Impaired weight gain predicts risk of late death after surgery for congenital heart defects.

Objectives: To describe long-term somatic growth in terms of weight for age in children operated on for congenital heart defects who die late (after the first 30 postoperative days) and to study the relationship between postoperative weight gain and survival after surgery for congenital heart defects.

Methods: This was a nested case-control study of 80 children born in 1990-2002 who died late after surgery for congenital heart defects at Rikshospitalet, Norway. Weight data were obtained for 74 children, of whom 31 with no extra-cardiac anomalies were defined as cases and 31 surviving children with similar surgical complexity were defined as controls.

Results: In the 74 children who died late, mean weight for age converted to z scores at birth, at last operation and at last recorded weight were 0.12, -1.31 and -2.09. In the 31 children defined as cases, the same weight z scores were 0.07, -1.21 and -2.01 compared with 0.05, -1.10 and -0.99 in the 31 matched controls. The odds ratio (OR) for death was 13.5 (95% CI 3.6 to 51.0) if there was a decrease in weight z score of >0.67 after the last operation. Median follow-up time after operation was 5.7 months.

Conclusions: A decrease in weight for age during the first months after surgery for congenital heart defects of more than 0.67 z scores, corresponding to a downward percentile crossing through at least one of the displayed percentile lines on standard growth charts, is strongly related to late mortality in children operated on for congenital heart defects.