(IP151) The Impact of Preoperative Beta-Blocker Use on Outcomes of Lower Extremity Bypass in Patients with Chronic Limb-Threatening Ischemia

Objectives: There is controversy in starting beta-blockers prior to vascular procedures, particularly infrainguinal bypasses performed for chronic limb-threatening ischemia (CLTI). We aim to compare outcomes of bypasses for CLTI based on preoperative beta-blocker use.

Methods: We used VQI data for lower extremity bypasses performed for CLTI (2011-2023). Patients were stratified by preoperative beta-blocker use. The primary outcome was 30-day mortality. Secondary outcomes included postoperative complications, return to the operating room (RTOR), prolonged length of stay (PLOS; ≥7-days), postoperative major amputation, and major adverse cardiovascular event (MACE). MACE was defined as myocardial infarction, stroke or in-hospital death. A secondary analysis of one-year outcomes was performed in patients on chronic beta-blocker use stratified by discharge beta-blocker continuation. Chi-square test, Kaplan-Meier survival estimates, and logistic and Cox regressions were used for analyses.

Results: A total of 37,703 limbs from 30,560 patients were studied: chronic preoperative beta-blocker use (for >30-days) (20,231, 53.7%), no beta-blocker use (15,305, 40.6%), beta-blocker use only on operative day (803, 2.1%), and beta-blocker use for 1-30 preoperative days (1,364, 3.6%). Patients in >30-days cohort were more likely to be older and have severe comorbidities. After adjusting for confounders, the pattern of preoperative beta-blocker use was not associated with 30-day mortality. However, no beta-blocker use was associated with decreased risk of stroke, MACE, and renal complications compared to >30-days (Table I). Additionally, beta-blocker use only on operative day and 1-30 days preoperatively were associated with increased risk of PLOS and RTOR, while 1-30 day use was also associated with an increased risk of renal complications (Table I). In the 1-year analysis, patients with chronic preoperative beta-blocker use that discontinued beta-blockers after discharge had increased hazards of 1-year mortality and combined mortality/major amputation compared to continued use after discharge (Figure I).

Conclusions: We found that beta-blocker use for >30-days was associated with poor outcomes compared to no beta-blockers due to higher age and comorbidities. Interestingly, we found that starting beta-blockers within a month of surgery was associated with a higher risk of RTOR, PLOS and renal complications. Additionally, continuing beta-blocker use following discharge in patients who were on chronic use before surgery was associated with improved overall and amputation-free survivals. We conclude that in patients without chronic beta-blocker use, initiation of beta-blockers before bypass is not beneficial. However, patients with chronic preoperative beta-blocker use benefit from continuation of beta-blockers after bypass. Further prospective studies are necessary to confirm our findings.