Screening for Dilated Cardiomyopathy in At-Risk First-Degree Relatives.

Area of Science:

• Cardiology
• Genetics
• Public Health

Background:

• Cardiovascular screening is recommended for first-degree relatives (FDRs) of patients with dilated cardiomyopathy (DCM).
• The diagnostic yield of screening FDRs is uncertain for specific populations and DCM subtypes.
• Uncertainty exists regarding screening yield in non-familial DCM, non-White FDRs, and for partial DCM phenotypes like left ventricular enlargement (LVE) or left ventricular systolic dysfunction (LVSD).

Purpose of the Study:

• To examine the diagnostic yield of clinical cardiovascular screening in reportedly unaffected FDRs of DCM patients.
• To assess how demographics, risk factors, and proband genetics influence screening outcomes in FDRs.

Main Methods:

• Adult FDRs of DCM patients underwent screening echocardiograms and ECGs across 25 clinical sites.
• Statistical analysis used mixed models to account for site heterogeneity and intrafamilial correlation.
• Outcomes were compared based on FDR demographics, cardiovascular risk factors, and proband genetic findings.

Main Results:

• A total of 1,365 FDRs were screened; 14.1% received new diagnoses of DCM (2.1%), LVSD (3.6%), or LVE (8.4%).
• New diagnoses were more frequent in FDRs aged 45-64 and those with hypertension or obesity.
• Screening yield did not differ significantly by race/ethnicity or sex, and was higher if probands had reportable genetic variants.

Conclusions:

• Cardiovascular screening effectively identifies new DCM-related findings in 1 in 7 reportedly unaffected FDRs.
• The value of clinical screening is confirmed across all FDRs, irrespective of race and ethnicity.
• Screening is crucial for early detection of DCM and related phenotypes in family members of affected individuals.