with a minimally dilated left ventricle (!6 cm end-systolic dimension), they developed a simple procedure for relocation of the posterior papillary muscle tip to treat type IIIb leaflet motion after mitral annuloplasty. In patients with a dilated left ventricle (O6 cm end-systolic
Surgical Alternatives for the Palliation of Heart Failure
dimension), a Dor procedure relocates the papillary muscle base (see ventricular restoration).17 Ventricular Restoration Ischemic cardiomyopathy after myocardial infarction results from loss of LV contraction in the infarcted areas and subsequent remodeling of noninfarcted tissue. Attempts to surgically address aneurysmal areas were pioneered by Cooley and his first report in 1958 served as the benchmark against which subsequent reports were compared.18 Cooley’s direct repair was felt by some surgeons to be suboptimal and Dor reported an innovative method of surgical repair of aneurysmal and infracted or akinetic territories.19 Vincent Dor described an intraventricular patch to exclude all akinetic, nonresectable areas and thus restore a more normal ventricular cavity as well as complete revascularization. Dor reported his initial experience in 25 patients in 1985, while at the same time Jatene accomplished the same LV reduction by external circular reduction with imbrication of the akinetic septum. Jatene described the use of a patch in 10% of patients and revascularization in only 20% of patients.20 Cooley updated his series in 1989 describing endoaneurysmorrhaphy with a Dacron patch to address the same problem.21 Each new method sought to improve on the results of Cooley’s 1958 description of linear closure of LV aneurysms.18 There have been many recent advances in the diagnosis and treatment of idiopathic dilated cardiomyopathy. Although surgical approaches continue to evolve, the basic goal is consistent: restoration of the normal elliptical geometry of the left ventricle. The Dor procedure (endoventricular circular patch plasty) is a relatively new surgical technique that applies to patients with ventricular dysfunction after an infarction for either akinesia or dyskinesia. It consists of reducing and reconstructing the left ventricular chamber by using an endoventricular circular patch and grafting diseased coronary vessels (Fig. 1). The goal of the intraventricular patch is to convert large areas of akinetic muscle into a much smaller region. The basis is that progressive heart failure and death does not occur with limited infarctions. The exclusion of large akinetic sections of ventricular wall also diminishes ventricular size which provides a favorable prognosis with less chance of recurrent heart failure.22 The surgical approach to endoventricular circular patch plasty excludes all scar tissue. The most important aspect of this procedure is that it is applicable to akinesia as well as dyskinesia. Maxey et al reported that their experience of ventricular reconstruction with CABG is not only safe in patients with ischemic cardiomyopathy but also improves survival.23 Dor’s approach has been confirmed in a multicenter registry.24 Surgical mortality is low and 3-year survival is gratifying. Most importantly, rehospitalization for CHF was significantly less than with coronary bypass alone.
Maxey et al
673
The decision to approach the CHF patient with a dilated ventricle by ventricular restoration is made preoperatively based on echocardiography, and ventriculograms. The importance of accurate ventricular volume measurements cannot be overemphasized as this is far more predictive of outcome than ejection fraction.25 The morphology of the lesion must be appreciated and areas of akinesia and dyskinesia must be recognized preoperatively or intraoperatively.26 Often times there may appear to be normal, somewhat thickened muscle in the anterior apical segment. One must see beyond the normal appearing epicardium and exclude the entire segment to delete the mid-myocardial and endocardial scar. Extensive ventricular dilation can stretch the remote muscle and cause displacement of normal papillary muscles resulting in MR. Researchers at the University of Virginia and others have demonstrated correction can be achieved by reducing the area between the widened papillary muscles with sutures.17 Di Donato et al have shown that late MR after the Dor procedure is associated with poor prognosis and emphasized the efficacy of early correction.27 Mitral repair or replacement is associated with LV reconstruction when needed; however, it is not well established which technique is most effective. The mitral annulus can be narrowed either through the ventricular approach with sutures or by placement of an annuloplasty ring via the atrial route. The repair of MR, therefore, is aimed at the apparatus as a whole and not its individual components.28 Menicanti et al described their technique of repairing moderate to severe MR during the LV restoration procedure.29 It consists of reducing the mitral annulus and imbricating the papillary muscles without a prosthetic ring, approaching the valve through the ventricle through the same incision necessary to perform ventricular restoration. This aggressive, combined surgical approach is aimed at correcting the 3 components of ischemic cardiomyopathy: relieving ischemia, reducing LV wall tension by decreasing LV volumes, and reducing volume overload and pulmonary hypertension by repairing the mitral valve. Despite a relatively high perioperative mortality rate (15.2%), patients experienced improved clinical functional class and thus quality of life. Cumulative survival at a 30-month followup was 63%. Investigators at the University of Virginia have reviewed an early series of 34 patients who underwent the Dor procedure.28 Those investigators examined not only the preand postoperative ventricular function, but also mitral valve function after ventricular restoration. They noted an improvement in MR in 64% of patients despite no mitral intervention. This amelioration of mitral insufficiency after the Dor procedure is related to the remodeled ventricle. Restoration of the LV geometry results in a narrowed configuration of papillary muscles with an improvement in the degree of mitral insufficiency. The long-term effects of this reshaped geometry and the realignment of the mitral apparatus, however, need to be elucidated.
674 Journal of Cardiac Failure Vol. 11 No. 9 December 2005
Fig. 1. The Dor procedure. (A) Transmyocardial Incision made in anterior surface through scar or dyskinetic area. (B) Scar excluded with 2 or more purse string sutures. (C) Incision closed. Reprinted with permission: Ó The Cleveland Clinic 2004. The Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH. www.clevelandclinic.org
Several recent articles have suggested a possible benefit to combining ventricular restoration with coronary artery bypass in appropriate patients. The STICH trial (Surgical Treatment for Ischemic Heart Failure) is a multicenter, randomized international trial that seeks to answer questions with regard to both CABG and ventricular restoration. It seeks enroll 2800 patients with ejection fractions less than 35% from 100 centers (Fig. 2). The surgical arms will compare ventricular restoration and CABG and medical therapy versus CABG and medical therapy versus medical therapy alone.30 The STICH researchers are seeking to define the role of CABG, ventricular restoration, and medical therapy in the palliation of heart failure (Fig. 2). As well, the STICH trial will focus on the most appropriate preoperative determinant of myocardial viability. Results of this randomized trial will no doubt have an impact on the surgical management of heart failure.30 CorCap and CoapSys With limited donor organ availability for transplantation, some researchers have turned to prosthetic devices to limit
or potentially reverse further ventricular dilation. The CorCap Cardiac Support Device (Acorn Cardiovascular, Inc, St. Paul, MN) is a meshlike device designed to circumferentially support the myocardium thereby reducing wall tension.31 CorCap was implanted in 48 patients as part of an initial safety study, and 11 of these patients have had follow-up to 3 years. All 11 demonstrated a significantly decreased LV end-diastolic dimension within 6 months after insertion, and lLVEF increased. These results have been durable to 3 years. In a multicenter randomized study involving 300 patients, patients with dilated cardiomyopathy and NYHA Class III–IV heart failure were randomized into 1 of 2 groups based on optimal therapy. A total of 193 patients underwent mitral valve repair or replacement with or without the addition of CorCap, and 107 patients underwent either optimal medical therapy or optimal medical therapy plus CorCap. Patients who underwent CorCap insertion had a statistically significant reduction in LV end-diastolic and end-systolic volumes, fewer transplantations, fewer ventricular assist device insertions, and a significant improvement in quality of life with a median follow-up of 22 months. There was no difference is hospital admissions
Fig. 2. Schematic detailing Surgical Treatment for Ischemic Heart Failure trial.
Surgical Alternatives for the Palliation of Heart Failure
or adverse events between the group with CorCap insertion and the group without. Approval of this device is currently pending in the United States.32 Investigators at the Cleveland Clinic are currently investigating CoapSys (Myocor; Maple Grove, MN), which is a device used to treat functional mitral regurgitation. It consists of 2 epicardial pads connected by a subvalvular cord and functions by reducing annular diameter and displacement of the papillary muscles. To date, the device has only been implanted in a canine model of heart failure after rapid ventricular pacing with excellent results. Although no human studies have been reported to date, the concept and initial animal data are promising.33,34 Conclusion End-stage congestive heart failure is a disease with limited treatment options making palliative efforts the mainstay of therapy. Surgical efforts to palliate the patient in NYHA Class III or IV heart failure are focused on the restoration of blow flood to hibernating myocardium, the correction of valvular insufficiency, and the restoration of normal ventricular form and function. Therapy is individualized based on the cause of cardiomyopathy, and outcomes vary. Because organs for possible transplantation remain in high demand, the expanding role for the surgical treatment of heart failure is inevitable. References 1. Elefteriades JA, Tolis G Jr, Levi E, Mills LK, Zaret BL. Coronary artery bypass grafting in severe left ventricular dysfunction: excellent survival with improved ejection fraction and functional state. J Am Coll Cardiol 1993;22:1411–7. 2. Langenburg SE, Buchanan SA, Blackbourne LH, Scheri RP, Sinclair KN, et al. Predicting survival after coronary revascularization for ischemic cardiomyopathy. Ann Thorac Surg 1995;60:1193–6; discussion 1196–7. 3. Luciani GB, Faggian G, Razzolini R, Livi U, Bortolotti U, Mazzucco A. Severe ischemic left ventricular failure: coronary operation or heart transplantation. Ann Thorac Surg 1993;55:719–23. 4. Kron IL, Flanagan TL, Blackbourne LH, Schroeder RA, Nolan SP. Coronary revascularization rather than cardiac transplantation for chronic ischemic cardiomyopathy. Ann Surg 1989;210:348–54. 5. Sedlis SP, Ramanathan KB, Morrison DA, Sethi G, Sacks J, et al. Outcome of percutaneous coronary intervention versus coronary bypass grafting for patients with low left ventricular ejection fractions, unstable angina pectoris, and risk factors for adverse outcomes with bypass (the AWESOME Randomized Trial and Registry). Am J Cardiol 2004; 94:118–20. 6. Kron IL, Cope JT, Baker LD Jr, Spotnitz HM. The risks of reoperative coronary artery bypass in chronic ischemic cardiomyopathy: results of the CABG Patch Trial. Circulation 1997;96 Suppl:II-21–5. 7. Flack JE 3rd, Cook JR, May SJ, Lemeshow S, Engelman RM, et al. Does cardioplegia type affect outcome and survival in patients with advanced left ventricular dysfunction? Results from the CABG Patch Trial. Circulation 2000;102(Suppl 3):III84–9. 8. Dupuis JY, Bondy R, Cattran C, et al. Amrinone and dobutamine as primary treatment of low cardiac output syndrome following coronary artery surgery: a comparison of their effects on hemodynamics and outcome. J Cardiothorac Vasc Anesth 1992;6:542–53.
Maxey et al
675
9. Kono T, Sabbah HN, Rosman H, Alam M, Jafri S, Goldstein S. LV shape is the primary determinant of functional MR in heart failure. J Am Coll Cardiol 1992;20:1594–8. 10. Bolling SF, Pagani FD, Deeb GM, Bach DS. Intermediate-term outcome of mitral reconstruction in cardiomyopathy. J Thorac Cardiovasc Surg 1998;115:381–6; discussion 387–8. 11. Reece TB, Tribble CG, Ellman PI, Maxey TS, Woodford RL, Dimeling GM, et al. Mitral repair is superior to replacement when associated with coronary artery disease. Ann Surg 2004;239:671–5; discussion 675–7. 12. Goldman ME, Mora F, Guarino T, Fuster V, Mindich BP. Mitral valvuloplasty is superior to valve replacement for preservation of left ventricular function: an intraoperative two-dimensional echocardiographic study. J Am Coll Cardiol 1987;10:568–75. 13. Wu AH, Aaronson KD, Bolling SF, Pagani FD, Welch K, et al. Impact of mitral valve annuloplasty on mortality risk in patients with mitral regurgitation and left ventricular systolic dysfunction. J Am Coll Cardiol 2005;45:381–7. 14. Grossi EA, Bizekis CS, LaPietra A, Derivaux CC, Galloway AC, et al. Late results of isolated mitral annuloplasty for ‘‘functional’’ ischemic mitral insufficiency. J Card Surg 2001;16:328–32. 15. Liel-Cohen N, Guerrero JL, Otsuji Y, Handschumacher MD, Rudski LG, Hunziker PR, et al. Design of a new surgical approach for ventricular remodeling to relieve ischemic mitral regurgitation: insights from 3-dimensional echocardiography. Circulation 2000;101: 2756–63. 16. Messas E, Guerrero JL, Handschumacher MD, Conrad C, Chow CM, Sullivan S, et al. Chordal cutting: a new therapeutic approach for ischemic mitral regurgitation. Circulation 2001;104:1958–63. 17. Kron IL, Green GR, Cope JT. Surgical relocation of the posterior papillary muscle in chronic ischemic mitral regurgitation. Ann Thorac Surg 2002;74:600–1. 18. Cooley DA, Collins HA, Morris GC Jr, Chapman DW. Ventricular aneurysm after myocardial infarction; surgical excision with use of temporary cardiopulmonary bypass. J Am Med Assoc 1958;167: 557–60. 19. Dor V, Kreitmann P, Jourdan J, et al. Interest in physiologic closure of left ventricle after resection and endocardiectomy for aneurysm of akinetic zone comparison with classical technique about a series of 209 left ventricular resections (abstract). J Cardiovasc Surg 1985;26:73. 20. Jatene AD. Left ventricular aneurysmectomy resection or reconstruction. J Thorac Cardiovasc Surg 1985;89:321–31. 21. Cooley D. Ventricular endoaneurysmorrhaphy: a simplified repair for extensive postinfarction aneurysm. J Card Surg 1989;4:200–5. 22. Migrino RQ, Young JB, Ellis SG, White HD, Lundergan CF, et al. End-systolic volume index at 90–180 minutes into reperfusion therapy for acute myocardial infarction is a strong predictor of early and late mortality. Circulation 1997;96:116–21. 23. Maxey TS, Reece TB, Ellman PI, Butler PD, Kern JA, Tribble CG, et al. Coronary artery bypass with ventricular restoration is superior to coronary artery bypass alone in patients with ischemic cardiomyopathy. J Thorac Cardiovasc Surg 2004;127:428–34. 24. Athanasuleas CL, Buckberg GD, Stanley AW, Siler W, Dor V, Di Donato M, et al. Surgical ventricular restoration in the treatment of congestive heart failure due to post-infarction ventricular dilation. J Am Coll Cardiol 2004;44:1439–45. 25. Vanoverschelde JL, Depre C, Gerber BL, Borgers M, Wijns W, Robert A, et al. Time course of functional recovery after coronary artery bypass graft surgery in patients with chronic left ventricular ischemic dysfunction. Am J Cardiol 2000;85:1432–9. 26. Di Donato M, Sabatier M, Dor V, Toso A, Maioli M, Fantini F. Akinetic versus dyskinetic postinfarction scar: relation to surgical outcome in patients submitted to endoventricular circular patch plasty repair. J Am Coll Cardiol 1997;29:1569–75. 27. Di Donato M, Sabatier M, Dor V, Gensini GF, Toso A, Maioli M, et al. Effects of Dor procedure on left ventricular dimension and shape and geometric correlates of mitral regurgitation one year after surgery. J Thorac Cardiovasc Surg 2001;121:91–6.
676 Journal of Cardiac Failure Vol. 11 No. 9 December 2005 28. Kaza AK, Patel MR, Fiser SM, Long SM, Kern JA, et al. Ventricular reconstruction results in improved left ventricular function and amelioration of mitral insufficiency. Ann Surg 2002;235:828–32. 29. Menicanti L, Di Donato M, Frigiola A, Buckberg G, Santambrogio C, Ranucci M, et al. Ischemic mitral regurgitation: intraventricular papillary muscle imbrication without mitral ring during left ventricular restoration. J Thorac Cardiovasc Surg 2002;123:1041–50. 30. Joyce D, Loebe M, Noon GP, McRee S, Southard R, et al. Revascularization and ventricular restoration in patients with ischemic heart failure: the STICH trial. Curr Opin Cardiol 2003;18:454–7. 31. Starling RC, Jessup M. Worldwide clinical experience with the CorCap Cardiac Support Device. J Card Fail 2004;10(Suppl): S225–33.
32. Clinical Evaluation of the CorCap Cardiac Support Device in Patients with Dilated Cardiomyopathy. Available from: http://www.acorncv. com/healthcare_providers/StudyResults.pdf. Accessed August 19, 2005. 33. Fukamachi K, Inoue M, Popovic ZB, Doi K, Schenk S, et al. Offpump mitral valve repair using the Coapsys device: a pilot study in a pacing-induced mitral regurgitation model. Ann Thorac Surg 2004;77:688–92; discussion 692–3. 34. Fukamachi K, Popovic ZB, Inoue M, Doi K, Schenk S, et al. Changes in mitral annular and left ventricular dimensions and left ventricular pressure-volume relations after off-pump treatment of mitral regurgitation with the Coapsys device. Eur J Cardiothorac Surg 2004;25: 352–7.
Perspective
Surgical Alternatives for the Palliation of Heart Failure: A Prospectus THOMAS S. MAXEY, MD, W. BRENT KEELING, MD, AND K. ERIC SOMMERS, MD Tampa, Florida
ABSTRACT Background: Congestive heart failure (CHF) is the leading cause of hospital admissions in the United States. Methods and Results: CHF has a variety of palliative options for treatment and 1 curative one: cardiac transplantation. Palliative medical therapies are often limited in effectiveness by progression of the disease or patient intolerance. Because of limited donor availability, alternative surgical strategies are now being relied on for palliation of patients in end-stage CHF. Conclusion: In this manuscript, we review the principles, outcomes, and practices of some of these surgical strategies often used in the palliation of end-stage CHF. Key Words: Heart failure, Surgery, Coronary artery bypass, Mitral valve, Ventricular restoration.
coronary revascularization, mitral valve reconstruction, and endoventricular circular patch plasty. This article will review the concepts, techniques, and outcomes of these restorative procedures.
Heart transplantation is an established and effective therapy for patients with end-stage congestive heart failure (CHF). However, limits in available donor organs severely restrict transplantation for CHF. Effective medical therapy for heart failure is limited in many cases by disease progression. Therefore, a need for innovative surgical approaches aimed at palliation of heart failure exists. The aim of surgical palliation of dilated cardiomyopathy is to restore normal anatomic relationships of the left ventricle and mitral apparatus. Procedures designed to restore ventricular shape and subsequently improve left ventricular function are based on the specific etiologies of cardiomyopathy. Contributing factors include: (1) infarcted or ischemic muscle (regional ischemia), (2) secondary dilation after valvular insufficiency, and (3) intrinsic myocyte dysfunction as in idiopathic dilated cardiomyopathy, Chagas disease, and other direct muscle disorders. Several surgical procedures are under evaluation for palliation of heart failure including
Coronary Revascularization Patients with coronary artery disease and decreased left ventricular function have a poor outlook despite maximum medical therapy with a two year survival rate of only 20% to 30%. Coronary artery bypass grafting (CABG) for ischemic cardiomyopathy has been shown to be a reasonable alternative to transplantation and medical treatment of patients with advanced ventricular dysfunction.1,2 Given the shortage of organs for transplantation, high-risk CABG is an increasingly appealing option for patients with endstage heart failure and operable coronary disease. Although patients with ischemic cardiomyopathy may have coronary revascularization as an option, it can be difficult to predict outcome. In analyzing 143 patients with an ejection fraction less than 30%, Luciani and associates suggested that perioperative angina may be a predictor of a good result.3 Twenty patients underwent myocardial revascularization and showed no difference in actuarial survival when compared with the 51 patients who underwent transplantation. Angina was the most common presenting symptom of the patients undergoing CABG. The University of Virginia experience has shown
From the Department of Surgery, University of South Florida, Tampa, Florida. Manuscript received April 5, 2005; revised manuscript received July 11, 2005; revised manuscript accepted July 14, 2005. Reprint requests: K. Eric Sommers, MD, Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive Tampa, FL 33612. 1071-9164/$ - see front matter Ó 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.cardfail.2005.07.004
670
Surgical Alternatives for the Palliation of Heart Failure
that although this may be true, the lack of angina did not predict a worse outcome.2 96 patients in this study underwent CABG with an ejection fraction (EF) !25%. All patients were either New York Heart Association (NYHA) class III or IV. The only independent predictors of poor outcome in this cohort were age (O68.8) and poor target vessel quality. Interestingly, the presence or absence of angina, preoperative EF, preoperative arrhythmias, aortic crossclamp time, and the number of grafts had no significant effect on outcome. Results from the same center evaluated the outcomes of 39 patients with a mean preoperative EF was 18.3% who underwent CABG for ischemic cardiomyopathy. There was 1 operative mortality, 8 late deaths (7 of which were due to dysrhythmia), and 3-year survival was 83%.4 The AWESOME study (Angina With Extremely Serious Operative Mortality Evaluation) included 446 patients with a left ventricular ejection fraction less than 35%.5 Survival in this large group of patients ranged from 59% to 72% at 36 months after CABG. Given the power of this study, the outcomes are encouraging. Results from the CABG Patch Trial further elucidated the role of primary coronary bypass in patients with low ejection fractions. This randomized multicenter trial evaluated 1429 patients who underwent either primary or repeat CABG. All patients had an ejection fraction less than 36%. Operative mortality was significantly higher in patients who underwent repeat CABG (12.0% versus 4.6%).6 Table 1 summarizes the results of these studies. The lower limit of left ventricular (LV) function that will allow for a safe operation is not known. Selection of patients for high-risk CABG involves multiple considerations. It is important to determine first if any conditions exist that may preclude intervention or that could raise the risk of revascularization above any potential benefit. These include patients who have severe comorbid diseases including renal failure, pulmonary disease, or cerebral vascular disease. Furthermore, patients with other longevity limiting illnesses should be excluded (ie, cancer, severe lung or liver disease, advanced diabetes, collagen vascular disease). Finally, technical factors including previous myocardial revascularization or a history of chest radiation should alert the cardiac surgeon that the risk of revascularization may be too high. Perhaps the most important discriminator in preoperative patient selection, however, should be myocardial viability and the presence of ischemia in the viable myocardium. Patients with evidence of flow metabolism mismatches
Maxey et al
671
are much more likely to have a subsequent myocardial infarction as opposed to patients that do not. Myocardial viability has been assessed using a number of methods including positron emission testing, cardiac magnetic resonance imaging, and nuclear medicine studies. Although the best test for myocardial viability remains debatable, the need for preoperative myocardial viability testing is unquestioned in the setting of ischemic cardiomyopathy. The concept of reversible hibernating myocardium is also clinically important because ischemic ventricular functional abnormalities have been shown to ameliorate by favorably altering myocardial supply/demand imbalance. Preoperative tests are important not only in determining the presence of ischemia (which may not be well correlated with angina in many patients) but also in determining the absolute amount of myocardium that could be revascularized. In general, if left ventricular volumes are large (greater than 250 mL), meaningful improvement of ejection fraction is unlikely with CABG alone. If the ventricle is not greatly enlarged and there is extensive jeopardized viable myocardium corresponding to greater than 20% of LV mass, functional improvement is likely, and these patients should be selected for surgical revascularization regardless of ejection fraction. Finally, any test for myocardial viability and ischemia must be correlated with cardiac catheterization findings to determine the technical suitability of coronary artery bypass grafting in each particular patient. Technical considerations include the quality of distal vessels for bypass targets. Operative time spent grafting very small or diseased vessels is counterproductive, and additional techniques such as endarterectomy may not be helpful and may increase surgical risk. The use of internal mammary arteries is clearly beneficial if the conduit is of good caliber. Absolute attention to myocardial protection, and the careful use of antegrade and retrograde blood cardioplegia should be encouraged.7 Transesophageal echocardiography used in the operating room to assess regional myocardial contractility before and after revascularization is helpful. The use of the intra-aortic balloon pump and non–b receptor agonist inotropes such as phosodiesterase inhibitors have further increased the likelihood of a good outcome in these patients from an operative standpoint.8 There are many reports of off-pump CABG being used in this subset of patients and if expertise and experience with the technique is available, it may provide satisfactory outcomes.
Table 1. Chart Comparing Recent Outcomes of CABG Performed in the Setting of Low EF Number of Patients Elefteriades et al (1993) Langenburg et al (1989) Kron et al (1989) Lucciani et al (1993) AWESOME trial (2004) a
83 96 39 20 140
Mean Preoperative EF 24.6% 20.0% 18.3% 22% 25%–30%
Mean EF at Follow-up
Hospital Mortality
Survival
33.2% d
8.4% 8.0% 2.6% 14.3% d
80% (3 year) d 83% (3 year) 80% (5 year) 59–72% (3 year)
42%a d
EF determined by echocardiography; remaining EFs determined by angiography. CABG, coronary artery bypass graft; EF, ejection fraction; AWESOME, Angina With Extremely Serious Operative Mortality Evaluation.
672 Journal of Cardiac Failure Vol. 11 No. 9 December 2005 Mitral Valve Repair/Replacement Functional mitral regurgitation (MR) of varying severity accompanies many patients with end-stage cardiomyopathy. Normal mitral valve competence results from the interaction between the annulus, leaflets, chordae tendinae, papillary muscles, and the ventricular free wall. In dilated cardiomyopathy, MR usually results from an alteration in the annular-ventricular apparatus and altered ventricular geometry.9 In the healthy state, mitral leaflet area is 2.5 times the area of the mitral orifice. As ventricular and annular enlargement occurs, this ratio is diminished such that coaptation of the mitral leaflets becomes ineffective and functional regurgitation develops.9 The diameter of the mitral annulus is therefore the most important factor in mitral valve competence. Evolution of mitral valve surgery in patients with LV dysfunction has been greatly advanced by the observation that preservation of annulo-papillary continuity and preservation of subvalvular structures leads to improved outcomes. The additional experience with mitral valve repair versus replacement provided the rationale for the series of mitral valve repairs in patients with depressed LV function described by Bolling et al.10 In this series, 48 patients underwent mitral annuloplasty. All patients were NYHA Class III or IV. Actuarial survival was 82% at 1 year and 71% at 2 years. Only 1 patient progressed to transplantation. More recent investigations from the University of Virginia have clearly demonstrated that mitral repair is superior to mitral replacement when associated with coronary artery disease in terms of perioperative morbidity and hospital mortality.11 This study consisted of 100 patients who underwent CABG in conjunction with their respective mitral valve procedure. Interestingly, the in-hospital mortality of patients undergoing mitral valve replacement was 10.7%, whereas the mortality for those patients undergoing repair was 1.9% (P ! .05). The conclusion of the authors was that mitral valve repair was clearly the preferred procedure when performed in conjunction with coronary revascularization. Results of either mitral valve replacement or repair are less favorable in patients with ischemic cardiomyopathy secondary to the progression of coronary artery disease and continued loss of LV function.10,12 In spite of the optimism engendered by prior studies, recent information from the University of Michigan indicates that mortality rates in patients with MR and LV dysfunction is not improved.13 All patients in this study had an EF of less than 30%. Because this study contained excellent statistical analysis, the investigators first established end points (death, ventricular device insertion, transplantation) and then delineated risk factors leading to the prescribed end points. Of the patients deemed to be candidates for surgery, mortality was 38% for those not undergoing mitral valve annuloplasty versus 48% for those who underwent mitral valve annuloplasty (P 5 NS). Mitral valve annuloplasty, therefore, had no bearing on clinical outcome.
Patients with ischemic MR are a heterogeneous group which explains the wide range of outcomes after surgery in these patients. Observational studies in both experimental animals and clinical subjects demonstrate varied mechanisms. Carpentier’s functional classification of leaflet motion describes two plausible mechanisms. In patients with Carpentier type I dysfunction, leaflet motion is unrestricted and ischemic mitral regurgitation occurs on the basis of posterior annular dilatation; this process is ordinarily corrected by ring annuloplasty. Type IIIb leaflet motion is caused by tethering of the anterior and posterior leaflets to the posterior papillary muscle and subjacent left ventricle. Annuloplasty alone is occasionally inadequate in type IIIb disease as residual leaflet tethering after annuloplasty results in mitral regurgitation despite adequate annular area reduction. This mechanism leads to progressive mitral regurgitation and has been observed in 20% of patients after mitral annuloplasty as reported by investigators from the University of Virginia and confirmed by Grossi and associates.14 Carpentier recommends further downsizing of the ring to treat residual mitral regurgitation after annuloplasty for type IIIb ischemic mitral regurgitation. Although this may be effective, it fails to identify and specifically address the mechanism of residual mitral regurgitation, leaving the pathophysiologic process of leaflet tethering uncorrected. Liel-Cohen and associates, using 3-dimensional echocardiography, showed that apical displacement of the posterior papillary muscle tip after posterolateral ischemia is a prevalent mechanism of ischemic MR.15 Through a series of provocative experimental studies, that group developed 2 experimental surgical strategies for treatment of ischemic MR from this mechanism. The first procedure sought to reposition the posterior papillary muscle tip through plication of the infarcted posterolateral epicardial left ventricular surface. By relocating the posterior papillary muscle tip, apical tethering of the posterior leaflet was reduced, resulting in less mitral regurgitation. In a more recent publication from that group, cutting second-order chordae tendinae to the anterior leaflet of was shown to improve coaptation and decrease MR.16 Using a porcine model of MR, these investigators cut 2 central basal chordae without subsequent prolapse. All 8 pigs showed a dramatic improvement in MR from 7.1 mL per beat before cutting to 0.9 mL per beat after. This procedure prevents tethering of the leaflet by uncoupling a segment of the subvalvular apparatus. The tip of the posterior papillary muscle could therefore remain abnormally positioned without regional leaflet restriction. Building on these data, surgeons at the University of Virginia have adopted a policy of surgical relocation of the subvalvular apparatus in all cases of chronic ischemic mitral regurgitation with previous transmural inferior wall infarctions. In patients with a minimally dilated left ventricle (!6 cm end-systolic dimension), they developed a simple procedure for relocation of the posterior papillary muscle tip to treat type IIIb leaflet motion after mitral annuloplasty. In patients with a dilated left ventricle (O6 cm end-systolic
Surgical Alternatives for the Palliation of Heart Failure
dimension), a Dor procedure relocates the papillary muscle base (see ventricular restoration).17 Ventricular Restoration Ischemic cardiomyopathy after myocardial infarction results from loss of LV contraction in the infarcted areas and subsequent remodeling of noninfarcted tissue. Attempts to surgically address aneurysmal areas were pioneered by Cooley and his first report in 1958 served as the benchmark against which subsequent reports were compared.18 Cooley’s direct repair was felt by some surgeons to be suboptimal and Dor reported an innovative method of surgical repair of aneurysmal and infracted or akinetic territories.19 Vincent Dor described an intraventricular patch to exclude all akinetic, nonresectable areas and thus restore a more normal ventricular cavity as well as complete revascularization. Dor reported his initial experience in 25 patients in 1985, while at the same time Jatene accomplished the same LV reduction by external circular reduction with imbrication of the akinetic septum. Jatene described the use of a patch in 10% of patients and revascularization in only 20% of patients.20 Cooley updated his series in 1989 describing endoaneurysmorrhaphy with a Dacron patch to address the same problem.21 Each new method sought to improve on the results of Cooley’s 1958 description of linear closure of LV aneurysms.18 There have been many recent advances in the diagnosis and treatment of idiopathic dilated cardiomyopathy. Although surgical approaches continue to evolve, the basic goal is consistent: restoration of the normal elliptical geometry of the left ventricle. The Dor procedure (endoventricular circular patch plasty) is a relatively new surgical technique that applies to patients with ventricular dysfunction after an infarction for either akinesia or dyskinesia. It consists of reducing and reconstructing the left ventricular chamber by using an endoventricular circular patch and grafting diseased coronary vessels (Fig. 1). The goal of the intraventricular patch is to convert large areas of akinetic muscle into a much smaller region. The basis is that progressive heart failure and death does not occur with limited infarctions. The exclusion of large akinetic sections of ventricular wall also diminishes ventricular size which provides a favorable prognosis with less chance of recurrent heart failure.22 The surgical approach to endoventricular circular patch plasty excludes all scar tissue. The most important aspect of this procedure is that it is applicable to akinesia as well as dyskinesia. Maxey et al reported that their experience of ventricular reconstruction with CABG is not only safe in patients with ischemic cardiomyopathy but also improves survival.23 Dor’s approach has been confirmed in a multicenter registry.24 Surgical mortality is low and 3-year survival is gratifying. Most importantly, rehospitalization for CHF was significantly less than with coronary bypass alone.
Maxey et al
673
The decision to approach the CHF patient with a dilated ventricle by ventricular restoration is made preoperatively based on echocardiography, and ventriculograms. The importance of accurate ventricular volume measurements cannot be overemphasized as this is far more predictive of outcome than ejection fraction.25 The morphology of the lesion must be appreciated and areas of akinesia and dyskinesia must be recognized preoperatively or intraoperatively.26 Often times there may appear to be normal, somewhat thickened muscle in the anterior apical segment. One must see beyond the normal appearing epicardium and exclude the entire segment to delete the mid-myocardial and endocardial scar. Extensive ventricular dilation can stretch the remote muscle and cause displacement of normal papillary muscles resulting in MR. Researchers at the University of Virginia and others have demonstrated correction can be achieved by reducing the area between the widened papillary muscles with sutures.17 Di Donato et al have shown that late MR after the Dor procedure is associated with poor prognosis and emphasized the efficacy of early correction.27 Mitral repair or replacement is associated with LV reconstruction when needed; however, it is not well established which technique is most effective. The mitral annulus can be narrowed either through the ventricular approach with sutures or by placement of an annuloplasty ring via the atrial route. The repair of MR, therefore, is aimed at the apparatus as a whole and not its individual components.28 Menicanti et al described their technique of repairing moderate to severe MR during the LV restoration procedure.29 It consists of reducing the mitral annulus and imbricating the papillary muscles without a prosthetic ring, approaching the valve through the ventricle through the same incision necessary to perform ventricular restoration. This aggressive, combined surgical approach is aimed at correcting the 3 components of ischemic cardiomyopathy: relieving ischemia, reducing LV wall tension by decreasing LV volumes, and reducing volume overload and pulmonary hypertension by repairing the mitral valve. Despite a relatively high perioperative mortality rate (15.2%), patients experienced improved clinical functional class and thus quality of life. Cumulative survival at a 30-month followup was 63%. Investigators at the University of Virginia have reviewed an early series of 34 patients who underwent the Dor procedure.28 Those investigators examined not only the preand postoperative ventricular function, but also mitral valve function after ventricular restoration. They noted an improvement in MR in 64% of patients despite no mitral intervention. This amelioration of mitral insufficiency after the Dor procedure is related to the remodeled ventricle. Restoration of the LV geometry results in a narrowed configuration of papillary muscles with an improvement in the degree of mitral insufficiency. The long-term effects of this reshaped geometry and the realignment of the mitral apparatus, however, need to be elucidated.
674 Journal of Cardiac Failure Vol. 11 No. 9 December 2005
Fig. 1. The Dor procedure. (A) Transmyocardial Incision made in anterior surface through scar or dyskinetic area. (B) Scar excluded with 2 or more purse string sutures. (C) Incision closed. Reprinted with permission: Ó The Cleveland Clinic 2004. The Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH. www.clevelandclinic.org
Several recent articles have suggested a possible benefit to combining ventricular restoration with coronary artery bypass in appropriate patients. The STICH trial (Surgical Treatment for Ischemic Heart Failure) is a multicenter, randomized international trial that seeks to answer questions with regard to both CABG and ventricular restoration. It seeks enroll 2800 patients with ejection fractions less than 35% from 100 centers (Fig. 2). The surgical arms will compare ventricular restoration and CABG and medical therapy versus CABG and medical therapy versus medical therapy alone.30 The STICH researchers are seeking to define the role of CABG, ventricular restoration, and medical therapy in the palliation of heart failure (Fig. 2). As well, the STICH trial will focus on the most appropriate preoperative determinant of myocardial viability. Results of this randomized trial will no doubt have an impact on the surgical management of heart failure.30 CorCap and CoapSys With limited donor organ availability for transplantation, some researchers have turned to prosthetic devices to limit
or potentially reverse further ventricular dilation. The CorCap Cardiac Support Device (Acorn Cardiovascular, Inc, St. Paul, MN) is a meshlike device designed to circumferentially support the myocardium thereby reducing wall tension.31 CorCap was implanted in 48 patients as part of an initial safety study, and 11 of these patients have had follow-up to 3 years. All 11 demonstrated a significantly decreased LV end-diastolic dimension within 6 months after insertion, and lLVEF increased. These results have been durable to 3 years. In a multicenter randomized study involving 300 patients, patients with dilated cardiomyopathy and NYHA Class III–IV heart failure were randomized into 1 of 2 groups based on optimal therapy. A total of 193 patients underwent mitral valve repair or replacement with or without the addition of CorCap, and 107 patients underwent either optimal medical therapy or optimal medical therapy plus CorCap. Patients who underwent CorCap insertion had a statistically significant reduction in LV end-diastolic and end-systolic volumes, fewer transplantations, fewer ventricular assist device insertions, and a significant improvement in quality of life with a median follow-up of 22 months. There was no difference is hospital admissions
Fig. 2. Schematic detailing Surgical Treatment for Ischemic Heart Failure trial.
Surgical Alternatives for the Palliation of Heart Failure
or adverse events between the group with CorCap insertion and the group without. Approval of this device is currently pending in the United States.32 Investigators at the Cleveland Clinic are currently investigating CoapSys (Myocor; Maple Grove, MN), which is a device used to treat functional mitral regurgitation. It consists of 2 epicardial pads connected by a subvalvular cord and functions by reducing annular diameter and displacement of the papillary muscles. To date, the device has only been implanted in a canine model of heart failure after rapid ventricular pacing with excellent results. Although no human studies have been reported to date, the concept and initial animal data are promising.33,34 Conclusion End-stage congestive heart failure is a disease with limited treatment options making palliative efforts the mainstay of therapy. Surgical efforts to palliate the patient in NYHA Class III or IV heart failure are focused on the restoration of blow flood to hibernating myocardium, the correction of valvular insufficiency, and the restoration of normal ventricular form and function. Therapy is individualized based on the cause of cardiomyopathy, and outcomes vary. Because organs for possible transplantation remain in high demand, the expanding role for the surgical treatment of heart failure is inevitable. References 1. Elefteriades JA, Tolis G Jr, Levi E, Mills LK, Zaret BL. Coronary artery bypass grafting in severe left ventricular dysfunction: excellent survival with improved ejection fraction and functional state. J Am Coll Cardiol 1993;22:1411–7. 2. Langenburg SE, Buchanan SA, Blackbourne LH, Scheri RP, Sinclair KN, et al. Predicting survival after coronary revascularization for ischemic cardiomyopathy. Ann Thorac Surg 1995;60:1193–6; discussion 1196–7. 3. Luciani GB, Faggian G, Razzolini R, Livi U, Bortolotti U, Mazzucco A. Severe ischemic left ventricular failure: coronary operation or heart transplantation. Ann Thorac Surg 1993;55:719–23. 4. Kron IL, Flanagan TL, Blackbourne LH, Schroeder RA, Nolan SP. Coronary revascularization rather than cardiac transplantation for chronic ischemic cardiomyopathy. Ann Surg 1989;210:348–54. 5. Sedlis SP, Ramanathan KB, Morrison DA, Sethi G, Sacks J, et al. Outcome of percutaneous coronary intervention versus coronary bypass grafting for patients with low left ventricular ejection fractions, unstable angina pectoris, and risk factors for adverse outcomes with bypass (the AWESOME Randomized Trial and Registry). Am J Cardiol 2004; 94:118–20. 6. Kron IL, Cope JT, Baker LD Jr, Spotnitz HM. The risks of reoperative coronary artery bypass in chronic ischemic cardiomyopathy: results of the CABG Patch Trial. Circulation 1997;96 Suppl:II-21–5. 7. Flack JE 3rd, Cook JR, May SJ, Lemeshow S, Engelman RM, et al. Does cardioplegia type affect outcome and survival in patients with advanced left ventricular dysfunction? Results from the CABG Patch Trial. Circulation 2000;102(Suppl 3):III84–9. 8. Dupuis JY, Bondy R, Cattran C, et al. Amrinone and dobutamine as primary treatment of low cardiac output syndrome following coronary artery surgery: a comparison of their effects on hemodynamics and outcome. J Cardiothorac Vasc Anesth 1992;6:542–53.
Maxey et al
675
9. Kono T, Sabbah HN, Rosman H, Alam M, Jafri S, Goldstein S. LV shape is the primary determinant of functional MR in heart failure. J Am Coll Cardiol 1992;20:1594–8. 10. Bolling SF, Pagani FD, Deeb GM, Bach DS. Intermediate-term outcome of mitral reconstruction in cardiomyopathy. J Thorac Cardiovasc Surg 1998;115:381–6; discussion 387–8. 11. Reece TB, Tribble CG, Ellman PI, Maxey TS, Woodford RL, Dimeling GM, et al. Mitral repair is superior to replacement when associated with coronary artery disease. Ann Surg 2004;239:671–5; discussion 675–7. 12. Goldman ME, Mora F, Guarino T, Fuster V, Mindich BP. Mitral valvuloplasty is superior to valve replacement for preservation of left ventricular function: an intraoperative two-dimensional echocardiographic study. J Am Coll Cardiol 1987;10:568–75. 13. Wu AH, Aaronson KD, Bolling SF, Pagani FD, Welch K, et al. Impact of mitral valve annuloplasty on mortality risk in patients with mitral regurgitation and left ventricular systolic dysfunction. J Am Coll Cardiol 2005;45:381–7. 14. Grossi EA, Bizekis CS, LaPietra A, Derivaux CC, Galloway AC, et al. Late results of isolated mitral annuloplasty for ‘‘functional’’ ischemic mitral insufficiency. J Card Surg 2001;16:328–32. 15. Liel-Cohen N, Guerrero JL, Otsuji Y, Handschumacher MD, Rudski LG, Hunziker PR, et al. Design of a new surgical approach for ventricular remodeling to relieve ischemic mitral regurgitation: insights from 3-dimensional echocardiography. Circulation 2000;101: 2756–63. 16. Messas E, Guerrero JL, Handschumacher MD, Conrad C, Chow CM, Sullivan S, et al. Chordal cutting: a new therapeutic approach for ischemic mitral regurgitation. Circulation 2001;104:1958–63. 17. Kron IL, Green GR, Cope JT. Surgical relocation of the posterior papillary muscle in chronic ischemic mitral regurgitation. Ann Thorac Surg 2002;74:600–1. 18. Cooley DA, Collins HA, Morris GC Jr, Chapman DW. Ventricular aneurysm after myocardial infarction; surgical excision with use of temporary cardiopulmonary bypass. J Am Med Assoc 1958;167: 557–60. 19. Dor V, Kreitmann P, Jourdan J, et al. Interest in physiologic closure of left ventricle after resection and endocardiectomy for aneurysm of akinetic zone comparison with classical technique about a series of 209 left ventricular resections (abstract). J Cardiovasc Surg 1985;26:73. 20. Jatene AD. Left ventricular aneurysmectomy resection or reconstruction. J Thorac Cardiovasc Surg 1985;89:321–31. 21. Cooley D. Ventricular endoaneurysmorrhaphy: a simplified repair for extensive postinfarction aneurysm. J Card Surg 1989;4:200–5. 22. Migrino RQ, Young JB, Ellis SG, White HD, Lundergan CF, et al. End-systolic volume index at 90–180 minutes into reperfusion therapy for acute myocardial infarction is a strong predictor of early and late mortality. Circulation 1997;96:116–21. 23. Maxey TS, Reece TB, Ellman PI, Butler PD, Kern JA, Tribble CG, et al. Coronary artery bypass with ventricular restoration is superior to coronary artery bypass alone in patients with ischemic cardiomyopathy. J Thorac Cardiovasc Surg 2004;127:428–34. 24. Athanasuleas CL, Buckberg GD, Stanley AW, Siler W, Dor V, Di Donato M, et al. Surgical ventricular restoration in the treatment of congestive heart failure due to post-infarction ventricular dilation. J Am Coll Cardiol 2004;44:1439–45. 25. Vanoverschelde JL, Depre C, Gerber BL, Borgers M, Wijns W, Robert A, et al. Time course of functional recovery after coronary artery bypass graft surgery in patients with chronic left ventricular ischemic dysfunction. Am J Cardiol 2000;85:1432–9. 26. Di Donato M, Sabatier M, Dor V, Toso A, Maioli M, Fantini F. Akinetic versus dyskinetic postinfarction scar: relation to surgical outcome in patients submitted to endoventricular circular patch plasty repair. J Am Coll Cardiol 1997;29:1569–75. 27. Di Donato M, Sabatier M, Dor V, Gensini GF, Toso A, Maioli M, et al. Effects of Dor procedure on left ventricular dimension and shape and geometric correlates of mitral regurgitation one year after surgery. J Thorac Cardiovasc Surg 2001;121:91–6.
676 Journal of Cardiac Failure Vol. 11 No. 9 December 2005 28. Kaza AK, Patel MR, Fiser SM, Long SM, Kern JA, et al. Ventricular reconstruction results in improved left ventricular function and amelioration of mitral insufficiency. Ann Surg 2002;235:828–32. 29. Menicanti L, Di Donato M, Frigiola A, Buckberg G, Santambrogio C, Ranucci M, et al. Ischemic mitral regurgitation: intraventricular papillary muscle imbrication without mitral ring during left ventricular restoration. J Thorac Cardiovasc Surg 2002;123:1041–50. 30. Joyce D, Loebe M, Noon GP, McRee S, Southard R, et al. Revascularization and ventricular restoration in patients with ischemic heart failure: the STICH trial. Curr Opin Cardiol 2003;18:454–7. 31. Starling RC, Jessup M. Worldwide clinical experience with the CorCap Cardiac Support Device. J Card Fail 2004;10(Suppl): S225–33.
32. Clinical Evaluation of the CorCap Cardiac Support Device in Patients with Dilated Cardiomyopathy. Available from: http://www.acorncv. com/healthcare_providers/StudyResults.pdf. Accessed August 19, 2005. 33. Fukamachi K, Inoue M, Popovic ZB, Doi K, Schenk S, et al. Offpump mitral valve repair using the Coapsys device: a pilot study in a pacing-induced mitral regurgitation model. Ann Thorac Surg 2004;77:688–92; discussion 692–3. 34. Fukamachi K, Popovic ZB, Inoue M, Doi K, Schenk S, et al. Changes in mitral annular and left ventricular dimensions and left ventricular pressure-volume relations after off-pump treatment of mitral regurgitation with the Coapsys device. Eur J Cardiothorac Surg 2004;25: 352–7.