Effects of calcium channel blockers in patients with heart failure with preserved ejection fraction: A protocol for systematic review and meta-analysis

Background: Nearly half of patients with heart failure (HF) have preserved ejection fraction (EF) and the mortality and morbidity of patients with HF with preserved EF (HFpEF) are high. Patients with HFpEF are often elderly and their primary chronic symptom is severe exercise intolerance. Due to the frequent coexistence of hypertension in HFpEF patients, the use of anti-hypertensive medications is common in their treatment. While many cohort studies and several randomized controlled trials (RCTs) have examined the effectiveness of various anti-hypertensive drugs such as beta-blockers and renin-angiotensin system inhibitors in HFpEF, the role of calcium channel blockers (CCBs) remains uncertain. Despite several RCTs and cohort studies exploring the effects of CCBs on prognosis and exercise capacity in HFpEF patients, the findings have been inconsistent, likely due to limited statistical power and/or variations in study design. Therefore, our aim is to conduct a systematic review and meta-analysis of studies on the effects of CCBs in these patients. Methods: This meta-analysis will include RCTs and cohort studies on the effect of CCBs in HFpEF patients. Information of studies will be collected from PubMed, Web of Science, and Scopus. The primary outcome of interest will be prognosis. The secondary outcome of interest will be exercise capacity. Discussion: Synthesizing our meta-analytical results with expert consensus could contribute to the formulation of updated clinical guidelines. Our systematic review and meta-analysis will provide directions for future research on the use of CCBs in HFpEF patients. Systematic review registration: INPLASY202430097.