Natural history of cardiac involvement in myotonic dystrophy type 1 - Emphasis on the need for lifelong follow-up

Area of Science:

• Cardiology
• Neurology
• Genetics

Background:

• Cardiac involvement is a primary cause of mortality in myotonic dystrophy type 1 (DM1).
• Sudden cardiac death (SCD) prevention is critical in DM1 patient care.
• Understanding the natural history of cardiac issues in DM1 is essential for refining follow-up protocols.

Purpose of the Study:

• To investigate the natural history of cardiac involvement in DM1 patients.
• To establish an evidence-based foundation for adjusting DM1 cardiac follow-up protocols.

Main Methods:

• Retrospective analysis of electronic health records for 195 genetically confirmed DM1 patients.
• Data collection included patient characteristics, ECG, Holter monitoring, echocardiography, and clinical outcomes.
• Mean age at baseline was 41 years, with a median follow-up of 10.5 years.

Main Results:

• Cardiac involvement prevalence rose from 42% to 66% over follow-up.
• Male patients showed a higher prevalence of cardiac involvement (74% vs. 44%).
• Conduction abnormalities (48%), arrhythmias (35%), and left ventricular dysfunction (21%) were most common; only 17% reported symptoms. ECG detected 49% at latest follow-up, with Holter and echocardiography increasing yield.

Conclusions:

• Cardiac involvement is highly prevalent and progressive in DM1 patients.
• Lifelong cardiac surveillance using ECG, Holter monitoring, and echocardiography is warranted.
• These findings support the need for adjusted follow-up protocols for DM1 patients.