- Email: [email protected]
Clinical and angiographic outcome after stent placement for chronic coronary occlusion
14. Lincoff AM, Califf RM, Anderson KM, Weisman FH, Aguirre FV, Kleiman NS, Harrington RA, Topol EJ. Evidence for prevention of death and myocardial infarction with platelet membrane glycoprotein IIb/IIIa receptor blockade by abciximab (c7E3 Fab) among patients with unstable angina undergoing percutaneous coronary revascularization. J Am Coll Cardiol 1997;30:149 –156. 15. Lefkovits J, Ivanhoe RJ, Califf RM, Bergelson BA, Anderson KM, Stoner GL, Weisman HF, Topol EJ. Effects of platelet glycoprotein IIb/IIIa receptor
blockade by a chimeric monoclonal antibody (Abciximab) on acute and sixmonth outcomes after percutaneous transluminal coronary angioplasty for acute myocardial infarction. Am J Cardiol 1996;77:1045–1051. 16. The Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO IIb) Angioplasty Substudy Investigators. A clinical trial comparing primary coronary angioplasty with tissue plasminogen activator for acute myocardial infarction. N Engl J Med 1997;336:1621–1628.
Clinical and Angiographic Outcome After Stent Placement for Chronic Coronary Occlusion Shpend Elezi, MD, Adnan Kastrati, MD, Anne Wehinger, MD, Hanna Walter, Helmut Schu¨hlen, MD, Martin Hadamitzky, MD, Josef Dirschinger, MD, Franz-Josef Neumann, MD, and Albert Scho ¨ mig, MD anagement of patients with chronic coronary occlusion remains difficult because of a lower M initial success rate with angioplasty and a higher 1–10
frequency of restenosis, reocclusion, and adverse clinical events.3,11,12 Catheter-based approaches such as excimer laser and directional and high speed rotational atherectomy have been used with a favorable angiographic success rate and an acceptable clinical complication rate.13,14 Recently, stent placement in chronic coronary occlusion has been reported in several studies.11,15–18 In a randomized study,11 stent placement in native vessels has been shown to be superior to coronary angioplasty with respect to restenosis, reocclusion, and clinical outcome. However, comparative data of stent placement in chronic coronary occlusions and in stenotic lesions are still missing. The objectives of this study were to analyze the angiographic and clinical outcome in patients with successful stent placement in chronic coronary occlusions and to compare these results with those achieved after stenting of stenotic lesions. •••
Stent placement was attempted in 2,186 patients with symptomatic coronary artery disease during May 1992 through September 1996. Patients were excluded from this study if they had coronary stent implantation in the setting of cardiogenic shock complicating acute myocardial infarction (34 patients, 1.6%) and if they had unsuccessful stenting (54 patients, 2.5%). Thus, 2,098 patients with successful stent placement in 2,667 coronary lesions (148 chronically occluded and 2,519 stenotic lesions) were eligible for the study. The stent implantation technique has been described previously.19 Different stent types were implanted but the most prevalent were Palmaz-Schatz stents (66.8%). All patients were given orally 100 mg of aspirin twice daily, and this therapy was continued indefinitely; 26.6% of patients were treated with an anticoagulation regimen comprising heparin for 5 to 10 days From Medizinische Klinik rechts der Isar and Deutsches Herzzentrum,Technische Universita¨t Mu¨nchen, Munich, Germany. Dr. Elezi’s address is: Deutsches Herzzentrum Mu¨nchen, Lazarettstrasse 36, 80636 Mu¨nchen, Germany. Manuscript received January 20, 1998; revised manuscript received and accepted April 27, 1998.
MD,
and phenprocoumon (Marcumar, Hoffmann-La Roche, Germany) for 4 to 6 weeks, and 73.1% were treated with combined antiplatelet therapy with ticlopidine 250 mg twice daily. All patients were asked to undergo a control angiography at 6 months. All total occlusions (Thrombolysis In Myocardial Infarction trial flow 0 or 1) with unknown duration and those associated with documented myocardial infarction older than 2 weeks were considered chronic. Occlusion age was estimated by using available clinical information (acute myocardial infarction corresponding to the occluded vessel, sudden change in angina pattern) or information from previous cardiac catheterizations. Quantitative angiographic analysis was done using the automated edge-detection system CMS (Medis, Nuenen, The Netherlands). Restenosis was defined as a diameter stenosis $50% at control angiography. Major adverse cardiovascular events were defined as death of cardiac or procedure-related origin, nonfatal myocardial infarction, and target lesion revascularization due to symptoms and/or objective signs of ischemia (aortocoronary bypass surgery or repeat angioplasty of the stented vessel). Diagnosis of acute myocardial infarction was defined as a clinical episode of prolonged chest pain and an increase in serum cardiac enzyme levels to .2 times the upper normal limit, or the appearance of .1 new pathologic Q wave. Analyses were performed on a per-patient basis, selecting the occluded lesion or randomly only 1 lesion in patients with multilesion interventions. The discrete variables were expressed as counts and compared with Fisher’s exact test. Continuous variables were expressed as mean 6 SD and compared by means of unpaired, 2-tailed t test. Multivariable logistic regression was used to investigate potential independent risk factors for angiographic restenosis after 6 months. Survival curves were constructed by means of the Kaplan-Meier method and compared with the logrank test. In addition, the Cox proportional-hazards regression model was used to test for independent association of chronic occlusions with adverse clinical events. A p value ,0.05 was considered statistically significant. BRIEF REPORTS
803
of event-free survival was significantly lower in patients with chronic Chronic Stenotic occluded coronary vessels than with Occlusions Lesions stenotic lesions (64.4% vs 77.2%, p (n 5 132) (n 5 1,966) p Value ,0.001, Figure 1). This was due to a Women (%) 17 24 0.109 higher rate of repeat percutaneous Age (yr) 61610 63611 0.107 transluminal coronary angioplasty in Cigarette smoking (%) 46 42 0.466 chronically occluded lesions (31.1%) Hypercholesterolemia (%) 42 42 0.978 than in stenotic lesions (17.9%), Arterial hypertension (%) 53 64 0.011 Diabetes mellitus (%) 21 19 0.600 whereas the rate of coronary artery Unstable angina (%) 43 32 0.007 bypass graft surgery was similar in Previous myocardial infarction (%) 41 31 ,0.001 both groups (1.5% vs 1.8%, respecPrevious PTCA (%) 16 18 0.533 tively). To adjust for the differences Previous CABG (%) 6 8 0.534 in baseline clinical, angiographic, Multilesion intervention (%) 20 21 0.793 Multivessel disease (%) 67 71 0.388 and procedural characteristics beReduced left ventricular function (%) 33 23 0.008 tween the 2 groups (Tables I and II), we developed a multivariate model Data are expressed as mean 6 SD or percentages. CABG 5 aortocoronary bypass surgery; PTCA 5 percutaneous transluminal coronary angioplasty. using Cox proportional-hazards regression analysis for event-free survival, with 19 variables entered into the model as covariates. The results TABLE II Angiographic and Procedure-Related Characteristics of the model (R 5 0.2, p ,0.0001) demonstrated that chronic occlusion Chronic Stenotic is an independent risk factor for the Occlusions Lesions (n 5 132) (n 5 1,966) p Value occurrence of major adverse cardiac events during 1-year follow-up with Vessel a hazard ratio of 1.64 (95% confiLeft main artery (%) 0 0.2 0.493 Left anterior descending artery (%) 27 43 ,0.001 dence interval 1.16 to 2.32); addiCircumflex artery (%) 21 17 0.022 tional independent risk factors were Right coronary artery (%) 47 33 ,0.001 diabetes mellitus, localization of the Saphenous vein graft (%) 5.3 5.5 0.844 lesion in left anterior descending arRestenotic lesions (%) 13 14 0.675 tery, small vessel size, multiple stent Dissection before stenting (%) 46 46 0.887 Vessel size (mm) 3.0 6 0.5 3.1 6 0.5 0.115 placement, and greater residual steMLD before intervention (mm) 0 0.8 6 0.5 ,0.001 nosis after the procedure. MLD after intervention (mm) 2.9 6 0.5 3.0 6 0.5 0.014 Angiographic follow-up was perBalloon pressure (atm) 14 6 2.7 14 6 2.9 0.407 formed in 1,647 patients (82% of elB/RD ratio 1.1 6 0.1 1.1 6 0.1 0.911 Acute gain (mm) 2.9 6 0.4 2.2 6 0.6 ,0.001 igible patients) after a comparable Stent length (mm) 24 6 20 22 6 14 ,0.001 time interval (190 6 55 vs 191 6 66 DS before intervention (%) 100 74 6 15 ,0.001 days, p 5 0.74). Angiographic data DS after intervention (%) 8.1 6 12 5.9 6 10 0.032 at follow-up are listed in Table III. Data are expressed as mean 6 SD or percentages. Patients with chronic occlusions had B/RD 5 ; DS 5 diameter stenosis; MLD 5 minimal lumen diameter. a greater lumen loss but a larger net gain than patients with stenotic lesions. Diameter stenosis in the occlusion group was significantly greater than in the ste••• Analyses of baseline clinical characteristics (Table notic group, leading to a significantly higher restenoI) revealed that patients with chronic coronary occlu- sis rate. The occlusion rate was higher in the chronic sions had a significantly higher incidence of unstable occlusion group than in the stenotic group. In 23.1% angina (p 5 0.007) and previous documented myo- of the cases, reocclusion in patients in the chronic occlusion group was associated with myocardial incardial infarction (p ,0.001). Table II illustrates angiographic and procedural farction. The restenosis rate remained significantly characteristics. After stent implantation, chronically higher in the subgroup of the initially occluded lesions occluded lesions had a significantly smaller minimal that were not totally occluded at follow-up angiogralumen diameter (p 5 0.014) and greater diameter phy (37.9% vs 24.3%, p 5 0.003). The same was also stenosis (p 5 0.032) than stenotic lesions. A signifi- true for late lumen loss (1.23 6 0.73 vs 1.03 6 0.72 cantly larger number of stents were implanted in mm, p 5 0.01). In a multivariate logistic regression chronic occlusions than in stenotic lesions (p ,0.001). model including the same variables as in the Cox There were no significant differences between groups proportional-hazards regression model (accuracy 73%, p ,0.0001), chronic occlusion remained a sigwith respect to the stent type used. After 1 year, the probability of survival free of nificant independent risk factor for restenosis with an myocardial infarction was not significantly different odds ratio of 1.98 (95% confidence interval 1.30 to (93.9% vs 95.9%, p 5 0.27). However, the probability 3.00); additional independent risk factors were diabeTABLE I Clinical Characteristics of Patients
804 THE AMERICAN JOURNAL OF CARDIOLOGYT
VOL. 82
SEPTEMBER 15, 1998
FIGURE 1. Kaplan-Meier survival curves for freedom from major adverse cardiac events. The rate of eventfree survival was significantly lower among patients with chronic occlusions than among those with stenotic lesions.
TABLE III Results of Follow-Up Angiography
MLD (mm) Late loss (mm) Loss index Net gain (mm) DS (%) Reocclusion rate (%) Restenosis rate (%)
Chronic Occlusions (n 5 105)
Stenotic Lesions (n 5 1,543)
p Value
1.5 6 0.9 1.4 6 0.8 0.5 6 0.3 1.5 6 0.9 51 6 26 8.7 43
1.9 6 0.9 1.1 6 0.8 0.5 6 0.4 1.1 6 0.9 39 6 24 3.0 27
,0.001 0.001 0.282 ,0.001 ,0.001 0.002 ,0.001
Data are expressed as means 6 SD or percentages. Abbreviations as in Table II.
tes mellitus, small vessel size, and multiple stent placement. •••
Restenosis rate in the present study was higher in patients with stent placement for total chronic coronary occlusion. This may explain the more frequent need for target vessel revascularization in this group. This higher rate of angiographic restenosis was not due to the higher reocclusion rate because restenosis rate remained significantly higher even after lesions with repeat total occlusion were excluded. Our study concurs with previous reports11,16,17 with respect to a lower reocclusion rate after stenting versus up to 20% reported for percutaneous transluminal coronary angioplasty of chronic occlusions.1,4,12,20 This reduced risk for reocclusion after stenting may be attributed to a potent antithrombotic therapy given for 1 month and to the bigger lumen achieved with stenting. However, the precise mechanisms of a lower reocclusion after stenting remain to be elucidated. Differences in baseline and procedural characteristics and in inclusion criteria, may account for the different restenosis rates between the present and pre-
vious studies.11,15–18 Ozaki et al18 found a 29% restenosis rate after stenting in 20 lesions with chronic occlusion. They used laser angioplasty followed by implantation of a new type of Wallstent in a group of patients with a lower incidence of cardiovascular risk factors than in our study cohort. Sirnes et al11 found a 32% restenosis rate in 58 patients with chronic occlusion who received Palmaz-Schatz stents. This study excluded lesions with complex anatomy, angiographically visible thrombus, previous angioplasty, and with stenting for suboptimal results after percutaneous transluminal coronary angioplasty,11 which did not serve as exclusion criteria in the present study. Data about the presence and degree of collateral circulation in our patients are missing. This precludes an analysis of a possible influence of this factor on the angiographic and clinical outcome. The clinical outcome described here refers only to patients with chronic occlusions and successful intervention. In fact, despite major advances in coronary interventions, this has contributed little to improve the procedural success in patients with chronically occluded vessels. In summary, the clinical outcome of patients with chronically occluded coronary lesions during the first year after successful coronary stent placement is characterized by a greater frequency of target lesion revascularizations than those in patients with stenotic lesions. The greater need for target lesion revascularization is the clinical consequence of the higher incidence of restenosis and reocclusion in this group of patients. 1. Bell MR, Berger PB, Bresnahan JF, Reeder GS, Bailey KR, Holmes DR Jr.
Initial and long-term outcome of 354 patients after coronary balloon angioplasty of total coronary artery occlusions. Circulation 1992;85:1003–1011. 2. DiSciascio G, Vetrovec GW, Cowley MJ, Wolfgang TC. Early and late outcome of percutaneous transluminal coronary angioplasty for subacute and chronic total coronary occlusion. Am Heart J 1986;111:833– 839.
BRIEF REPORTS
805
3. Ellis SG, Shaw RE, Gershony G, Thomas R, Roubin GS, Douglas JS Jr, Topol EJ, Startzer SH, Myler RK, King SB III. Risk factors, time course and treatment effect for restenosis after successful percutaneous transluminal coronary angioplasty of chronic total occlusion. Am J Cardiol 1989;63:897–901. 4. Ivanhoe RJ, Weintraub WS, Douglas JS Jr, Lembo NJ, Furman M, Gershony G, Cohen CL, King SB III. Percutaneous transluminal coronary angioplasty of chronic total occlusions. Primary success, restenosis, and ong-term clinical follow-up. Circulation 1992;85:106 –115. 5. Melchior JP, Meier B, Urban P, Finci L, Steffenino G, Noble J, Rutishauser W. Percutaneous transluminal coronary angioplasty for chronic total coronary arterial occlusion. Am J Cardiol 1987;59:535–538. 6. Puma JA, Sketch MH Jr, Tcheng JE, Harrington RA, Phillips HR, Stack RS, Califf RM. Percutaneous revascularization of chronic coronary occlusions: an overview. J Am Coll Cardiol 1995;26:1–11. 7. Ruocco NA Jr, Ring ME, Holubkov R, Jacobs AK, Detre KM, Faxon DP. Results of coronary angioplasty of chronic total occlusions (the National Heart, Lung, and Blood Institute 1985-1986 Percutaneous Transluminal Angioplasty Registry). Am J Cardiol 1992;69:69 –76. 8. Serruys PW, Umans V, Heyndrickx GR, van den Brand M, de Feyter PJ, Wijns W, Jaski B, Hugenholtz PG. Elective PTCA of totally occluded coronary arteries not associated with acute myocardial infarction; short-term and long-term results. Eur Heart J 1985;6:2–12. 9. Stewart JT, Denne L, Bowker TJ, Mulcahy DA, Williams MG, Buller NP, Sigwart U, Rickards AF. Percutaneous transluminal coronary angioplasty in chronic coronary artery occlusion. J Am Coll Cardiol 1993;21:1371–1376. 10. Stone GW, Rutherford BD, McConahay DR, Johnson WL Jr, Giorgi LV, Ligon RW, Hartzler GO. Procedural outcome of angioplasty for total coronary artery occlusion: an analysis of 971 lesions in 905 patients. J Am Coll Cardiol 1990;15:849 – 856. 11. Sirnes P, Golf S, Myreng Y, Molstad P, Emanuelsson H, Albertsson P, Brekke M, Mangschau A, Endresen K, Kjekshus J. Stenting in Chronic Coronary Occlusion (SICCO): a randomized, controlled trial of adding stent implantation after successful angioplasty. J Am Coll Cardiol 1996;28:1444 –1451. 12. Violaris AG, Melkert R, Serruys PW. Long-term luminal renarrowing after
successful elective coronary angioplasty of total occlusions. A quantitative angiographic analysis. Circulation 1995;91:2140 –2150. 13. Holmes DR Jr, Forrester JS, Litvack F, Reeder GS, Leon MB, Rothbaum DA, Cummins FE, Goldenberg T, Bresnahan JF. Chronic total obstruction and shortterm outcome: the Excimer Laser Coronary Angioplasty Registry experience. Mayo Clin Proc 1993;68:5–10. 14. Hinohara T, Rowe MH, Robertson GC, Selmon MR, Braden L, Leggett JH, Vetter JW, Simpson JB. Effect of lesion characteristics on outcome of directional coronary atherectomy. J Am Coll Cardiol 1991;17:1112–1120. 15. Maiello L, Colombo A, Almagor Y, Bouzon R, Thomas J, Zerboni S, Finci L. Coronary stenting with a balloon-expandable stent after the recanalization of chronic total occlusions. Cathet Cardiovasc Diagn 1992;25:293–296. 16. Medina A, Melian F, Suarez de Lezo J, Pan M, Romero M, Hernandez E, Marrero J, Ortega JR, Pavlovic D. Effectiveness of coronary stenting for the treatment of chronic total occlusion in angina pectoris. Am J Cardiol 1994;73: 1222–1224. 17. Goldberg SL, Colombo A, Maiello L, Borrione M, Finci L, Almagor Y. Intracoronary stent insertion after balloon angioplasty of chronic total occlusions. J Am Coll Cardiol 1995;26:713–719. 18. Ozaki Y, Violaris AG, Hamburger J, Melkert R, Foley D, Keane D, de Feyter P, Serruys PW. Short- and long-term clinical and quantitative angiographic results with the new, less shortening Wallstent for vessel reconstruction in chronic total occlusion: a quantitative angiographic study. J Am Coll Cardiol 1996;28:354 –360. 19. Scho¨mig A, Neumann FJ, Kastrati A, Schuhlen H, Blasini R, Hadamitzky M, Walter H, Zitzmann-Roth EM, Richardt G, Alt E, Schmitt C, Ulm K. A randomized comparison of antiplatelet and anticoagulant therapy after the placement of coronary-artery stents. N Engl J Med 1996;334:1084 –1089. 20. Berger P, Holmes DR Jr, Ohman E, O’Hanesian M, Murphy J, Schwartz R, Serruys P, Faxon D. Restenosis, reocclusion and adverse cardiovascular events after successful balloon angioplasty of occluded versus nonoccluded coronary arteries. Results from the Multicenter American Research Trial With Cilazapril After Angioplasty to Prevent Transluminal Coronary Obstruction and Restenosis (MARCATOR). J Am Coll Cardiol 1996;27:1–7.
Myocardial Doppler Velocity Imaging—A Quantitative Technique for Interpretation of Dobutamine Echocardiography Elina Yamada,
MD,
Mario Garcia, MD, James D. Thomas, Thomas H. Marwick, MD, PhD
obutamine stress echocardiography (DSE) has become accepted as a safe and accurate methD odology for detecting ischemia, risk stratification, 1,2 3
4,5
6
and for detection of viability. However, interpretation of this test is limited by training, subjectivity, and image quality.7 Analysis of myocardial Doppler velocity (MDV) permits measurement of tissue velocity with a high spatial and temporal resolution, and may be performed using pulsed8,9 or color Doppler approaches.10 –12 Apical imaging with pulsewave myocardial Doppler imaging may be used to examine apex-based movement.13 This movement corresponds to the contraction vector of subendocardial myocytes,14 which are most susceptible to ischemia. We therefore sought to establish the feasibility of pulsewave MDV during dobutamine stress and to evaluate its correlation with qualitative DSE interpretation. •••
Seventy patients (67 6 10 years old, 22 women) undergoing DSE in the course of management of From the Cleveland Clinic Foundation, Cleveland, Ohio. Dr. Marwick’s address is: Department of Medicine, University of Queensland, Princess Alexandra Hospital, Brisbane, Queensland QLD 4102, Australia. Manuscript received March 12, 1998; revised manuscript received and accepted April 27, 1998.
806 THE AMERICAN JOURNAL OF CARDIOLOGYT
VOL. 82
MD,
and
known or suspected coronary artery disease were studied. Because the protocol involved segmental comparison with 2-dimensional images, studies with inadequate image quality were excluded. Patients consented to undergo the test, which was performed according to standard institutional guidelines. Dobutamine was infused in 3-minute dose increments from 5 to 50 mg/ kg/min. Dobutamine stress echocardiographic data were analyzed using the standard 16-segment model of the American Society of Echocardiography by 2 independent experienced observers blinded to the MDV results. Normal segments had normal contractility at rest and increased with stress. Hypertrophic segments defined as having wall thickness .12 mm were analyzed separately as well as normal segments (nonischemic, nonscarred segments) of ventricles with an abnormal response to stress. Ischemia was diagnosed in the presence of new or worsening wall motion abnormalities with stress. Wall motion abnormalities at rest that did not improve with dobutamine infusion identified scarring. Segments with a biphasic response showed improvement in contractility at low dose and demonstrated deterioration at the peak dose of dobutamine. A commercially available ultrasound system was used for image acquisition (Sequoia C 256, Acuson SEPTEMBER 15, 1998
blockade by a chimeric monoclonal antibody (Abciximab) on acute and sixmonth outcomes after percutaneous transluminal coronary angioplasty for acute myocardial infarction. Am J Cardiol 1996;77:1045–1051. 16. The Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO IIb) Angioplasty Substudy Investigators. A clinical trial comparing primary coronary angioplasty with tissue plasminogen activator for acute myocardial infarction. N Engl J Med 1997;336:1621–1628.
Clinical and Angiographic Outcome After Stent Placement for Chronic Coronary Occlusion Shpend Elezi, MD, Adnan Kastrati, MD, Anne Wehinger, MD, Hanna Walter, Helmut Schu¨hlen, MD, Martin Hadamitzky, MD, Josef Dirschinger, MD, Franz-Josef Neumann, MD, and Albert Scho ¨ mig, MD anagement of patients with chronic coronary occlusion remains difficult because of a lower M initial success rate with angioplasty and a higher 1–10
frequency of restenosis, reocclusion, and adverse clinical events.3,11,12 Catheter-based approaches such as excimer laser and directional and high speed rotational atherectomy have been used with a favorable angiographic success rate and an acceptable clinical complication rate.13,14 Recently, stent placement in chronic coronary occlusion has been reported in several studies.11,15–18 In a randomized study,11 stent placement in native vessels has been shown to be superior to coronary angioplasty with respect to restenosis, reocclusion, and clinical outcome. However, comparative data of stent placement in chronic coronary occlusions and in stenotic lesions are still missing. The objectives of this study were to analyze the angiographic and clinical outcome in patients with successful stent placement in chronic coronary occlusions and to compare these results with those achieved after stenting of stenotic lesions. •••
Stent placement was attempted in 2,186 patients with symptomatic coronary artery disease during May 1992 through September 1996. Patients were excluded from this study if they had coronary stent implantation in the setting of cardiogenic shock complicating acute myocardial infarction (34 patients, 1.6%) and if they had unsuccessful stenting (54 patients, 2.5%). Thus, 2,098 patients with successful stent placement in 2,667 coronary lesions (148 chronically occluded and 2,519 stenotic lesions) were eligible for the study. The stent implantation technique has been described previously.19 Different stent types were implanted but the most prevalent were Palmaz-Schatz stents (66.8%). All patients were given orally 100 mg of aspirin twice daily, and this therapy was continued indefinitely; 26.6% of patients were treated with an anticoagulation regimen comprising heparin for 5 to 10 days From Medizinische Klinik rechts der Isar and Deutsches Herzzentrum,Technische Universita¨t Mu¨nchen, Munich, Germany. Dr. Elezi’s address is: Deutsches Herzzentrum Mu¨nchen, Lazarettstrasse 36, 80636 Mu¨nchen, Germany. Manuscript received January 20, 1998; revised manuscript received and accepted April 27, 1998.
MD,
and phenprocoumon (Marcumar, Hoffmann-La Roche, Germany) for 4 to 6 weeks, and 73.1% were treated with combined antiplatelet therapy with ticlopidine 250 mg twice daily. All patients were asked to undergo a control angiography at 6 months. All total occlusions (Thrombolysis In Myocardial Infarction trial flow 0 or 1) with unknown duration and those associated with documented myocardial infarction older than 2 weeks were considered chronic. Occlusion age was estimated by using available clinical information (acute myocardial infarction corresponding to the occluded vessel, sudden change in angina pattern) or information from previous cardiac catheterizations. Quantitative angiographic analysis was done using the automated edge-detection system CMS (Medis, Nuenen, The Netherlands). Restenosis was defined as a diameter stenosis $50% at control angiography. Major adverse cardiovascular events were defined as death of cardiac or procedure-related origin, nonfatal myocardial infarction, and target lesion revascularization due to symptoms and/or objective signs of ischemia (aortocoronary bypass surgery or repeat angioplasty of the stented vessel). Diagnosis of acute myocardial infarction was defined as a clinical episode of prolonged chest pain and an increase in serum cardiac enzyme levels to .2 times the upper normal limit, or the appearance of .1 new pathologic Q wave. Analyses were performed on a per-patient basis, selecting the occluded lesion or randomly only 1 lesion in patients with multilesion interventions. The discrete variables were expressed as counts and compared with Fisher’s exact test. Continuous variables were expressed as mean 6 SD and compared by means of unpaired, 2-tailed t test. Multivariable logistic regression was used to investigate potential independent risk factors for angiographic restenosis after 6 months. Survival curves were constructed by means of the Kaplan-Meier method and compared with the logrank test. In addition, the Cox proportional-hazards regression model was used to test for independent association of chronic occlusions with adverse clinical events. A p value ,0.05 was considered statistically significant. BRIEF REPORTS
803
of event-free survival was significantly lower in patients with chronic Chronic Stenotic occluded coronary vessels than with Occlusions Lesions stenotic lesions (64.4% vs 77.2%, p (n 5 132) (n 5 1,966) p Value ,0.001, Figure 1). This was due to a Women (%) 17 24 0.109 higher rate of repeat percutaneous Age (yr) 61610 63611 0.107 transluminal coronary angioplasty in Cigarette smoking (%) 46 42 0.466 chronically occluded lesions (31.1%) Hypercholesterolemia (%) 42 42 0.978 than in stenotic lesions (17.9%), Arterial hypertension (%) 53 64 0.011 Diabetes mellitus (%) 21 19 0.600 whereas the rate of coronary artery Unstable angina (%) 43 32 0.007 bypass graft surgery was similar in Previous myocardial infarction (%) 41 31 ,0.001 both groups (1.5% vs 1.8%, respecPrevious PTCA (%) 16 18 0.533 tively). To adjust for the differences Previous CABG (%) 6 8 0.534 in baseline clinical, angiographic, Multilesion intervention (%) 20 21 0.793 Multivessel disease (%) 67 71 0.388 and procedural characteristics beReduced left ventricular function (%) 33 23 0.008 tween the 2 groups (Tables I and II), we developed a multivariate model Data are expressed as mean 6 SD or percentages. CABG 5 aortocoronary bypass surgery; PTCA 5 percutaneous transluminal coronary angioplasty. using Cox proportional-hazards regression analysis for event-free survival, with 19 variables entered into the model as covariates. The results TABLE II Angiographic and Procedure-Related Characteristics of the model (R 5 0.2, p ,0.0001) demonstrated that chronic occlusion Chronic Stenotic is an independent risk factor for the Occlusions Lesions (n 5 132) (n 5 1,966) p Value occurrence of major adverse cardiac events during 1-year follow-up with Vessel a hazard ratio of 1.64 (95% confiLeft main artery (%) 0 0.2 0.493 Left anterior descending artery (%) 27 43 ,0.001 dence interval 1.16 to 2.32); addiCircumflex artery (%) 21 17 0.022 tional independent risk factors were Right coronary artery (%) 47 33 ,0.001 diabetes mellitus, localization of the Saphenous vein graft (%) 5.3 5.5 0.844 lesion in left anterior descending arRestenotic lesions (%) 13 14 0.675 tery, small vessel size, multiple stent Dissection before stenting (%) 46 46 0.887 Vessel size (mm) 3.0 6 0.5 3.1 6 0.5 0.115 placement, and greater residual steMLD before intervention (mm) 0 0.8 6 0.5 ,0.001 nosis after the procedure. MLD after intervention (mm) 2.9 6 0.5 3.0 6 0.5 0.014 Angiographic follow-up was perBalloon pressure (atm) 14 6 2.7 14 6 2.9 0.407 formed in 1,647 patients (82% of elB/RD ratio 1.1 6 0.1 1.1 6 0.1 0.911 Acute gain (mm) 2.9 6 0.4 2.2 6 0.6 ,0.001 igible patients) after a comparable Stent length (mm) 24 6 20 22 6 14 ,0.001 time interval (190 6 55 vs 191 6 66 DS before intervention (%) 100 74 6 15 ,0.001 days, p 5 0.74). Angiographic data DS after intervention (%) 8.1 6 12 5.9 6 10 0.032 at follow-up are listed in Table III. Data are expressed as mean 6 SD or percentages. Patients with chronic occlusions had B/RD 5 ; DS 5 diameter stenosis; MLD 5 minimal lumen diameter. a greater lumen loss but a larger net gain than patients with stenotic lesions. Diameter stenosis in the occlusion group was significantly greater than in the ste••• Analyses of baseline clinical characteristics (Table notic group, leading to a significantly higher restenoI) revealed that patients with chronic coronary occlu- sis rate. The occlusion rate was higher in the chronic sions had a significantly higher incidence of unstable occlusion group than in the stenotic group. In 23.1% angina (p 5 0.007) and previous documented myo- of the cases, reocclusion in patients in the chronic occlusion group was associated with myocardial incardial infarction (p ,0.001). Table II illustrates angiographic and procedural farction. The restenosis rate remained significantly characteristics. After stent implantation, chronically higher in the subgroup of the initially occluded lesions occluded lesions had a significantly smaller minimal that were not totally occluded at follow-up angiogralumen diameter (p 5 0.014) and greater diameter phy (37.9% vs 24.3%, p 5 0.003). The same was also stenosis (p 5 0.032) than stenotic lesions. A signifi- true for late lumen loss (1.23 6 0.73 vs 1.03 6 0.72 cantly larger number of stents were implanted in mm, p 5 0.01). In a multivariate logistic regression chronic occlusions than in stenotic lesions (p ,0.001). model including the same variables as in the Cox There were no significant differences between groups proportional-hazards regression model (accuracy 73%, p ,0.0001), chronic occlusion remained a sigwith respect to the stent type used. After 1 year, the probability of survival free of nificant independent risk factor for restenosis with an myocardial infarction was not significantly different odds ratio of 1.98 (95% confidence interval 1.30 to (93.9% vs 95.9%, p 5 0.27). However, the probability 3.00); additional independent risk factors were diabeTABLE I Clinical Characteristics of Patients
804 THE AMERICAN JOURNAL OF CARDIOLOGYT
VOL. 82
SEPTEMBER 15, 1998
FIGURE 1. Kaplan-Meier survival curves for freedom from major adverse cardiac events. The rate of eventfree survival was significantly lower among patients with chronic occlusions than among those with stenotic lesions.
TABLE III Results of Follow-Up Angiography
MLD (mm) Late loss (mm) Loss index Net gain (mm) DS (%) Reocclusion rate (%) Restenosis rate (%)
Chronic Occlusions (n 5 105)
Stenotic Lesions (n 5 1,543)
p Value
1.5 6 0.9 1.4 6 0.8 0.5 6 0.3 1.5 6 0.9 51 6 26 8.7 43
1.9 6 0.9 1.1 6 0.8 0.5 6 0.4 1.1 6 0.9 39 6 24 3.0 27
,0.001 0.001 0.282 ,0.001 ,0.001 0.002 ,0.001
Data are expressed as means 6 SD or percentages. Abbreviations as in Table II.
tes mellitus, small vessel size, and multiple stent placement. •••
Restenosis rate in the present study was higher in patients with stent placement for total chronic coronary occlusion. This may explain the more frequent need for target vessel revascularization in this group. This higher rate of angiographic restenosis was not due to the higher reocclusion rate because restenosis rate remained significantly higher even after lesions with repeat total occlusion were excluded. Our study concurs with previous reports11,16,17 with respect to a lower reocclusion rate after stenting versus up to 20% reported for percutaneous transluminal coronary angioplasty of chronic occlusions.1,4,12,20 This reduced risk for reocclusion after stenting may be attributed to a potent antithrombotic therapy given for 1 month and to the bigger lumen achieved with stenting. However, the precise mechanisms of a lower reocclusion after stenting remain to be elucidated. Differences in baseline and procedural characteristics and in inclusion criteria, may account for the different restenosis rates between the present and pre-
vious studies.11,15–18 Ozaki et al18 found a 29% restenosis rate after stenting in 20 lesions with chronic occlusion. They used laser angioplasty followed by implantation of a new type of Wallstent in a group of patients with a lower incidence of cardiovascular risk factors than in our study cohort. Sirnes et al11 found a 32% restenosis rate in 58 patients with chronic occlusion who received Palmaz-Schatz stents. This study excluded lesions with complex anatomy, angiographically visible thrombus, previous angioplasty, and with stenting for suboptimal results after percutaneous transluminal coronary angioplasty,11 which did not serve as exclusion criteria in the present study. Data about the presence and degree of collateral circulation in our patients are missing. This precludes an analysis of a possible influence of this factor on the angiographic and clinical outcome. The clinical outcome described here refers only to patients with chronic occlusions and successful intervention. In fact, despite major advances in coronary interventions, this has contributed little to improve the procedural success in patients with chronically occluded vessels. In summary, the clinical outcome of patients with chronically occluded coronary lesions during the first year after successful coronary stent placement is characterized by a greater frequency of target lesion revascularizations than those in patients with stenotic lesions. The greater need for target lesion revascularization is the clinical consequence of the higher incidence of restenosis and reocclusion in this group of patients. 1. Bell MR, Berger PB, Bresnahan JF, Reeder GS, Bailey KR, Holmes DR Jr.
Initial and long-term outcome of 354 patients after coronary balloon angioplasty of total coronary artery occlusions. Circulation 1992;85:1003–1011. 2. DiSciascio G, Vetrovec GW, Cowley MJ, Wolfgang TC. Early and late outcome of percutaneous transluminal coronary angioplasty for subacute and chronic total coronary occlusion. Am Heart J 1986;111:833– 839.
BRIEF REPORTS
805
3. Ellis SG, Shaw RE, Gershony G, Thomas R, Roubin GS, Douglas JS Jr, Topol EJ, Startzer SH, Myler RK, King SB III. Risk factors, time course and treatment effect for restenosis after successful percutaneous transluminal coronary angioplasty of chronic total occlusion. Am J Cardiol 1989;63:897–901. 4. Ivanhoe RJ, Weintraub WS, Douglas JS Jr, Lembo NJ, Furman M, Gershony G, Cohen CL, King SB III. Percutaneous transluminal coronary angioplasty of chronic total occlusions. Primary success, restenosis, and ong-term clinical follow-up. Circulation 1992;85:106 –115. 5. Melchior JP, Meier B, Urban P, Finci L, Steffenino G, Noble J, Rutishauser W. Percutaneous transluminal coronary angioplasty for chronic total coronary arterial occlusion. Am J Cardiol 1987;59:535–538. 6. Puma JA, Sketch MH Jr, Tcheng JE, Harrington RA, Phillips HR, Stack RS, Califf RM. Percutaneous revascularization of chronic coronary occlusions: an overview. J Am Coll Cardiol 1995;26:1–11. 7. Ruocco NA Jr, Ring ME, Holubkov R, Jacobs AK, Detre KM, Faxon DP. Results of coronary angioplasty of chronic total occlusions (the National Heart, Lung, and Blood Institute 1985-1986 Percutaneous Transluminal Angioplasty Registry). Am J Cardiol 1992;69:69 –76. 8. Serruys PW, Umans V, Heyndrickx GR, van den Brand M, de Feyter PJ, Wijns W, Jaski B, Hugenholtz PG. Elective PTCA of totally occluded coronary arteries not associated with acute myocardial infarction; short-term and long-term results. Eur Heart J 1985;6:2–12. 9. Stewart JT, Denne L, Bowker TJ, Mulcahy DA, Williams MG, Buller NP, Sigwart U, Rickards AF. Percutaneous transluminal coronary angioplasty in chronic coronary artery occlusion. J Am Coll Cardiol 1993;21:1371–1376. 10. Stone GW, Rutherford BD, McConahay DR, Johnson WL Jr, Giorgi LV, Ligon RW, Hartzler GO. Procedural outcome of angioplasty for total coronary artery occlusion: an analysis of 971 lesions in 905 patients. J Am Coll Cardiol 1990;15:849 – 856. 11. Sirnes P, Golf S, Myreng Y, Molstad P, Emanuelsson H, Albertsson P, Brekke M, Mangschau A, Endresen K, Kjekshus J. Stenting in Chronic Coronary Occlusion (SICCO): a randomized, controlled trial of adding stent implantation after successful angioplasty. J Am Coll Cardiol 1996;28:1444 –1451. 12. Violaris AG, Melkert R, Serruys PW. Long-term luminal renarrowing after
successful elective coronary angioplasty of total occlusions. A quantitative angiographic analysis. Circulation 1995;91:2140 –2150. 13. Holmes DR Jr, Forrester JS, Litvack F, Reeder GS, Leon MB, Rothbaum DA, Cummins FE, Goldenberg T, Bresnahan JF. Chronic total obstruction and shortterm outcome: the Excimer Laser Coronary Angioplasty Registry experience. Mayo Clin Proc 1993;68:5–10. 14. Hinohara T, Rowe MH, Robertson GC, Selmon MR, Braden L, Leggett JH, Vetter JW, Simpson JB. Effect of lesion characteristics on outcome of directional coronary atherectomy. J Am Coll Cardiol 1991;17:1112–1120. 15. Maiello L, Colombo A, Almagor Y, Bouzon R, Thomas J, Zerboni S, Finci L. Coronary stenting with a balloon-expandable stent after the recanalization of chronic total occlusions. Cathet Cardiovasc Diagn 1992;25:293–296. 16. Medina A, Melian F, Suarez de Lezo J, Pan M, Romero M, Hernandez E, Marrero J, Ortega JR, Pavlovic D. Effectiveness of coronary stenting for the treatment of chronic total occlusion in angina pectoris. Am J Cardiol 1994;73: 1222–1224. 17. Goldberg SL, Colombo A, Maiello L, Borrione M, Finci L, Almagor Y. Intracoronary stent insertion after balloon angioplasty of chronic total occlusions. J Am Coll Cardiol 1995;26:713–719. 18. Ozaki Y, Violaris AG, Hamburger J, Melkert R, Foley D, Keane D, de Feyter P, Serruys PW. Short- and long-term clinical and quantitative angiographic results with the new, less shortening Wallstent for vessel reconstruction in chronic total occlusion: a quantitative angiographic study. J Am Coll Cardiol 1996;28:354 –360. 19. Scho¨mig A, Neumann FJ, Kastrati A, Schuhlen H, Blasini R, Hadamitzky M, Walter H, Zitzmann-Roth EM, Richardt G, Alt E, Schmitt C, Ulm K. A randomized comparison of antiplatelet and anticoagulant therapy after the placement of coronary-artery stents. N Engl J Med 1996;334:1084 –1089. 20. Berger P, Holmes DR Jr, Ohman E, O’Hanesian M, Murphy J, Schwartz R, Serruys P, Faxon D. Restenosis, reocclusion and adverse cardiovascular events after successful balloon angioplasty of occluded versus nonoccluded coronary arteries. Results from the Multicenter American Research Trial With Cilazapril After Angioplasty to Prevent Transluminal Coronary Obstruction and Restenosis (MARCATOR). J Am Coll Cardiol 1996;27:1–7.
Myocardial Doppler Velocity Imaging—A Quantitative Technique for Interpretation of Dobutamine Echocardiography Elina Yamada,
MD,
Mario Garcia, MD, James D. Thomas, Thomas H. Marwick, MD, PhD
obutamine stress echocardiography (DSE) has become accepted as a safe and accurate methD odology for detecting ischemia, risk stratification, 1,2 3
4,5
6
and for detection of viability. However, interpretation of this test is limited by training, subjectivity, and image quality.7 Analysis of myocardial Doppler velocity (MDV) permits measurement of tissue velocity with a high spatial and temporal resolution, and may be performed using pulsed8,9 or color Doppler approaches.10 –12 Apical imaging with pulsewave myocardial Doppler imaging may be used to examine apex-based movement.13 This movement corresponds to the contraction vector of subendocardial myocytes,14 which are most susceptible to ischemia. We therefore sought to establish the feasibility of pulsewave MDV during dobutamine stress and to evaluate its correlation with qualitative DSE interpretation. •••
Seventy patients (67 6 10 years old, 22 women) undergoing DSE in the course of management of From the Cleveland Clinic Foundation, Cleveland, Ohio. Dr. Marwick’s address is: Department of Medicine, University of Queensland, Princess Alexandra Hospital, Brisbane, Queensland QLD 4102, Australia. Manuscript received March 12, 1998; revised manuscript received and accepted April 27, 1998.
806 THE AMERICAN JOURNAL OF CARDIOLOGYT
VOL. 82
MD,
and
known or suspected coronary artery disease were studied. Because the protocol involved segmental comparison with 2-dimensional images, studies with inadequate image quality were excluded. Patients consented to undergo the test, which was performed according to standard institutional guidelines. Dobutamine was infused in 3-minute dose increments from 5 to 50 mg/ kg/min. Dobutamine stress echocardiographic data were analyzed using the standard 16-segment model of the American Society of Echocardiography by 2 independent experienced observers blinded to the MDV results. Normal segments had normal contractility at rest and increased with stress. Hypertrophic segments defined as having wall thickness .12 mm were analyzed separately as well as normal segments (nonischemic, nonscarred segments) of ventricles with an abnormal response to stress. Ischemia was diagnosed in the presence of new or worsening wall motion abnormalities with stress. Wall motion abnormalities at rest that did not improve with dobutamine infusion identified scarring. Segments with a biphasic response showed improvement in contractility at low dose and demonstrated deterioration at the peak dose of dobutamine. A commercially available ultrasound system was used for image acquisition (Sequoia C 256, Acuson SEPTEMBER 15, 1998