[Risk factors analysis and prediction model construction of major adverse cardiovascular events in pregnant women with valvular heart disease].

Objective: To analysis the risk factors for major adverse cardiovascular event (MACE) in pregnant women with valvular heart disease (VHD) and to construct a risk prediction model. Methods: The clinical data of 245 pregnant women with VHD who were hospitalized in Beijing Anzhen Hospital from January 1, 2012, to June 1, 2023 were retrospectively analyzed, including general information, pre-pregnancy and pregnancy-associated cardiac conditions, and MACE. Univariate analysis and logistic regression models were employed to identify risk factors for MACE during pregnancy among pregnant women with VHD. Furthermore, a predictive model was constructed and internal validation was conducted using bootstrap techniques. Results: (1) Among 245 pregnant women with VHD, the incidence of MACE was 18.0% (44/245), and the most common MACE was heart failure (61.4%, 27/44). The mitral valve was the most frequently affected valve (64.9%, 159/245). Prior to pregnancy, the most common type of valve surgery undertaken was mechanical valve replacement, representing 31.4% (77/245) of surgeries. In contrast, among those pregnant women who did not undergo valve surgery before pregnancy, the most common lesion type was mitral regurgitation (17.6%, 43/245). (2) Comparing the maternal and infant outcomes of warfarin, low molecular weight heparin (LMWH) and LMWH sequential with warfarin, the fetal loss rate (36%, 15/42) and malformation rate (7%, 3/42) were the highest, but the MACE rate (12%, 5/42) was the lowest in warfarin group. The fetal loss rate (1/19), malformation rate (1/19) and artificial valve thrombosis rate (0) of LMWH sequential with warfarin were the lowest, and the fetal loss rate and artificial valve thrombosis rate of the three anticoagulation methods were statistically significant (all P<0.05). (3) There were no significant differences in gestational age, age of diagnosis of heart disease, weight at delivery, pre-pregnancy body mass index, proportion of multiparous women and chronic medical history between women with MACE and those without MACE (all P>0.05). (4) Binary logistic regression analysis identified the following as risk factors for MACE during the second trimester of pregnancy among pregnant women with VHD: pre-pregnancy cardiac symptoms, history of corrective surgery for congenital heart disease, pregnancy risk grade Ⅴ, anticoagulation with LMWH during pregnancy, and arrhythmia (all P<0.05). Based on the results of multivariate analysis, a receiver operating characteristic curve was constructed, with an area under the curve of 0.837, indicating good discriminative ability. The calibration plot demonstrated a close alignment between the standard curve and the calibration prediction curve, suggesting excellent calibration of the model. Conclusions: Pregnant women with VHD are at a high risk of experiencing MACE during gestation. Five risk factors, including pre-pregnancy cardiac symptoms, history of corrective surgery for congenital heart disease, pregnancy risk grade Ⅴ, anticoagulation with LMWH, and arrhythmia, could aid in identifying high-risk pregnant women.