Background — Middle aged women are at higher risk than men of death following coronary artery revascularization. Maternal placental syndromes (MPS) - gestational hypertension, preeclampsia, placental abruption and placental infarction - are associated with premature coronary artery disease, but their influence on survival following coronary artery revascularization is unknown.
Objective — To determine whether a history of MPS alters the risk of death following 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 healthcare includes all aspects of antenatal and delivery care, as well as all outpatient and inpatient healthcare, including coronary revascularization. We included 1985 middle aged women who underwent a first percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) between 1993 and 2012, and who had ≥ 1 prior 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 mortality. Hazard ratios (aHRs) 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 — 362 of 1985 women (18.2%) who underwent coronary artery revascularization had a prior MPS event. The mean age at index coronary revascularization was 45 years; PCI comprised about 80% of procedures. After a mean follow-up of about 5 years, 41 deaths (2.2 per 100 person-years) occurred in women with prior MPS and 83 deaths (1.1 per 100 person-years) in women without MPS (aHR 1.96, 95% CI 1.29-2.99). Of the MPS sub-types, the risk of death was significant in women with placental abruption (aHR 2.79, 95% CI 1.31 to 5.96) and placental infarction (aHR 3.09, 95% CI 1.23 to 7.74), and those with preeclampsia (aHR 1.61, 95% CI 1.00 to 2.58). Women with MPS in ≥ 2 pregnancies had the highest aHR of death (4.31, 95% CI 1.71 to 10.89).
Conclusion — In middle aged women who undergo coronary revascularization, previous MPS doubles the risk of death, and recurrent MPS quadruples that risk. Some covariates and secondary measures may not have been well captured and classified herein, leading to residual confounding.