Contributor: Mat Bull
Less is more when it comes to heart rate in HF. Ivabradine, a sinus node inhibitor, lowers heart rate, thereby decreasing myocardial demand. Some beta blockers have mortality benefit in HFrEF as shown by the MERIT-HF and COPERNICUS trials, and a side effect of these drugs is heart rate lowering. Thus, beta-blockers are standard of care in HFrEF; however, at maximally indicated doses, undesired side effects often occur. Since ivabradine targets very specific ion channels within the SA node, further heart rate reduction is possible. But which patients are eligible for this therapy? Read on.
SHIFT was a randomized placebo-controlled study demonstrating an 18% reduction in the composite of cardiovascular mortality and HF hospitalization at 23 months in select patients treated with ivabradine. Indication for ivabradine use included symptomatic HFrEF (NYHA II-IV: LVEF ≤ 35%), sinus resting heart rate ≥ 70 bpm on standard of care medical therapy and at least one hospitalization for heart failure within the previous year.
Das et al evaluated 26,404 patients from the SwedeHF registry to determine eligibility for ivabradine in a broader population. The patients in SwedeHF were divided into SHIFT eligible (14.2% 3741) and non-SHIFT eligible (85.8% 22,663) based on SHIFT trial inclusion criteria. These cohorts were followed for 12 months and re-assessed for eligibility. At 12 months, 7% of the entire cohort remained eligible, 5% shifted to eligible, 11% shifted to ineligible. There were no factors predictive of changing eligibility.
No study is perfect. Higher beta-blocker usage in the SwedeHF registry compared to typical outpatient practice may have reduced “eligibility” for ivabradine. Furthermore, no available data on the number of ivabradine-treated patients within SwedeHF registry may also confound results.
In a heartbeat… Ivabradine is a useful addition in a small number of select patients with HFrEF. Ongoing patient assessment is necessary to evaluate for eligibility.
Study Link: Ivabradine in Heart Failure: The Representativeness of SHIFT (Systolic Heart Failure Treatment With the IF Inhibitor Ivabradine Trial) in a Broad Population of Patients With Chronic Heart Failure