Exercise-based cardiac rehabilitation after stroke and the risk of incident dementia: an observational study from a global federated network

Introduction Dementia is a common and disabling complication after stroke. Exercise-based cardiac rehabilitation (EXCR) may influence vascular and inflammatory mechanisms relevant to cognitive decline. We investigated the association between EXCR initiation after stroke and incident dementia. Patients and methods Using TriNetX, we identified adults with ischaemic stroke or TIA. Patients with recorded ICD-10-CM codes indicating an NIHSS score ≥ 16 were excluded from the primary analysis. Patients initiating EXCR within 6 months were compared with those without documented post-index EXCR. Propensity score matching balanced demographics, comorbidities, medication use and available stroke-severity measures. Outcomes were assessed at 3 and 5 years. Results The unmatched cohorts included 4226 patients initiating EXCR (mean age, 64.7 years; 60.8% male) and 1,889,796 without EXCR (mean age, 66.3 years; 48.2% male). After matching, 4138 patients remained in each cohort. At 5 years, EXCR was associated with lower hazards of incident dementia (HR, 0.70; 95% CI, 0.59–0.82), all-cause mortality (HR, 0.50; 95% CI, 0.45–0.55) and recurrent stroke (HR, 0.75; 95% CI, 0.61–0.91), but a higher hazard of rehospitalisation (HR, 1.21; 95% CI, 1.06–1.38); no significant association was observed for acute myocardial infarction. The association with incident dementia remained consistent across sensitivity analyses. Discussion The observed association with lower dementia risk suggests that the potential benefits of post-stroke EXCR may extend beyond cardiovascular and functional outcomes. Conclusions EXCR initiation after ischaemic stroke or TIA was associated with a lower hazard of incident dementia. This association remained consistent across the 3-year, 30-day landmark, 1-year lagged and all-stroke-severity sensitivity analyses.