Associations of cognitive decline with outcomes of cardiovascular rehabilitation in patients with cardiovascular disease

Background: Patients with cardiovascular disease (CVD) are often contending with various comorbidities including cognitive decline. Cognitive decline is a risk marker for adverse outcomes in these patients. On the other hand, cardiovascular rehabilitation (CVR) improves clinical outcomes. However, it remains uncertain whether CVR is associated with favorable outcomes in patients with CVD and cognitive decline. Therefore, the present study aimed to investigate whether CVR is associated with favorable outcomes in patients with CVD and cognitive decline.

Methods: We reviewed 4232 patients admitted for CVD. Cognitive function was assessed using the Mini-Cog at hospital discharge, and a score of <3 was defined as cognitive decline. We measured the 6-min walking distance (6MWD) at discharge and 5 months after CVR prescription for participants in outpatient CVR. The primary outcome was change in exercise tolerance (Δ6MWD), and the secondary outcome was composite events (all-cause death and/or re-admission due to CVD). We compared Δ6MWD between patients with and without cognitive decline and examined the association between outpatient CVR participation and composite events.

Results: Of all patients, 768 had cognitive decline. There was no significant difference in Δ6MWD between the cognitive decline and non-cognitive decline groups, even after adjusting for confounders [estimated mean difference: 2.20 m; 95 % confidence interval (CI): -0.60-5.00 m]. Additionally, participation in outpatient CVR was associated with lower rate of composite events, regardless of cognitive decline [adjusted hazard ratio (aHR): 0.589; 95 % CI: 0.552-0.627 in the cognitive decline group and aHR: 0.767; 95 % CI: 0.742-0.793 in the non-cognitive decline group]. An interaction was observed based on the presence of cognitive decline (p = 0.011).

Conclusion: Regardless of cognitive decline, participation in outpatient CVR was associated with increased exercise tolerance. Furthermore, outpatient CVR was linked to reduced composite events in both, with particularly potent association in cognitively impaired patients.