Predictive accuracy of three clinical risk assessment systems for cardiac complications among Chinese pregnant women with congenital heart disease

Abstract

Objective: To compare the predictive accuracy of three risk assessment systems for cardiac complications among pregnant women with congenital heart disease (CHD).

Methods: In a retrospective study, data were assessed from women with CHD at more than 20weeks of pregnancy who attended Shanghai Obstetrical Cardiology Intensive Care Center, China, between January 1, 1993 and December 31, 2014. CARPREG and ZAHARA risk scores, and modified WHO (mWHO) risk classification were applied retrospectively. Predictive accuracy was compared by receiver operating characteristic curve analysis.

Results: A total of 730 women were included. The frequency of expected versus observed cardiac events was, respectively, 5.0% versus 7.8%, 27.0% versus 47.1%, and 75.0% versus 75.0% among patients with CARPREG scores of 0, 1, and >1; and 2.9% versus 5.8%, 7.5% versus 36.5%, 17.5% versus 30.8%, 43.1% versus 50.0%, and 70.0% versus 17.6% among those with ZAHARA scores of 0-0.50, 0.51-1.50, 1.51-2.50, 2.51-3.50, and 3.51 or more. For mWHO risk classifications I-IV, the cardiac event rate was 0%, 8.2%, 26.7%, 18.4%, and 15.4%, respectively. The area under the curve was 0.71 (95% confidence interval [CI] 0.67-0.76; P<0.001) for mWHO, 0.68 (95% CI 0.60-0.75; P<0.001) for ZAHARA, and 0.63 (95% CI 0.57-0.71; P=0.001) for CARPREG.

Conclusion: The mWHO risk classification was the best system for predicting cardiac complications among Chinese pregnant women with CHD.

Keywords: Cardiac complications; Congenital heart disease; Pregnancy; Risk score.