Potential use of ivabradine in postoperative junctional ectopic tachycardia: a systematic review and single-arm meta-analysis

Postoperative junctional ectopic tachycardia (JET) is a frequent, hemodynamically consequential arrhythmia after congenital heart surgery. Ivabradine is increasingly used off-label, but its effectiveness and safety in pediatric postoperative JET remain uncertain. We conducted a systematic review and single‑arm meta‑analysis of studies enrolling children (< 18 years) with postoperative JET treated with oral or nasogastric ivabradine. Outcomes included conversion to sinus rhythm, time to conversion, recurrence, use of concomitant antiarrhythmic drugs (AADs), adverse events (AEs) (bradycardia, hypotension, QT prolongation, atrioventricular block), and all‑cause mortality. Study‑level event rates were pooled as proportions using random‑effects models. Five studies (1 randomized trial arm, 3 cohorts, 1 case series; N = 87) met the inclusion criteria. Ivabradine dosing ranged from 0.05 to 0.1 mg/kg every 12 h. Across ivabradine‑based regimens, the pooled conversion proportion was 98.8% (95% CI 93.8–100), with reported mean times to stable sinus rhythm between 7.1 and 55.5 h. The pooled JET recurrence proportion was 3% (95% CI 0–12.1). Concomitant intravenous or oral AADs were used in 48.3% of patients (95% CI 10.4–87.2). No ivabradine-attributed bradycardia, hypotension, QT-interval prolongation, or new/worsening atrioventricular block was reported; all‑cause mortality was 2.1% (95% CI 0–10.1), attributed in the primary reports to postoperative complications rather than directly to ivabradine. In a sensitivity analysis restricted to two studies with ≤ 25% concomitant antiarrhythmic drug use, the conversion proportion remained high (98%), but confidence intervals for recurrence and mortality were wide. In the small, predominantly observational studies available, ivabradine-based regimens were associated with high conversion to sinus rhythm and low short-term recurrence of postoperative JET, with no hemodynamic or conduction AEs reported among 87 patients. Interpretation is limited by nonrandomized designs, frequent cotreatment with other AADs, short follow‑up, and regional concentration of data; the pooled proportions should be viewed as exploratory summaries rather than estimates of ivabradine’s independent effect. Multicentre randomized trials are needed to define causal efficacy, optimal dosing, and longer‑term safety. This systematic review and single-arm meta-analysis was prospectively registered with PROSPERO (CRD420251080412).