Cardiovascular events more than 6 months after pregnancy in patients with congenital heart disease

Patients with congenital heart disease (CHD) are increasingly pursuing pregnancy, highlighting the need for data on late cardiovascular events (more than 6 months after delivery). We aimed to determine the incidence of late cardiovascular events in postpartum patients with CHD and evaluate the accuracy of the existing risk scores in predicting these events.

We identified patients with CHD who delivered between 2008 and 2020 at a tertiary centre and had follow-up data for greater than 6 months post partum. Late cardiovascular events were defined as heart failure, arrhythmia, thromboembolic events, endocarditis, urgent cardiovascular interventions or death. Survival analysis and Cox proportional model were used to estimate the incidence of late cardiovascular events and determine the hazard ratio of factors associated with these events.

Of 117 patients, 19% had 36 late cardiovascular events over a median follow-up of 3.8 years. Annual incidence of any late cardiovascular event was 5.7%. Hazards of late cardiovascular events were significantly higher among those with higher Cardiac Disease in Pregnancy Study (CARPREG) II and Zwangerschap bij Aangeboren HARtAfwijking-Pregnancy in Women With Congenital Heart Disease (ZAHARA) risk scores and among patients with prepregnancy New York Heart Association class≥II. C-statistic to predict the late cardiovascular events was highest for ZAHARA (0.7823), followed by CARPREG II (0.6902) and prepregnancy New York Heart Association class≥ II (0.6677).

Currently available risk tools designed for prognostication during the peripartum period can also be used to determine risks of late maternal cardiovascular events among those with CHD. These findings provide important new information for counselling and risk modification.