Prevalence of atrial fibrillation in myotonic dystrophy type 1: A systematic review

Area of Science:

• Cardiology
• Genetics
• Neurology

Background:

• Myotonic dystrophy type 1 (DM1) frequently involves cardiac complications, with up to 80% of patients affected.
• While cardiac conduction abnormalities are well-documented, the prevalence of atrial fibrillation (AF) in DM1 remains unclear.
• Existing data on AF prevalence in DM1 patients are conflicting, necessitating a comprehensive review.

Purpose of the Study:

• To systematically assess the prevalence of atrial fibrillation (AF) in patients with myotonic dystrophy type 1 (DM1).
• To identify clinical features associated with AF in DM1 patients.
• To determine factors that may predispose to AF or influence prognosis in DM1.

Main Methods:

• A systematic literature search was conducted across major databases (MEDLINE, EMBASE, Cochrane, Web of Science) for studies published between January 2002 and January 2020.
• Included were retrospective/prospective cohort studies and case series evaluating AF prevalence using ECG, Holter monitoring, or implantable device data in DM1 patients.
• Exclusion criteria comprised case reports, reviews, commentaries, and editorials.

Main Results:

• Thirteen studies met the eligibility criteria, encompassing 3677 DM1 patients.
• The pooled mean prevalence of AF in DM1 patients was found to be 10.9% (404 cases).
• Male sex, pre-existing conduction defects, and prolonged atrial electromechanical delay on echocardiography were identified as factors associated with AF onset.

Conclusions:

• Atrial fibrillation affects approximately 10.9% of DM1 patients, with male sex and conduction defects being significant associated factors.
• DM1 patients who develop AF appear to face an elevated risk of both cardiovascular and non-cardiovascular mortality.
• Further research is warranted to refine AF prevalence estimates and elucidate associated ECG abnormalities and clinical predictors in the DM1 population.