P4399Inspiratory muscle training and functional electrical stimulation in heart failure with preserved ejection fraction: results from a randomized clinical trial

Abstract

Background: Heart failure (HF) with preserved ejection fraction (HFpEF) has become the most prevalent form of HF in developed countries. However, there is no evidence‐based effective therapy for HFpEF. This study sought to evaluate whether inspiratory muscle training (IMT), functional electrical stimulation (FES), or combination of both (IMT+FES) improve 12 and 24‐week exercise capacity as well as left ventricular diastolic function, biomarkers' profile, and quality of life (QoL) in patients with HFpEF. Methods and results: A total of 61 stable symptomatic patients (NYHA II‐III) with HFpEF were randomized (1:1:1:1) to receive a 12‐week program of IMT, FES, or IMT+FES vs. usual care (UC) alone. Primary endpoint of the study was to evaluate change in peak VO2. Secondary endpoints were changes in QoL (Minnesota Heart Failure Living Test), echocardiogram parameters and prognostic biomarkers. We used a mixed‐effects model for repeated‐measures to compare endpoints changes. Mean of age was 74±9 years and proportion of women were 58%. Cardiopulmonary exercise test at baseline showed a mean peak VO2 of 9.9±2.5 ml/min/kg (respiratory exchange ratio of 1.05±0.09). At 12‐week, the mean increase in peak VO2 (ml/kg/min) compared with UC group, was 2.98, 2.93, and 2.47 for IMT, FES, and IMT+FES respectively (p<0.001) and this beneficial effect persisted after 3‐ months (1.95, 2.08, and 1.56; p<0.003). Similar results were observed for QoL scores with a mean decrease at 12‐week of 13.85, 10.91, and 16.34 for IMT, FES, and IMT+FES respectively (p<0.001). No changes in peak VO2 or QoL were found in UC arm. No relevant changes in E/E' ratio, left atrial volume and N‐terminal pro‐B‐type natriuretic peptide were found. Conclusions: In HFpEF patients with low aerobic capacity, IMT and EMF was associated with marked improvement in exercise capacity and QoL.