Language

English

Publication Date

4-7-2026

Journal

Journal of Neuromuscular Diseases

DOI

10.1177/22143602261433484

PMID

41944172

Abstract

Cardiac disease is a well-established manifestation of myotonic dystrophy type 1 (DM1), characterized by progressive cardiac conduction slowing with increased risk of atrial and ventricular arrhythmias, heart block, and sudden cardiac death. Multiple disease modifying therapies are in clinical trials for DM1 and show promise in improving skeletal muscle weakness and myotonia. Testing the effects of these medicines, or others, in the heart is of critical importance, but requires identification of endpoints of cardiac function that accurately reflect the state of DM1 cardiac disease. To better define cardiac endpoints, the Myotonic Dystrophy Clinical Research Network (DMCRN) and the Myotonic Dystrophy Foundation (MDF) convened a workshop entitled ''Cardiac Endpoint Workshop'' in May 2025 at the Myotonic Dystrophy Foundation International Conference. Here, we summarize the discussion at the workshop and perform secondary analysis of cardiac outcomes in the published literature to evaluate cardiac endpoints for clinical impact and trial feasibility. This analysis demonstrates that major cardiac events are too infrequent (< 1% annual incidence), and alternatives such as composite endpoints or progression of cardiac conduction prolongation would likely be underpowered in a conventional clinical trial. Given these limitations, we identify areas for further natural history study to better describe longitudinal cardiac structural and functional changes to inform specialized patient selection or identify alternative measures with sensitivity to detect therapeutic impact in a trial.

Keywords

cardiac conduction, cardiac endpoint, cardiac imaging, clinical endpoint, clinical trial, myotonic dystrophy

Published Open-Access

yes

Download

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.