Influence of hormone replacement therapy on graft patency after femoropopliteal bypass grafting

Abstract

Objective: Thromboembolic events are more frequent in women with established cardiovascular disease who are receiving hormone replacement therapy (HRT). The effect of HRT on the outcome of women undergoing infrainguinal bypass grafting is unknown. The purpose of this study was to estimate the influence of risk factors, in particular HRT, on the outcome of women undergoing femoropopliteal bypass grafting. Methods: During a 5-year period (between 1993 and 1998), 131 femoropopliteal bypass graft procedures were performed in 106 women. The criteria prepared by the Ad Hoc Committee on Reporting Standards (Society for Vascular Surgery/North American Chapter of the International Society for Cardiovascular Surgery) were followed. Both univariate (Kaplan-Meier method) and multivariate analyses (Cox proportional hazards model) were used to determine the association among preoperative variables, graft patency, limb salvage, and survival. Results: The average age of the patients was 66.4 years; 26% of the patients were receiving HRT. Indications for femoropopliteal bypass grafting were limb salvage (80%) and disabling claudication (20%). Autogenous vein was used in 48% of procedures, polytetrafluoroethylene (PTFE) in 49%, and PTFE-vein composite grafts in 3%. Distal popliteal anastomosis was above the knee in 52% and below the knee in 48%. Overall primary patency rate was 81% at 1 year, 65% at 3 years, and 56% at 5 years. Primary patency rates at 1, 3, and 5 years were 75%, 45%, and 23%, respectively, for HRT users and 84%, 72%, and 65%, respectively, for nonusers of HRT. Overall, cumulative 1- and 5-year limb salvage results were 96% and 92%, respectively, and long-term survival at 1, 3, and 5 years was 96%, 86% and 74%, respectively. With univariate and Cox regression analyses, HRT was identified as the only independent predictor of reduced primary graft patency (Kaplan-Meier method, log-rank test, P =.004; relative risk, 2.5; 95% CI, 1.3-4.8). Women receiving HRT who underwent a procedure with PTFE had the lowest primary graft patency rates (relative risk, 3.4; 95% CI, 1.5-7.8; P =.006). Conclusions: Women undergoing femoropopliteal bypass graft procedures who are receiving HRT have significantly reduced primary graft patency rates. The risk of graft failure increases when prosthetic materials are used. (J Vasc Surg 2000;32:506-18.)