Not All Beta-Blockers Are Equal in the Management of Long QT Syndrome Types 1 and 2

作者:Chockalingam Priya; Crotti Lia; Girardengo Giulia; Johnson Jonathan N; Harris Katy M; van der Heijden Jeroen F; Hauer Richard N W; Beckmann Britt M; Spazzolini Carla; Rordorf Roberto; Rydberg Annika; Clur Sally Ann B; Fischer Markus; van den Heuvel Freek; Kaeaeb Stefan; Blom Nico A; Ackerman Michael J; Schwartz Peter J; Wilde Arthur A M*
来源:Journal of the American College of Cardiology, 2012, 60(20): 2092-2099.
DOI:10.1016/j.jacc.2012.07.046

摘要

Objectives The purpose of this study was to compare the efficacy of beta-blockers in congenital long QT syndrome (LQTS). %26lt;br%26gt;Background Beta-blockers are the mainstay in managing LQTS. Studies comparing the efficacy of commonly used beta-blockers are lacking, and clinicians generally assume they are equally effective. %26lt;br%26gt;Methods Electrocardiographic and clinical parameters of 382 LQT1/LQT2 patients initiated on propranolol (n = 134), metoprolol (n = 147), and nadolol (n = 101) were analyzed, excluding patients %26lt;1 year of age at beta-blocker initiation. Symptoms before therapy and the first breakthrough cardiac events (BCEs) were documented. %26lt;br%26gt;Results Patients (56% female, 27% symptomatic, heart rate 76 +/- 16 beats/min, QTc 472 +/- 46 ms) were started on beta-blocker therapy at a median age of 14 years (interquartile range: 8 to 32 years). The QTc shortening with propranolol was significantly greater than with other beta-blockers in the total cohort and in the subset with QTc %26gt;480 ms. None of the asymptomatic patients had BCEs. Among symptomatic patients (n = 101), 15 had BCEs (all syncopes). The QTc shortening was significantly less pronounced among patients with BCEs. There was a greater risk of BCEs for symptomatic patients initiated on metoprolol compared to users of the other 2 beta-blockers combined, after adjustment for genotype (odds ratio: 3.95, 95% confidence interval: 1.2 to 13.1, p = 0.025). Kaplan-Meier analysis showed a significantly lower event-free survival for symptomatic patients receiving metoprolol compared to propranolol/nadolol. %26lt;br%26gt;Conclusions Propranolol has a significantly better QTc shortening effect compared to metoprolol and nadolol, especially in patients with prolonged QTc. Propranolol and nadolol are equally effective, whereas symptomatic patients started on metoprolol are at a significantly higher risk for BCEs. Metoprolol should not be used for symptomatic LQT1 and LQT2 patients.

  • 出版日期2012-11-13