Cardiac function and the effect of heart failure treatment in patients with genotype-positive dilated cardiomyopathy

BACKGROUND: Dilated cardiomyopathy (DCM) and nondilated left ventricular cardiomyopathy (NDLVC) are commonly caused by pathogenic genetic variants. Heart failure (HF) treatment recommendations for genotype-positive patients with early disease are lacking. OBJECTIVES: This study aims to assess HF outcome in genotype-positive DCM/NDLVC patients in early disease stages who received HF treatment vs no HF treatment. METHODS: This observational study enrolled genotype-positive DCM/NDLVC patients. The authors recorded the use of HF medication and analyzed echocardiographic examinations at baseline and last follow-up. Patients were stratified according to left ventricular ejection fraction (LVEF) as preserved (≥50%), mildly reduced (40%-49%), and reduced (<40%). HF outcome was defined as decline of LVEF <40% in patients with preserved or mildly reduced LVEF at baseline. In patients with mildly reduced LVEF, all echocardiographic examinations were analyzed by mixed model regression analyses stratified by HF treatment and no HF treatment. Genotype-specific analyses were performed for high-risk and low-risk genotypes. RESULTS: A total of 712 patients (mean age: 40 years, 52% women, 20% probands) were followed for 3.1 years. Of 407 patients with preserved or mildly reduced LVEF, 24 (6%) patients declined to LVEF <40%. In 130 patients with mildly reduced LVEF, HF treatment was associated with 1.8 percentage points (95% CI: 0.7-2.9; P = 0.01) higher LVEF and 2.4 percentage points (95% CI: 0.3-4.4; P = 0.02) higher LVEF in high-risk genotypes. CONCLUSIONS: In genotype-positive DCM/NDLVC patients with mildly reduced LVEF, the authors found a 1.8 percentage points higher LVEF in patients receiving HF treatment. This should be considered when planning larger trials for guideline-directed HF treatment.