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

BACKGROUND

Dilated cardiomyopathy (DCM) and non-dilated left ventricular (LV) dysfunction (NDLVD) comprise patients with heterogeneous genetics and prognosis. This study aimed to investigate genotype-phenotype relationship and prognosis in DCM and NDLVD.

METHODS

Patients with a comprehensive clinical, genetic and CMR assessment, with LV ejection fraction (LVEF) <57% were included. Patients were categorized into DCM or NDLVD according to LV dilation (end-diastolic volume >96 ml/m2 in women, >105 ml/m2 in men). Patients with coronary artery disease, valvular, congenital, hypertrophic, inflammatory or infiltrative disease were excluded. The primary endpoint was a composite of cardiovascular death, sustained ventricular arrhythmias or appropriate defibrillator intervention. The secondary endpoint included also heart failure hospitalizations.

RESULTS

The cohort included 249 patients (age 53±14 years, 166 males) with median LVEF 45% (IQ range 33-51%), divided in 143 DCM and 106 NDLVD patients. Pathogenic/likely pathogenic mutations were present in 67 (27%), but were neither associated with phenotype, nor with prognosis. During a 72 (35-119) month follow-up, 54 patients (22%) experienced the composite event, 67 patients (27%) the secondary endpoint. At multivariate analysis, male sex, disease duration, natriuretic peptides, non-sustained ventricular arrhythmias, LVEF, left atrial volume and CMR-derived LV filling pressure predicted the primary endpoint (p<0.05). Moreover, disease duration, natriuretic peptides, non-sustained ventricular arrhythmias, right ventricular ejection fraction and CMR-derived LV filling pressure predicted the secondary endpoint (p<0.05).

CONCLUSIONS

In this cohort of patients with non-ischaemic cardiomyopathy, biventricular systolic function, left atrial volume and CMR-derived LV filling pressure were predictors of poor prognosis, while gene mutations were not.