Risk adjustment for congenital heart surgery (RACHS): is it useful in a single-center series of newborns as a predictor of outcome in a high-risk population?

OBJECTIVE

Risk adjustment for congenital heart surgery (RACHS) was developed to compare outcome data for pediatric patients undergoing cardiac surgery. RACHS stratifies anatomic diversity into 6 categories based on age, type of surgery performed, and similar in-hospital mortality. The purpose of this retrospective review was to evaluate the use of RACHS in a single-center series as a predictor of outcome in a high-risk newborn population.

METHODS

In 2003, 793 pediatric cardiac surgical operations (584 open; 209 closed) were performed at our institution. Mortality was 2.1%. Of the 793 operations, 114 were in newborns less than 15 days of age. These 114 newborns were stratified according to RACHS. Two patients could not be stratified and were excluded from analysis. Preoperative, operative, and postoperative variables were compared between the RACHS stratified newborns.

RESULTS

Unexpectedly, newborns in RACHS category 4 had lower birth weights (3.0 +/- 0.5 kg vs. 3.5 +/- 0.5 kg; P < .05) and a trend toward increased postoperative inotropic score (19 +/- 7 vs. 16 +/- 4), increased postoperative lactic acid (72 +/- 48 vs. 63 +/- 25), increased length of mechanical ventilation (23 +/- 72 days vs. 8 +/- 6 days), increased length of stay (34 +/- 72 days vs. 31 +/- 17 days), and increased mortality (16% vs. 11%) compared with newborns in RACHS category 6.

CONCLUSION

Limitations of risk assessment using RACHS in a single-center series of high-risk newborns include the lack of consideration of confounding variables. Further risk adjustments that include such confounding variables are warranted.