Preoperative β-blockers do not improve cardiac outcomes after major elective vascular surgery and may be harmful

Abstract

Objective: Routine initiation β-blocker medications before vascular surgery is controversial due to conflicting data. The purpose of this analysis was to determine whether prophylactic use of β-blockers before major elective vascular surgery decreased postoperative cardiac events or mortality.

Methods: The Society for Vascular Surgery Vascular Quality Initiative (SVS-VQI) data set was used to perform a retrospective cohort analysis of infrainguinal lower extremity bypass (LEB), aortofemoral bypass (AFB), and open abdominal aortic aneurysm (AAA) repair patients. Chronic (>30 days preoperatively) β-blocker patients were excluded, and comparisons were made between preoperative (0-30 day) and no β-blocker groups. Patients were risk stratified using a novel prediction tool derived specifically from the SVS-VQI data set. Propensity-matched pairs and interprocedural specific risk stratification comparisons were performed. End points included in-hospital major adverse cardiac events (MACEs), including myocardial infarction (MI; defined as new ST or T wave electrocardiographic changes, troponin elevation, or documentation by echocardiogram or other imaging modality), dysrhythmia, and congestive heart failure, and 30-day mortality.

Results: The study analyzed 13,291 patients (LEB, 68% [n = 9047]; AFB, 11% [n = 1474]; and open AAA, 21% [n = 2770]); of these, 67.7% (n = 8999) were receiving β-blockers at time of their index procedure. Specifically, 13.2% (n = 1753) were identified to have been started on a preoperative β-blocker, 54.5% (n = 7426) were on chronic β-blockers, and 32.3% (n = 4286) were on no preoperative β-blockers. Among the three procedures, patients had significant demographic and comorbidity differences and thus were not combined. A 1:1 propensity-matched pairs analysis (1459 pairs) revealed higher rates of postoperative MI with preoperative β-blockers (preoperative β-blocker relative risk, 1.65; 95% confidence interval, 1.02-2.68; P = .05 vs no β-blocker), with no difference in dysrhythmia, congestive heart failure, or 30-day mortality. When stratified into low-risk, medium-risk, and high-risk groups within each procedure, all groups of preoperative β-blocker patients had no difference or higher rates of MACEs and 30-day mortality, with the exception of high-risk open AAA patients, who had a lower rate of MI (odds ratio, 0.35; 95% confidence interval, 011-0.87; P = .04).

Conclusions: Exclusive of high-risk open AAA patients, preoperative β-blockers did not decrease rates of MACEs or mortality after LEB, AFB, or open AAA. Importantly, exposure to prophylactic preoperative β-blockers increased the rates of some adverse events in several subgroups. Given these data, the SVS-VQI cannot support routine initiation of preoperative β-blockers before major elective vascular surgery in most patients.