Causes and predictors of maternal mortality in pregnant women with heart disease: data from the Brazilian Pregnancy and Heart Disease Registry (REBECGA-Trial)

Abstract Introduction Heart disease, affecting approximately 4% of pregnancies, is the leading non-obstetric cause of maternal mortality. It is estimated that 40% of these deaths could be prevented by both stratifying pregnancy-related risks and knowledgement about the significant number of deaths that occur postpartum. Objectives To study maternal mortality during pregnancy, as well as both immediate and late mortality in women with heart diseases, and to analyze the predictive factors for these deaths. Methods A multicenter, retrospective Brazilian study on maternal mortality—including causes and predictive factors—was conducted with 638 women (mean age 30.4 ± 7.3 years) with heart diseases, followed during pregnancy and up to 12 months postpartum. The conditions were categorized as valvular heart disease (37.8%), congenital heart disease (35.7%), arrhythmias without structural cardiac lesions (14.7%), cardiomyopathies (11.3%), and other cardiac diseases (6.4%). The variables considered to predictive analysis were: 1) maternal age; 2) World Health Organization classification ( mWHO); 3) NYHA functional class (FC); 4) baseline diagnosis of the cardiac disease; and 5) complicating factors of the underlying disease (ventricular dysfunction, pulmonary hypertension, hypoxemia, atrial fibrillation, residual lesions after interventions, and prosthetic valve dysfunction). Immediate and late maternal mortality were defined as occurring within 42 days and up 12 months postpartum, respectively. Logistic regression analysis was used to assess the predictive variables related to maternal mortality. Results Eighteen (2.8%) maternal deaths were recorded: three (16.6%) during pregnancy, 10 immediate deaths (55.5%), and five (27.7%) late deaths. Four cases of COVID-19 infection preceded maternal death (cases 8, 9, 10, and 14). Three emergency procedures were performed in an attempt to mother´s survival: 1) aortic dissection repair (case 13); 2) mitral valve intervention, one with cardiopulmonary bypass and the other transcatheter valve-in-valve, both due to bioprosthetic valve calcification (cases 10 and 12). ( Table 1) Multivariate analysis identified mWHO class IV (OR 3.51; 95% CI 1.75–7.04; p0.001), NYHA FC III/IV (OR 2.27; 95% CI 1.12–4.60; p=0.023), and pulmonary hypertension (OR 2.45; 95% CI 1.05–5.70; p=0.037) as predictive variables for maternal deaths (Figure 1). Conclusions This study highlighted heart failure as the leading maternal complication, identified the postpartum period as a critical time for maternal deaths, and recognized the WHO classification, NYHA FC, and pulmonary hypertension as key predictors of maternal mortality. All of these factors should be considered for pregnancy counseling in women with heart disease.Description of maternal deaths Predictors of maternal deaths