Prognosis after maternal placental events and revascularization: PAMPER study

Background: Middle-aged women are at higher risk than men of death after coronary artery revascularization. Maternal placental syndromes (gestational hypertension, preeclampsia, placental abruption, and placental infarction) are associated with premature coronary artery disease, but their influence on survival after coronary artery revascularization is unknown.

Objective: The purpose of this study was to determine whether a history of maternal placental syndromes alters the risk of death after coronary artery revascularization in middle-aged women.

Study design: We completed a population-based retrospective cohort study among all hospitals in Ontario, Canada, where universal health care includes all aspects of antenatal and delivery care as well as all outpatient and inpatient health care, which includes coronary revascularization. We included 1985 middle-aged women who underwent a first percutaneous coronary intervention or coronary artery bypass grafting between 1993 and 2012 and who had ≥1 previous delivery. We excluded those with cardiovascular disease ≤1 year before or coronary revascularization ≤90 days after any delivery. The main study outcome, determined a priori, was all-cause death. Hazard ratios were adjusted for age, socioeconomic status, parity, revascularization type, time since last delivery, hypertension, diabetes mellitus, obesity, dyslipidemia, tobacco or drug dependence, and kidney disease.

Results: Three hundred sixty-two of 1985 women (18.2%) who underwent coronary artery revascularization had a previous maternal placental syndrome event. The mean age at index coronary revascularization was 45 years; percutaneous coronary intervention comprised approximately 80% of procedures. After a mean follow-up time of approximately 5 years, 41 deaths (2.2 per 100 person-years) occurred in women with previous maternal placental syndromes and 83 deaths (1.1 per 100 person-years) in women without maternal placental syndrome (adjusted hazard ratio, 1.96; 95% confidence interval, 1.29-2.99). Of the maternal placental syndrome subtypes, the risk of death was significant in women with placental abruption (adjusted hazard ratio, 2.79; 95% confidence interval, 1.31-5.96), placental infarction (adjusted hazard ratio, 3.09; 95% confidence interval, 1.23-7.74), and preeclampsia (adjusted hazard ratio, 1.61; 95% confidence interval, 1.00-2.58). Women with maternal placental syndrome in ≥2 pregnancies had the highest adjusted hazard ratio of death (4.31; 95% confidence interval, 1.71-10.89).

Conclusion: In middle-aged women who undergo coronary revascularization, previous maternal placental syndrome doubles the risk of death; recurrent maternal placental syndrome quadruples that risk. Some covariates and secondary measures may not have been well-captured and classified herein, leading to residual confounding.