Exploring Functional Improvements by Sex in Six-Minute Walk Test, Exertional Angina, and Dyspnea After Enhanced External Counterpulsation Therapy

Abstract

Purpose: The objective of this study was to explore functional improvements by sex for patients with refractory angina pectoris using a 6-min walk test (6MWT) after enhanced external counterpulsation (EECP) therapy. Methods: All patients who completed EECP from 2015 to 2023 were identified for analysis retrospectively, utilizing the electronic medical record. Patients completed 35 1-hr EECP sessions 5 d/wk over 7 wk. All baseline and post-EECP intervention 6MWT, exertional angina, and dyspnea measurements were assessed on the first and last sessions, respectively. Paired and unpaired t tests and linear and stepwise multivariable regression analyses were performed. Results: The cohort consisted of 116 patients (24 female) with a mean age of 69 ± 13 yr. After EECP, there was a mean improvement of 128 m (72%) in distance walked during the 6MWT (P < .001) with 126 ± 91 m improvement in males and 134 ± 73 m in females. The improvement in angina and dyspnea scores was 3.5 ± 2.1 and 4.2 ± 2.4, respectively. There were no differences between the sexes for improvements in 6MWT distance, angina, or dyspnea. Univariate associations for change in 6MWT distance included body mass index (BMI; adjusted R 2 = .05) and being a nonsmoker (adjusted R 2 = .03). The only independent predictor for increasing distance during 6MWT was BMI (adjusted R 2 = .1; P = .001). Conclusion: Patients who have refractory angina pectoris can improve their functional capacity while simultaneously decreasing exertional angina and dyspnea using EECP. This study highlights the equal efficacy of EECP therapy for females.