The effects of estrogen and hormone replacement therapy on platelet activity: a review.

Many studies have shown that an increase in cardiovascular disease in women is related to hormonal changes occurring particularly after menopause with increasing age. While the results of large clinical trials reporting no benefit of hormone replacement therapy (HRT) in cardiovascular disease have been known for some time, there is an increasing body of knowledge regarding the various mechanisms by which estrogen modulates platelet function that could in part explain the higher cardiovascular risk occurring in postmenopausal women and potential benefits of HRT on cardiovascular health. Our review summarizes our current knowledge regarding the effect of endogenous and exogenous estrogen on platelet activity, which can help researchers design future studies. We collected information from 21 peer-reviewed articles published from 1993 to 2021. Studies have indicated that postmenopausal women have higher platelet activity than premenopausal women, which can increase the risk of thrombo-embolic events and cardiovascular disease. Although some studies have reported pro-thrombotic effects of estrogen replacement therapy such as increased platelet activation and adhesion, other studies demonstrated decreased platelet aggregation by inhibiting GP IIb/IIIa receptor expression. This is mediated by estrogen receptors on the platelet membrane in a non-genomic manner and suggests an opportunity for the usage of estrogen replacement therapy with subtle changes in the formulation and route, particularly if started early after menopause. The effect of estrogen on platelet activity is promising as an important factor in reducing the risk of cardiovascular events, warranting further investigation.

The effects of estrogen and hormone replacement therapy on cardiovascular systems.

Postmenopausal women have an increased risk of cardiovascular disease, which is believed to correlate with lower estrogen level. There are conflicting data regarding hormone replacement therapy (HRT) based on the timing of this therapy. After large randomized trials showed no cardiovascular benefit of hormone replacement, estrogen replacement therapy was dramatically reduced even though starting hormone replacement in early postmenopausal period had shown significant benefit. There are hardly any reviews discussing in detail the effect of HRT on cardiovascular system while briefly discussing other effects of this therapy in postmenopausal women. The novelty of this review is the comprehensive discussion of this effect that can help researchers and clinicians to design future research or trials. In this manuscript, the effect of HRT on cardiovascular system in clinical trials and basic science will be reported and potentially erroneous conclusions drawn by various studies will be discussed. Furthermore, various noncardiovascular effect of HRT will be analyzed.

Mortality trends for non-ST-segment elevation myocardial infarction (NSTEMI) in the United States from 1988 to 2004.

BACKGROUND: Non-ST-segment myocardial infarction (NSTEMI) is one of the major causes of hospital admissions. Mortality trend in patients with NSTEMI over the years has not been studied well. The goal of this study is to explore age-adjusted long-term mortality trends from NSTEMI in the United States using a very large database. METHODS: We used the National Inpatient Sample (NIS) database, a component of the Health Care Cost and Utilization (HCUP) project, for this study. International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes were used to identify NSTEMI cases in patients >40 years old. Age-adjusted mortality rates for NSTEMI cases were calculated by multiplying the age-specific mortality rates of NSTEMI by age-specific weights. RESULTS: A total of 1,400,234 patients above the age of 40 years were identified. The mean age of this cohort was 77.1±10.7 years, with a total of 179,361 deaths being reported over this 16-year period. Among patients who died, 51.2% were men and 48.8% were women. The age-adjusted mortality from NSTEMI declined from 1988 (727 per 100,000) to 2004 (305 per 100,000) until the middle of the decade when mortality from NSTEMI started leveling off. Total mortality decreased from 29.6% in 1988 to 11.3% in 2004. CONCLUSIONS: Our analysis showed a significant reduction in the age-adjusted and total mortality for NSTEMI over the years studied. The cause of this trend is not known but most likely reflects advancement in the treatment of patients with acute coronary syndrome.

Trends in the age adjusted mortality from acute ST segment elevation myocardial infarction in the United States (1988-2004) based on race, gender, infarct location and comorbidities.

Treatment of acute ST-segment elevation myocardial infarction (STEMI) has dramatically changed over the past 2 decades. The goal of this study was to determine trends in the mortality of patients with acute STEMIs in the United States over a 16-year period (1988 to 2004) on the basis of gender, race, infarct location, and co-morbidities. The Nationwide Inpatient Sample database was used to analyze the age-adjusted mortality rates for STEMI from 1988 to 2004 for inpatients age >40. International Classification of Diseases, Ninth Revision, Clinical Modification codes consistent with acute STEMI were used. The Nationwide Inpatient Sample database contained a total of 1,316,216 patients who had diagnoses of acute STEMIs from 1988 to 2004. The mean age of these patients was 66.92 +/- 12.82 years. A total of 163,915 hospital deaths occurred during the study period. From 1988, the age-adjusted mortality rate decreased gradually for all acute STEMIs for the entire study period (in 1988, 406.86 per 100,000, 95% confidence interval 110.25 to 703.49; in 2004, 286.02 per 100,000, 95% confidence interval 45.21 to 526.84). Furthermore, unadjusted mortality decreased from 15% in 1988 to 10% in 2004 (p <0.01). This decrease was similar between the genders, among most ethnicities, and in patients with diabetes and those with congestive heart failure. However, women and African Americans had higher rates of acute STEMI-related mortality compared to men and Caucasians over the years studied. In conclusion, age-adjusted mortality from acute STEMIs has significantly decreased over the past 16 years, with persistent higher mortality rates in women and African Americans the study period.