Pulse Pressure and Long-Term Survival After Coronary Artery Bypass Graft Surgery

Abstract

Data from longitudinal studies reveal that widened pulse pressure (PP) is a major predictor of coronary heart disease and mortality, but it is unknown whether PP similarly decreases survival after coronary artery bypass graft (CABG) surgery for coronary heart disease. We therefore assessed long-term survival in patients with increased PP at the time of presentation for CABG surgery. In this retrospective observational study of patients undergoing CABG surgery between January 1993 and July 2004, 973 subjects were included for assessment of long-term survival. Baseline arterial blood pressure (BP) measurements were defined as the median of the first 3 measurements recorded by the automated record keeping system before induction of anesthesia. The effect of baseline PP on survival after surgery was evaluated using a Cox proportional hazards regression model and bootstrap resampling with baseline mean arterial BP, systolic BP, diastolic BP, diabetes, Hannan risk index, aprotinin use, and cardiopulmonary bypass time as covariates. There were 220 deaths (22.9%) during the follow-up period (median, 7.3 yr [Q1: 5, Q3: 10 yr]) including 94 deaths from cardiovascular causes. Increased baseline PP was a significant predictor of reduced long-term survival (P < 0.001) along with Hannan risk index (P < 0.001), duration of cardiopulmonary bypass (P < 0.001), and diabetes (P < 0.001). Baseline systolic (P = 0.40), diastolic (P = 0.38), and mean arterial BPs (P = 0.78) were not associated with long-term survival. The hazard ratio for PP (adjusted for other covariates in the model) was 1.11 (1.05-1.18) per 10-mm Hg increase. An increase in perioperative PP is associated with poor long-term survival after CABG surgery. Together with our previous report linking PP to in-hospital fatal and nonfatal vascular complications, the established models for surgical risk assessment, patient counseling, and treatment should be revised to include PP.