Impact of adding aspirin to beta-blocker and statin in high-risk patients undergoing major vascular surgery.

BACKGROUND: Beta-blockers (BB) and statins (S) independently have been shown to reduce perioperative mortality and myocardial infarction (MI) in patients undergoing vascular surgery. In this study we evaluated the benefits of adding aspirin (A) to BB and S (ABBS), with/without angiotensin-converting enzyme inhibitor (ACE-I) on postoperative outcome in high-risk patients undergoing major vascular surgery. METHODS: Analysis of consecutive patients undergoing elective vascular surgery at the University of Michigan Cardiovascular Center was performed. Univariate and multivariate analyses were done using cardiac risk index [Revised Cardiac Risk Index (RCRI), coronary artery disease (CAD), insulin-dependent diabetes mellitus (IDDM), cerebral vascular disease, renal dysfunction, congestive heart failure, and major surgery]; pulmonary disease; and A, BB, S (ABBS)±ACE-I use. Baseline clinical characteristics and medication were adjusted using propensity scores. Endpoints were bleeding, 30-day MI, stroke, and 12-month mortality. RESULTS: Between 2003 and 2010, 4,149 arterial procedures were performed, 819 of which were risk stratified as RCRI≥3. The incidence of MI was 3-fold lower (2.5% vs. 7.8%, OR 0.31, 95% CI 0.15-0.61, P=0.001) in ABBS±ACE-I (n=513) as compared with non-ABBS±ACE-I (n=306). The 12-month mortality was 8-fold lower in ABBS±ACE-I as compared non-ABBS±ACE-I (5.9% vs. 37.5%, HR 0.13, 95% CI 0.08-0.20, P<0.0001). After adjustment for the propensity to use various therapies, A (HR 0.35, 95% CI 0.24-0.53, P<0.0001), BB (HR 0.65, 95% CI 0.43-1.0, P=0.05), and S (HR 0.36, 95% CI 0.25-0.53, P<0.0001) remained associated with improved 12-month survival. ACE-I use (HR 0.80, 95% CI 0.54-1.19, P=0.27) was not predictive. Aspirin did not predict severe/moderate bleeding. CONCLUSIONS: In high-risk patients undergoing major vascular surgery, ABBS therapy has superior 30-day and 12-month risk reduction benefits for MI, stroke, and mortality as compared with A, BB, or S independently. ACE-I did not demonstrate additional risk-reduction benefits.