Comparing the outcomes of rheumatic heart disease in pregnancy complicated with and without atrial fibrillation: A propensity score matched analysis.

Background: Atrial fibrillation (AF) may increase the risk of adverse maternal and fetal outcomes among pregnant with rheumatic valvular lesions (RHD). We aimed to assess the rate of occurrence of AF in pregnant with RHD and its impact on cardiac and maternal-fetal outcomes compared to those without it.

Methods: The study group consisted of pregnant women with RHD and AF (cases) and a matched comparison group of pregnant women with RHD but without AF (controls) was derived from the database of pregnant women with RHD receiving care at our center between 2011 and 2021. Incidence of composite adverse outcomes(maternal death, heart failure, or thrombo-embolic events) and pregnancy outcomes were compared between them.

Results: Seventy-one (5.1%; 95%CI 4.1%-6.4%) pregnant women with RHD had AF during pregnancy and childbirth, most occurring in the late second or early third trimester. New-onset AF was diagnosed in 34 (47.9%) of them. After matching, the incidence of composite outcome was higher in women with AF (77.5% (95%CI 66.3%-85.7%) compared to women without AF (17.3%(95%CI 13.3%-22.1%), P < .001), with seven (9.9%) maternal deaths among cases and two (0.7%) in controls. Heart failure was the most common adverse cardiac event (26.7% vs. 4.2%, P < .001, cases vs controls). Those with AF had higher odds (adjusted OR 56.6 (14.1-226.8)) of adverse cardiac outcomes after adjusting for other risk factors. The frequency of most non-cardiac pregnancy complications was similar in both groups. However, there was a trend towards a higher rate of miscarriage (16.9% vs. 9.9%), small-for-gestational-age babies(16.3 vs. 9.0%), and cesarean rates(31.9% vs. 18.3%) women with AF compared to those who did not experience AF.

Conclusions: Atrial fibrillation in pregnancy among women with RHD was associated with an increased risk of maternal morbidity and mortality, with a trend towards an increase in some non-cardiac pregnancy complications compared to those pregnant women without AF. Our study results provide background data for developing and implementing a pregnancy-specific management strategy tailored to middle-income settings.