Left Ventricular Noncompaction Cardiomyopathy: Left Ventricular Dilation and Dysfunction at Baseline Portend the Risk of Death or Heart Transplantation.

Abstract

Left ventricular noncompaction (LVNC) is associated with genetic and phenotypic variability that influences outcomes. We aimed to identify risk factors for death or heart transplantation (HTx) in a paediatric LVNC cohort. We reviewed patients < 18 years of age (2001-2018) with LVNC, either isolated (I-LVNC) or with dilated phenotype (D-LVNC), and at least mildly reduced left ventricular ejection fraction (EF). Patients with dilated cardiomyopathy (DCM) were included as control subjects. Descriptive statistics, multivariate analysis, and time-to-event analysis were used. We included 188 patients, 34 (18%) with I-LVNC, 37 (20%) with D-LVNC, and 117 (62%) with DCM. Overall median age at diagnosis was 1.08 years (interquartile range [IQR] 0.22-10.65) and median follow-up was 1.4 years (IQR 0.2-5.2) years. I-LVNC patients' median baseline LVEF was 47%, compared with 33% for D-LVNC, and 21% for DCM (P < 0.0001); 62% of I-LVNC patients developed moderate to severe LV dysfunction during follow-up. The incidence of death or transplantation was 43.6% in the overall cohort. Freedom from death or HTx at 10 years after diagnosis was 88.6% (95% CI 76%-100%) for I-LVNC, 47% (95% CI 29%-65%) for D-LVNC, and 42.3% (95% CI 33%-52%) for DCM. On multivariable analysis, baseline LVEF and LV end-diastolic diameter (LVEDD) z-score were associated with death or transplantation. Patients with a baseline LVEDD z-score > 4 and moderate to severe LV dysfunction had a transplantation-free survival of 38%. Baseline LV dilation and systolic dysfunction were independently associated with progression to death or HTx in LVNC patients.