Abstract Body (Do not enter title and authors here): Objective: Ivabradine (IVBD) is a hyperpolarization-activated cyclic nucleotide-gated channel blocker that inhibits the pacemaker I_f current causing spontaneous depolarization in the sino-atrial node thereby regulating heart rate in patients with heart failure (HF). Previous reports state that IVB use is associated with an increase in risk of atrial fibrillation (AF). This study aims to determine the incidence of ivabradine-associated AF over 1 year in a real-world database of AF naïve patients with HF.
Methods: Rates of incident AF were determined using Merative Health MarketScan^® Commercial Claims and Medicare Supplemental Database. Using ICD codes and outpatient medication dispensing records, we extracted HF patients who filled a prescription for IVBD between 01/2015 and 12/2021. Patients with a prior diagnosis of AF before starting IVBD were excluded. The study endpoint was the first diagnosis of AF, defined by ICD 9 and 10 codes, after the index IVBD dispensing. The time to AF was projected using cumulative incidence calculation. We used Kaplan-Meier product limit estimator to calculate AF outcomes at 30, 90, 180, and 365 days from the index IVBD, where patients were censored at the end of enrollment or end of the one-year follow up.
Results: The analytic cohort at first IVB dispensing included 498 patients with mean (SD) age of 52.27 (12.47). Analytic cohort was slightly more weighted by male with a proportion of 53.2%. The cumulative incidence of AF at 30, 90, 180 and 365 days after the IVB use was 4.91%, 12.16%, 19.24%, and 28.11%, respectively. (Figure)
Conclusions: Cumulative incidence of AF after IVBD was higher than the published AF incidence among commercially insured HF patients. A comparative safety assessment is warranted to quantify the measure of association for the AF incidence and exposure to IVBD.