OBJECTIVES: The purpose of this study was to compare the efficacy of beta-blockers in congenital long QT syndrome (LQTS). 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. 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 <1 year of age at beta-blocker initiation. Symptoms before therapy and the first breakthrough cardiac events (BCEs) were documented. 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 >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. 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.
OBJECTIVES: The purpose of this study was to compare the efficacy of beta-blockers in congenital long QT syndrome (LQTS). 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. 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 <1 year of age at beta-blocker initiation. Symptoms before therapy and the first breakthrough cardiac events (BCEs) were documented. 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 >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. 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.
Authors: Arthur J Moss; Wataru Shimizu; Arthur A M Wilde; Jeffrey A Towbin; Wojciech Zareba; Jennifer L Robinson; Ming Qi; G Michael Vincent; Michael J Ackerman; Elizabeth S Kaufman; Nynke Hofman; Rahul Seth; Shiro Kamakura; Yoshihiro Miyamoto; Ilan Goldenberg; Mark L Andrews; Scott McNitt Journal: Circulation Date: 2007-04-30 Impact factor: 29.690
Authors: A J Moss; P J Schwartz; R S Crampton; D Tzivoni; E H Locati; J MacCluer; W J Hall; L Weitkamp; G M Vincent; A Garson Journal: Circulation Date: 1991-09 Impact factor: 29.690
Authors: Christian Steinberg; Gareth J Padfield; Basil Al-Sabeq; Arnon Adler; John A Yeung-Lai-Wah; Charles R Kerr; Marc W Deyell; Jason G Andrade; Matthew T Bennett; Raymond Yee; George J Klein; Martin Green; Zachary W M Laksman; Andrew D Krahn; Santabhanu Chakrabarti Journal: J Interv Card Electrophysiol Date: 2016-07-09 Impact factor: 1.900
Authors: Giovanni Fazio; Federica Vernuccio; Giuseppe Lo Re; Giuseppe Grutta; Maurizio Mongiovì Journal: Ann Noninvasive Electrocardiol Date: 2013-05-03 Impact factor: 1.468