What is the clinical evidence from this study?

Study design: Cohort. Population: Congenital Long QT Syndrome (n=64). Intervention: Left cardiac sympathetic denervation (LCSD) monotherapy. Primary outcome: Nonlethal, post-LCSD breakthrough cardiac event.

November 17, 2020Open Access

Left Cardiac Sympathetic Denervation Monotherapy in Patients With Congenital Long QT Syndrome

Key Result

Left cardiac sympathetic denervation monotherapy in patients with long QT syndrome resulted in only 3 nonlethal breakthrough cardiac events (4.7%) over a mean follow-up of 2.7 years.

Study Design

Type

Cohort (n=64)

Multicenter

Structured PICO

Does left cardiac sympathetic denervation (LCSD) monotherapy prevent breakthrough cardiac events in patients with congenital Long QT Syndrome who do not tolerate beta-blockers?

Population

64 patients with long QT syndrome treated with left cardiac sympathetic denervation monotherapy, primarily due to beta-blocker intolerance, followed for a mean of 2.7 years.

Exposure

Videoscopic left cardiac sympathetic denervation (LCSD) as 1-time stand-alone monotherapy

Outcome

Breakthrough cardiac events after LCSDhard clinical

LCSD monotherapy appears to be a safe and effective alternative for carefully selected patients with congenital Long QT Syndrome who cannot tolerate beta-blockers, though it is not curative.

Abstract

BACKGROUND: Videoscopic left cardiac sympathetic denervation (LCSD) is an effective antifibrillatory, minimally invasive therapy for patients with potentially life-threatening arrhythmia syndromes like long QT syndrome (LQTS). Although initially used primarily for treatment intensification following documented LQTS-associated breakthrough cardiac events while on beta-blockers, LCSD as 1-time monotherapy for certain patients with LQTS requires further evaluation. We are presenting our early experience with LCSD monotherapy for carefully selected patients with LQTS. METHODS: Among the 1400 patients evaluated and treated for LQTS, a retrospective review was performed on the 204 patients with LQTS who underwent LCSD at our institution since 2005 to identify the patients where the LCSD served as stand-alone, monotherapy. Clinical data on symptomatic status before diagnosis, clinical, and genetic diagnosis, and breakthrough cardiac events after diagnosis were analyzed to determine efficacy of LCSD monotherapy. RESULT: Overall, 64 of 204 patients (31%) were treated with LCSD alone (37 58% female, mean QTc 466±30 ms, 16 25% patients were symptomatic before diagnosis with a mean age at diagnosis 17.3±11.8 years, 5 had 8% ≥1 breakthrough cardiac event after diagnosis, and mean age at LCSD was 21.1±11.4 years). The primary motivation for LCSD monotherapy was an unacceptable quality of life stemming from beta-blocker related side effects (ie, beta-blocker intolerance) in 56/64 patients (88%). The underlying LQTS genotype was LQT1 in 36 (56%) and LQT2 in 20 (31%). There were no significant LCSD-related surgical complications. With a mean follow-up of 2.7±2.4 years so far, only 3 patients have experienced a nonlethal, post-LCSD breakthrough cardiac event in 180 patient-years. CONCLUSIONS: LCSD may be a safe and effective stand-alone therapy for select patients who do not tolerate beta-blockers. However, LCSD is not curative and patient selection will be critical when potentially considering LCSD as monotherapy.