HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Felix Hernandez Jeremy Morton William Nugent Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by O'Rourke, D. J. Articles by Malenka, D. J. Search for Related Content PubMed PubMed Citation Articles by O'Rourke, D. J. Articles by Malenka, D. J. Related Collections Coronary disease

Ann Thorac Surg 2004;78:466-470
© 2004 The Society of Thoracic Surgeons

---

Original article: cardiovascular

Survival in patients with peripheral vascular disease after percutaneous coronary intervention and coronary artery bypass graft surgery

^a Section of Cardiology, Veterans Affairs Hospital, White River Junction, Vermont, USA
^b Section of Cardiology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
^g Section of Cardiothoracic Surgery, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
^c Section of Clinical Research, Dartmouth Medical School, Hanover, New Hampshire, USA
^d Section of Cardiothoracic Surgery, Eastern Maine Medical Center, Bangor, Maine, USA
^e Section of Cardiothoracic Surgery, Maine Medical Center, Portland, Maine, USA
^f Section of Cardiology, Catholic Medical Center, Manchester, New Hampshire, USA

Accepted for publication January 22, 2004.

^* Address reprint requests to Dr O'Rourke, Medical Service-Cardiology, Veterans Affairs Medical Center, Hartland Rd, White River Junction, VT 05006, USA
e-mail: daniel.o'rourke{at}hitchcock.org

	Abstract

Top Abstract Introduction Material and methods Results Comment References

 
BACKGROUND: Patients with peripheral vascular disease (PVD) undergoing coronary revascularization have high rates of adverse outcomes. Whether there are important differences in outcomes for surgical versus percutaneous coronary revascularization is unknown. The objective of this study was to compare survival in patients with PVD who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) surgery for multivessel coronary artery disease.

METHODS: In-hospital data were collected on 1,305 consecutive patients undergoing coronary revascularization (PCI, n = 341; CABG, n = 964) in northern New England from 1994 to 1996. Patient records were linked to the National Death Index to assess survival out to 3 years (mean 1.2 years). Logistic and Cox proportional hazards regression were used to calculate risk-adjusted odds ratios and hazard ratios.

RESULTS: Compared with CABG patients, those undergoing PCI were more often women, had more renal failure, more prior coronary revascularizations, were more likely to have two-vessel coronary artery disease and were more likely to undergo the procedure emergently. They were less likely to have a history of heart failure. After adjusting for differences in baseline characteristics, patients undergoing CABG had better intermediate survival than did PCI patients (hazard ratio 0.68; 95% confidence interval, 0.46 to 1.00; p = 0.05).

CONCLUSIONS: Patients with multivessel coronary artery disease and PVD undergoing CABG surgery have better intermediate survival out to 3 years than similar patients undergoing PCI. This information may be useful in counseling patients with PVD requiring coronary revascularization.

	Introduction

Top Abstract Introduction Material and methods Results Comment References

 
Historically, coronary artery bypass grafting (CABG) has been accepted as the preferred method of coronary revascularization for patients with multivessel coronary artery disease (CAD) [1]. Recently, several randomized trials have compared percutaneous coronary intervention (PCI) with CABG for treatment of select patients with multivessel CAD [2]. These studies showed no differences in the rates of myocardial infarction or survival. Although patients undergoing PCI had a lower upfront risk of experiencing adverse events than did patients undergoing CABG, they more often required repeat revascularization and medications to treat recurrent angina. Although the Bypass Angioplasty Revascularization Investigation (BARI) also reported that 5-year survival was similar for PCI and CABG in most patients, notable exceptions were patients with diabetes, who had a survival benefit with CABG [3].

Because of the diffuse nature of the atherosclerotic process, patients with peripheral vascular disease (PVD) often have concomitant multivessel CAD [4]. Peripheral vascular disease is an important predictor of adverse outcomes after coronary revascularization. Patients with PVD have been found to have higher rates of adverse outcomes and poorer survival compared with patients without PVD [5–9]. Only one study has compared the outcomes of CABG versus PCI in patients with multivessel CAD and PVD [9]; a nonsignificant trend was found for improved survival with CABG (adjusted relative risk = 0.87, p = 0.40).

The question of whether surgical revascularization is superior to PCI for patients with PVD remains an open question. Therefore, we used our regional registry of consecutive coronary revascularizations to compare the in-hospital, 30-day, and intermediate survival out to 3 years among patients with PVD and multivessel CAD who underwent PCI or CABG in northern New England.

	Material and methods

Top Abstract Introduction Material and methods Results Comment References

 
Database
Data were obtained from the registries of the Northern New England Cardiovascular Disease Study Group, a regional, voluntary, multidisciplinary group of clinicians, hospital administrators, and health care research personnel from all the medical centers in the region who are the sole providers of coronary revascularization. This group seeks to improve continuously the quality, safety, effectiveness, and cost of cardiovascular care within the region [10, 11].

Patients
Between January 1, 1994, and December 31, 1996, data were prospectively collected on 19,119 consecutive patients undergoing coronary revascularization (PCI = 9,832; CABG = 9,287). Patients with single-vessel CAD (7,489) and left main occlusion of at least 50% (2,474) were excluded because in most cases such patients are not candidates for both PCI and CABG. After these exclusions, 9,156 patients remained; 1,305 (14.3%) with PVD (PCI = 341; CABG = 964) became the study cohort. Data were collected on patient demographics, past medical history, comorbidities, primary indication for the intervention, therapy, cardiac anatomy and function, surgical indication and priority, procedural information, and outcomes as described previously [10–13]. Peripheral vascular disease was defined as the presence of cerebrovascular disease including prior cerebrovascular accident, prior transient ischemic attack, carotid stenosis by history or carotid bruit; or lower extremity vascular disease including claudication, amputation, prior lower extremity bypass, absent pedal pulses, or lower extremity ulcers.

Outcome measures
The primary outcomes of interest included in-hospital, 30-day, and intermediate survival out to 3 years. In-hospital mortality was obtained from the Northern New England Cardiovascular Disease Study Group database. The National Death Index [14, 15] was searched to obtain data on 30-day and intermediate survival through December 31, 1996 (mean follow-up 1.2 years, range 0 to 3 years). These data were merged to the registry through a probabilistic match using some combination of name, social security number, date of birth, sex, date last known alive, and state of last known residence. The accuracy of the National Death Index is between 92% and 99%, depending on which patient identifiers are available [16, 17].

Statistical analysis
Comparisons of means and proportions were performed using standard statistical techniques. Multivariate models were used to adjust for difference in case-mix and severity of illness between patients undergoing PCI versus CABG. Patient and procedural characteristics associated with mortality (p < 0.01) in univariate analyses were included in a final multivariate model. The variables used to adjust for case-mix in the final model included: age, sex, surgical priority, three vessel coronary artery disease, prior CABG, congestive heart failure, ejection fraction, chronic obstructive pulmonary disease, dialysis-dependent renal failure, and diabetes. Logistic regression was used to determine the adjusted odds ratios (OR) for in-hospital and 30-day mortality and direct standardization was used to calculate adjusted rates. Cox proportional hazards regression was used to determine the adjusted hazard ratio (HR) for survival. All analyses were performed using Stata Statistical Software Release 6.0 (Stata Corporation, College Station, TX) and SAS 8.2 (SAS Institute, Cary, NC). Statistical significance was defined as a two-tailed p value less than 0.05.

	Results

Top Abstract Introduction Material and methods Results Comment References

 
Patients undergoing PCI and CABG were of similar age (Table 1). However, patients undergoing PCI were more often women (p < 0.01), had more renal failure (p < 0.01), were much more likely to have undergone previous CABG (p < 0.01), and were more likely to have undergone the procedure emergently (p < 0.01). Patients undergoing CABG were more likely to have three-vessel disease (p < 0.01) and more likely to have a history of heart failure (p < 0.04). Despite these differences, the reported ejection fractions and left ventricular end-diastolic pressure measurements were similar. No significant differences were noted in the prevalence of diabetes, chronic obstructive lung disease, history of myocardial infarction, or prior PCI. The mean and median number of distal anastomoses in CABG patients was 3.6 and 3.0, respectively. Twenty-one percent of PCI patients had a multivessel intervention.

View larger version (14K): [in this window] [in a new window]   Fig 1. Survival of patients with peripheral vascular disease by procedure. (CABG = coronary artery bypass grafting; PCI = percutaneous coronary intervention.)

	Comment

Top Abstract Introduction Material and methods Results Comment References

Short-term and intermediate-term outcome
The presence of PVD has been found to be an important predictor of both short-term and intermediate-term survival out to 3 years in patients undergoing coronary revascularization. Birkmeyer and colleagues [6] found that the adjusted in-hospital mortality for CABG was 73% higher for patients with PVD than for patients without PVD (OR = 1.73; 95% CI, 1.19 to 2.51), a finding similar to those of other investigators [13, 18, 19]. O'Connor and colleagues [13, 20] identified PVD as an important predictor of in-hospital outcome for both PCI and CABG. After more than 5 years of follow-up, Birkmeyer and colleagues [7] found a twofold increase in the mortality rate in patients with PVD compared with patients without PVD after bypass surgery (HR = 2.01; 95% CI, 1.57 to 2.58; p < 0.01). Eagle and coworkers [5] also found that PVD was an independent risk factor for long-term mortality in patients undergoing CABG, and that PVD was associated with an adverse long-term outcome (HR = 1.25; 95% CI, 1.15 to 1.36; p < 0.001).

Coronary artery bypass grafting versus percutaneous coronary intervention
Only one other study has compared survival after CABG to PCI in patients with PVD and multivessel CAD [9]. The BARI investigators reported on survival in a subgroup of 303 patients with PVD. The 5-year cumulative survival rates were similar between groups (80.3% CABG compared with 71.4% PCI, p = 0.11) and after adjusting for baseline characteristics no significant difference was found in survival between CABG and PCI (HR 0.87; 95% CI, 0.83 to 1.20; p = 0.40).

There are several possible explanations for our findings. Compared with PCI, CABG surgery offers more complete revascularization, which has been linked to survival [21]. Although we have no global measure of revascularization, in our CABG group the mean number of distal anastomoses was 3.6, whereas in the PCI group the mean number of vessels intervened on was 1.02, suggesting more complete revascularization with surgery. The durability of revascularization may be playing a role. The weak point of PCI is restenosis, which in the largely pre-stent era of this study was approximately 40%. Bypass grafts, particularly mammary grafts, have high long-term patency rates [22]. This advantage could result in less ischemia among CABG patients and possibly a lower incidence of life-threatening arrhythmic events. Some 40% of our patient population had diabetes, for which we have previously determined CABG is superior [23]. Because diabetes and PVD independently influence outcome after CABG, we sought to separate the independent effects of the two risk factors. We found that in patients with PVD and without diabetes, CABG was associated with improved survival compared with PCI (HR 0.63; 95% CI, 0.39 to 1.02; p = 0.063). Therefore, independent of diabetes, PVD was associated with improved survival in patients undergoing bypass surgery compared with PCI. Finally, more than twice as many patients who underwent PCI had a history of CABG, compared with the percentage of CABG patients who had a history of PCI. Therefore, we controlled for the variable prior CABG in our Cox model. After adjusting for differences in baseline characteristics, including prior CABG, we found that patients undergoing CABG had better intermediate survival out to 3 years than did patients undergoing PCI (HR 0.68; 95% CI, 0.46 to 1.00; p = 0.05). Perhaps part of the statistically significant survival benefit observed in the CABG group resulted from subsequent PCI for in-graft stenosis or new disease in the native circulation. Our database does not allow us to assess the proportion of CABG patients requiring reintervention or the proportion of PCI patients requiring subsequent CABG.

Why did the BARI results differ from ours? As the BARI investigators acknowledged, their study was underpowered to detect a difference between CABG and PCI survival. Interestingly, their nonsignificant HR (0.87) falls within the significant confidence intervals of our study (95% CI, 0.46 to 1.00). Although the details of revascularization in the BARI subgroup of PVD patients were not reported, in the overall study, 70% of PCI patients had multivessel intervention, compared with 21% in our study. Thus, more complete revascularization in BARI PCI patients may have resulted in survival more comparable to CABG.

Study limitations
Unlike BARI, patients in our study were not randomized to treatment. Our results may have been confounded by unmeasured differences in case-mix, although to the extent that this choice was based on measured patient characteristics this lack of randomization should not be a problem. We did not use an objective measure to define the presence of PVD. However, our clinical definition for PVD was similar to that adopted by the American College of Cardiology [24]. Finally, the practice of PCI is ever changing and we are now in the era of stents, IIb/IIIa inhibitors, and distal protection devices. To the extent that these practices improve vessel patency and curtail myocardial damage, they may result in improved survival after PCI, a possibility that merits further study.

Conclusions
In the mid-1990s, in northern New England, patients with PVD and multivessel CAD undergoing CABG had better intermediate survival out to 3 years than did patients undergoing PCI. If generalizable, this finding would be another important piece of information for patients with PVD and their physicians to consider when developing a strategy for coronary revascularization.

	References

Top Abstract Introduction Material and methods Results Comment References

 

1. Yusef 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;344:563-570.[Medline]
2. Pocock S.J., Henderson R.A., Phillips H.R., III, et al. Meta-analysis of randomised trials comparing coronary angioplasty with bypass surgery. Lancet 1995;346:1184-1189.[Medline]
3. The Bypass Angioplasty Revascularization Investigation (BARI) Investigators. Comparison of coronary bypass surgery with angioplasty in patients with multivessel disease. N Engl J Med 1996;335:217-225.[Abstract/Free Full Text]
4. Hertzer N.R., Beven E.G., Young J.R., et al. Coronary artery disease in peripheral vascular patients: a classification of 1000 coronary angiograms and results of surgical management. Ann Surg 1984;199:223-233.[Medline]
5. Eagle K.A., Rihal C.S., Foster E.D., Mickel M.C., Gersh B.J., Coronary Artery Surgery Study (CASS) Investigators. Long-term survival in patients with coronary artery disease. Importance of peripheral vascular disease. J Am Coll Cardiol 1994;23:1091-1095.[Abstract]
6. Birkmeyer J.D., O'Connor G.T., Quinton H.B., et al. Northern New England Cardiovascular Disease Study Group. The effect of peripheral vascular disease on in-hospital mortality rates with coronary artery bypass surgery. J Vasc Surg 1995;21:445-452.[Medline]
7. Birkmeyer J.D., Quinton H.B., O'Connor N.J., et al. Northern New England Cardiovascular Disease Study Group. The effect of peripheral vascular disease on long-term mortality after coronary artery bypass surgery. Arch Surg 1996;131:316-321.[Abstract]
8. Burek K.A., Sutton-Tyrrell K., Brooks M.M., et al. Prognostic importance of lower extremity arterial disease in patients undergoing coronary revascularization in the Bypass Angioplasty Revascularization Investigation (BARI). J Am Coll Cardiol 1999;34:716-721.[Abstract/Free Full Text]
9. Sutton-Tyrrell K., Rihal C., Sellers M.A., et al. BARI Investigators. Long-term prognostic value of clinically evident noncoronary vascular disease in patients undergoing coronary revascularization in the Bypass Angioplasty Revascularization Investigation (BARI). Am J Cardiol 1998;81:375-381.[Medline]
10. Malenka D.J., Northern New England Cardiovascular Disease Study Group. Indications, practice, and procedural outcomes of percutaneous transluminal coronary angioplasty in Northern New England in the early 1990s. Am J Cardiol 1996;78:260-265.[Medline]
11. O'Connor G.T., Plume S.K., Olmstead E.M., et al. Northern New England Cardiovascular Disease Study Group. A regional prospective study of in-hospital mortality associated with coronary artery bypass grafting. JAMA 1991;266:803-809.[Abstract]
12. Malenka D.J., O'Connor G.T., Quinton H., et al. Differences in outcomes between women and men associated with percutaneous transluminal coronary angioplasty. Circulation 1996;94(Suppl 2):II99-104.
13. O'Connor G.T., Plume S.K., Olmstead E.M., et al. Multivariate prediction of in-hospital mortality associated with coronary artery bypass graft surgery. Circulation 1992;85:2110-2118.[Abstract/Free Full Text]
14. Wentworth D.N., Neaton J.D., Rasmussen W.L. An evaluation of the Social Security Administration master beneficiary record and the national death index in the ascertainment of vital status. Am J Public Health 1983;73:1270-1274.[Abstract/Free Full Text]
15. National Center for Health Statistics. National death index: user's manual. . Hyattsville, MD: US Department of Health and Human Services, Centers for Disease Control, National Center for Health Statistics, 1997.
16. Williams B.C., Demitrack L.B., Fries B.E. The accuracy of the National Death Index when personal identifiers other than social security number are used. Am J Public Health 1992;82:1145-1147.[Abstract/Free Full Text]
17. Rich-Edwards J.W., Corsano K.A., Stampfer M.J. Test of the National Death Index and Equifax nationwide death search. Am J Epidemiol 1994;140:1016-1019.[Abstract/Free Full Text]
18. Grover F.L., Hammermeister K.E., Burchfiel C. Initial report of the Veterans Administration Preoperative Risk Assessment Study for Cardiac Surgery. Ann Thorac Surg 1990;50:12-28.[Abstract]
19. Higgins T.L., Estafanous F.G., Loop F.D., Beck G.J., Blum J.M., Paranandi L. Stratification of morbidity and mortality outcome by preoperative risk factors in coronary artery bypass patients: a clinical severity score. JAMA 1992;267:2344-2348.[Abstract]
20. O'Connor G.T., Malenka D.J., Quinton H., et al. Northern New England Cardiovascular Disease Study Group. Multivariate prediction of in-hospital mortality after percutaneous coronary interventions in 1994–1996. J Am Coll Cardiol 1999;34:681-691.[Abstract/Free Full Text]
21. Bell M.R., Gersh B.J., Schaff H.V., et al. Effect of completeness of revascularization on long-term outcome of patients with three-vessel disease undergoing coronary artery bypass surgery: a report from the Coronary Artery Surgery Study (CASS) registry. Circulation 1992;86:446-457.[Abstract/Free Full Text]
22. Loop F.D., Lytle B.W., Cosgrove D.M., et al. Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events. N Engl J Med 1986;314:1-6.[Abstract]
23. Niles N.W., McGrath P.D., Malenka D.J., et al. Northern New England Cardiovascular Disease Study Group. Survival of patients with diabetes and multivessel coronary artery disease after surgical or percutaneous coronary revascularization: results of a large regional prospective study. J Am Coll Cardiol 2001;37:1008-1015.[Abstract/Free Full Text]
24. The American College of Cardiology National Cardiovascular Data Registry (ACC-NCDR). Cath lab module v2.0c: core data element definitions. Available at: http://www.acc.org/ncdr/cathlab.htm. Accessed April 29, 2003

This article has been cited by other articles:

				J. S. Rankin, R. H. Tuttle, A. S. Wechsler, T. L. Teichmann, D. D. Glower, and R. M. Califf Techniques and Benefits of Multiple Internal Mammary Artery Bypass at 20 Years of Follow-Up Ann. Thorac. Surg., March 1, 2007; 83(3): 1008 - 1015. [Abstract] [Full Text] [PDF]

				J. S. Rankin and F. E. Harrell Jr Measuring the therapeutic efficacy of coronary revascularization: Implications for future management J. Thorac. Cardiovasc. Surg., May 1, 2006; 131(5): 944 - 948. [Full Text] [PDF]

				H.-J. Priebe Perioperative myocardial infarction--aetiology and prevention Br. J. Anaesth., July 1, 2005; 95(1): 3 - 19. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Felix Hernandez Jeremy Morton William Nugent Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by O'Rourke, D. J. Articles by Malenka, D. J. Search for Related Content PubMed PubMed Citation Articles by O'Rourke, D. J. Articles by Malenka, D. J. Related Collections Coronary disease