Beta-Blockers Equivalent in Long QT Syndrome Genotype 1
(HealthDay News) — For patients with long QT syndrome (LQTS), different β-blockers are effective for reducing the risk for first cardiac event in LQT1, but only nadolol is effective in LQT2, according to a study published in the September 30 issue of the Journal of the American College of Cardiology.
Abeer Abu-Zeitone, PhD, from the University of Rochester Medical Center in New York, and colleagues compared the efficacy of different β-blockers in LQTS and in genotype-positive patients with LQT1 and LQT2. Participants included 1,530 patients from a LQTS Registry.
The researchers found that, compared with being off β-blockers, the hazard ratios for first cardiac events were 0.71 (95% confidence interval [CI], 0.50–1.01) for atenolol; 0.70 (95% CI, 0.43–1.15) for metoprolol; 0.65 (95% CI, 0.46–0.90) for propranolol; and 0.51 (95% CI, 0.35–0.74) for nadolol. A similar risk reduction for first cardiac events was seen among the four β-blockers in LQT1, while in LQT2, the only significant risk reduction was seen for nadolol (hazard ratio, 0.40; 95% CI, 0.16–0.98). The efficacy for recurrent events differed by drug among patients who had a prior cardiac event while taking β-blockers (P=0.004), with propranolol the least effective.
"Although the four β-blockers are equally effective in reducing the risk of a first cardiac event in LQTS, their efficacy differed by genotype," the authors write.
The study was partially funded by GeneDx.