Isometric exercise training in patients with heart failure with preserved ejection fraction: A randomised controlled study.

Aim: Heart failure with preserved ejection fraction (HFpEF) is a complex clinical condition associated with poor health-related quality of life and high mortality rates. Limited therapeutic options highlight the need for innovative approaches. Isometric exercise training (IET) produces cardiovascular benefits; however, the effects of IET in patients with HFpEF have not yet been studied. This study aimed to determine the feasibility of an IET programme and explore safety and efficacy outcomes in patients with HFpEF.

Methods: Medically optimised HFpEF participants were randomised to a 4-week IET intervention (n=19) or usual care (n=19). Resting haemodynamics, cardiac function and patient reported outcomes were measured before and after the intervention. Global longitudinal strain (GLS) and left atrial reservoir strain (LAr) were assessed using 2D speckle tracking echocardiography. Patient-reported outcomes were evaluated using the Kansas City Cardiomyopathy Questionnaire (KCCQ-12).

Results: 33 (87%) participants completed the study. IET produced significant reductions in resting systolic (-8.52±2.7 mmHg, p=0.003), mean (-4.94±2 mmHg, p=0.018), and diastolic (-4.62±1.8 mmHg, p=0.016) blood pressure, as well as total peripheral resistance (270.4±75.4 dyne·s·cm-5, p =0.001) compared to usual care. Additionally, significant improvements were observed in GLS (2.18±0.7%, p=0.005), LAr (4.59±1.7%, p =0.012), LA stiffness index (-0.2±0.06), and the physical limitation subscale of the KCCQ (10.27±4.56, p=0.032) following IET.

Conclusions: IET is a feasible and safe therapeutic intervention for patients with HFpEF, with cardiovascular and quality of life improvements. A larger scale, multi-centre study is required to confirm findings and establish the wider utility and long-term safety of IET in HFpEF.