Abstract 12229: Left Ventricular Non-Compaction in Childhood: Echocardiographic Follow-Up and Prevalence in First-Degree Relatives

Introduction:Left ventricular non-compaction (LVNC) is characterized by excessive trabeculations of the left ventricular wall and may be associated with reduced systolic function. It is debated whether LVNC is congenital or may develop later as part of other cardiomyopathies. The clinical importance and heredity of LVNC with normal systolic function is unclear.We aimed to describe the cardiac development in children with LVNC from birth to 2-4 years of age, compared to matched controls. Additionally, we aimed to describe the prevalence of LVNC in first-degree relatives.Methods:A follow-up transthoracic echocardiography was performed in children at 2-4 years of age diagnosed with LVNC at birth (<30 days) in the Copenhagen Baby Heart Study. Cases were matched to controls on mothers age at delivery, parity, and age of child at follow-up. First-degree relatives (parents, siblings and half-siblings) were also included. LVNC was defined as a non-compact to compact ratio of myocardium of ≥2 in at least one left ventricular segment, measured in 24 segments in end-diastole perpendicular to the left ventricular cavity as previously suggested.Results:Of the 16 children diagnosed with LVNC at birth, 10 have been reevaluated (age 3.5 (interquartile range (IQR) 3, 4) years, 80% male) together with 20 matched controls (age 4 (IQR 3, 4) years, 70% male), 29 first-degree relatives in case group (age 29 (IQR 4, 35) years, 45% male) and 55 first-degree relatives in control group (age 32 (IQR 11, 36) years, 51% male). In probands, the extent of trabeculation (13% vs. 12%, p=0.97) and fractional shortening (FS) (29% vs. 31%, p=0.24) were unchanged from birth to follow-up. At follow-up, the median left ventricular FS was significantly lower in probands compared to matched controls (31% vs. 33%, p=0.03). Ten (35%) first-degree relatives to probands fulfilled criteria for LVNC compared to 0 (0%) of first-degree relatives to controls (p<0.001).Conclusions:Children with LVNC diagnosed neonatally as part of a population study had no further progression of left ventricular dysfunction or extent of trabeculation at the age of 2-4 years, but systolic function was reduced compared to matched controls. One third of first-degree relatives to children with LVNC fulfilled criteria for LVNC.