Left bundle branch block in Duchenne muscular dystrophy: Prevalence, genetic relationship and prognosis.

Abdallah Fayssoil,Anthony Behin,Bernard Clair,Guillaume Nicolas,Rabah Ben Yaou,Cendrine Chaffaut,Karim Wahbi,Adam Ogna,David Orlikowski,Denis Duboc,Djillali Annane,Helene Prigent,France Leturcq,Frederic Lofaso,Sylvie Chevret,Pascal Crenn,Olivier Nardi,Pascal Laforet,Diego Fraidenraich

doi:10.1371/journal.pone.0190518

Abstract

BackgroundDuchenne muscular dystrophy (DMD) is an inherited myogenic disorder due to mutations in the dystrophin gene on chromosome Xp21.1. We designed this study to determine the prevalence of left bundle branch block (LBBB), whether there is a relationship between LBBB and genetic pattern, and to assess predictive factors for acute cardiac events and mortality in adult DMD patients.MethodsWe reviewed the charts of DMD followed at the Home Mechanical Ventilation Unit of the Raymond Poincare University Hospital.ResultsA total of 121 patients, aged from 18 to 41 years have been included in our study. Median vital capacity (VC) was 12% [7; 19.5] of predicted. Almost all patients were on home mechanical ventilation (95%). LBBB was present in 15 patients (13%); among them, 10 disclosed exonic deletions. After a median follow up of 6 years, 21 patients (17%) experienced acute heart failure (AHF), 7 patients (6%) supraventricular arrhythmia, 3 patients (2.4%) ventricular tachycardia, 4 patients (3%) significant electrical disturbances. LBBB was significantly associated with cardiac events (OR = 12.7; 95%CI [3.78–42.7]; p <0.0001) and mortality (OR = 4.4; 95%CI [1.44–13.7]; p 0.009). Presence of residual dystrophin protein was not associated with significant less cardiac events. Age and LVEF were also predictive factors for cardiac events and mortality.ConclusionLBBB is relatively frequent in DMD and is a major predictive factor for cardiac events and mortality. Presence of residual dystrophin protein was not associated with a lower incidence of cardiac events.

Highlights

Duchenne muscular dystrophy (DMD) is an inherited myogenic disorder due to mutations in the dystrophin gene DMD on chromosome Xp21.1
left bundle branch block (LBBB) is relatively frequent in DMD and is a major predictive factor for cardiac events and mortality
We designed this study to determine the prevalence of LBBB, the potential relationship between LBBB and genetic pattern and to assess predictive factors for acute cardiac events and mortality in adult DMD patients

Summary

Introduction

Duchenne muscular dystrophy (DMD) is an inherited myogenic disorder due to mutations in the dystrophin gene DMD on chromosome Xp21.1. DMD arises from out of frame DMD gene mutations which lead to the absence or the presence of very low amounts of dystrophin It is the most common and one of the severe forms of muscular dystrophy and occurs in 1 / 5000 male births [1]. We designed this study to determine the prevalence of LBBB, the potential relationship between LBBB and genetic pattern and to assess predictive factors for acute cardiac events and mortality in adult DMD patients. We designed this study to determine the prevalence of left bundle branch block (LBBB), whether there is a relationship between LBBB and genetic pattern, and to assess predictive factors for acute cardiac events and mortality in adult DMD patients

Objectives

Results

Conclusion