Letters Section Editor: Jody W. Zylke, MD, Senior Editor.
Author Affiliations: Cardiology Department, Cochin Hospital, Paris, France (email@example.com).
In Reply: Drs Groh and Bhakta raise several methodological issues regarding our study.1 We found that an invasive strategy based on electrophysiological study followed by prophylactic pacing when necessary was associated with a longer mean survival compared with a noninvasive strategy, reserving the implantation of permanent pacemakers for patients presenting with high-degree atrioventricular block. Ever since prophylactic pacing in DM1 was assigned a class IIb indication in the American College of Cardiology/American Heart Association practice guidelines,2 both strategies have been used equally in clinical practice and, in our study, the assignment of patients to a strategy was left to the judgment of the cardiologist in charge of the patient. We found that the most gravely ill patients were more likely to undergo invasive management, which tended to diminish the benefit conferred by this strategy. Of 914 patients, we excluded 4 from the analysis who underwent prophylactic pacing without prior electrophysiological study. This small number of patients is not surprising, given the low power of the electrocardiogram to predict sudden death. Reclassifying these patients to the noninvasive group had no influence on the 75% lower hazard of dying suddenly.
Wahbi K, Duboc D. Arrhythmia Management in Myotonic Dystrophy Type 1—Reply. JAMA. 2012;308(4):337-338. doi:10.1001/jama.2012.6809