Accuracy of risk prediction scores in pregnant women with congenital heart disease

Abstract

Objective: To assess performance of risk stratification schemes in predicting adverse cardiac outcomes in pregnant women with congenital heart disease (CHD) and to compare these schemes to clinical factors alone.Design: Single-center retrospective study.Setting: Tertiary care academic hospital. Patients: Women ≥18 years with International Classification of Diseases, NinthRevision, Clinical Modification codes indicating CHD who delivered between 1998 and 2014. CARPREG I and ZAHARA risk scores and modified World Health Organization (WHO) criteria were applied to each woman. Outcome Measures:The primary outcome was defined by ≥1 of the following: arrhythmia, heart failure/pulmonary edema, transient ischemic attack, stroke, dissection, myocardial infarction, cardiac arrest, death during gestation and up to 6 months postpartum. Results:Of 178 women, the most common CHD lesions were congenital aortic stenosis (15.2%), ventricular septal defect (13.5%), atrial septal defect (12.9%), and tetralogy of Fallot (12.9%). Thirty-five women (19.7%) sustained 39 cardiac events.Observed vs expected event rates were 9.9% vs 5% (P = .02) for CARPREG I score 0 and 26.1% vs 7.5% (P < .001) for ZAHARA scores 0.51-1.5. ZAHARA outperformed CARPREG I at predicting adverse cardiovascular outcomes (AUC 0.80 vs 0.72, P = .03) but was not significantly better than modified WHO. Clinical predictors of adverse cardiac event were symptoms (P = .002), systemic ventricular dysfunction (P < .001), and subpulmonary ventricular dysfunction (P = .03) with an AUC 0.83 comparable to ZAHARA (P = .66).Conclusions: CARPREG I and ZAHARA scores underestimate cardiac risk for lower risk pregnancies in these women. Of the three risk schemes, CARPREG I performed least well in predictive capacity. Clinical factors specific to the population studied are comparable to stratification schemes. K E Y W O R D Sadult congenital heart disease, outcomes, pregnancy, risk stratification | 471 KIM et al. | INTRODUC TI ONAs survival of those born with congenital heart disease (CHD) shifts toward adulthood, there are a growing number of females with CHD who reach childbearing age. From 1998 to 2007, the proportion of hospitalizations for delivery increased by 34.9% in women with CHD compared to 21.3% in the female general population. 1 Pregnancy outcomes for women with CHD can be highly variable and pose special challenges for congenital cardiovascular specialists and high-risk obstetricians who are tasked with counseling these women and managing them throughout pregnancy, delivery, and postpartum period. Risk stratification schemes predicting adverse outcomes in pregnant women with CHD have been published 2-6 with variable accuracy. 7-12 The objectives of this study were (1) to assess the performance of CARPREG I, ZAHARA, and the modified World Health Organization (WHO) classification in predicting adverse cardiovascular outcomes in women with CHD at a single tertiary care center with an established adult CHD program in an urban North American setting and (2) to compare the...

Comparison of risk stratification models for pregnancy in congenital heart disease

“…Based on the ratio of observed to estimated number of events, the ZAHARA risk model provided the most accurate risk estimate of maternal complications in our study population. Our findings differ from conclusions of other similar studies [11][12][13][14]21], but these studies did not only include CHD patients. The ESC guidelines 2018 on pregnancy indicated that the mWHO classification is considered the best model for the estimation of maternal cardiac risk [5].…”

“…Maternal adverse cardiac events occurred in 8% of our study population, which is similar to the incidence of the cardiac events reported in other studies [7][8][9][11][12][13][14][15][16][17][18][19][20]. There is a certain variation of event rates among different studies, ranging from 6.7 to 25%, which is likely due to the heterogeneity of the study populations.…”

Cardiac Complications during Pregnancy Related to Parity in Women with Congenital Heart Disease

“…Of the 77 women with cardiac disease in that study, 9% had cardiac complications during the first pregnancy and 6% had cardiac complications during the second pregnancy; the difference was not statistically significant. We found that the CARPREG I and mWHO risk scores were associated with higher OR of cardiac complications with higher scoring as described previously [14]. There was no clear signal indicating that parity per se was associated with a higher risk of having a cardiac complication during subsequent pregnancies, which is valuable information in prepregnancy counselling (Table 3).…”

Validación de los modelos de predicción de desenlaces cardiacos adversos CARPREG II (Cardiac Disease in Pregnancy) y clasificación modificada de la Organización Mundial de la Salud (OMS) en gestantes con cardiopatía

“…El riesgo de complicaciones durante el embarazo depende de factores como el tipo de enfermedad cardiaca, la función ventricular y valvular, la clase funcional, la presencia de cianosis, la presión de la arteria pulmonar, las comorbilidades. Por otra parte, se han publicado múltiples esquemas para la estratificación del riesgo con exactitud variable en el nivel de predicción 4 . Estos predictores y las puntuaciones de riesgo son herramientas que deben ser usadas teniendo en cuenta la información específica de la enfermedad cardiaca y la condición clínica de cada paciente 5 .…”