Sex-based differences in functional capacity and cardiovascular risk factor control following cardiac rehabilitation programs

Background Secondary prevention in cardiovascular (CV) diseases includes multidisciplinary programs with exercise prescription, CV risk factor modification, and psychosocial and nutritional support - cardiac rehabilitation programs (CRP). Sex differences in CV disease presentation, physiology, and recovery may influence responses to CRP. Understanding sex differences is essential to optimize CRP components and improve outcomes. Purpose The aim of the study was to compare CRP outcomes by sex. Methods A retrospective single-center study of patients who completed a cardiac rehabilitation program (CRP) and who underwent cardiopulmonary exercise testing (CPET) between January and June 2025 was conducted. Comorbidities, number of CRP sessions, and parameters before and after CRP were registered and compared by sex: smoking status, physical activity habits, blood pressure (BP), body mass index (BMI), abdominal waist circumference, low-density lipoprotein (LDL) cholesterol and glycated hemoglobin levels, and CPET peak oxygen consumption (VO2), O2 pulse and anaerobic threshold (AT). Chi-square test and Wilcoxon tests were used for statistical analysis. Results This study included 69 patients, with a median age of 60 [17] years old, of whom 54 (78.3%) males. CRP included 59 (85.5%) patients in the context of coronary artery disease, 8 (11.6%) due to heart failure and 2 (2.9%) after valvular surgery. All the patients were submitted to a minute/minute Bruce protocol on CPET. Comparison by sex is described in Table 1. CV risk factors were similar, as well as number of CRP sessions (p = 0.430). VO2 was different by sex before and after CRP (p = 0.006). In males, a reduction in LDL (64 [72] mg/dL to 58 [22] mg/dL, p = 0.006) and an increase in VO2 (83 [27] % to 99 [29] %, p<0.001), AT (53 [16] % to 58 [16] %, p <0.001) and O2 pulse (97 [25] % to 107 [23] %, p <0.001) was verified. In females, BP was reduced (systolic BD: 133 [43] mmHg to 118 [22] mmHg, p = 0.005; diastolic BP: 76 [21] mmHg to 75 [18] mmHg, p = 0.046), and VO2 (92 [24] % to 112 [23] %, p<0.001; and 18.2 [45] mL/Kg/min to 20.5 [4.6] mL/Kg/min, p = 0.006), and O2 pulse (111 [28] % to 124 [48] %, p <0.001) also improved. Conclusion Both men and women experienced significant improvements in functional capacity following CPET-guided cardiac rehabilitation, although baseline performance and the magnitude of specific gains differed by sex. Men showed greater improvements in lipid profile, while women demonstrated meaningful reductions in blood pressure. CPET parameters improved across both groups, underscoring the effectiveness of individualized, CPET-based rehabilitation. These findings highlight the importance of considering sex-specific characteristics when tailoring cardiac rehabilitation strategies to optimize patient outcomes.Results by sex