Efficacy and Safety of the Ultra-Short-Acting β1-Selective Blocker Landiolol in Patients With Recurrent Hemodynamically Unstable Ventricular Tachyarrhymias ― Outcomes of J-Land II Study ―

BACKGROUND: We aimed to investigate the efficacy and safety of landiolol in Japanese patients with recurrent hemodynamically unstable ventricular tachycardia or recurrent ventricular fibrillation (recurrent VT/VF).Methods and Results:This was an open-label, uncontrolled, multicenter study. Patients with hemodynamically unstable VT or VF 24 h prior to providing informed consent, and who were refractory to class III antiarrhythmic drugs, were enrolled. Landiolol was started at a dose of 1 μg/kg/min, after VT/VF was suppressed with electrical defibrillation. Landiolol was titrated up to 10 μg/kg/min in 1 h and adjusted between 1 and 40 μg/kg/min for the efficacy assessment (1-49 h). The primary efficacy endpoint was the proportion of patients free from recurrent VT/VF. Secondary efficacy endpoints included the number of recurrent VT/VF events and the survival rate 30 days after the start of landiolol treatment. Adverse events (AEs) were assessed for safety; 27 and 29 patients were analyzed for efficacy and safety, respectively. The proportion of patients free from recurrent VT/VF was 77.8% (95% CI 57.1-89.3). The mean (±standard deviation) number of recurrent VT/VF events was 9.3±7.9. The survival rate was 96.3%. The overall incidence of AEs and of serious AEs was 72.4% and 6.9%, respectively. CONCLUSIONS: Landiolol may be useful for Japanese patients with recurrent VT/VF who do not respond to class III antiarrhythmic drugs.