Etripamil Nasal Spray Reduces Heart Rate in Patients with Paroxysmal Supraventricular Tachycardia Prior to Conversion to Sinus Rhythm

Introduction: Etripamil (E) is a rapidly and short acting, nasally administered calcium channel blocker being developed to terminate AV nodal-dependent PSVT. The NODE-301 first in class, multicenter study, evaluated self-administration of E nasal spray 70 mg outside a healthcare environment for acute termination of PSVT. This post-hoc analysis addresses the effect of E on heart rate (HR) during PSVT prior to conversion to sinus rhythm (SR). Methods: In NODE-301, 156 subjects experienced a vagal-maneuver refractory, symptomatic episode of confirmed PSVT, 107 subjects self-administered E and 49 placebo (P) (2:1 randomization) during PSVT. Each PSVT was documented by an ambulatory cardiac monitoring system that was placed on the chest after symptoms began. Baseline (average of four values before drug administration), and every minute of HR data were captured from baseline until one minute before the PSVT was converted to SR. Adequate HR data were available for 150 subjects, 102 on E and 48 on P. Six subjects were not included in this analysis, 4 converted before one minute (3 E and 1 P) and 2 E subjects experienced an early defect of recording. Results: Baseline mean (±SE) HR were 179 (±2.8) and 174 (±4.0) bpm for E and P respectively. Mean change in HR from baseline was greater in the E group than P group ( p <0.0001). This decrease appeared within the first minute (-5 bpm ±0.9), 3 min (-10 bpm ±1.2), 10 min (-16 bpm ±2.1), 30 min (-14 bpm ±3.4) and 40 min (-13 bpm ±2.9) after E administration. The notable decrease in the E group was sustained through the 60minute observation period. A statistically significant difference in HR was reached between E and P notably at 3 ( p <0.03), 10 ( p <0.0001), 30 ( p <0.0002), and 40 min ( p <0.004). Conclusion: Etripamil significantly decreases the HR in PSVT prior to conversion to SR and is sustained over the 60 min observation. This finding may provide clinical benefits to patients for self-management of PSVT.