Hypoplastic left heart syndrome with atrial level restriction in the era of prenatal diagnosis.

Background: Despite recent improvements in survival of patients with hypoplastic left heart syndrome, those with severe atrial level restriction continue to face higher rates of mortality. We sought to assess the impact of prenatal diagnosis and immediate intervention on the outcome of this high-risk population.

Methods: We performed a retrospective review of patients with hypoplastic left heart syndrome and restriction at the atrial level born between 1997 and 2006. Patients with an intact atrial septum or an interatrial communication less than 2 mm by color Doppler flow mapping on initial postnatal study, or evidence of obstruction to left atrial egress on fetal echocardiogram, were included. Patients were subdivided into two groups based on severity of obstruction.

Results: Thirty-eight patients met inclusion criteria; 16 had the most severe form of anatomic obstruction (group 1), and 22 had a lesser degree of obstruction (group 2). Thirty-day cumulative survival for all was 68%: 38% for group 1 and 94% for group 2 (p = 0.001). Twenty-six of the 38 patients (68%) were prenatally diagnosed. Prenatal diagnosis did not improve initial hospital survival or cumulative survival for either group. Eight patients had progression of atrial level restriction from the first fetal study to the first postnatal study. Seven patients prenatally diagnosed with severe restriction underwent planned cesarean section followed by immediate surgical or catheter-based intervention, with only 2 survivors (28%).

Conclusions: Hypoplastic left heart syndrome with an intact atrial septum is a highly lethal condition despite prenatal diagnosis and immediate intervention at birth. Fetal intervention should be considered for these high-risk fetuses.