Complications and risk factors for mortality during congenital heart surgery admissions

We have previously reported a high rate (32%) of complications among congenital heart surgery admissions. The association among reported complications and other risk factors for mortality during congenital heart surgery admissions has not been assessed.

We identified congenital heart surgery admissions, ages less than 18 years, within the Kids' Inpatient Database 2000, and applied a complication screening method using "International Classification of Disease, 9th Revision, Clinical Modification." Complication diagnoses were classified into four categories, complications due to the following: (1) drugs; (2) procedures; (3) devices, implants, and grafts; and (4) radiation. We examined the independent effect of a complication diagnosis code and complication subcategory on mortality using generalized estimating equations controlling for case-mix using the Risk Adjustment for Congenital Heart Surgery (RACHS-1) method, as well as other previously reported predictors for mortality.

Among the 10,032 congenital heart surgical admissions, 32% had at least one complication diagnosis. Seventy-eight percent of complication diagnoses were procedure related, 18% device, implant, or graft related, and 4% drug related. There were no radiation complications identified. After adjusting for case-mix, gender, race, insurance, and hospital surgical volume, admissions with a complication diagnosis had a substantially greater odds of death compared with admissions without a complication (odds ratio [OR] 2.4, p < 0.001). Among complication subcategories, procedure (OR 2.3, p < 0.001), and device, implant, or graft (OR 2.7, p < 0.001) related complications contributed to higher death risk.

Complication diagnoses occur frequently during congenital heart surgery admissions and are associated with an increased risk of death even after controlling for other known mortality risk factors. Identification of complication diagnoses is an important first step. Subsequent efforts must further examine these events to determine their degree of preventability and develop strategies to reduce them. Such an effort may reduce death in this vulnerable population. This study represents preliminary work in an effort to improve outcomes in this complex patient population.