Rationale and design of a randomized, double-blind, placebo-controlled outcome trial of ivabradine in chronic heart failure: the Systolic Heart Failure Treatment with the I-f Inhibitor Ivabradine Trial (SHIFT)

Elevated heart rate is a significant marker for mortality and morbidity in cardiovascular disease including heart failure. Despite background treatment with a beta-blocker, many patients with heart failure and low ejection fraction maintain a heart rate above 70 b.p.m. Ivabradine reduces heart rate directly through inhibition of the I-f ionic current. SHIFT is a randomized, double-blind study designed to compare ivabradine with placebo on outcomes in patients with symptomatic chronic heart failure (NYHA class II-IV), left-ventricular ejection fraction < 35%, and a prior hospitalization for worsening heart failure within the previous 12 months. Randomized treatment is given on top of guidelines-based therapy for chronic heart failure, including a beta-blocker at optimized dose. Resting heart rate at baseline must be >= 70 b.p.m. The primary endpoint is the composite of the time to first event of cardiovascular death or hospitalization for worsening heart failure. Secondary endpoints include all-cause, cardiovascular and heart failure mortality, and hospitalization. The randomized treatment period lasts approximately 12-48 months. The study will include approximately 6500 patients and will continue until >= 1600 primary endpoints have occurred. The first patient was randomized in October 2006, and the study is expected to end in 2010. The SHIFT study will assess if a heart rate reduction by direct sinus node inhibition can reduce cardiovascular outcomes in patients with chronic heart failure and left-ventricular systolic dysfunction.