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.

A Novel Inhibitor of Protease-activated Receptor 1: A Review of Chemical Structure and Mode of Action.

Limitations of current antiplatelet therapies have led to the discovery of new antiplatelet agents with new modes of action. Vorapaxar has been developed as a thrombin receptor antagonist. This drug works against the protease-activated receptor 1 (PAR1) and inhibits platelet aggregation mediated by PAR1. This article reviews this new class of antiplatelet therapy in detail with an acute focus on the TRACER (Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome) and TRA 2°P-TIMI 50 (Trial to Assess the Effects of Vorapaxar in Preventing Heart Attack and Stroke in Patients With Atherosclerosis-Thrombolysis In Myocardial Infarction 50) trials. Vorapaxar has proven to be beneficial when administered to stable atherosclerotic patients. However, it has been shown to increase risk of intracranial hemorrhage in patients with known, previous history of cerebrovascular incidence. Despite these limitations, TRA 2°P-TIMI 50 results showed that vorapaxar appears to have a definitive therapeutic benefit when administered alongside aspirin or when it is used as an addition to dual antiplatelet therapy for patients with stable atherosclerosis.