Assessment of Clinical Effect and Treatment Quality of Immediate-release Carvedilol-IR Versus SLOW Release Carvedilol-SR in Heart Failure Patients (SLOW-HF): Study Protocol for a Randomized Controlled Trial

Background: Carvedilol is a non-selective, third-generation beta-blocker and is one of the cornerstones for treatment for patients with heart failure and reduced ejection fraction (HFrEF). However, due to its short half-life, immediate-release carvedilol (IR) needs to be prescribed twice a day. Recently, slow-release carvedilol (SR) has been developed. The aim of this study is to evaluate whether carvedilol-SR is non-inferior to standard carvedilol-IR in terms of its clinical efficacy in patients with HFrEF.

Methods/design: Patients with stable HFrEF will be randomly assigned in a 1:1 ratio to the carvedilol-SR group (160 patients) and the carvedilol-IR group (160 patients). Patients aged ≥ 20 years, with a left ventricular ejection fraction ≤ 40%, N-terminal pro B-natriuretic peptide (NT-proBNP) ≥ 125 pg/ml or BNP ≥ 35 pg/ml, who are clinically stable and have no evidence of congestion or volume retention, will be eligible. After randomization, patients will be followed up for 6 months. The primary endpoint is the change in NT-proBNP level from baseline to the study end. The secondary endpoints include the proportion of patients with NT-proBNP increment > 10% from baseline, composite of all-cause mortality and readmission, mortality rate, readmission rate, changes in blood pressure, quality of life, and drug compliance.

Discussions: The SLOW-HF trial is a prospective, randomized, open-label, phase-IV, multicenter study to evaluate the therapeutic efficacy of carvedilol-SR compared to carvedilol-IR in HFrEF patients. If carvedilol-SR proves to be non-inferior to carvedilol-IR, a once-daily prescription of carvedilol may be recommended for patients with HFrEF.

Trial Registration: ClinicalTrials.gov, ID: NCT03209180 . Registered on 6 July 2017.