Abstract Background Although pulmonary vein isolation (PVI) is an extensively utilized atrial fibrillation (AF) treatment, many patients still experience AF recurrences. Multimorbidity care, including physical activity, may reduce recurrences. In Belgium, patients undergoing an ablation are entitled to a cardiac rehabilitation (CR) program after PVI, but not all do participate. More evidence that such (standardized) CR programs for AF patients after ablation can positively impact rhythm control is desirable. Purpose This study retrospectively investigated the impact of CR on AF recurrence after PVI. Methods We analysed an extensive database of a large Belgian tertiary care center with patients who underwent a primary PVI between 2007 and 2020 and who had a follow-up of at least 1 year. General cardiology follow-up included a 24h Holter monitoring 3 and 12 months after PVI. Patients were retrospectively divided into an intervention and control group based on their choice to participate in a standardized CR program. The Kaplan-Meier method was used to estimate the time-to-recurrence and event-free survival curves after the primary ablation. Differences between curves were tested with the log-rank test. Mann-Whitney U test was used to analyze continuous variables and the Chi-square test for categorical variables. Results In total, 1767 patients were included, of which 589 participated to CR and 1178 served as controls (median 64 (56-70) y, 68.9% male, median BMI 27.5 (24.7-30.7) kg/m2). There was no significant difference between CR and controls in median age (64y vs. 63y respectively; p=0.203), the proportion of male (57.9% vs. 47.0% respectively; p=0.111) and the proportion of paroxysmal AF (66.4% vs. 70.6% respectively; p=0.210). The proportion with recurrent AF at the end of study follow-up (with a three-month initial blanking period) in the CR and control group was similar (32.6% vs. 35.1% respectively; p=0.288), and also survival analysis demonstrated no significant difference (p=0.827; Figure 1). We noted a cross-over of the recurrence curves after about 1500 days, but the rate of AF recurrence was not different among CR and controls within the first year post-ablation (p=0.136) nor when analysed from day 365 until the end of the study (p=0.341) (Figure 2). There was no significant difference in AF recurrences between CR and controls for either paroxysmal AF (p= 0.551) or persistent AF (p=0.181) based on the survival analysis. Conclusions This retrospective analysis could not demonstrate reduced AF recurrence in post-PVI patients following a structured CR program. The unexpected crossover of curves could point to earlier AF detection in CR patients, while there might be long-term benefit of physical activity. Multivariable analysis will have to evaluate whether impact of CR is related to certain clinical patient characteristics, which might also have contributed to inclusion bias.Figure 1Figure 2