Dilated cardiomyopathy vs. non-dilated left ventricular dysfunction: genotype-phenotype relationship and outcome

Area of Science:

• Cardiology
• Genetics
• Cardiovascular Imaging

Background:

• Dilated cardiomyopathy (DCM) and non-dilated left ventricular dysfunction (NDLVD) present heterogeneous genetic profiles and prognoses.
• Understanding the genotype-phenotype relationship is crucial for managing these conditions.

Purpose of the Study:

• To investigate the relationship between genetic mutations and clinical presentation in DCM and NDLVD patients.
• To identify prognostic factors for cardiovascular events in patients with non-ischemic cardiomyopathy.

Main Methods:

• Included 249 patients with left ventricular ejection fraction (LVEF) <57% undergoing clinical, genetic, and cardiac magnetic resonance (CMR) assessment.
• Categorized patients into DCM or NDLVD based on LV dilation criteria, excluding other cardiac pathologies.
• Assessed a composite endpoint of cardiovascular death, sustained ventricular arrhythmias, or defibrillator intervention, and a secondary endpoint including heart failure hospitalizations.

Main Results:

• Pathogenic/likely pathogenic mutations were found in 27% of patients but showed no association with phenotype or prognosis.
• During follow-up (median 72 months), 22% experienced the primary composite event and 27% the secondary endpoint.
• Multivariate analysis identified male sex, disease duration, natriuretic peptides, non-sustained ventricular arrhythmias, LVEF, left atrial volume, and CMR-derived LV filling pressure as predictors of poor prognosis.

Conclusions:

• In non-ischemic cardiomyopathy, biventricular systolic function, left atrial volume, and CMR-derived LV filling pressure predict poor prognosis.
• Genetic mutations were not found to be significant predictors of outcome in this cohort.