Recent cardiac rehabilitation and its impact on cardiopulmonary exercise test variables in Brazilian cardiac transplant recipients

Abstract Introduction Heart transplantation (HTx) is an option for restoring the functional capacity of individuals with end-stage heart failure (HF). Cardiac rehabilitation (CR) plays an important role in improving variables related to cardiopulmonary exercise testing (CPET) in post-HTx patients. Purpose To evaluate whether CR is effective in improving CPET variables in Brazilian patients post-recent HTx compared to a Control Group (CG). Methods Retrospective comparative study composed of two groups: CR group (CRG) and CG. These recent HTx patients (aged 14 to 73 years) initiated CR within 150 days and were recruited from an HTx outpatient clinic at a south Brazilian public university hospital between 2014 and 2023. CPET was performed at three different times: pre-HTx (Time 01), post-recent HTx (Time 02), and post-CR or post-follow-up for CG (Time 03). This study was approved by the Institutional Review Board (protocol No. 20180651). Statistical analysis used Generalized Estimating Equations with alpha ≤ 0.05, and the mean difference (MD) data were presented along with 95% confidence interval (CI). Results CRG (n=18) had a mean age of 47.3±15.6 years and CG (n=11) 48.6±12.5 years (P=0.81). The mean time to start CRG was 62.2±9.6 days (minimum: 21; maximum: 147). There was an interaction for the Group*Time factor for the following CPET variables: VO2peak (P=0.039); VEmax (P=0.009); VO2 on second ventilatory threshold (P<0.001); HR on VT2 (P=0.030) and T½ (P=0.002). The main results are summarized in Table 1. We highlight that there was a difference in the comparison between groups at Time 03 for the variable VO2peak: MD: 5.16 ± 1.95 (95% CI: 1.3 to 9.0; P = 0.008), favorable to CRG. Conclusion Early CR after very recent HTx significantly increase peak VO2peak, VEmax, T½ and VO2 and HR at the VT2 compared to the control group (CG).