Background: In this study, we evaluated the clinical outcomes of open heart surgery in low body weight babies and compared correlations of these results with RACHS-1 and Aristotle classifications.

Methods: Between January 1999 and September 2009, 4303 patients with congenital heart disease were operated on in our institution. Of these cases 950 had closed cardiac procedures and 3353 patients had open heart surgery. Of the patients who underwent open heart surgery, 128 patients (mean age 36±34 day), with body weight under 3 kg (mean 2.82±0.2 kg) were enrolled in this study.

Results: Thirty-nine patients (30.5%) were in the 4^th risk group and over according to RACHS-1 classification and 80 patients (62.5%) had a Basic Aristotle score of 10 or over. In-hospital mortality was 36.7% (47 patients). Correlation of mortality and morbidity with risk score in RACHS-1 and Basic Aristotle classification was found to be insignificant (p>0.05).

Conclusion: Postoperative mortality and morbidity in patients below 3 kg who undergo open heart surgery depend on a variety of factors. Although outcomes of surgery in our series is similar to reported results in the literature, they were irrelevant to the suggested results of risk scoring systems. In this study it is suggested that RACHS-1 and Basic Aristotle classifications can be useful to predict preoperative risks with large groups, but they are not satisfactory in predicting individual risk in low weight open heart surgery.

Keywords : Congenital cardiac surgery; low body weight; risk stratification