Limitations in the cardiac risk reduction provided by coronary revascularization prior to elective vascular surgery

Abstract

Objective: The objective of this study was to evaluate the proposed cardiac protective effect of previous coronary revascularization (coronary artery bypass grafting [CABG] or percutaneous transluminal coronary angioplasty [PTCA]) before elective major arterial surgery.

Method: Preoperative cardiac risk stratification using American College of Cardiology/American Heart Association (ACC/AHA) guidelines was done on 425 consecutive patients undergoing 481 elective major vascular operations at an academic VA Medical Center. The algorithm assumed asymptomatic patients with prior coronary revascularization (CABG, <5 year; PTCA, <2 year) were low cardiac risk. Coronary angiography was done for recurrent symptoms with secondary intervention when appropriate. Outcomes (myocardial infarction, unstable angina, congestive heart failure, ventricular arrhythmia, cardiac death, and mortality) within 30 days of vascular surgery were compared between patients with and without previous CABG or PTCA by contingency table and logistic regression analyses.

Results: Coronary revascularization was classified as recent (CABG, <1 year; PTCA, <6 months) in 35 cases (7%), prior (1 year < or = CABG < 5 year, 6 months < or = PTCA < 2 year) in 45 cases (9%), and remote (CABG, > or = 5 year; PTCA, > or = 2 year) in 48 cases (10%). A larger fraction of patients with previous revascularization possessed pathologic cardiac risk variables and were stratified as high-risk preoperatively than their nonrevascularized counterparts. Outcomes in patients with previous PTCA were similar to those after CABG (P =.7). Significant differences in adverse cardiac events (P =.01) and mortality (P =.05) were found between patients with CABG done within 5 years or PTCA within 2 years (6.3%, 1.3%, respectively), individuals with remote revascularization (10.4%, 6.3%), and nonrevascularized patients stratified at high risk (13.3%, 3.3%) or intermediate/low (2.8%, 0.9%) risk. De novo or recurrent 3-vessel coronary disease by angiography, but not the presence or timing of previous revascularization, was an independent predictor of cardiac events after vascular operations, whereas remote revascularization was associated with fatal outcomes by multivariate analysis.

Conclusions: Previous coronary revascularization (CABG, <5 years; PTCA, <2 years) may provide only modest protection against adverse cardiac events and mortality following major arterial reconstruction.