Conotruncal heart defects: impact of genetic syndromes on immediate operative mortality.

Background: The surgical outcome of conotruncal heart defects in patients with genetic syndromes has been poorly studied. The aim of this prospective 5-year multicenter study was to elucidate the post-surgical death rate of children with conotruncal heart defects in relation to the presence of associated genetic syndromes.

Methods: Two institutions enrolled 350 consecutive inpatients with conotruncal heart defects, aged between 1 day and 60 months, who were submitted to surgery; all patients were evaluated by a clinical geneticist and had a standard metaphase chromosome analysis and a fluorescent in situ hybridization study searching for deletion of chromosome 22q11 (del22q11).

Results: No genetic syndrome was diagnosed in 289 patients; among the other 61 patients, 27 had DiGeorge velocardiofacial syndrome (del22q11), 16 patients had Down syndrome, and 18 presented with other genetic syndromes. The overall post-surgical death rate was higher in syndromic patients (18%) than in non-syndromic ones (10.7%) with a relative risk of 1.9 (p = 0.06). However, children with del22q11 showed a higher risk for surgical mortality (25.9 vs 10.7%; relative risk 2.4, p = 0.03). Del22q11 was identified as a risk factor for immediate surgical mortality in patients with pulmonary atresia and ventricular septal defect and in patients with interrupted aortic arch.

Conclusions: Down syndrome is not a risk factor for surgery in children with conotruncal heart defects. The presence of a del22q11 may influence the surgical results in children with pulmonary atresia and ventricular septal defect and in those with interrupted aortic arch. Patients with genetic syndromes other than del22q11 and Down syndrome have a higher surgical mortality compared to that observed in non-syndromic patients. These data may be useful for preoperative counseling and for the elaboration of specific protocols of perioperative treatment.