Cardiac surgery in infants with low birth weight is associated with increased mortality: Analysis of the Society of Thoracic Surgeons Congenital Heart Database

Objective: The evaluation of operative mortality risk for cardiac surgery in infants with low weight is limited. To determine whether low weight is a risk factor for increased mortality, we reviewed the experience within the Society of Thoracic Surgeons Congenital Heart Surgery Database of infants who have undergone surgical correction or palliation for congenital heart disease. Methods: We analyzed mortality in 3022 infants ages 0 to 90 days weighing 1 to 2.5 kg (n = 517) and greater than 2.5 to 4 kg ( n = 2505) who underwent cardiac surgery from 2002 through 2004 at 32 participating centers. Patients were grouped according to the primary procedure performed and analyzed according to their weight at the time of surgical intervention. Patients were also analyzed according to Risk Adjustment for Congenital Heart Surgery-1 and Aristotle Basic Complexity scores. Results: Compared with infants weighing 2.5 to 4 kg, infants weighing less than 2.5 kg had a significantly higher mortality for the following operations: repair of coarctation of the aorta, total anomalous pulmonary venous connection repair, arterial switch procedure, systemic to pulmonary artery shunt, and the Norwood procedure. Lower infant weight remained strongly associated with mortality risk after stratifying the population by Risk Adjustment for Congenital Heart Surgery-1 levels 2 through 6 and Aristotle Basic Complexity levels 2 through 4. Conclusions: Low weight at the time of surgical intervention is associated with increased mortality in patients undergoing several types of cardiovascular procedures. These data do not allow assessment of specific risks or benefits of any particular treatment strategy. However, they do support the need for prospective analysis of specific treatment strategies for these high-risk patients.