PRIME‐HF: Novel Exercise for Older Patients with Heart Failure. A Pilot Randomized Controlled Study

OBJECTIVES: To test the hypothesis that (1) older patients with heart failure (HF) can tolerate COMBined moderate‐intensity aerobic and resistance training (COMBO), and (2) 4 weeks of Peripheral Remodeling through Intermittent Muscular Exercise (PRIME) before 4 weeks of COMBO will improve aerobic capacity and muscle strength to a greater extent than 8 weeks of COMBO. DESIGN: Prospective randomized parallel open‐label blinded end point. SETTING: Single‐site Australian metropolitan hospital. PARTICIPANTS: Nineteen adults (72.8 ± 8.4 years of age) with heart failure with reduced ejection fraction (HFrEF). INTERVENTION: Participants were randomized to 4 weeks of PRIME or COMBO (phase 1). All participants subsequently completed 4 weeks of COMBO (phase 2). Sessions were twice a week for 60 minutes. PRIME is a low‐mass, high‐repetition regime (40% one‐repetition maximum [1RM], eight strength exercises, 5 minutes each). COMBO training involved combined aerobic (40%‐60% of peak aerobic capacity [VO(2peak)], up to 20 minutes) and resistance training (50‐70% 1RM, eight exercises, two sets of 10 repetitions). MEASUREMENTS: We measured VO(2peak), VO(2) at anaerobic threshold (AT), and muscle voluntary contraction (MVC). RESULTS: The PRIME group significantly increased VO(2peak) after 8 weeks (2.4 mL/kg/min; 95% confidence interval [CI] = .7‐4.1; P = .004), whereas the COMBO group showed minimal change (.2; 95% CI −1.5 to 1.8). This produced a large between‐group effect size of 1.0. VO(2) at AT increased in the PRIME group (1.6 mL/kg/min; 95% CI .0‐3.2) but not in the COMBO group (−1.2; 95% CI −2.9 to .4), producing a large between‐group effect size. Total MVC increased significantly in both groups in comparison with baseline; however, the change was larger in the COMBO group (effect size = .6). CONCLUSION: Traditional exercise approaches (COMBO) and PRIME improved strength. Only PRIME training produced statistically and clinically significant improvements to aerobic capacity. Taken together, these findings support the hypothesis that PRIME may have potential advantages for older patients with HFrEF and could be a possible alternative exercise modality.