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Short- and Long-Term Outcomes After Stent-Assisted Percutaneous Treatment of Saphenous Vein Grafts in the Drug-Eluting Stent Era
Short- and Long-Term Outcomes After Stent-Assisted Percutaneous Treatment of Saphenous Vein Grafts in the Drug-Eluting Stent Era Tereza Pucelikova, MD, Roxana Mehran, MD*, Ajay J. Kirtane, MD, SM, Young-Hak Kim, MD, Martin Fahy, MSc, Giora Weisz, MD, Alexandra J. Lansky, MD, Issam Moussa, MD, William A. Gray, MD, Michael B. Collins, MD, Susheel K. Kodali, MD, Gregg W. Stone, MD, Jeffrey W. Moses, MD, Martin B. Leon, MD, and George Dangas, MD, PhD Percutaneous treatment of saphenous vein graft (SVG) lesions has been associated with higher rates of periprocedural complications and restenosis compared with non-SVG lesions. Whether these outcomes are similar in contemporary clinical practice, particularly when drug-eluting stents are used, is unknown. We evaluated outcomes of 110 consecutive patients who were treated with stent-assisted percutaneous coronary intervention for 145 SVG lesions (drug-eluting stents used in 91.0% of lesions). Embolic protection devices were used in 52.1% of treated grafts. Adverse events were recorded up to 1 year. Major or minor periprocedural myocardial necrosis occurred in 11 patients (10.9%). At 1-year clinical follow-up, we observed 13 myocardial infarctions (13.7%), 8 target lesion revascularizations (8.4%), 18 target vessel revascularizations (19.0%), 2 stent thromboses (2.1%), and 7 deaths (7.4%). The incidence of major adverse cardiac events, defined as death, myocardial infarction, or target vessel revascularization, was 30.5% at 1 year. By multivariable analysis, the presence of thrombus inside the graft before the procedure and the length of the stented segment were independent predictors of major adverse cardiac events at 1 year (hazard ratio for thrombus 4.07, 95% confidence interval 1.90 to 8.68, p ⴝ 0.0003; hazard ratio per millimeter of stented length 1.02, 95% confidence interval 1.01 to 1.03, p ⴝ 0.025). In conclusion, our data show that patients with SVG lesions remain a high-risk subgroup with worse outcomes after percutaneous coronary intervention compared with native vessel disease even in the era of drug-eluting stents. © 2008 Elsevier Inc. All rights reserved. (Am J Cardiol 2008;101:63– 68)
Because 1/2 of vein grafts develop significant stenosis or occlusion within 10 years after coronary artery bypass grafting, treatment of saphenous vein graft (SVG) disease remains a major challenge.1 Percutaneous coronary intervention of SVG lesions is associated with high rates of periprocedural complications and restenosis at long-term follow-up.2– 4 Several studies have confirmed that use of bare metal stents in SVGs improves outcomes compared with balloon angioplasty.5,6 Although drug-eluting stents have been proved to further decrease rates of repeat revascularization in native vessels, their safety and efficacy have not been established in SVGs. Whether the use of drugeluting stents combined with contemporary techniques as embolic protection might improve the outcomes of SVG percutaneous coronary intervention is unknown. We report a single-center experience with stent-assisted percutaneous treatment of SVG lesions in nonselected consecutive patients when most patients had been treated with drug-eluting stents. Columbia University Medical Center and the Cardiovascular Research Foundation, New York, New York. Manuscript received May 9, 2007; revised manuscript received and accepted July 16, 2007. *Corresponding author: Tel: 212-851-9340; fax: 212-223-4109. E-mail address: [email protected] (R. Mehran). 0002-9149/08/$ – see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.amjcard.2007.07.048
Methods The study population included consecutive patients enrolled in a prospective single-center clinical registry who underwent SVG intervention with stent implantation between August 2004 and at the end of 2005. Only the first procedure for each patient was included in the analysis. All demographic, clinical, angiographic, and procedural data were collected prospectively and entered into a computerized database. Qualitative and quantitative angiographic evaluations were performed at baseline. Percutaneous coronary intervention was performed by standard techniques. All patients were pretreated with aspirin 325 mg and clopidogrel 300 mg orally before the procedure. Bivalirudin as a 0.75-mg/kg bolus followed by a 1.75-mg/kg/hour infusion was administered during the procedure. The choice of stent, use of embolic protection device, and use of glycoprotein IIb/IIIa receptor inhibitors were at the discretion of the operating physicians. Clinical follow-up was secured by telephone contact or doctors’ office visits, and adverse events were verified through procurement of source documentation. Follow-up angiography was performed only if clinically driven. No patient was enrolled in the study with mandatory angiographic follow-up. The protocol for this study was approved by the institutional review board of our hospital. www.AJConline.org
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The American Journal of Cardiology (www.AJConline.org) Table 2 Procedural characteristics of treated grafts (n ⫽ 119)
Table 1 Baseline characteristics of treated patients (n ⫽ 110) Men Age (yrs) Diabetes mellitus Hypertension Hypercholesterolemia Chronic heart failure Renal disease Peripheral vascular disease Previous myocardial infarction* Previous percutaneous coronary intervention History of malignancy Height (cm) Weight (kg) Body mass index (kg/m2) Left ventricular ejection fraction (%) Myocardial infarction at presentation No. of grafts treated/patient 1 2 3
90 (82%) 69.2 ⫾ 11.1 43 (40%) 91 (84%) 92 (86%) 15 (14%) 26 (24%) 14 (13%) 55 (51%) 69 (63%) 17 (16%) 170.1 ⫾ 8.2 81.5 ⫾ 15.6 28.2 ⫾ 5.4 43.8 ⫾ 14.1 15 (14%) 101 (92%) 7 (6%) 1 (1%)
Values are expressed as counts (percentages) or means ⫾ SDs. * Myocardial infarction that occurred within 7 days before the procedure.
All baseline coronary angiograms were analyzed offline using a Cardiovascular Measurement System (CMSMEDIS, Medical Imaging Systems, Leiden, The Netherlands). Angiographic measurements were made in stent and in segment (defined as the stent plus the 5-mm edges proximal and distal to the stent, if possible). In cases where overlapping stents were placed, a single in-stent value was measured. An interpolated method was used for calculation of reference vessel diameters in all but a few cases of ostial and anastomotic lesions in extremely tapered vessels (difference between edge diameters ⬎50% and in-segment minimal lumen diameter ⱕ5 mm from the end of segment), where a larger edge reference vessel diameter was used instead. Otherwise, standard definitions were used for angiographic analysis. Thrombolysis In Myocardial Infarction (TIMI) flow and TIMI frame count were assessed before and after the procedure. The presence of thrombus was defined as a filling defect seen in multiple projections surrounded by contrast medium. Binary angiographic restenosis was defined as a diameter stenosis ⬎50% at follow-up. Restenosis patterns were assessed using the classification system of Mehran et al.7 Periprocedural increases of cardiac markers were classified as major or minor. Major periprocedural myocardial infarction and out-of-hospital myocardial infarction were defined as an increase of creatine kinase-MB or cardiac troponin I ⬎3 times above the upper limit of the normal range (5.5 or 0.4 ng/ml, respectively). Minor periprocedural myocardial damage was defined as postprocedural increase of creatinine kinase-MB or troponin I above the upper limit of the normal range or total creatinine kinase ⬎2 times the upper limit of the normal range, if criteria for major periprocedural myocardial infarction were not fulfilled and baseline cardiac markers were normal.8 Target lesion revascularization (TLR) was defined as repeat revascularization within the stent or within the 5-mm
Graft age (yrs) Recipient native coronary artery Left anterior descending/diagonal/ramus Circumflex/obtuse marginal Right Lesion location in the graft Aorto-ostial Distal anastomosis In-stent restenotic lesions Presence of thrombus Preprocedural TIMI grade flow 0 1 2 3 Preprocedural TIMI frame count (frames) Postprocedural TIMI grade flow 0 1 2 3 Postprocedural TIMI frame count (frames) No. of lesions/graft No. of stents/graft Total stent length/graft (mm) Stent length/graft by QCA (mm) Overlapping stents Stents used in grafts Sirolimus-eluting stents Paclitaxel-eluting stents Bare metal stents Use of embolic protection device Use of thrombectomy device
11.5 ⫾ 6.2 28 (24%) 44 (37%) 47 (40%) 36 (30%) 31 (26%) 26 (22%) 33 (29%) 7 (6%) 0 37 (31%) 75 (63%) 51.0 ⫾ 22.6 0 1 (1%) 11 (9%) 107 (90%) 38.2 ⫾ 18.6 1.2 ⫾ 0.5 1.45 ⫾ 0.77 30.0 ⫾ 22.3 (8–132) 27.8 ⫾ 18.9 (8–122) 21 (18%) 76 (64%) 37 (31%) 10 (8%) 62 (52%) 6 (5%)
Categorical variables are expressed as counts (percentages). Continuous variables are expressed as means ⫾ SDs (ranges) if indicated. All variables are counted per treated graft. QCA ⫽ quantitive coronary angiography.
borders proximal and distal to the stent on follow-up angiogram. Target vessel revascularization (TVR) was defined as repeat revascularization within the treated vessel (vein graft or native vessel). Stent thrombosis was defined as angiographic documentation of stent occlusion, unexplained death within 30 days, or target vessel myocardial infarction at follow-up. Major adverse cardiac events (MACEs) were defined as death, myocardial infarction including major periprocedural myocardial infarction, and TVR at follow-up. Quantitative angiographic data were analyzed on a perlesion basis, whereas qualitative angiographic and procedural data were assessed per graft. Demographic and clinical data were assessed per patient. Clinical events were analyzed on a per-graft or per-patient level, depending on type of analysis. Statistical analysis was performed using SAS 9.0 (SAS Institute, Cary, North Carolina). Continuous variables were expressed as means ⫾ SDs and compared by nonpaired 2-sample t test, and categorical variables were presented as counts and percentages and compared with chi-square or Fisher’s exact test. Survival curves were generated using the Kaplan-Meier method. A 2-sided p value ⬍0.05 was considered statistically significant for all comparisons. Multi-
Coronary Artery Disease/Outcomes After Treatment of Saphenous Vein Grafts Table 3 Quantitative coronary measurements of treated lesions (n ⫽ 145) No. of stents/lesion Baseline Lesion length (mm) Reference vessel diameter (mm) Minimal lumen diameter (mm) Diameter stenosis (%) After procedure Stent length (mm) In-segment reference vessel diameter (mm) Minimal lumen diameter (mm) Diameter stenosis (%) Acute gain (mm) In-stent minimal lumen diameter (mm) Diameter stenosis (%)
1.2 ⫾ 0.5 14.3 ⫾ 13.4 3.16 ⫾ 0.66 1.02 ⫾ 0.61 69.0 ⫾ 17.6 22.7 ⫾ 14.0 3.30 ⫾ 0.47 2.65 ⫾ 0.55 20.4 ⫾ 10.9 1.62 ⫾ 0.68 2.78 ⫾ 0.53 16.7 ⫾ 9.6
Values are expressed as means ⫾ SDs.
variable Cox models were used to determine independent predictors of MACEs at 1 year. Candidate variables were gender, diabetes mellitus, treatment of in-stent restenosis, distal anastomotic lesion, lesion with thrombus, lesion with TIMI grade 0 to 2 flow, vessel diameter, use of bare metal stent, and length of the stented segment. Only significant univariate predictors of MACEs were entered into the model. Results Between August 2004 and December 2005, 119 grafts (110 patients, 145 lesions) were successfully treated with stents. Baseline characteristics of these patients are listed in Table 1. This “real-world” population contained patients and lesions with various high-risk features as presented in Table 2. In total, 145 lesions were treated with 202 stents, i.e., 13 lesions (9.0%) with bare metal stents, 92 lesions (63.4%) with sirolimus-eluting stents, and 40 lesions (27.6%) with paclitaxel-eluting stents. A distal or proximal embolic protection device was used in 52.1% of treated SVGs (proximal occlusion system in 13.4% of all grafts). Angiographic lesion measurements are listed in Table 3. Clinical follow-up was available for 100%, 90.9%, and 86.4% of patients at discharge, 6 months, and 1 year, respectively. Major or minor periprocedural myocardial infarction occurred in 11 cases (10.9%) at hospital. In 5 of these cases, only criteria for minor myocardial damage were fulfilled and myocardial necrosis was clinically silent (5.0%). Two patients died (1.8%), 1 had acute stent thrombosis (0.9%), and none underwent repeat revascularization. Periprocedural myocardial infarction was associated with lower TIMI flow after the procedure; 5 of 12 patients (41.7%) with postprocedure TIMI grade 1 or 2 flow had periprocedural myocardial infarction compared with 6 of 107 patients (5.6%) with TIMI grade 3 flow (p ⬍0.0001). In-hospital event rates did not differ when stratified by use of embolic protection device. Short- and long-term outcomes are presented in Table 4. At 1 year, rates of death, myocardial infarction (including major periprocedural myocardial infarction), TLR, and TVR were 7.4%, 13.7%, 8.4%, and 19.0%, respectively. TVR was performed for myocardial infarction in 4 cases
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Table 4 Short- and long-term outcomes after stent-assisted percutaneous treatment of saphenous vein grafts (n ⫽ 110) Adverse event In hospital MACEs* Death Myocardial infarction TVR Acute stent thrombosis 6 mos MACEs* Death Myocardial infarction TLR TVR 1 yr MACEs* Death Myocardial infarction TLR TVR Late stent thrombosis Any stent thrombosis
7 (6%) 2 (2%) 6 (6%) 0 1 (1%) 18 (18%) 5 (5%) 11 (11%) 3 (3%) 6 (6%) 29 (31%) 7 (7%) 13 (14%) 8 (8%) 18 (19%) 1 (1%) 2 (2%)
Values are expressed as counts (percentages). * MACEs were defined as death, myocardial infarction, and/or TVR.
and for angina in all other cases (78%). One patient (1.1%) developed late stent thrombosis that presented as non–STelevation myocardial infarction and led to TLR. No patient needed repeat surgical revascularization at follow-up. Overall incidence of MACE was 30.5% at 1 year (Figure 1). At 1 year, aspirin, thienopyridine, and lipid-lowering therapy were used in 97%, 87%, and 93% of patients, respectively. Clinically driven angiographic follow-up (all angiographies ⱖ30 days, mean length of follow-up 218 ⫾ 134) was available for 43 grafts (36.1%). Twenty-five of these grafts (58.1%) were found patent without restenosis and 18 grafts (41.9%) were restenosed or occluded (7 grafts totally occluded, 10 grafts with in-stent restenosis, 1 graft with restenosis outside the stent site). In-stent restenoses were focal or multifocal in 8 cases (Ic or Id according to Mehran classification), diffuse proliferative in 2 cases (pattern III), and totally occluded in 7 cases (pattern IV). Figure 2 shows clinical outcomes in groups stratified by the presence of thrombus and total stent length per graft. Presence of thrombus was associated with a significantly higher incidence of 1-year death (20.7% vs 1.4%, p ⫽ 0.0021) and MACEs (55.2% vs 18.1%, p ⫽ 0.0005) and with higher rates of myocardial infarction in hospital and at 1 year (12.1% vs 2.3%, p ⫽ 0.049; 24.1% vs 8.3%, p ⫽ 0.047, respectively). Grafts with longer stented segments had a higher rate of myocardial infarction (26.5% vs 6.0%, p ⫽ 0.0089) at 1-year follow-up. By multivariable analysis, presence of thrombus before the procedure and stent length were independent predictors of MACEs at 1-year follow-up (hazard ratio for thrombus 4.07, 95% confidence interval 1.90 to 8.68, p ⫽ 0.025; hazard ratio per millimeter of stent 1.02, 95% confidence interval 1.01 to 1.03, p ⫽ 0.0003, respectively).
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The American Journal of Cardiology (www.AJConline.org)
Figure 1. Kaplan-Meier 1-year MACE-free survival curve.
Figure 2. In-hospital myocardial infarction (IH MI) rates and 1-year clinical outcomes stratified by presence of visible thrombus (A) and total length of stented segment per graft (B). All significant p values (p ⬍0.05) are presented. *MACEs were defined as death, myocardial infarction, and TVR. MI ⫽ 1-year myocardial infarction; ST ⫽ stent thrombosis.
Discussion In this study, we used a 2-level definition for periprocedural myocardial infarction similar to that of Vermeersch et al.9 We registered not only major periprocedural adverse events but also cases of minor myocardial necrosis, demonstrating a strong association between periprocedural myocardial necrosis and abnormal postprocedural TIMI flow. Stenting has been proved to be superior to plain balloon angioplasty for treatment of SVG lesions.5,6 However, bare metal stenting studies have reported event-free survival of only 70% to 80% in the first year after the procedure with an incidence of restenosis up to 37% at 9-month follow-
up.5,6,10 –13 Studies evaluating polytetrafluoroethylene-covered stents in vein grafts have consistently showed similar or slightly worse results than bare metal stents.14 –16 Drugeluting stents have lower rates of restenosis in native vessels, but concerns about a possible higher incidence of stent thrombosis necessitate a careful approach to their general adoption as standard treatment strategy for all lesion types. Several registries and 1 randomized study evaluating outcomes of patients after treatment of SVG lesions with drug-eluting stents have been published previously.9,17–20 Results of these studies including our data are presented in Table 5.
Coronary Artery Disease/Outcomes After Treatment of Saphenous Vein Grafts
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Table 5 Outcomes of patients after drug-eluting stent implantation in previously published reports Study Vermeersch et al9 Ge et al20 Lee et al19 Tsuchida et al18 Chu et al17 Chu et al17 Present study* Present study*
No. of Patients
Used Stent
In-hospital MI
Length of Follow-up
Death
MI
TLR
TVR
38 61 139 40 47 42 101 101
SES DES DES PES SES PES DES DES
5.3% 6.6% NA 2.5% 4% 7.1% 6.0% —
6 mos 6 mos 9 mos 1 yr 6 mos 6 mos 6 mos 1 yr
2.6% 0% 1% 0% 4.3% 5.3% 4.3% 6.8%
7.9% 8.2% 4.3% 2.5% 8.5% 10.5% 10.8% 13.6%
5.3% 3.3% NA 2.5% 2.1% 2.6% 3.2% 9.1%
5.3% 4.9% 10.1% 5.0% 4.3% 5.3% 5.4% 19.3%
* Patients with bare metal stents were excluded. DES ⫽ drug-eluting stent; MI ⫽ myocardial infarction; NA ⫽ not available; PES ⫽ paclitaxel-eluting stent; SES ⫽ sirolimus-eluting stent.
The only published randomized study comparing sirolimus-eluting stents (n ⫽ 38) with bare metal stents (n ⫽ 37) reported significantly lower rates of restenosis and repeat revascularization with sirolimus-eluting stents compared with bare metal stents at 6 months.9 Our data are consistent with outcomes in previous drug-eluting stent registries demonstrating low rates of TLR (up to 5.9%) and TVR (up to 10.1%) at 6 months.9,17,19,20 However, repeat revascularization rates in our cohort had almost tripled 6 to 12 months after the procedure. Only 1 previous study reported 1-year outcomes of 40 patients after treatment of SVGs with drugeluting stents; this study demonstrated a MACE rate of 7.5%,18 which is significantly lower than what we observed, although the reported characteristics of patients and lesions were quite similar in the 2 cohorts. We also observed relatively high rates of 1-year death (7.4%) and myocardial infarction (13.7%). Waksman et al21 also reported strikingly high rates of 1-year death and Qwave myocardial infarction in 132 patients who were treated with Palmaz-Schatz stents for SVG lesions (death 15.7%, Q-wave myocardial infarction 15.0%). Survival data of 2,556 patients published by Ashfaq et al.22 also found a very high rate of death after angioplasty of SVGs (⬃26%) at 5 years. These rates are very unfavorable compared with outcomes of patients after coronary artery bypass grafting, as reported by the Coronary Artery Surgery Study23 at 5 years (death 5%, Q-wave myocardial infarction 14%), which implies a significantly negative impact of SVG disease on prognosis of patients after coronary artery bypass surgery. In a multivariate analysis, we identified 2 predictors that were associated with increased incidence of adverse events after percutaneous treatment of SVG disease, namely presence of a filling defect consistent with thrombus inside the treated graft and length of stented segment. These 2 variables were associated with higher rates of myocardial infarction, but importantly, presence of a filling defect was also significantly associated with higher rate of death at 1 year. In the previously mentioned studies, no case of stent thrombosis was registered after treatment of SVG lesions with drug-eluting stents.9,17,19,20 We recorded 2 cases of stent thrombosis that occurred in drug-eluting stents. Stent thrombosis might be an important mechanism of stent occlusion in vein grafts. The large lumen of the vein graft and smaller lumen of the outflow vessel can contribute to slower
flow, possible suboptimal stent deployment, and prothrombotic environment inside grafts. However, graft occlusions might result in less serious clinical consequences than stent thromboses of native vessels because of ischemic preconditioning of the affected territory. It is of note that those 7 documented graft occlusions at follow-up were clinically silent. Our study reports quite high rates of adverse events. However, the data are hardly comparable with bare metal stent studies because our cohort contained a significant percentage of high-risk patients with diffusely degenerated grafts treated with multiple stents, whereas bare metal stent studies mostly included patients with easy focal lesions treated with single stents.6,10,11 We report a real-world single-center experience with treatment of SVGs in the era of drug-eluting stents. Limitations of the present study include a small sample, inhomogenous use of stents, low use of embolic protection devices, lack of systematic angiographic follow-up, and an adequate control group. Greater use of embolic protection devices might have improved the short- and long-term outcomes in our cohort. Acknowledgment: We thank the entire data center team at Columbia University Medical Center led by Theresa Franklin-Bond for their help and management of the interventional procedures database of our interventional cardiology department. 1. Bourassa MG, Fisher LD, Campeau L, Gillespie MJ, McConney M, Lesperance J. Long-term fate of bypass grafts: the Coronary Artery Surgery Study (CASS) and Montreal Heart Institute experiences. Circulation 1985;72(suppl):V71–V78. 2. Shaia N, Heuser RR. Distal embolic protection for SVG interventions: can we afford not to use it? J Interv Cardiol 2005;18:481– 484. 3. Silva JA, White CJ. Percutaneous intervention of old degenerated saphenous vein grafts. Int J Cardiovasc Intervent 2001;4:187–194. 4. Watson PS, Hadjipetrou P, Cox SV, Pyne CT, Gossman DE, Piemonte TC, Eisenhauer AC. Angiographic and clinical outcomes following acute infarct angioplasty on saphenous vein grafts. Am J Cardiol 1999;83:1018 –1021. 5. Hanekamp CE, Koolen JJ, Den Heijer P, Schalij MJ, Piek JJ, Bar FW, De Scheerder I, Bonnier HJ, Pijls NH. Randomized study to compare balloon angioplasty and elective stent implantation in venous bypass grafts: the Venestent study. Catheter Cardiovasc Interv 2003;60:452– 457. 6. Savage MP, Douglas JS Jr, Fischman DL, Pepine CJ, King SB III, Werner JA, Bailey SR, Overlie PA, Fenton SH, Brinker JA, Leon MB,
68
7.
8.
9.
10.
11.
12.
13.
14.
The American Journal of Cardiology (www.AJConline.org) Goldberg S. Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators. N Engl J Med 1997;337:740 –747. Mehran R, Dangas G, Abizaid AS, Mintz GS, Lansky AJ, Satler LF, Pichard AD, Kent KM, Stone GW, Leon MB. Angiographic patterns of in-stent restenosis: classification and implications for long-term outcome. Circulation 1999;100:1872–1878. The Joint European Society of Cardiology/American College of Cardiology Committee. Myocardial infarction redefined—a consensus document of the Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. Eur Heart J 2000;21:1502–1513. Vermeersch P, Agostoni P, Verheye S, Van den Heuvel P, Convens C, Bruining N, Van den Branden F, Van Langenhove G. Randomized double-blind comparison of sirolimus-eluting stent versus bare-metal stent implantation in diseased saphenous vein grafts: six-month angiographic, intravascular ultrasound, and clinical follow-up of the RRISC Trial. J Am Coll Cardiol 2006;48:2423–2431. Wong SC, Baim DS, Schatz RA, Teirstein PS, King SB III, Curry RC Jr, Heuser RR, Ellis SG, Cleman MW, Overlie P, et al. Immediate results and late outcomes after stent implantation in saphenous vein graft lesions: the multicenter U.S. Palmaz-Schatz stent experience. The Palmaz-Schatz Stent Study Group. J Am Coll Cardiol 1995;26:704 –712. Fenton SH, Fischman DL, Savage MP, Schatz RA, Leon MB, Baim DS, King SB, Heuser RR, Curry RC Jr, Rake RC, et al. Long-term angiographic and clinical outcome after implantation of balloon-expandable stents in aortocoronary saphenous vein grafts. Am J Cardiol 1994;74:1187–1191. Ahmed JM, Dangas G, Lansky AJ, Mehran R, Hong MK, Mintz GS, Pichard AD, Satler LF, Kent KM, Stone GW, Leon MB. Influence of gender on early and one-year clinical outcomes after saphenous vein graft stenting. Am J Cardiol 2001;87:401– 405. Brener SJ, Ellis SG, Apperson-Hansen C, Leon MB, Topol EJ. Comparison of stenting and balloon angioplasty for narrowings in aortocoronary saphenous vein conduits in place for more than five years. Am J Cardiol 1997;79:13–18. Stankovic G, Colombo A, Presbitero P, van den Branden F, Inglese L, Cernigliaro C, Niccoli L, Bartorelli AL, Rubartelli P, Reifart N, et al. Randomized evaluation of polytetrafluoroethylene-covered stent in saphenous vein grafts: the Randomized Evaluation of polytetrafluoro-
15.
16.
17.
18.
19. 20.
21.
22.
23.
ethylene COVERed stent in Saphenous vein grafts (RECOVERS) Trial. Circulation 2003;108:37– 42. Turco MA, Buchbinder M, Popma JJ, Weissman NJ, Mann T, Doucet S, Johnson WL Jr, Greenberg JD, Leadley K, Russell ME. Pivotal, randomized U.S. study of the Symbiot trade mark covered stent system in patients with saphenous vein graft disease: eight-month angiographic and clinical results from the Symbiot III trial. Catheter Cardiovasc Interv 2006;68:379 –388. Stone GW, Goldberg S, Mehran R, O’Shaughnessy C, Midei M, Siegel R, George B, Salter S, Rainzer A, Negoita M, et al. A prospective, randomized U.S. trial of the PTFE-covered JOSTENT for the treatment of diseased saphenous vein grafts: the BARRICADE trial. J Am Coll Cardiol 2005;45(suppl A):27A. Chu WW, Kuchulakanti PK, Wang B, Clavijo LC, Suddath WO, Pichard AD, Satler LF, Kent KM, Waksman R. Efficacy of sirolimuseluting stents as compared to paclitaxel-eluting stents for saphenous vein graft intervention. J Interv Cardiol 2006;19:121–125. Tsuchida K, Ong AT, Aoki J, van Mieghem CA, Rodriguez-Granillo GA, Valgimigli M, Sianos G, Regar E, McFadden EP, van der Giessen WJ, et al. Immediate and one-year outcome of percutaneous intervention of saphenous vein graft disease with paclitaxel-eluting stents. Am J Cardiol 2005;96:395–398. Lee MS, Shah AP, Aragon J, Jamali A, Dohad S, Kar S, Makkar RR. Drug-eluting stenting is superior to bare metal stenting in saphenous vein grafts. Catheter Cardiovasc Interv 2005;66:507–511. Ge L, Iakovou I, Sangiorgi GM, Chieffo A, Melzi G, Cosgrave J, Montorfano M, Michev I, Airoldi F, Carlino M, Corvaja N, Colombo A. Treatment of saphenous vein graft lesions with drug-eluting stents: immediate and midterm outcome. J Am Coll Cardiol 2005;45:989 –994. Waksman R, Weintraub WS, Ghazzal Z, Scott NA, Shen Y, King SB III, Douglas JS Jr. Short- and long-term outcome of narrowed saphenous vein bypass graft: a comparison of Palmaz-Schatz stent, directional coronary atherectomy, and balloon angioplasty. Am Heart J 1997;134:274 –281. Ashfaq S, Ghazzal Z, Douglas JS, Morris DC, Veledar E, Weintraub WS. Impact of diabetes on five-year outcomes after vein graft interventions performed prior to the drug-eluting stent era. J Invasive Cardiol 2006;18:100 –105. CASS Investigators. Myocardial infarction and mortality in the Coronary Artery Surgery Study (CASS) randomized trial. N Engl J Med 1984;310:750 –758.
Because 1/2 of vein grafts develop significant stenosis or occlusion within 10 years after coronary artery bypass grafting, treatment of saphenous vein graft (SVG) disease remains a major challenge.1 Percutaneous coronary intervention of SVG lesions is associated with high rates of periprocedural complications and restenosis at long-term follow-up.2– 4 Several studies have confirmed that use of bare metal stents in SVGs improves outcomes compared with balloon angioplasty.5,6 Although drug-eluting stents have been proved to further decrease rates of repeat revascularization in native vessels, their safety and efficacy have not been established in SVGs. Whether the use of drugeluting stents combined with contemporary techniques as embolic protection might improve the outcomes of SVG percutaneous coronary intervention is unknown. We report a single-center experience with stent-assisted percutaneous treatment of SVG lesions in nonselected consecutive patients when most patients had been treated with drug-eluting stents. Columbia University Medical Center and the Cardiovascular Research Foundation, New York, New York. Manuscript received May 9, 2007; revised manuscript received and accepted July 16, 2007. *Corresponding author: Tel: 212-851-9340; fax: 212-223-4109. E-mail address: [email protected] (R. Mehran). 0002-9149/08/$ – see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.amjcard.2007.07.048
Methods The study population included consecutive patients enrolled in a prospective single-center clinical registry who underwent SVG intervention with stent implantation between August 2004 and at the end of 2005. Only the first procedure for each patient was included in the analysis. All demographic, clinical, angiographic, and procedural data were collected prospectively and entered into a computerized database. Qualitative and quantitative angiographic evaluations were performed at baseline. Percutaneous coronary intervention was performed by standard techniques. All patients were pretreated with aspirin 325 mg and clopidogrel 300 mg orally before the procedure. Bivalirudin as a 0.75-mg/kg bolus followed by a 1.75-mg/kg/hour infusion was administered during the procedure. The choice of stent, use of embolic protection device, and use of glycoprotein IIb/IIIa receptor inhibitors were at the discretion of the operating physicians. Clinical follow-up was secured by telephone contact or doctors’ office visits, and adverse events were verified through procurement of source documentation. Follow-up angiography was performed only if clinically driven. No patient was enrolled in the study with mandatory angiographic follow-up. The protocol for this study was approved by the institutional review board of our hospital. www.AJConline.org
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The American Journal of Cardiology (www.AJConline.org) Table 2 Procedural characteristics of treated grafts (n ⫽ 119)
Table 1 Baseline characteristics of treated patients (n ⫽ 110) Men Age (yrs) Diabetes mellitus Hypertension Hypercholesterolemia Chronic heart failure Renal disease Peripheral vascular disease Previous myocardial infarction* Previous percutaneous coronary intervention History of malignancy Height (cm) Weight (kg) Body mass index (kg/m2) Left ventricular ejection fraction (%) Myocardial infarction at presentation No. of grafts treated/patient 1 2 3
90 (82%) 69.2 ⫾ 11.1 43 (40%) 91 (84%) 92 (86%) 15 (14%) 26 (24%) 14 (13%) 55 (51%) 69 (63%) 17 (16%) 170.1 ⫾ 8.2 81.5 ⫾ 15.6 28.2 ⫾ 5.4 43.8 ⫾ 14.1 15 (14%) 101 (92%) 7 (6%) 1 (1%)
Values are expressed as counts (percentages) or means ⫾ SDs. * Myocardial infarction that occurred within 7 days before the procedure.
All baseline coronary angiograms were analyzed offline using a Cardiovascular Measurement System (CMSMEDIS, Medical Imaging Systems, Leiden, The Netherlands). Angiographic measurements were made in stent and in segment (defined as the stent plus the 5-mm edges proximal and distal to the stent, if possible). In cases where overlapping stents were placed, a single in-stent value was measured. An interpolated method was used for calculation of reference vessel diameters in all but a few cases of ostial and anastomotic lesions in extremely tapered vessels (difference between edge diameters ⬎50% and in-segment minimal lumen diameter ⱕ5 mm from the end of segment), where a larger edge reference vessel diameter was used instead. Otherwise, standard definitions were used for angiographic analysis. Thrombolysis In Myocardial Infarction (TIMI) flow and TIMI frame count were assessed before and after the procedure. The presence of thrombus was defined as a filling defect seen in multiple projections surrounded by contrast medium. Binary angiographic restenosis was defined as a diameter stenosis ⬎50% at follow-up. Restenosis patterns were assessed using the classification system of Mehran et al.7 Periprocedural increases of cardiac markers were classified as major or minor. Major periprocedural myocardial infarction and out-of-hospital myocardial infarction were defined as an increase of creatine kinase-MB or cardiac troponin I ⬎3 times above the upper limit of the normal range (5.5 or 0.4 ng/ml, respectively). Minor periprocedural myocardial damage was defined as postprocedural increase of creatinine kinase-MB or troponin I above the upper limit of the normal range or total creatinine kinase ⬎2 times the upper limit of the normal range, if criteria for major periprocedural myocardial infarction were not fulfilled and baseline cardiac markers were normal.8 Target lesion revascularization (TLR) was defined as repeat revascularization within the stent or within the 5-mm
Graft age (yrs) Recipient native coronary artery Left anterior descending/diagonal/ramus Circumflex/obtuse marginal Right Lesion location in the graft Aorto-ostial Distal anastomosis In-stent restenotic lesions Presence of thrombus Preprocedural TIMI grade flow 0 1 2 3 Preprocedural TIMI frame count (frames) Postprocedural TIMI grade flow 0 1 2 3 Postprocedural TIMI frame count (frames) No. of lesions/graft No. of stents/graft Total stent length/graft (mm) Stent length/graft by QCA (mm) Overlapping stents Stents used in grafts Sirolimus-eluting stents Paclitaxel-eluting stents Bare metal stents Use of embolic protection device Use of thrombectomy device
11.5 ⫾ 6.2 28 (24%) 44 (37%) 47 (40%) 36 (30%) 31 (26%) 26 (22%) 33 (29%) 7 (6%) 0 37 (31%) 75 (63%) 51.0 ⫾ 22.6 0 1 (1%) 11 (9%) 107 (90%) 38.2 ⫾ 18.6 1.2 ⫾ 0.5 1.45 ⫾ 0.77 30.0 ⫾ 22.3 (8–132) 27.8 ⫾ 18.9 (8–122) 21 (18%) 76 (64%) 37 (31%) 10 (8%) 62 (52%) 6 (5%)
Categorical variables are expressed as counts (percentages). Continuous variables are expressed as means ⫾ SDs (ranges) if indicated. All variables are counted per treated graft. QCA ⫽ quantitive coronary angiography.
borders proximal and distal to the stent on follow-up angiogram. Target vessel revascularization (TVR) was defined as repeat revascularization within the treated vessel (vein graft or native vessel). Stent thrombosis was defined as angiographic documentation of stent occlusion, unexplained death within 30 days, or target vessel myocardial infarction at follow-up. Major adverse cardiac events (MACEs) were defined as death, myocardial infarction including major periprocedural myocardial infarction, and TVR at follow-up. Quantitative angiographic data were analyzed on a perlesion basis, whereas qualitative angiographic and procedural data were assessed per graft. Demographic and clinical data were assessed per patient. Clinical events were analyzed on a per-graft or per-patient level, depending on type of analysis. Statistical analysis was performed using SAS 9.0 (SAS Institute, Cary, North Carolina). Continuous variables were expressed as means ⫾ SDs and compared by nonpaired 2-sample t test, and categorical variables were presented as counts and percentages and compared with chi-square or Fisher’s exact test. Survival curves were generated using the Kaplan-Meier method. A 2-sided p value ⬍0.05 was considered statistically significant for all comparisons. Multi-
Coronary Artery Disease/Outcomes After Treatment of Saphenous Vein Grafts Table 3 Quantitative coronary measurements of treated lesions (n ⫽ 145) No. of stents/lesion Baseline Lesion length (mm) Reference vessel diameter (mm) Minimal lumen diameter (mm) Diameter stenosis (%) After procedure Stent length (mm) In-segment reference vessel diameter (mm) Minimal lumen diameter (mm) Diameter stenosis (%) Acute gain (mm) In-stent minimal lumen diameter (mm) Diameter stenosis (%)
1.2 ⫾ 0.5 14.3 ⫾ 13.4 3.16 ⫾ 0.66 1.02 ⫾ 0.61 69.0 ⫾ 17.6 22.7 ⫾ 14.0 3.30 ⫾ 0.47 2.65 ⫾ 0.55 20.4 ⫾ 10.9 1.62 ⫾ 0.68 2.78 ⫾ 0.53 16.7 ⫾ 9.6
Values are expressed as means ⫾ SDs.
variable Cox models were used to determine independent predictors of MACEs at 1 year. Candidate variables were gender, diabetes mellitus, treatment of in-stent restenosis, distal anastomotic lesion, lesion with thrombus, lesion with TIMI grade 0 to 2 flow, vessel diameter, use of bare metal stent, and length of the stented segment. Only significant univariate predictors of MACEs were entered into the model. Results Between August 2004 and December 2005, 119 grafts (110 patients, 145 lesions) were successfully treated with stents. Baseline characteristics of these patients are listed in Table 1. This “real-world” population contained patients and lesions with various high-risk features as presented in Table 2. In total, 145 lesions were treated with 202 stents, i.e., 13 lesions (9.0%) with bare metal stents, 92 lesions (63.4%) with sirolimus-eluting stents, and 40 lesions (27.6%) with paclitaxel-eluting stents. A distal or proximal embolic protection device was used in 52.1% of treated SVGs (proximal occlusion system in 13.4% of all grafts). Angiographic lesion measurements are listed in Table 3. Clinical follow-up was available for 100%, 90.9%, and 86.4% of patients at discharge, 6 months, and 1 year, respectively. Major or minor periprocedural myocardial infarction occurred in 11 cases (10.9%) at hospital. In 5 of these cases, only criteria for minor myocardial damage were fulfilled and myocardial necrosis was clinically silent (5.0%). Two patients died (1.8%), 1 had acute stent thrombosis (0.9%), and none underwent repeat revascularization. Periprocedural myocardial infarction was associated with lower TIMI flow after the procedure; 5 of 12 patients (41.7%) with postprocedure TIMI grade 1 or 2 flow had periprocedural myocardial infarction compared with 6 of 107 patients (5.6%) with TIMI grade 3 flow (p ⬍0.0001). In-hospital event rates did not differ when stratified by use of embolic protection device. Short- and long-term outcomes are presented in Table 4. At 1 year, rates of death, myocardial infarction (including major periprocedural myocardial infarction), TLR, and TVR were 7.4%, 13.7%, 8.4%, and 19.0%, respectively. TVR was performed for myocardial infarction in 4 cases
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Table 4 Short- and long-term outcomes after stent-assisted percutaneous treatment of saphenous vein grafts (n ⫽ 110) Adverse event In hospital MACEs* Death Myocardial infarction TVR Acute stent thrombosis 6 mos MACEs* Death Myocardial infarction TLR TVR 1 yr MACEs* Death Myocardial infarction TLR TVR Late stent thrombosis Any stent thrombosis
7 (6%) 2 (2%) 6 (6%) 0 1 (1%) 18 (18%) 5 (5%) 11 (11%) 3 (3%) 6 (6%) 29 (31%) 7 (7%) 13 (14%) 8 (8%) 18 (19%) 1 (1%) 2 (2%)
Values are expressed as counts (percentages). * MACEs were defined as death, myocardial infarction, and/or TVR.
and for angina in all other cases (78%). One patient (1.1%) developed late stent thrombosis that presented as non–STelevation myocardial infarction and led to TLR. No patient needed repeat surgical revascularization at follow-up. Overall incidence of MACE was 30.5% at 1 year (Figure 1). At 1 year, aspirin, thienopyridine, and lipid-lowering therapy were used in 97%, 87%, and 93% of patients, respectively. Clinically driven angiographic follow-up (all angiographies ⱖ30 days, mean length of follow-up 218 ⫾ 134) was available for 43 grafts (36.1%). Twenty-five of these grafts (58.1%) were found patent without restenosis and 18 grafts (41.9%) were restenosed or occluded (7 grafts totally occluded, 10 grafts with in-stent restenosis, 1 graft with restenosis outside the stent site). In-stent restenoses were focal or multifocal in 8 cases (Ic or Id according to Mehran classification), diffuse proliferative in 2 cases (pattern III), and totally occluded in 7 cases (pattern IV). Figure 2 shows clinical outcomes in groups stratified by the presence of thrombus and total stent length per graft. Presence of thrombus was associated with a significantly higher incidence of 1-year death (20.7% vs 1.4%, p ⫽ 0.0021) and MACEs (55.2% vs 18.1%, p ⫽ 0.0005) and with higher rates of myocardial infarction in hospital and at 1 year (12.1% vs 2.3%, p ⫽ 0.049; 24.1% vs 8.3%, p ⫽ 0.047, respectively). Grafts with longer stented segments had a higher rate of myocardial infarction (26.5% vs 6.0%, p ⫽ 0.0089) at 1-year follow-up. By multivariable analysis, presence of thrombus before the procedure and stent length were independent predictors of MACEs at 1-year follow-up (hazard ratio for thrombus 4.07, 95% confidence interval 1.90 to 8.68, p ⫽ 0.025; hazard ratio per millimeter of stent 1.02, 95% confidence interval 1.01 to 1.03, p ⫽ 0.0003, respectively).
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The American Journal of Cardiology (www.AJConline.org)
Figure 1. Kaplan-Meier 1-year MACE-free survival curve.
Figure 2. In-hospital myocardial infarction (IH MI) rates and 1-year clinical outcomes stratified by presence of visible thrombus (A) and total length of stented segment per graft (B). All significant p values (p ⬍0.05) are presented. *MACEs were defined as death, myocardial infarction, and TVR. MI ⫽ 1-year myocardial infarction; ST ⫽ stent thrombosis.
Discussion In this study, we used a 2-level definition for periprocedural myocardial infarction similar to that of Vermeersch et al.9 We registered not only major periprocedural adverse events but also cases of minor myocardial necrosis, demonstrating a strong association between periprocedural myocardial necrosis and abnormal postprocedural TIMI flow. Stenting has been proved to be superior to plain balloon angioplasty for treatment of SVG lesions.5,6 However, bare metal stenting studies have reported event-free survival of only 70% to 80% in the first year after the procedure with an incidence of restenosis up to 37% at 9-month follow-
up.5,6,10 –13 Studies evaluating polytetrafluoroethylene-covered stents in vein grafts have consistently showed similar or slightly worse results than bare metal stents.14 –16 Drugeluting stents have lower rates of restenosis in native vessels, but concerns about a possible higher incidence of stent thrombosis necessitate a careful approach to their general adoption as standard treatment strategy for all lesion types. Several registries and 1 randomized study evaluating outcomes of patients after treatment of SVG lesions with drug-eluting stents have been published previously.9,17–20 Results of these studies including our data are presented in Table 5.
Coronary Artery Disease/Outcomes After Treatment of Saphenous Vein Grafts
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Table 5 Outcomes of patients after drug-eluting stent implantation in previously published reports Study Vermeersch et al9 Ge et al20 Lee et al19 Tsuchida et al18 Chu et al17 Chu et al17 Present study* Present study*
No. of Patients
Used Stent
In-hospital MI
Length of Follow-up
Death
MI
TLR
TVR
38 61 139 40 47 42 101 101
SES DES DES PES SES PES DES DES
5.3% 6.6% NA 2.5% 4% 7.1% 6.0% —
6 mos 6 mos 9 mos 1 yr 6 mos 6 mos 6 mos 1 yr
2.6% 0% 1% 0% 4.3% 5.3% 4.3% 6.8%
7.9% 8.2% 4.3% 2.5% 8.5% 10.5% 10.8% 13.6%
5.3% 3.3% NA 2.5% 2.1% 2.6% 3.2% 9.1%
5.3% 4.9% 10.1% 5.0% 4.3% 5.3% 5.4% 19.3%
* Patients with bare metal stents were excluded. DES ⫽ drug-eluting stent; MI ⫽ myocardial infarction; NA ⫽ not available; PES ⫽ paclitaxel-eluting stent; SES ⫽ sirolimus-eluting stent.
The only published randomized study comparing sirolimus-eluting stents (n ⫽ 38) with bare metal stents (n ⫽ 37) reported significantly lower rates of restenosis and repeat revascularization with sirolimus-eluting stents compared with bare metal stents at 6 months.9 Our data are consistent with outcomes in previous drug-eluting stent registries demonstrating low rates of TLR (up to 5.9%) and TVR (up to 10.1%) at 6 months.9,17,19,20 However, repeat revascularization rates in our cohort had almost tripled 6 to 12 months after the procedure. Only 1 previous study reported 1-year outcomes of 40 patients after treatment of SVGs with drugeluting stents; this study demonstrated a MACE rate of 7.5%,18 which is significantly lower than what we observed, although the reported characteristics of patients and lesions were quite similar in the 2 cohorts. We also observed relatively high rates of 1-year death (7.4%) and myocardial infarction (13.7%). Waksman et al21 also reported strikingly high rates of 1-year death and Qwave myocardial infarction in 132 patients who were treated with Palmaz-Schatz stents for SVG lesions (death 15.7%, Q-wave myocardial infarction 15.0%). Survival data of 2,556 patients published by Ashfaq et al.22 also found a very high rate of death after angioplasty of SVGs (⬃26%) at 5 years. These rates are very unfavorable compared with outcomes of patients after coronary artery bypass grafting, as reported by the Coronary Artery Surgery Study23 at 5 years (death 5%, Q-wave myocardial infarction 14%), which implies a significantly negative impact of SVG disease on prognosis of patients after coronary artery bypass surgery. In a multivariate analysis, we identified 2 predictors that were associated with increased incidence of adverse events after percutaneous treatment of SVG disease, namely presence of a filling defect consistent with thrombus inside the treated graft and length of stented segment. These 2 variables were associated with higher rates of myocardial infarction, but importantly, presence of a filling defect was also significantly associated with higher rate of death at 1 year. In the previously mentioned studies, no case of stent thrombosis was registered after treatment of SVG lesions with drug-eluting stents.9,17,19,20 We recorded 2 cases of stent thrombosis that occurred in drug-eluting stents. Stent thrombosis might be an important mechanism of stent occlusion in vein grafts. The large lumen of the vein graft and smaller lumen of the outflow vessel can contribute to slower
flow, possible suboptimal stent deployment, and prothrombotic environment inside grafts. However, graft occlusions might result in less serious clinical consequences than stent thromboses of native vessels because of ischemic preconditioning of the affected territory. It is of note that those 7 documented graft occlusions at follow-up were clinically silent. Our study reports quite high rates of adverse events. However, the data are hardly comparable with bare metal stent studies because our cohort contained a significant percentage of high-risk patients with diffusely degenerated grafts treated with multiple stents, whereas bare metal stent studies mostly included patients with easy focal lesions treated with single stents.6,10,11 We report a real-world single-center experience with treatment of SVGs in the era of drug-eluting stents. Limitations of the present study include a small sample, inhomogenous use of stents, low use of embolic protection devices, lack of systematic angiographic follow-up, and an adequate control group. Greater use of embolic protection devices might have improved the short- and long-term outcomes in our cohort. Acknowledgment: We thank the entire data center team at Columbia University Medical Center led by Theresa Franklin-Bond for their help and management of the interventional procedures database of our interventional cardiology department. 1. Bourassa MG, Fisher LD, Campeau L, Gillespie MJ, McConney M, Lesperance J. Long-term fate of bypass grafts: the Coronary Artery Surgery Study (CASS) and Montreal Heart Institute experiences. Circulation 1985;72(suppl):V71–V78. 2. Shaia N, Heuser RR. Distal embolic protection for SVG interventions: can we afford not to use it? J Interv Cardiol 2005;18:481– 484. 3. Silva JA, White CJ. Percutaneous intervention of old degenerated saphenous vein grafts. Int J Cardiovasc Intervent 2001;4:187–194. 4. Watson PS, Hadjipetrou P, Cox SV, Pyne CT, Gossman DE, Piemonte TC, Eisenhauer AC. Angiographic and clinical outcomes following acute infarct angioplasty on saphenous vein grafts. Am J Cardiol 1999;83:1018 –1021. 5. Hanekamp CE, Koolen JJ, Den Heijer P, Schalij MJ, Piek JJ, Bar FW, De Scheerder I, Bonnier HJ, Pijls NH. Randomized study to compare balloon angioplasty and elective stent implantation in venous bypass grafts: the Venestent study. Catheter Cardiovasc Interv 2003;60:452– 457. 6. Savage MP, Douglas JS Jr, Fischman DL, Pepine CJ, King SB III, Werner JA, Bailey SR, Overlie PA, Fenton SH, Brinker JA, Leon MB,
68
7.
8.
9.
10.
11.
12.
13.
14.
The American Journal of Cardiology (www.AJConline.org) Goldberg S. Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators. N Engl J Med 1997;337:740 –747. Mehran R, Dangas G, Abizaid AS, Mintz GS, Lansky AJ, Satler LF, Pichard AD, Kent KM, Stone GW, Leon MB. Angiographic patterns of in-stent restenosis: classification and implications for long-term outcome. Circulation 1999;100:1872–1878. The Joint European Society of Cardiology/American College of Cardiology Committee. Myocardial infarction redefined—a consensus document of the Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. Eur Heart J 2000;21:1502–1513. Vermeersch P, Agostoni P, Verheye S, Van den Heuvel P, Convens C, Bruining N, Van den Branden F, Van Langenhove G. Randomized double-blind comparison of sirolimus-eluting stent versus bare-metal stent implantation in diseased saphenous vein grafts: six-month angiographic, intravascular ultrasound, and clinical follow-up of the RRISC Trial. J Am Coll Cardiol 2006;48:2423–2431. Wong SC, Baim DS, Schatz RA, Teirstein PS, King SB III, Curry RC Jr, Heuser RR, Ellis SG, Cleman MW, Overlie P, et al. Immediate results and late outcomes after stent implantation in saphenous vein graft lesions: the multicenter U.S. Palmaz-Schatz stent experience. The Palmaz-Schatz Stent Study Group. J Am Coll Cardiol 1995;26:704 –712. Fenton SH, Fischman DL, Savage MP, Schatz RA, Leon MB, Baim DS, King SB, Heuser RR, Curry RC Jr, Rake RC, et al. Long-term angiographic and clinical outcome after implantation of balloon-expandable stents in aortocoronary saphenous vein grafts. Am J Cardiol 1994;74:1187–1191. Ahmed JM, Dangas G, Lansky AJ, Mehran R, Hong MK, Mintz GS, Pichard AD, Satler LF, Kent KM, Stone GW, Leon MB. Influence of gender on early and one-year clinical outcomes after saphenous vein graft stenting. Am J Cardiol 2001;87:401– 405. Brener SJ, Ellis SG, Apperson-Hansen C, Leon MB, Topol EJ. Comparison of stenting and balloon angioplasty for narrowings in aortocoronary saphenous vein conduits in place for more than five years. Am J Cardiol 1997;79:13–18. Stankovic G, Colombo A, Presbitero P, van den Branden F, Inglese L, Cernigliaro C, Niccoli L, Bartorelli AL, Rubartelli P, Reifart N, et al. Randomized evaluation of polytetrafluoroethylene-covered stent in saphenous vein grafts: the Randomized Evaluation of polytetrafluoro-
15.
16.
17.
18.
19. 20.
21.
22.
23.
ethylene COVERed stent in Saphenous vein grafts (RECOVERS) Trial. Circulation 2003;108:37– 42. Turco MA, Buchbinder M, Popma JJ, Weissman NJ, Mann T, Doucet S, Johnson WL Jr, Greenberg JD, Leadley K, Russell ME. Pivotal, randomized U.S. study of the Symbiot trade mark covered stent system in patients with saphenous vein graft disease: eight-month angiographic and clinical results from the Symbiot III trial. Catheter Cardiovasc Interv 2006;68:379 –388. Stone GW, Goldberg S, Mehran R, O’Shaughnessy C, Midei M, Siegel R, George B, Salter S, Rainzer A, Negoita M, et al. A prospective, randomized U.S. trial of the PTFE-covered JOSTENT for the treatment of diseased saphenous vein grafts: the BARRICADE trial. J Am Coll Cardiol 2005;45(suppl A):27A. Chu WW, Kuchulakanti PK, Wang B, Clavijo LC, Suddath WO, Pichard AD, Satler LF, Kent KM, Waksman R. Efficacy of sirolimuseluting stents as compared to paclitaxel-eluting stents for saphenous vein graft intervention. J Interv Cardiol 2006;19:121–125. Tsuchida K, Ong AT, Aoki J, van Mieghem CA, Rodriguez-Granillo GA, Valgimigli M, Sianos G, Regar E, McFadden EP, van der Giessen WJ, et al. Immediate and one-year outcome of percutaneous intervention of saphenous vein graft disease with paclitaxel-eluting stents. Am J Cardiol 2005;96:395–398. Lee MS, Shah AP, Aragon J, Jamali A, Dohad S, Kar S, Makkar RR. Drug-eluting stenting is superior to bare metal stenting in saphenous vein grafts. Catheter Cardiovasc Interv 2005;66:507–511. Ge L, Iakovou I, Sangiorgi GM, Chieffo A, Melzi G, Cosgrave J, Montorfano M, Michev I, Airoldi F, Carlino M, Corvaja N, Colombo A. Treatment of saphenous vein graft lesions with drug-eluting stents: immediate and midterm outcome. J Am Coll Cardiol 2005;45:989 –994. Waksman R, Weintraub WS, Ghazzal Z, Scott NA, Shen Y, King SB III, Douglas JS Jr. Short- and long-term outcome of narrowed saphenous vein bypass graft: a comparison of Palmaz-Schatz stent, directional coronary atherectomy, and balloon angioplasty. Am Heart J 1997;134:274 –281. Ashfaq S, Ghazzal Z, Douglas JS, Morris DC, Veledar E, Weintraub WS. Impact of diabetes on five-year outcomes after vein graft interventions performed prior to the drug-eluting stent era. J Invasive Cardiol 2006;18:100 –105. CASS Investigators. Myocardial infarction and mortality in the Coronary Artery Surgery Study (CASS) randomized trial. N Engl J Med 1984;310:750 –758.