Background: The optimal method of coronary revascularization in dialysis patients is controversial, as previous small retrospective studies have reported increased cardiac events after percutaneous transluminal coronary angioplasty (PTCA) compared with coronary artery bypass (CAB) surgery. The purpose of this study was to compare the long-term survival of chronic dialysis patients in the United States following PTCA or CAB surgery.
Methods: Dialysis patients hospitalized from 1978 to 1995 for first coronary revascularization procedure after initiation of renal replacement therapy were retrospectively identified from the United States Renal Data System database. Survival for the endpoints of all-cause death, cardiac death, myocardial infarction, and cardiac death or myocardial infarction was estimated by the life-table method and was compared by the log-rank test. The impact of independent predictors on survival was examined in a Cox regression model with comorbidity adjustment.
Results: The in-hospital mortality was 5.4% for 6887 PTCA patients and 12.5% for 7419 CAB patients. The two-year event-free survival (+/-SE) of PTCA patients was 52.9 +/- 0.7% for all-cause death, 72.5 +/- 0.7% for cardiac death, and 62.0 +/- 0.7% for cardiac death or myocardial infarction. In CAB patients, the comparable survivals were 56.9 +/- 0.6, 75.8 +/- 0.6, and 71.3 +/- 0. 6%, respectively (P < 0.02 for PTCA vs. CAB surgery for all endpoints). After comorbidity adjustment, the relative risk of CAB surgery (vs. PTCA) performed 1990 to 1995 for all-cause death was 0. 91 (95% CI, 0.86 to 0.97); cardiac death, 0.85 (95% CI, 0.78 to 0. 92); myocardial infarction, 0.37 (95% CI, 0.32 to 0.43); and cardiac death or myocardial infarction 0.69 (95% CI, 0.64 to 0.74).
Conclusions: In this retrospective study, dialysis patients in the United States had better survival after CAB surgery compared with PTCA, but our study does not exclude the possibility of more unfavorable coronary anatomy in the PTCA patients at baseline. Our data support the need for prospective trials of newer percutaneous coronary revascularization procedures in dialysis patients.