Female patients have fewer limb amputations compared to male patients in the BEST-CLI trial

Abstract

Objective: Female patients are less likely to be diagnosed with and treated for peripheral artery disease. When treated, there are also reported sex disparities in short- and long-term outcomes. We designed this study to compare outcomes after open and endovascular revascularization in the Best Endovascular vs best Surgical Therapy in patients with Critical Limb Ischemia (BEST-CLI) trial between females and males, and to examine outcomes of each revascularization type in an all-female cohort.

Methods: In a secondary analysis of cohorts 1 and 2 of the BEST-CLI Trial, patients with chronic limb-threatening ischemia (CLTI) undergoing open surgical bypass (with or without adequate conduit) and endovascular therapy were stratified by sex. In addition, in a female-only cohort, we evaluated differences in outcomes between treatment arm (combined all bypasses from cohorts 1 and 2 and compared with all endovascular treatment in cohorts 1 and 2). Outcomes included major amputation, reintervention, major adverse limb event (MALE, a composite of major amputation and reintervention), all-cause death, and composite outcome of MALE or all-cause death. Univariable and adjusted Cox regressions were used to assess outcome between males and females. Similar methods were used to assess differences in outcomes between treatment arm in females.

Results: Among 1830 patients, females were significantly underrepresented, comprising only 28% (n = 519) of the BEST-CLI cohort. Overall, the characteristics of females enrolled in the trial had some differences compared with males: females were more likely to have rest pain alone (72% vs 60%; P < .0001) and when presenting with an ischemic wound, were less likely to have a wound infection (38% vs 47%; P = .01). Females were less likely to have an adequate single-segment greater saphenous vein (SSGSV) available (82% vs 89%; P = .01). Controlled for baseline clinical factors, at 1 year, females had significantly lower rates of major limb amputation compared with males (hazard ratio [HR], 0.70; P = .023), which drove better amputation- and MALE-free survival rates. All-cause death at 1 year was not statistically different between sexes (11.8% vs 11.2%; P = .286). In the all-female cohort, results paralleled the overall trial; open surgical bypass (with any conduit) had significantly better outcomes compared with endovascular therapy. Specifically, among females undergoing endovascular therapy, the rate of major reintervention was particularly high compared with females undergoing open surgical bypass (24.8% vs 10.5%; P < .001).

Conclusions: Despite being underrepresented in BEST-CLI, the primary results of the trial, namely, improved MALE-free survival with open surgical bypass with SSGSV, were mirrored in the all-female subset. Female patients enrolled in BEST-CLI had better amputation-free survival at 1 year compared with male patients. These findings suggest that in treating female patients with CLTI considered appropriate for both open and endovascular revascularization, surgical bypass with optimal conduit is the preferred treatment option and can potentially ameliorate poor limb preservation outcomes associated with sex.

Keywords: Gender-based outcomes; Healthcare disparities; Peripheral artery disease.