Spectrum and Outcome of Primary Cardiomyopathies Diagnosed During Fetal Life

Abstract Objectives The purpose of this study was to determine the phenotypic presentation, causes, and outcome of fetal cardiomyopathy (CM) and to identify early predictors of outcome. Background Although prenatal diagnosis is possible, there is a paucity of information about fetal CM. Methods This was a retrospective review of 61 consecutive fetal cases with a diagnosis of CM at a single center between 2000 and 2012. Results Nonhypertrophic CM (NHCM) was diagnosed in 40 and hypertrophic CM (HCM) in 21 fetuses at 24.7 ± 5.7 gestational weeks. Etiologies included familial (13%), inflammatory (15%), and genetic-metabolic (28%) disorders, whereas 44% were idiopathic. The pregnancy was terminated in 13 of 61 cases (21%). Transplantation-free survival from diagnosis to 1 month and 1 year of life for actively managed patients was better in those with NHCM (n = 31; 58% and 58%, respectively) compared with those with HCM (n = 17; 35% and 18%, respectively; hazard ratio [HR]: 0.44; 95% confidence interval [CI]: 0.12 to 0.72; p = 0.007). Baseline echocardiographic variables associated with mortality in actively managed patients included ventricular septal thickness (HR: 1.21 per z -score increment; 95% CI: 1.07 to 1.36; p = 0.002), cardiothoracic area ratio (HR: 1.06 per percent increment; 95% CI: 1.02 to 1.10; p = 0.006), ≥3 abnormal diastolic Doppler flow indexes (HR: 1.44; 95% CI: 1.07 to 1.95; p = 0.02), gestational age at CM diagnosis (HR: 0.91 per week increment; 95% CI: 0.83 to 0.99; p = 0.03), and, for fetuses in sinus rhythm, a lower cardiovascular profile score (HR: 1.45 per point decrease; 95% CI: 1.16 to 1.79; p = 0.001). Conclusions Fetal CM originates from a broad spectrum of etiologies and is associated with substantial mortality. Early echocardiographic findings appear useful in predicting adverse perinatal outcomes.