Quality of life measures with etripamil self-administration for acute episodes of paroxysmal supraventricular tachycardia in a medically unsupervised setting: patient-reported outcomes from NODE-303
Authors: Camm A J , Ip J E , Coutu B , Ip J H , Noseworthy P , Parody M L , Rafii F , Sears S F , Singh N , Stambler B , Tahirkheli N , Agudelo-Uribe J , Szakacs C , Shardonofsky S , Bharucha D 
Published: October 2024

Abstract

Background
Etripamil nasal spray (NS) is a fast-acting, self-administered calcium-channel blocker in development for the conversion of AV-nodal dependent paroxysmal supraventricular tachycardia (PSVT) in a medically unsupervised setting. Prior studies show favorable safety and efficacy in converting single episodes of PSVT to sinus rhythm (SR).

Purpose
In NODE-303, patient-reported outcome (PRO) instruments assessed quality of life (QoL) over multiple etripamil-treated episodes of PSVT.

Methods
NODE-303 was an event-driven, multi-center, open-label Phase 3 study in North and South American patients with documented PSVT that evaluated the safety and efficacy of etripamil in PSVT termination, over multiple episodes and without the need for prior test dosing. Enrolled patients who perceived PSVT symptoms applied an ambulatory ECG cardiac monitoring system (CMS), performed a pre-trained vagal maneuver and, if symptoms persisted, self-administered etripamil NS 70 mg. A study amendment allowed a repeat dose (etripamil NS, 70 mg) if symptoms persisted 10 min after the first dose. Each patient could self-treat up to 4 episodes. Safety was assessed through adverse events, clinical data, and ECG CMS recordings. The Treatment Satisfaction Questionnaire for Medication (TSQM; validated for acute episodic assessments) and other PROs were administered, and healthcare utilization data were acquired. Patients completed PROs at baseline (BL), monthly, and per PSVT episode, which collected information on symptoms, episode characteristics, rescue medications, and emergency room visits. Additional PROs were the Brief Illness Perception Questionnaire (BIPQ), Cardiac Anxiety Questionnaire (CAQ), and 36-Item Short Form Health Survey (SF-36).

Results
There were higher proportions of patients reporting mild, minimal or no disease severity, every 6 months, than at BL; extremely severe, severe, and moderate disease severity was reported by smaller proportions of patients than at BL, though incomplete surveys at later visits may limit this analysis. Anxiety and stress about future PSVT episodes were consistently reduced from BL. Measures of treatment satisfaction, effectiveness, and convenience were consistent across multiple episodes, and were at levels considered favorable for the TSQM instrument (Table 1). Rates of emergency-room visits and hospital admissions across multiple, treated PSVT episodes were similar to those observed in trials assessing single episodes (Table 2). The BIPQ, CAQ or SF-36 had no notable changes from BL.

Conclusions
Etripamil self-administration was associated with patient-reported improvements in degree of disease severity, decreased anxiety and stress over future PSVT episodes, and levels of treatment satisfaction, effectiveness, and convenience considered favorable for respective PRO instrument. Using a symptom-prompted, self-administered treatment for PSVT could potentially improve QoL measures and reduce healthcare resource utilization.