Exercise Training Outcomes in Patients with Chronic Heart Failure with Reduced Ejection Fraction Depend on Medications and Disease Conditions: Proposal of SEEM Score to Judge Exercise Suitability

Abstract

Background: Exercise training is an accepted evidence-based adjunct treatment modality for patients with chronic heart failure. However, the influence of medications or conditions on exercise has not been fully explored. Methods: The patient records of the Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training (HF-ACTION) study were obtained from the National Heart, Lung, and Blood Institute, and analyzed by medications used at baseline (renin-angiotensin system inhibitors [RASIs], beta-blockers [BBs], and combination of both) with multivariable Cox regression models focusing on the interactions with exercise effects, and a score to indicate exercise training suitability was proposed accordingly. Results: Medication type strongly influenced the exercise effect on all-cause death (AD) (P = 0.007) even though medication itself did not change prognosis significantly in HF-ACTION trial. In patients taking both BBs and RASIs at baseline, exercise reduced the AD risk (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.75-0.98), whereas in patients not taking BBs, exercise increased the risk (HR, 4.58; 95% CI, 2.90-6.86). The exercise on AD was also influenced by pulse pressure, hemoglobin level, electrocardiography conditions, body mass index, and history of stroke. Accordingly, we constructed the Score for Eligibility of Exercise on Mortality (SEEM). When exercise training was chosen based on SEEM score, both AD and AD and hospitalization (ADH) risks were expected to reduce significantly (HR, 0.54; 95% CI, 0.44-0.68; HR, 0.83; 95% CI, 0.75-0.93, respectively). Conclusions: Exercise training in patients with heart failure should be recommended carefully with consideration of patient background.