Hormone therapy and in-hospital survival after myocardial infarction in postmenopausal women

Background-Although postmenopausal hormone therapy (HRT) commonly is used i n hope of preventing coronary heart disease, the effect of HRT on case fata lity of myocardial infarction has never been studied. We evaluated HRT as a predictor of survival after MI in postmenopausal women. Methods and Results-The present study was performed with 114 724 women of a ge greater than or equal to 55 years with confirmed myocardial infarction w ho presented between April 1998 and January 2000 to I of 1674 hospitals par ticipating in the National Registry of Myocardial Infarction-3. Presenting characteristics, treatment, and clinical outcome data were obtained by char t review. At time of hospitalization, 7353 (6.4%) women reported current us e of HRT, defined as use of estrogen, progestin, or estrogen/progestin for reasons other than contraception. Unadjusted mortality was 7.4% in users of HRT and 16.2% in nonusers (odds ratio 0.41, 95% confidence interval 0.36 t o 0.43). After adjustment's were made for prior medical history, clinical c haracteristics, treatments received in-hospital, and likelihood of receivin g HRT, FIRT remained associated with an improved rate of survival (odds rat io 0.65, 95% confidence interval 0.59 to 0.72). Significant association of HRT with decreased mortality after myocardial infarction was observed in al l age strata. Conclusions-Postmenopausal HRT appears to be associated with reduced mortal ity after myocardial infarction. This finding could be caused by therapeuti c effect of HRT, selection and adherence bias, or sonic combination of both .