Surgical interventions for atrioventricular septal defect subtypes: the pediatric heart network experience

Abstract

Background: The influence of atrioventricular septal defect (AVSD) subtype on outcomes after repair is poorly understood.

Methods: Demographic, procedural, and outcome data were obtained 1 and 6 months after AVSD repair in an observational study conducted at 7 North American centers.

Results: The 215 AVSD patients were subtyped as 60 partial, 27 transitional, 120 complete, and 8 with canal-type VSD. Preoperatively, transitional patients had the highest prevalence of moderate or severe left atrioventricular valve regurgitation (LAVVR, p = 0.01). At repair, complete AVSD and canal-type VSD patients, both with the highest prevalence of trisomy 21 (p < 0.001), were younger (p < 0.001), had lower weight-for-age z scores (p = 0.005), and had more associated cardiac defects (p < 0.001). Annuloplasty was similar among subtypes (p = 0.91), with longer duration of ventilation and hospitalization for complete AVSD (p < 0.001). Independent predictors of moderate or severe LAVVR at the 6-month follow-up were older log(age) at repair (p = 0.02) but not annuloplasty, subtype, or center (p > 0.4). Weight-for-age z scores improved in all subtypes at the 6-month follow-up, and improvement was similar among subtypes (p = 0.17).

Conclusions: AVSD subtype was significantly associated with patient characteristics and clinical status before repair and influenced age at repair. Significant postoperative LAVVR is the most common sequela, with a similar prevalence across centers 6 months after the intervention. Annuloplasty failed to decrease the postoperative prevalence of moderate or severe LAVVR at 6 months. After accounting for age at repair, AVSD subtype was not associated with postoperative LAVVR severity or growth failure at 6 months. Further investigation is needed to determine if interventional strategies specific to AVSD subtype improve surgical outcomes.

Fig 1

Smoothed nonparametric regression estimates depict the relationship between age-at-repair (years) and the percentage of subjects with moderate/severe (≥ moderate) left atrioventricular valve regurgitation (LAVVR) for the (A) partial, (B) transitional, and (C) complete subtype. Canal-type VSD was not included because of the small sample size. The green hash marks denote age at repair for patients with moderate/none LAVVR. The purple hash marks denote age at repair for patients with moderate/severe LAVVR.

Fig 2

Weight-for-age z score by atrioventricular septal defect (AVSD) subtype and time point (paired data). The horizontal line in the middle of each box indicates the 50th percentile; the top and bottom borders of the box mark the 75th and 25th percentiles, respectively; and the whiskers mark the 90th and 10th percentiles. The asterisk (*) denotes the mean. Red denotes the z score at operation, and blue denotes the z score at 6 months. Growth improved significantly in patients with all subtypes.