Hormones Inflammation and Thrombosis (HIT2)

The investigators are attempting to determine if the response to aspirin in women is related to the level of estrogen and progesterone that a woman has.

Thrombosis plays a significant role in both acute coronary syndromes (ACS) and early saphenous vein graft (SVG) failure. Women with coronary heart disease have higher levels of the inflammatory mediator thromboxane, which is produced by platelets, monocytes, macrophages and the endothelium. Data show that higher levels of urinary thromboxane (UTXB2) are associated with SVG failure 6 months after Coronary Artery Bypass Graft (CABG). Women in the study cohort had higher levels of UTXB2 and higher odds of graft failure when compared to men. The elevated urinary thromboxane seen in the women in our study cohort may represent a marker and/or an etiology of thrombosis. Are the levels of UTXB2 higher in women due to hormonal differences? In a prior pilot study we investigated whether hormonal levels are associated with changes in urinary thromboxane. We looked at hormonal and urinary thromboxane levels in 48 postmenopausal and 52 premenopausal women. We found that postmenopausal women had higher levels of UTXB2 than did premenopausal women (2495 vs. 2299, p=.02) and that in premenopausal women a higher estrogen/progesterone ratio was associated with the highest levels of urinary thromboxane. The goal of the current study is to measure the response to seven days of aspirin administration as it relates to urinary thromboxane levels in pre and post-menopausal women. With this study we will be able to examine the change in UTXB2 comparing the premenopausal to post menopausal women. We will also be able to see if the change in UTXB2 in response to aspirin is affected by hormone levels in the premenopausal women. Lastly this study will provide reference data for more far-reaching studies exploring how global changes in hormonal balance (as seen in pregnancy or menopause) or in the level of inflammation (as seen in aging or with Coronary Artery Disease (CAD) risk factors), affect UTXB2 and platelet hyperreactivity.

Urinary thromboxane (pg/mg creatinine) will be measured in premenopausal and postmenopausal women at baseline and then after taking on aspirin for 7 days.

Measurement of urinary thromboxane (pg/mg creatinine) in relation to estrogen to progesterone level in premenopausal women on aspirin for 7 days.

Comparing premenopausal women to postmenopausal women, the level of urinary thromboxane (pg/mg creatinine) in response to aspirin

Comparing premenopausal women to postmenopausal women, the level of urinary thromboxane (pg/mg creatinine) in response to aspirin

Inclusion Criteria: Women age 18-80 Signed informed consent. Exclusion Criteria: History of CAD, Cerebrovascular Accident (CVA) or Peripheral Artery Disease (PAD), On chronic aspirin therapy, On chronic NSAID therapy. Chronic anticoagulation with coumadin, Known thrombocytopenia (Platelet count < 100,000), Pregnancy (self-report), Currently on any type of contraceptive or hormone replacement therapy, Hysterectomy and/or oophorectomy. Recent GI bleeding Bleeding diathesis Chronic Systemic Infection