Exercise-Based Cardiac Rehabilitation Improves Exercise Capacity Regardless of the Response to Cardiac...

In patients with chronic heart failure with reduced ejection fraction (HFrEF), cardiac resynchronization therapy (CRT) improves left ventricular ejection fraction (LVEF) and exercise-based cardiac rehabilitation (ECR) enhances exercise capacity. This study examined the relationship between the 2 responses.

Sixty-four consecutive HFrEF patients who participated in a 3-month ECR program after CRT were investigated. Patients were categorized according to a median improvement in peak oxygen uptake (PV̇O₂) after ECR of 7% as either good (n=32; mean percentage change in PV̇O₂[%∆PV̇O₂]=23.2%) or poor (n=32; mean %∆PV̇O₂=2.5%) responders. There was no significant difference in baseline characteristics between the good and poor responders, except for PV̇O₂(51% vs. 59%, respectively; P=0.01). The proportion of good CRT responders was similar between the good and poor responders (%∆LVEF ≥10%; 53% vs. 47%, respectively; P=NS). Overall, there was no significant correlation between %∆LVEF after CRT and %∆PV̇O₂after ECR. Notably, among poor CRT responders (n=32), the prevalence of atrial fibrillation (0% vs. 29%; P<0.03) and baseline PV̇O₂(48% vs. 57%; P<0.05) were significantly lower among those with a good (n=15) than poor (n=17) response to ECR.

In patients with HFrEF, good ECR and CRT responses are unrelated. A good PV̇O₂response to ECR can be achieved even in poor CRT responders, particularly in those with a sinus rhythm or low baseline PV̇O₂.