Chockalingam، نويسنده , , Priya and Crotti، نويسنده , , Lia and Girardengo، نويسنده , , Giulia and Johnson، نويسنده , , Jonathan N. and Harris، نويسنده , , Katy M. and van der Heijden، نويسنده , , Jeroen F. and Hauer، نويسنده , , Richard N.W. and Beckmann، نويسنده , , Britt M. and Spazzolini، نويسنده , , Carla and Rordorf، نويسنده , , Roberto and Rydberg، نويسنده , , Annika and Clur، نويسنده , , Sally-Ann B. and Fischer، نويسنده , , Markus and van den Heuvel، نويسنده , , Freek and Kننb، نويسنده , , Stefan and Blom، نويسنده , , Nico A. and Ackerman، نويسنده , , Michael J. and Schwartz، نويسنده , , Peter J. and Wilde، نويسنده , , Arthur A.M.، نويسنده ,
rpose of this study was to compare the efficacy of beta-blockers in congenital long QT syndrome (LQTS).
lockers 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.
ocardiographic 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.
ts (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.
nolol 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.
breakthrough cardiac events , Congenital long QT syndrome , Metoprolol , Nadolol , Propranolol