title: Efficacy of different beta-blockers in the treatment of long QT syndrome.
abstract: BACKGROUND
  In LQTS, β-blocker therapy is effective in reducing the risk of cardiac events (syncope, aborted cardiac arrest, sudden cardiac death). Limited studies have compared the efficacy of different β-blockers.
  
  
  OBJECTIVE
  The goal of this study was to compare the efficacy of different β-blockers in long QT syndrome (LQTS) and in genotype-positive patients with LQT1 and LQT2.
  
  
  METHODS
  The study included 1,530 patients from the Rochester, New York-based LQTS Registry who were prescribed common β-blockers (atenolol, metoprolol, propranolol, or nadolol). Time-dependent Cox regression analyses were used to compare the efficacy of different β-blockers with the risk of cardiac events in LQTS.
  
  
  RESULTS
  Relative to being off β-blockers, the hazard ratios and 95% confidence intervals (CIs) for first cardiac events for atenolol, metoprolol, propranolol, and nadolol were 0.71 (0.50 to 1.01), 0.70 (0.43 to 1.15) 0.65 (0.46 to 0.90), and 0.51 (0.35 to 0.74), respectively. In LQT1, the risk reduction for first cardiac events was similar among the 4 β-blockers, but in LQT2, nadolol provided the only significant risk reduction (hazard ratio: 0.40 [0.16 to 0.98]). Among patients who had a prior cardiac event while taking β-blockers, efficacy for recurrent events differed by drug (p = 0.004), and propranolol was the least effective compared with the other β-blockers.
  
  
  CONCLUSIONS
  Although the 4 β-blockers are equally effective in reducing the risk of a first cardiac event in LQTS, their efficacy differed by genotype; nadolol was the only β-blocker associated with a significant risk reduction in patients with LQT2. Patients experiencing cardiac events during β-blocker therapy are at high risk for subsequent cardiac events, and propranolol is the least effective drug in this high-risk group.
authors.affiliation: Cardiology Division, Department of Medicine, University of Rochester Medical Center, Rochester, New York. Electronic address: abeer_abuzeitone@urmc.rochester.edu.
authors.forename: Abeer
authors.initials: A
authors.lastname: Abu-Zeitone
authors.affiliation: Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, New York.
authors.forename: Derick R
authors.initials: DR
authors.lastname: Peterson
authors.affiliation: Cardiology Division, Department of Medicine, University of Rochester Medical Center, Rochester, New York.
authors.forename: Bronislava
authors.initials: B
authors.lastname: Polonsky
authors.affiliation: Cardiology Division, Department of Medicine, University of Rochester Medical Center, Rochester, New York.
authors.forename: Scott
authors.initials: S
authors.lastname: McNitt
authors.affiliation: Cardiology Division, Department of Medicine, University of Rochester Medical Center, Rochester, New York.
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: Moss
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D001262:Atenolol / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D005260:Female; D005838:Genotype; D006323:Heart Arrest / Q000517:prevention & control; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008133:Long QT Syndrome / Q000188:drug therapy*; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use; D015999:Multivariate Analysis; D009248:Nadolol / Q000627:therapeutic use; D016016:Proportional Hazards Models; D011433:Propranolol / Q000627:therapeutic use; D012042:Registries; D012044:Regression Analysis; D012307:Risk Factors; D013575:Syncope / Q000517:prevention & control; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000319:Adrenergic beta-Antagonists; D009248:Nadolol; D001262:Atenolol; D011433:Propranolol; D008790:Metoprolol
keywords: atenolol; long QT syndrome; metoprolol; nadolol; propranolol; β-blocker therapy