Aspirin reduces long-term stroke risk in women with prior hypertensive disorders of pregnancy

Objective To determine whether hypertensive disorders of pregnancy (HDP) increased long-term stroke risk in women in the California Teachers Study (CTS), a prospective cohort study, and whether aspirin or statin use modified this risk. Methods CTS participants <= 60 years of age at the time of enrollment in 1995 were followed up prospectively for validated stroke outcomes obtained via linkage with California hospital records through December 31, 2015. We calculated unadjusted and adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the primary outcomes of all stroke and stroke before 60 years of age among those with and without a history of HDP. We tested for interactions (p < 0.2) and performed stratified analyses to assess the risk of the primary outcomes in women with and without self-reported use of aspirin or statins. Results Of 83,749 women included in the analysis, 4,070 (4.9%) had HDP. Women with prior HDP had increased risk of all stroke (adjusted HR 1.3, 95% CI 1.2-1.4) but no increased risk of stroke before age 60 (adjusted HR 1.2, 95% CI 0.9-1.7). There was an interaction (p = 0.18) between aspirin use and HDP history on risk of stroke before age 60: nonusers of aspirin had higher risk (adjusted HR 1.5, 95% CI 1.0-2.1) while aspirin users did not (adjusted HR 0.8, 95% CI 0.4-1.7). This effect was not seen with statins. Conclusions After controlling for comorbid conditions, women with prior HDP had increased long-term stroke risk, which was reduced by aspirin use. Randomized trials may be needed to assess whether long-term aspirin use could benefit selected women with a history of HDP.