Incomplete Revascularization After Coronary Artery Bypass Graft Operations Is Independently Associated With Worse Long-Term Survival

Abstract

Complete revascularization (CR) has been suggested to provide benefits to both early and long-term outcomes, but the magnitude of the benefit and frequency of incomplete revascularization (IR) after coronary artery bypass graft operations is rarely explored and is the subject of the present study. All patients who underwent isolated bypass operations (March 1995 to September 2007) at the Queen Elizabeth II Health Sciences Center (Halifax, NS, Canada) were identified. Revascularization was considered complete if each significantly diseased territory received at least 1 graft. Clinical characteristics of the CR and IR groups were examined to determine barriers of CR. A nonparsimonious Cox proportion model and survival curves were constructed to examine the association of CR and death after adjusting for clinically relevant covariates. A total of 8,570 patients underwent isolated nonredo bypass operations. IR, based on our strict definition, occurred in 19% of the patients. The territories most commonly affected were the right coronary and circumflex coronary territories. After adjustment for relevant clinical differences, IR was a significant independent predictor of long-term mortality (hazard ratio, 1.2; 95% confidence interval, 1.1 to 1.3). IR was also a significant independent predictor of hospital readmission for cardiac reasons after discharge (hazard ratio, 1.2; 95% confidence interval, 1.0 to 1.3). Despite advances in surgical revascularization, IR can occur in up to 19% of patients. IR significantly affects long-term death and readmission to hospital for cardiac reasons, and avoiding IR should therefore be a priority for surgeons during preoperative planning.