Abstract 1900: Cardiovascular Complications of Lower Extremity Bypass Surgery for Critical Limb Ischemia: Risk Factors and Outcomes
Objectives Patients with critical limb ischemia (CLI) requiring infrainguinal bypass (IB) for limb salvage are at high risk for cardiovascular complications (CVC), which incur significant morbidity, mortality, and cost. We sought to determine the risk factors and outcomes associated with perioperative (30-day) CVC following IB for CLI
Methods We performed a nested cohort study of 1404 patients in the PREVENT III multi-center trial, which was designed to examine the efficacy of edifoligide to prevent vein graft failure in CLI patients. Multivariate analysis examined risk factors for CVC, as well as survival and resource utilization outcomes.
Results Patient characteristics included mean age of 69 years, 64% male, 82% with hypertension, 64% with diabetes, and 48% with prior CAD. Preoperative medication usage included 76% antithrombotics, 48% beta-blockers, and 44% statins. Thirty-day and 1-year all-cause mortality were 2.7% and 15.8%, respectively. One hundred sixty-three (11.6%) patients had CVC within 30 days: 77 angina, 66 acute MI, 46 CHF, 28 cardiac arrest, 26 ventricular tachycardia, 22 CVA, and 8 with elevated troponin. CVC occurred at a median of 2 (mean of 5.5) days post-surgery; 45 (27.6%) complications occurred after discharge. CVC was highly associated with 30-day (OR 22.1, 95%CI 10.8 – 45.7, p=0.0001) and 1-year mortality (HR 2.86, 95%CI 2.15–3.81, p<0.0001)(Table 1⇓). Multivariate analysis showed age >75 (OR 1.66, 95%CI 1.18–2.33), prior MI (OR 1.56; 95%CI 1.10 –2.20), and beta-blocker use (OR 1.80, 95%CI 1.24 –2.6) were associated with CVC. Patients with CVC had an increased iLOS by 4 days (p<0.0001) and 1-year cumulative length of stay (cLOS) by 8 days (p =0.0400).
Conclusions This large multi-center trial demonstrates the incidence and sequela of CVC following IB for limb salvage. Older age, prior MI, and beta-blocker use were predictive for CVC. Improved prediction and treatment of these events may improve outcomes in this high-risk cohort.