View clinical trials related to Antiplatelet Therapy.
Filter by:This study will include the subjects who enrolled in DACAB trial (NCT02201771) to observe clinical outcomes 5 years after coronary artery bypass grafting（CABG）. The primary objective is to compare the occurrence of MACE-4 ( a composite of all-cause death, myocardial infarction, stroke, and coronary revascularization) among 3 randomized regimens (T+A, T alone, A alone) in previous DACAB trial within 5 years after CABG. The secondary objectives are to compare the occurrence of MACE-5( a composite of all-cause death, myocardial infarction, stroke, coronary revascularization and hospitalization for unstable angina); MACE-3 ( a composite of cardiovascular death, myocardial infarction, and stroke); all-cause death; cardiovascular death; myocardial infarction; stroke; coronary revascularization; hospitalization for unstable angina and grafts patency rate among 3 randomized regimens in previous DACAB trial within 5 years after CABG. The exploratory objectives are to compare the occurrence of MACE-4; MACE-5; MACE-3; all-cause death; cardiovascular death; myocardial infarction; stroke; coronary revascularization and hospitalization for unstable angina between 2 cohorts with or without grafts/vein grafts failure at 1 year angiographic follow-up.
About 35% of patients hospitalized with Acute Coronary Syndromes (ACS) have some degree of renal dysfunction. Chronic kidney disease (CKD) is not only associated to worse prognosis in ACS patients, but leads also to an increased risk of bleeding, which may importantly influence the risk-benefit ratio of antiplatelet therapy in this population. The responsible mechanisms for increased rate of ischemic events in this population are not completely elucidated. Antiplatelet therapy is of paramount importance in the treatment of ACS, but its benefit in CKD patients is not well established. This population is often excluded or underrepresented in large clinical trials, and the indication of antiplatelet therapy is often extrapolated from studies in patients with preserved renal function. In recent meta-analysis, Palmer et al. sought to evaluate the benefits and risks of antiplatelet agents in patients with CKD and concluded that in patients with ACS or scheduled for angioplasty already taking aspirin, the addition of clopidogrel or glycoprotein IIb / IIIa inhibitors have little or no impact in reducing the incidence of myocardial infarction, death or need for revascularization. In the PLATO trial, ticagrelor (a new reversible inhibitor of P2Y12 receptor with faster onset of action and greater platelet inhibition) was compared to clopidogrel in patients with high risk ACS and was associated to a 16% risk reduction on the occurrence of death from vascular causes, myocardial infarction, or stroke. In a pre-specified sub-analysis, data from patients with CKD were compared to those obtained from the population with normal renal function and suggests that the benefit of ticagrelor may be even greater in patients with CKD. Two hypotheses were considered to explain these results: 1. Greater and more consistent platelet inhibition achieved with ticagrelor would be more effective in reducing ischemic events in this population at increased thrombotic risk; 2. Pleiotropic effects of ticagrelor besides inhibition of the P2Y12 receptor. Ticagrelor might be associated with an elevation in serum levels of adenosine. This could improve myocardial perfusion through coronary vasodilation, and this effect would be more pronounced in patients with renal dysfunction. This project aims to validate (or not) these hypotheses, analyzing platelet aggregation and circulating adenosine levels in patients taking dual antiplatelet therapy with aspirin and clopidogrel or ticagrelor.
The main objective of the project is to assess the long-term prognostic impact of residual platelet reactivity after optimal antiplatelet therapy in a large cohort of patients with acute coronary syndrome undergoing invasive strategy. Follow-up length will be at least 24 months. The primary end-point of the study will be a composite of death, myocardial infarction, urgent target vessel revascularization, stent thrombosis or stroke.
Background: Dual antithrombotic treatment with aspirin and clopidogrel is recommended in patients with ST elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). The European Society of Cardiology (ESC) Guidelines recommend a bolus dose of aspirin of 250-500 mg and a 600 mg bolus dose of clopidogrel as soon as STEMI is suspected. Studies have shown that more newly produced platelets are present in the acute phase of STEMI, and it is likely that these immature platelets are haemostatically more active and might be of importance in thrombus formation. The enhanced platelet reactivity may reduce the effect of aspirin and clopidogrel in the acute phase of STEMI compared to measurements made in the same patients 3 months after primary PCI. Aim: This study aims to compare platelet response to aspirin and clopidogrel in the acute phase of STEMI with the platelet response in the same patients 3 months after STEMI . Design: This study is an observational follow-up study. Materials and methods: 46 patients with STEMI referred to primary PCI at Aarhus University Hospital, Skejby will be included in the study. A total of 3 blood samples are obtained in the acute phase of STEMI: Prior to primary PCI (Blood sample 1), at 4 hours (Blood sample 2) and at 12 hours (Blood sample 3) after administration of loading dose aspirin and clopidogrel. When patients are in a stable phase 3 month later, a final blood sample is taken (Blood sample 4). The blood is analyzed 30 minutes after withdrawal of blood by the platelet aggregation test Multiplate® aggregometry (agonists: Collagen, arachidonic acid and adenosinediphosphate) and VerifyNow® arachidonic acid and P2Y12 aggregometry. Platelet count, volume and the immature platelet fraction (IPF) will be measured using Sysmex® flowcytometry.