Women who develop hypertensive disorders of pregnancy (HDOP) in their first delivery have a significantly increased cause-specific hazard ratio (csHR) of incident atrial fibrillation (AFib) compared with women who do not, according to a study published Feb. 11 in Circulation.

Amy Johnston, PhD, CPH, et al., conducted a population-based retrospective cohort study of 771,521 women discharged from hospitals in Ontario, Canada, after delivery of their first live or stillborn singleton infant between 2002 and 2017. The authors obtained data from record-level, coded, population-based administrative databases that were linked and analyzed at the Institute for Clinical Evaluative Sciences.

The primary outcome was the association between exposure to any HDOP and subsequent incident AFib using a competing risks analytic framework. Patients were followed until they had an incident AFib diagnosis, died, were no longer eligible for the Ontario Health Insurance Program or at the end of study follow-up (Dec. 31, 2019), whichever came first.

Results showed that about 8% of women were diagnosed with HDOP. Over the 7,380,304 total person-years of follow-up, 2,483 patients (0.3%) had incident AFib and 2,951 (0.4%) died. The adjusted csHR associated with a history of any HDOP was 1.45 (95% CI, 1.28-1.64) for incident AFib and 1.31 (95% CI, 1.16-1.47) for death without a previous AFib diagnosis. The median time to event was seven years, and the associations were observed in relatively young women.

A dose-response relationship was suggested, with more severe HDOP subtypes and pre-pregnancy chronic hypertension associated with a 1.5- to 2.2-times higher cause-specific rate of AFib and a 1.4- to 2.1-times higher cause-specific rate of death compared with no HDOP.

The authors note that closer monitoring for early detection of AFib may be beneficial in women with an HDOP, especially in those with chronic hypertension before pregnancy. "Enhanced population-based surveillance of, and targeted strategies to prevent, [HDOP] as a female-specific cardiovascular risk factor are needed to mitigate intermediate- and long-term cardiovascular disease risk associated with these adverse pregnancy conditions," they write.