Association Between Timing of Surgical Repair and Resource Utilization in Infants with Complete Atrioventricular Septal Defect

Background: Preoperatively, patients with complete atrioventricular septal defects (CAVSD) may develop congestive heart failure and failure to thrive, and common viral illnesses may be poorly tolerated. These problems may lead to increased outpatient visits, cardiac testing, medication use, and hospitalizations. In the current era, complete AVSDs are repaired in infancy, yet practice variation exists regarding the timing of surgery, which may impact resource utilization. The objective of this study was to determine the association between timing of repair of CAVSD with resource utilization and clinical outcomes in the first year of life. We hypothesized that earlier repair would be associated with less resource consumption, but without change in clinical outcomes.

Methods: In this retrospective single center cohort study, we included patients with balanced CAVSDs repaired prior to 1 year of age between January 1, 2005 and December 30, 2019 at the Medical University of South Carolina who received outpatient cardiology care at one of three sites within the Children’s Heart Program of South Carolina. Exclusion criteria were any cardiac surgery prior to CAVSD repair, greater than moderate atrioventricular valve regurgitation preoperatively, concomitant outflow tract intervention, absent pulmonary valve syndrome, prematurity, chromosomal anomaly (except trisomy 21), and/or major non-cardiac comorbidities. Patients were divided into tertiles based on age at surgery (1st = 46 to 137 days, 2nd = 140 – 176 days, and 3rd = 178 – 316 days). The primary outcome was days alive and out of the hospital in the first year of life (DAOOH-FY). Multivariable regression was used to adjust for differences in baseline characteristics.

Results: Included were 76 patients. Birth weight and gender were significantly different across tertiles, and more patients in tertile 1 were hospitalized pre-operatively (Table 1). There were no significant differences among age tertiles for prenatal diagnosis, race, gestational age, presence of Trisomy 21 (T21), or repair type (Table 1). There was no significant difference among age tertiles for DAOOH-FY by univariate analysis (Table 2) or after adjusting for gender, prenatal diagnosis, or T21. No patients died in the first year of life. Among the perioperative variables, preoperative weight was significantly different, but weight-for-age z-scores were similar, as were preoperative number of medications and feeding route. Fewer postoperative ICU days were needed in the older tertiles, but days of mechanical ventilation and hospitalization were similar. There were no significant differences in post-operative complications or feeding route at discharge. Resource utilization in the first year of life was similar for unplanned cardiac reinterventions, number of total echocardiograms, number of outpatient cardiology clinic visits, and weight-for-age z-score at 1 year (Table 2).

Conclusion: For infant CAVSD repair, age at surgery was not associated with important differences in clinical outcomes or resource utilization in the first year of life.