Statin therapy in the heart and estrogen/progestin replacement study

Limited data exists to guide secondary prevention in postmenopausal women with coronary heart disease (CHD). Treatment with HMG-CoA reductase inhibitors (statins) is likely to be beneficial for these patients. Yet, clinical trial results are conflicting. Moreover, significant interactions may exist between statins and hormone replacement therapy (HRT) that may complicate this approach.

In a post hoc analysis of the HERS trial, patients who were taking a statin were compared to those who were not. Subjects were randomized to HRT or placebo. Statin therapy was not controlled by the trial investigators, but may have been prescribed by the patients' primary physicians. Use of statins was monitored throughout the trial. The primary outcome was the composite of myocardial infarction and death resulting from CHD, with all-cause mortality and venous thromboembolism (VTE) as secondary outcome measures.

At baseline, 1004 subjects were taking a statin, with 1234 subjects randomized to receive HRT, and 1237 to receive placebo. Baseline statin use was associated with lower rates of the primary outcome (MI or fatal CHD, RH=0.78, 95% CI 0.61 to 0.99, p=0.044), and all-cause mortality (RH=0.74, 95% CI 0.56 to 0.99, p=0.04). Statin therapy was associated with a reduced incidence of VTE in both the HRT group and the placebo arm. The negative effect of HRT on the primary outcome seen in the 1st year of treatment was much reduced among baseline statin users and was no longer statistically significant (RH=1.34, 95% CI 0.63 to 2.86, p=0.45).

Data from HERS supports the use of statins for secondary prevention in postmenopausal women with a history of cardiovascular disease. Statins may attenuate the increased cardiovascular risk of hormone replacement therapy.