Impact of structured cardiac rehabilitation program on functional capacity after acute coronary syndrome

Background Cardiac rehabilitation programs (CRP) are structured and multidisciplinary programs designed to optimize recovery and secondary prevention following an acute coronary syndrome (ACS). The assessment and monitoring of parameters obtained through cardiopulmonary exercise testing (CPET) can optimize exercise prescription and enable an accurate evaluation of the impact of CRP. Purpose The aim of the study was to assess the impact of a structured CRP based on CPET results, namely CPET duration, peak oxygen consumption (VO2), O2 pulse, anaerobic threshold (AT) and respiratory compensation point (RCP). Methods A retrospective single-center study of patients who completed a cardiac rehabilitation program (CRP) due to coronary artery disease and who underwent cardiopulmonary exercise testing (CPET) between January 2025 and June 2025 was conducted. Patients without CPET evaluation prior to CRP were excluded. Number of CRP sessions and CPET results before and after CRP (as described above) were collected. Wilcoxon tests were used to compare CPET results previously and after CRP. Results This study included 59 patients, 83.1% (n = 49) males, with a median age of 60 [17] years old. All the patients were submitted to a minute/minute Bruce protocol on CPET before and after CRP. CRP included a median of 21 [8] sessions. The improvements were significant in all the parameters of the CPET. A median duration of 10:00 [03:28] minutes in the first CPET (prior to CRP) was registered, and this time increased 2 minutes to 12:00 [03:35] minutes after CRP (p < 0.001). A 16% median increase in the percentage of VO2 with an absolute increase from 23.8 [7.9] mL/Kg/min before to 26.6 [7.7] mL/Kg/min after CRP was verified (p < 0.001). O2 pulse changed from 101 [24] % to 114 [28] % (p < 0.001). Median AT increased from 56 [16] % to 59 [14] % (p < 0.001). On the first CPET, 30 (50.8%) patients achieved RCP at a median value of 75 [14] %, and 64.4% (n = 38) of the patients had a median value of 80 [46] % of RCP on the second CPET (p = 0.032). Conclusion Participation in a structured CRP guided CPET was associated with significant improvements in exercise capacity and cardiopulmonary efficiency parameters. These findings highlight the effectiveness of individualized, CPET-based rehabilitation in enhancing functional performance and supporting secondary prevention in patients with coronary artery disease following ACS.