Coronary Artery Bypass is Superior to Drug-Eluting Stents in Multivessel Coronary Artery Disease
2006; Elsevier BV; Volume: 81; Issue: 6 Linguagem: Inglês
10.1016/j.athoracsur.2006.03.020
ISSN1552-6259
Autores Tópico(s)Antiplatelet Therapy and Cardiovascular Diseases
ResumoPercutaneous intervention for the treatment of multivessel coronary artery disease continues to displace coronary artery bypass graft surgery. But controlled trials of percutaneous intervention versus coronary bypass, in meta-analysis, have shown a significant survival advantage for coronary bypass. Studies of bare metal stents have not presented any data to prompt reversal of this conclusion for all but the small portion of patients most suited for stenting. Drug-eluting stents have no survival advantage compared with bare metal stents. Data from real-world registries have shown that the current therapy of multivessel disease patients has resulted in a relative excess mortality of as much as 46% in patients with initial stenting compared with patients with initial coronary bypass. Ethical considerations demand that patients with multivessel disease be informed of the documented mortality benefit of coronary bypass graft surgery. Percutaneous intervention for the treatment of multivessel coronary artery disease continues to displace coronary artery bypass graft surgery. But controlled trials of percutaneous intervention versus coronary bypass, in meta-analysis, have shown a significant survival advantage for coronary bypass. Studies of bare metal stents have not presented any data to prompt reversal of this conclusion for all but the small portion of patients most suited for stenting. Drug-eluting stents have no survival advantage compared with bare metal stents. Data from real-world registries have shown that the current therapy of multivessel disease patients has resulted in a relative excess mortality of as much as 46% in patients with initial stenting compared with patients with initial coronary bypass. Ethical considerations demand that patients with multivessel disease be informed of the documented mortality benefit of coronary bypass graft surgery. During the past 36 months, the author has received research grants, consultation fees/honoraria, and travel expenses from US Surgical Corporation, Guidant, Quest Medical, Medtronic, and Chase Medical. He has no investment interest in any of these corporations. During the past 36 months, the author has received research grants, consultation fees/honoraria, and travel expenses from US Surgical Corporation, Guidant, Quest Medical, Medtronic, and Chase Medical. He has no investment interest in any of these corporations. The utilization of coronary artery bypass surgery (CABG) for revascularization of patients with coronary artery disease has been the subject of extensive scrutiny for more than a quarter century, beginning with randomized trials of CABG versus medical therapy conducted in the late 1970s [1Yusuf S. Zucker D. Peduzzi P. et al.Effect of coronary artery bypass graft surgery on survival overview of 10-year results from randomised trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration.Lancet. 1994; 344: 563-570Abstract PubMed Scopus (1758) Google Scholar]. Percutaneous intervention (PCI) for coronary revascularization has improved and has been used progressively more frequently compared with CABG, proponents of PCI claiming equivalent survival with a strategy of initial PCI compared with a strategy of initial CABG. Improvement in restenosis with drug-eluting stents has accelerated the utilization of PCI in patients with multivessel disease (MVD) [2Klein L.W. Are drug-eluting stents the preferred treatment for multivessel coronary artery disease?.J Am Coll Cardiol. 2006; 47: 22-26Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar]. This analysis of recent publications will examine the studies comparing CABG with PCI and combine this evidence with studies comparing bare metal stents and drug-eluting stents. This combination presents compelling evidence that CABG as initial therapy is superior to initial PCI with drug-eluting stents in the treatment of patients with MVD. The accelerated application of PCI to patients with MVD is not warranted. More importantly, patients are not being given adequate information about relative survival outcomes. Numerous trials of CABG versus medical therapy were conducted in the late 1970s and early 1980s. These trials, taken separately, demonstrated that CABG was significantly better than medical therapy for left main disease and triple-vessel disease with some left ventricular dysfunction. An important reanalysis of data from these trials was published by Yusef and coworkers [1Yusuf S. Zucker D. Peduzzi P. et al.Effect of coronary artery bypass graft surgery on survival overview of 10-year results from randomised trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration.Lancet. 1994; 344: 563-570Abstract PubMed Scopus (1758) Google Scholar] in 1994. In the Yusef data reanalysis, the CABG versus medical therapy survival curves converge at 12 years, related to graft closure (almost all veins grafts were used in these patients), cross-over from medical therapy to CABG in 41% of patients by 10 years, and simple aging of the patients (all survival curves eventually converge). This convergence of survival curves does not imply equivalent survival benefit after 12 years. Yusef appropriately compared extension of life (the integration of the area under the survival curves) by initial CABG compared with initial medical therapy. A significant survival benefit was seen for CABG in patients with angina (class I to II, 3.3 months; class III to IV, 7.3 months), or with abnormal exercise tests (5.1 months), or with left ventricular dysfunction (10.6 months), or with triple-vessel disease (5.7 months). Subgroup analysis even revealed a significant 5-year survival benefit for patients with one- or two-vessel disease if there was disease of the proximal left anterior descending artery [1Yusuf S. Zucker D. Peduzzi P. et al.Effect of coronary artery bypass graft surgery on survival overview of 10-year results from randomised trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration.Lancet. 1994; 344: 563-570Abstract PubMed Scopus (1758) Google Scholar]. These trials of CABG versus medical therapy are the basis for current recommendations for the use of CABG for extension of survival in patients with MVD. Major improvements in medical therapy have occurred in the last 25 years, but these improvements apply to surgical patients as well as to medically treated patients. These trials are also the underpinning of inferences that PCI extends survival, based upon comparative studies of PCI versus CABG. Beginning in 1980, multiple randomized controlled trials (RCTs) of PCI versus CABG were conducted. The Emory Angioplasty Surgery Trial (EAST) screened 5118 patients and found 842 patients (16.5%) sufficiently suitable for either PCI or CABG who were eligible for enrollment. Three hundred ninety-two patients with MVD were randomly assigned (7.7% of 5,118 screened patients, mean age 62 years, 60% double-vessel disease, 40% triple-vessel disease) to PCI or CABG [3King III, S.B. Lembo N.J. Weintraub W.S. et al.A randomized trial comparing coronary angioplasty with coronary bypass surgery.N Engl J Med. 1994; 331: 1044-1050Crossref PubMed Scopus (680) Google Scholar]. This author participated in EAST. Enrollment became difficult at the end of the trial as referring cardiologists frequently sent patients to Emory with expressed preferences for PCI or CABG. Patients tended to be enrolled when the referring cardiologist thought that there would be no difference in outcomes. Eight-year mortality in the CABG group was 17.3% compared with a mortality of 21.7% in the PCI group. The relative mortality difference of 20% in the 7.7% of MVD patients most suitable for either PCI or CABG was not statistically significant because of the small size of the groups [4King III, S.B. Kosinski A.S. Guyton R.A. Lembo N.J. Weintraub W.S. Eight-year mortality in the Emory Angioplasty versus Surgery Trial (EAST).J Am Coll Cardiol. 2000; 35: 1116-1121Abstract Full Text Full Text PDF PubMed Scopus (261) Google Scholar]. Notably, the wisdom of steerage by referring cardiologists toward PCI or CABG (even within the small portion of MVD patients most suitable for either procedure) was validated by results from the EAST registry. Registry patients (eligible, but not randomized) had a significantly better 5-year survival compared with randomized patients [5King III, S.B. Barnhart H.X. Kosinski A.S. et al.Emory Angioplasty versus Surgery Trial InvestigatorsAngioplasty or surgery for multivessel coronary artery disease comparison of eligible registry and randomized patients in the EAST trial and influence of treatment selection on outcomes.Am J Cardiol. 1997; 79: 1453-1459Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar]. This registry versus randomized results makes it difficult to find fault with the behavior of clinicians in other PCI versus CABG studies in which selective enrollment of patients is commonplace. Unfortunately, such selective enrollment makes it very difficult to extend the results of randomized trials to the general population of patients with MVD. The largest randomized controlled trial of CABG versus PCI in MVD was the Bypass Angioplasty Revascularization Investigation (BARI) trial, conducted in 18 centers from 1988 to 1991. An analysis of enrollment was published by Bourassa and colleagues [6Bourassa M.G. Roubin G.S. Detre K.M. et al.Bypass Angioplasty Revascularization Investigation patient screening, selection, and recruitment.Am J Cardiol. 1995; 75: 3C-8CAbstract Full Text PDF PubMed Scopus (110) Google Scholar]. A total of 25,200 patients with MVD was screened. Approximately half were excluded for clinical, administrative, or major angiographic reasons (eg, left main stenosis). The analysis states: "Of 12,530 patients who met clinical eligibility for BARI, 67% were unsuitable for one or both procedures. In < 95% of the time this was due to technical unsuitability for PTCA. Although complete revascularization was not a requirement, the protocol called for anticipation of successful relief of the major areas of ischemia. To leave patients with large areas of unrevascularized myocardium was clearly not in the patient's best interest" [6Bourassa M.G. Roubin G.S. Detre K.M. et al.Bypass Angioplasty Revascularization Investigation patient screening, selection, and recruitment.Am J Cardiol. 1995; 75: 3C-8CAbstract Full Text PDF PubMed Scopus (110) Google Scholar]. In all, 1,829 patients entered the trial. Mean age was 61 years; 59% had two-vessel disease and 41% had three-vessel disease [7Alderman E.L. Andrews K. Bost J. et al.Comparison of coronary bypass surgery with angioplasty in patients with multivessel disease.N Engl J Med. 1996; 335: 217-225Crossref PubMed Scopus (1543) Google Scholar]. Only 7.3% of screened MVD patients were randomized [6Bourassa M.G. Roubin G.S. Detre K.M. et al.Bypass Angioplasty Revascularization Investigation patient screening, selection, and recruitment.Am J Cardiol. 1995; 75: 3C-8CAbstract Full Text PDF PubMed Scopus (110) Google Scholar]. At 7 years, there was a significant survival advantage for CABG versus PCI (absolute survival difference 2.5%, relative survival difference 15%; p = 0.043, Fig 1) [8The BARI InvestigatorsSeven-year outcome in the Bypass Angioplasty Revascularization Investigation (BARI) by treatment and diabetic status.J Am Coll Cardiol. 2000; 35: 1122-1129Abstract Full Text Full Text PDF PubMed Scopus (430) Google Scholar]. This significant 15% relative survival advantage for CABG occurred in the 7.3% of MVD patients screened in BARI who were most suitable for either procedure. A subgroup of 934 BARI patients were followed for 10 to 12 years in a study of outcome and cost. Costs for CABG were 53% higher initially, but the cost difference narrowed to 2% after 12 years, primarily because of repeat coronary intervention in the PCI group. The projected extension of life in the CABG group was 0.24 years, leading to a cost-effectiveness estimate of $11,300/quality adjusted life year (QALY) compared with PCI. (A cost effectiveness of less than $20,000/QALY is considered to be a highly effective treatment [9Hlatky M.A. Boothroyd D.B. Melsop K.A. et al.Medical costs and quality of life 10 to 12 years after randomization to angioplasty or bypass surgery for multivessel coronary artery disease.Circulation. 2004; 110: 1960-1966Crossref PubMed Scopus (88) Google Scholar]). Results from other trials of CABG versus PCI in MVD, in aggregate, are consistent with the result from the BARI trial. A meta-analysis of nine randomized controlled trials of CABG versus PCI in MVD revealed that survival was equivalent in these selected randomized patients at 1 year and 3 years, but initial CABG compared with initial PCI had a significant survival advantage at 5 years and 8 years (Fig 2, Fig 3) [10Hoffman S.N. TenBrook Jr, J.A. Wolf M.P. Pauker S.G. Salem D.N. Wong J.B. A meta-analysis of randomized controlled trials comparing coronary artery bypass graft with percutaneous transluminal coronary angioplasty one- to eight-year outcomes.J Am Coll Cardiol. 2003; 41: 1293-1304Abstract Full Text Full Text PDF PubMed Scopus (362) Google Scholar].Fig 3Data from meta-analysis of nine randomized controlled trials of coronary artery bypass graft surgery (CABG) versus percutaneous transluminal coronary angioplasty (PTCA) in multivessel disease. The 8-year mortality rate was 13.7% with CABG versus 17.1% with PTCA (p < 0.03). Relative mortality with PTCA was 25% higher than with CABG [10Hoffman S.N. TenBrook Jr, J.A. Wolf M.P. Pauker S.G. Salem D.N. Wong J.B. A meta-analysis of randomized controlled trials comparing coronary artery bypass graft with percutaneous transluminal coronary angioplasty one- to eight-year outcomes.J Am Coll Cardiol. 2003; 41: 1293-1304Abstract Full Text Full Text PDF PubMed Scopus (362) Google Scholar].View Large Image Figure ViewerDownload (PPT) The response of the interventional cardiology community to the survival advantage demonstrated in the RCTs of CABG versus PCI was rapid and, from a marketing perspective, effective. The RCTs were dissected in a post hoc manner, claiming that if high-risk subgroups were removed (specifically diabetic patients), then the residual patients exhibited no survival benefit from CABG [7Alderman E.L. Andrews K. Bost J. et al.Comparison of coronary bypass surgery with angioplasty in patients with multivessel disease.N Engl J Med. 1996; 335: 217-225Crossref PubMed Scopus (1543) Google Scholar]. The RCTs were already compromised by low enrollment and by a selection of patients thought not to be clinically disadvantaged by use of either technique. One may be somewhat incredulous that any reasonable reviewer might find it appropriate to peel off another layer of higher risk patients from this highly selected subgroup of MVD patients. The second, and equally effective, response of the interventional cardiology community was that PCI in the mid 1990s had evolved rapidly with the introduction of stenting and antithrombosis drugs, which almost eliminated acute occlusion, dramatically reduced the need for emergency CABG, and decreased the rate of restenosis of treated lesions. An equally strong argument can be made that the quality and efficacy of CABG improved in the early 1990s. Weintraub and associates [11Weintraub W.S. Craver J.M. Jones E.L. et al.Improving cost and outcome of coronary surgery.Circulation. 1998; 98: 23-28Google Scholar] at Emory examined outcomes and costs from 12,200 CABG patients from 1988 to1996. Multiple risk factors were significantly increased: age, prior coronary artery bypass, diabetes mellitus, prior myocardial infarction, class III or IV angina, congestive heart failure, hypertension, multivessel coronary disease, and low ejection fraction. Despite increased severity of disease, multiple outcome variables improved. Notably, operative mortality decreased from 4.7% to 2.7%. Accounting for the increased severity of patients, this was a 10% decrease in mortality per year (p = 0.0001). Postoperative length of stay decreased from 9.2 to 5.9 days. Related to this decrease in length of stay, hospital costs importantly decreased from $22,700 to $16,000 per case. Adjusting for increased patient severity, hospital costs decreased by $1,118 per year during this 9-year period [11Weintraub W.S. Craver J.M. Jones E.L. et al.Improving cost and outcome of coronary surgery.Circulation. 1998; 98: 23-28Google Scholar]. In addition to randomized controlled trials, a very important comparison of the relative utility of PCI and CABG comes from analysis of outcomes of the application of these interventions in the treatment of coronary artery disease in entire captive populations. As described above, the RCTs of PCI versus CABG are limited by highly selected enrollment and extrapolation of RCT results to entire MVD populations is simply inappropriate. Prospectively gathered data on the outcome of PCI and CABG as applied to an entire captive population provides our best evaluation of how successfully practioners have applied the evidence from RCTs, meta-analyses, and uncontrolled trials to the treatment of patients in the real world. A very important comparison of PCI versus CABG in the treatment of coronary disease comes from the New York State Cardiac Procedure Registries. Hannan and associates [12Hannan E.L. Racz M.J. McCallister B.D. et al.A comparison of three-year survival after coronary artery bypass graft surgery and percutaneous transluminal coronary angioplasty.J Am Coll Cardiol. 1999; 33: 63-72Abstract Full Text Full Text PDF PubMed Scopus (138) Google Scholar] compared results of PCI versus CABG in New York State residents from 1993 to 1995. Three-year mortality rates were adjusted using proportional hazards methods to account for baseline differences in patients' severity of illness. Practioners were skilled, with excellent results in both PCI and CABG (hospital mortality 0.4% for PCI and 1.9% for CABG). With 3-year follow-up, repeat revascularization rate was 11 times higher in the PCI group (37% PCI, 3.3% CABG). Most importantly, however, in MVD, mortality was significantly elevated in the PCI patients compared with CABG. In the case of triple-vessel disease, 3-year adjusted mortality was 43% higher with primary PCI relative to primary CABG (absolute 3-year mortality 13.9% with PCI, 9.7% with CABG). It certainly appears that, at least in 1993 to 1995, the enthusiasm of cardiologists for PCI led to utilization of PCI relative to CABG in a manner that may not have been in the best interests of New York State patients with MVD. Three major RCTs of PCI with stents versus CABG have been reported: the Arterial Revascularization Therapies Study (ARTS) with 5-year follow-up [13Serruys P.W. Ong A.T.L. van Herwerden L.A. et al.Five-year outcomes after coronary stenting versus bypass surgery for the treatment of multivessel disease.J Am Coll Cardiol. 2005; 46: 575-581Abstract Full Text Full Text PDF PubMed Scopus (551) Google Scholar], the Argentine Randomized Study: Coronary Angioplasty with Stenting versus Coronary Bypass Surgery in Multivessel Disease (ERACI II) with 5-year follow-up [14Rodriguez A.E. Baldi J. Pereira C.F. Navia J. Alemparte M.R. Five-year follow-up of the Argentine randomized trial of coronary angioplasty with stenting versus coronary bypass surgery in patients with multiple vessel disease (ERACI II).J Am Coll Cardiol. 2005; 46: 582-588Abstract Full Text Full Text PDF PubMed Scopus (216) Google Scholar], and the Stent or Surgery Trial (SoS) with 2-year follow-up [15The SoS InvestigatorsCoronary artery bypass surgery versus percutaneous coronary intervention with stent implantation in patients with multivessel coronary artery disease (the Stent or Surgery trial) a randomized controlled trial.Lancet. 2002; 360: 965-970Abstract Full Text Full Text PDF PubMed Scopus (497) Google Scholar]. The ARTS trial randomly assigned 1,205 patients with MVD in 67 centers [13Serruys P.W. Ong A.T.L. van Herwerden L.A. et al.Five-year outcomes after coronary stenting versus bypass surgery for the treatment of multivessel disease.J Am Coll Cardiol. 2005; 46: 575-581Abstract Full Text Full Text PDF PubMed Scopus (551) Google Scholar]. The ARTS was a very PCI-friendly trial with enrollment only when the cardiologist and surgeon agreed that equivalent revascularization of two or more lesions could be achieved with either method. Only 5% of screened patients were enrolled. Patients enrolled were very low risk patients: no previous intervention, no congestive heart failure, no recent myocardial infarction, no cerebrovascular accident, mean age 61 years, and mean ejection fraction 0.61. A major concern in the ARTS trial is a problematic difference between the PCI group and the CABG group in timely therapy after randomization. Treatment with with stents occurred an average of 11 days after randomization with no deaths, 1 myocardial infarction, and no strokes in this interval. Treatment with CABG averaged 27 days after randomization with 3 deaths, 4 myocardial infarctions, and 1 stroke in this interval. Delay in initiation of therapy in the surgical group led to a 0.5% mortality and more than 1% major adverse cardiac and cerebral event rate before therapy was initiated [16Serruys P.W. Unger F. Sousa J.E. et al.Comparison of coronary-artery bypass surgery and stenting for the treatment of multivessel disease.N Engl J Med. 2001; 344: 1117-1124Crossref PubMed Scopus (1019) Google Scholar]. The authors' analysis of results included these pretreatment events despite this problematic difference between the groups. The following paragraphs present a postprocedure outcomes analysis, which accommodates the difference in timeliness of therapy in the two groups. One-year results in ARTS were not surprising, with equivalent mortality and major adverse cardiac and cerebral event rate in each group. But despite PCI-friendly enrollment, deaths after the procedure were the same (15 in stent group, 14 in CABG group) at 1 year. As in EAST and BARI, percutaneous intervention for MVD does not have a lower early (1-year) mortality rate compared with CABG. This equal 1-year mortality is not the general perception of the public or of cardiologists. Additionally, 16.8% of the stent group versus only 3.5% of the CABG group required repeat revascularization by 1 year. Even with repeat revascularization, significantly more of the stent group had angina (21%) compared with the CABG group (10%) [16Serruys P.W. Unger F. Sousa J.E. et al.Comparison of coronary-artery bypass surgery and stenting for the treatment of multivessel disease.N Engl J Med. 2001; 344: 1117-1124Crossref PubMed Scopus (1019) Google Scholar]. Five-year follow-up of the ARTS trial revealed postprocedure mortality of 7.1% at 5 years in the CABG group and 8% in the stent group (yielding a rough relative risk of 1.13). Five-year postprocedure death, myocardial infarction, or stroke rate was 13.5 % for CABG and 18% for PCI/stents (relative risk approximately 1.33). Repeat revascularization was 8.8% for CABG and 30% for PCI/stents (relative risk approximately 3.46). Despite the fact that the study was not powered to detect a mortality, myocardial infarction, or stroke difference between groups and the postprocedure data favored CABG, the authors of the 5-year follow-up concluded: "At five years there was no difference in mortality between stenting and surgery for MVD. Furthermore, the incidence of stroke or myocardial infarction was not significantly different between the two groups." They further endorse stenting by stating that "the difference in outcomes seen between bare metal stents (BMS) versus CABG is likely to narrow substantially with the advent of drug-eluting stents (DES)" [13Serruys P.W. Ong A.T.L. van Herwerden L.A. et al.Five-year outcomes after coronary stenting versus bypass surgery for the treatment of multivessel disease.J Am Coll Cardiol. 2005; 46: 575-581Abstract Full Text Full Text PDF PubMed Scopus (551) Google Scholar]. The not-so-subtle bias of the ARTS authors favoring stenting is a particular concern because of at least one major conflict of interest that was not disclosed in the 1-year and 3-year reports. Doctor Brian Firth was on the board of governors of the study group and was acknowledged "for … careful review of the manuscript and for … constructive suggestions" [16Serruys P.W. Unger F. Sousa J.E. et al.Comparison of coronary-artery bypass surgery and stenting for the treatment of multivessel disease.N Engl J Med. 2001; 344: 1117-1124Crossref PubMed Scopus (1019) Google Scholar]. Undisclosed was the fact that Dr Firth was Vice President of Cordis, a division of Johnson and Johnson, the stent manufacturer that supported the study [172002 Cordis to host analyst meeting at transcatheter cardiovascular therapeutics symposium. Available at: http://www.jnj.com/news/jnj_news/. Accessed October 20, 2005.Google Scholar]. In the report of 5-year results, Dr Firth was a coauthor of the report, and it was disclosed that he was "an employee of Cordis" [13Serruys P.W. Ong A.T.L. van Herwerden L.A. et al.Five-year outcomes after coronary stenting versus bypass surgery for the treatment of multivessel disease.J Am Coll Cardiol. 2005; 46: 575-581Abstract Full Text Full Text PDF PubMed Scopus (551) Google Scholar]. The extent of this conflict is beyond the usual standards for properly run RCTs. The ERACI II trial randomly assigned 450 MVD patients over 2 years in seven Argentine centers. The mean age of patients was 61 to 62 years; 40% of the patients had two-vessel disease. The 30-day mortality was 5.6% in the CABG group and 0.9% in the stent group. The remarkably high CABG mortality was attributed to unstable angina in 91% of the CABG patients. As in the ARTS trial, there was a relative delay in therapy for CABG patients after randomization (13.2 days for CABG and 4.2 days for stent). One death occurred in the CABG group before the procedure and no deaths in the stent group. The high 30-day mortality for CABG led to a significantly better 5-year mortality with stenting: 7.2% versus 11.6%. Five-year major adverse cardiac and cerebral event rate was better with CABG: 23.6% versus 34.7% (related to more revascularization in the stent group) [14Rodriguez A.E. Baldi J. Pereira C.F. Navia J. Alemparte M.R. Five-year follow-up of the Argentine randomized trial of coronary angioplasty with stenting versus coronary bypass surgery in patients with multiple vessel disease (ERACI II).J Am Coll Cardiol. 2005; 46: 582-588Abstract Full Text Full Text PDF PubMed Scopus (216) Google Scholar, 18Rodriguez A. Bernardi V. Navia J. et al.Argentine randomized study. Coronary angioplasty with stenting versus coronary bypass surgery in patients with multiple-vessel disease (ERACI II) 30-day and one-year follow-up results.J Am Coll Cardiol. 2001; 37: 51-58Abstract Full Text Full Text PDF PubMed Scopus (308) Google Scholar]. The major issue related to the outcomes in ERACI II is concern about the high 30-day CABG mortality. The yearly average CABG volume in the seven participating centers was 57 patients! Internal mammary artery use was 89% in these approximately 62-year-old patients. With an institutional CABG volume of 1 patient per week, a delay of 13 days for CABG (these would have to be called elective patients, despite the fact that they may have been "unstable" at the time of enrollment), internal mammary artery use in less than 90%, and a CABG operative mortality of 5.6%, a very serious question must be raised about the quality of surgical therapy in this study. The authors expressed concern about the unusually large percent of patients with unstable angina, stating that "results could change if the patient population treated had different baseline clinical characteristics or if technical proficiency for either treatment was altered" [14Rodriguez A.E. Baldi J. Pereira C.F. Navia J. Alemparte M.R. Five-year follow-up of the Argentine randomized trial of coronary angioplasty with stenting versus coronary bypass surgery in patients with multiple vessel disease (ERACI II).J Am Coll Cardiol. 2005; 46: 582-588Abstract Full Text Full Text PDF PubMed Scopus (216) Google Scholar, 18Rodriguez A. Bernardi V. Navia J. et al.Argentine randomized study. Coronary angioplasty with stenting versus coronary bypass surgery in patients with multiple-vessel disease (ERACI II) 30-day and one-year follow-up results.J Am Coll Cardiol. 2001; 37: 51-58Abstract Full Text Full Text PDF PubMed Scopus (308) Google Scholar]. The SoS trial from 53 centers in Europe and Canada randomly assigned 988 patients for whom revascularization was indicated and "appropriate by either strategy." The study sample size was calculated to detect a difference in revascularization in the two treatment strategies, assuming a repeat revascularization rate of 5% in the CABG group and 10% in the PCI group. At 2 years' median follow-up, revascularization was dramatically higher than assumed in the PCI group at 21%, compared with 6% in the CABG group (a 15% absolute difference rather than the 5% difference assumed when the study was designed, hazard ratio 3.85, p < 0.0001). Again there was a delay between randomization and therapy (mean 14 days for PCI and 23 days for CABG), but the CABG group was not disadvantaged by this delay (1 pretreatment death occurred, in the PCI group). The authors struggled with the fact that the CABG group had a significantly lower cumulative risk of death than the PCI group. At 2 years' median follow-up, mortality was 2% CABG versus 5% PCI (8 deaths versus 22 deaths, hazard ratio 2.91, p = 0.01). There was a higher rate of noncardiovascular death in the PCI group (9 versus 3, ratio 3:1), but even with the noncardiovascular deaths excluded,
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