Prevalence and Outcomes of Patients with Wolff-Parkinson-White in Danon Disease: Results of a Retrospective Analysis

Abstract

Danon Disease is a rare X-linked myopathy caused by defects in the lysosome-associated membrane 2 (LAMP2) gene. It is strongly associated with hypertrophic cardiomyopathy as well as Wolff-Parkinson-White (WPW) syndrome, but the prevalence of WPW in Danon is unclear. This study examined the prevalence of WPW and associated outcomes in a cohort of patients with Danon Disease. Records were reviewed for 41 patients with confirmed Danon Disease enrolled in a previously described retrospective registry, 31 of which had at least one electrocardiogram (EKG) on file. EKGs were assessed for the presence of WPW, as well as left and right ventricular hypertrophy (LVH, RVH), or both. WPW was defined as a PR interval ≤ 120 milliseconds, QRS interval ≥120 milliseconds, and delta wave. Charts were reviewed for internal cardiac defibrillator (ICD) placement, heart transplantation, and death. These outcomes were evaluated between patients with and without WPW on EKG using chi-square analysis, with p <0.05 noted to be significant. EKG criteria for LVH, RVH or both was met in 10 of the 11 WPW patients, compared to 9 of the 20 without WPW (p=0.012). ICD devices were present in 9 of the 11 WPW patients, 3 of which were placed for secondary prevention, compared to 9 of the 20 patients without WPW (p=0.119). Six of the 11 WPW patients eventually underwent heart transplant, compared to 4 of the 20 without WPW (p=0.058). Only one death was noted in this cohort, and was determined to not be cardiac related. In a cohort of patients with Danon Disease, approximately one-third had WPW syndrome on EKG. Those with WPW on EKG had higher rates of EKG criteria for LVH, RVH or both and were more likely to require advanced therapies such as ICD placement and cardiac transplant. Larger studies involving WPW in Danon Disease should seek to better characterize these outcomes.