Hybrid epicardial and endocardial sinus node-sparing ablation therapy for inappropriate sinus tachycardia: Rationale and design of the multicenter HEAL-IST IDE trial

BACKGROUND Inappropriate sinus tachycardia (IST) is defined as resting heart rate >100 beats/min and average 24-hour heart rate >90 beats/min. It is associated with distressing symptoms and sig-nificant loss of quality of life. Drugs are not effective in symptom control of IST in up to 30% of patients. Catheter ablation of the sinus node has a high recurrence rate, and the complications are significant. Recently, a novel hybrid sinus node-sparing ablation approach for IST was described. OBJECTIVE The objective of the Hybrid Epicardial and Endocardial Sinus Node Sparing Ablation Therapy for Inappropriate Sinus Tachy-cardia (HEAL-IST) investigational device exemption trial (NCT05280093) is to evaluate safety and effectiveness of the hybrid sinus node-sparing ablation procedure for the treatment of symp-tomatic, drug-refractory or drug-intolerant IST. METHODS The HEAL-IST trial is a prospective, multicenter, pivotal, single-arm trial. Up to 142 subjects in up to 40 centers will be treated in the trial with a Bayesian adaptive design. RESULTS Subjects will be assessed for primary safety through 30 days post-hybrid ablation procedure. The primary effectiveness endpoint will be freedom from IST at 12 months. Freedom from IST will be defined as mean heart rate of <= 90 beats/min or at least a 15% reduction in mean heart rate as compared with baseline, in the absence of new or higher dosage of previously failed medications at a 24-month follow-up assessment. CONCLUSION The HEAL-IST trial is the first multicenter trial eval-uating hybrid IST ablation in patients with symptomatic IST and re-fractory or intolerant to drugs. The results of this study will help guide decision making regarding the best management in this pop-ulation.