cangrelor and Coronary-Restenosis

New P2Y12 inhibitors can be classified as oral (prasugrel and ticagrelor) and intravenous drugs (cangrelor and elinogrel). These P2Y12 inhibitors might be superior to clopidogrel for reducing ischemic events in patients with coronary artery disease (CAD). We performed a meta-analysis of randomized trials that compared new oral or intravenous P2Y12 inhibitors with clopidogrel to determine their efficacy and safety in patients.. Twelve randomized, placebo-controlled studies and two subgroup analyses of included studies on ST-segment elevation myocardial infarction (STEMI) were included. The database consisted of 82,784 patients, with 43,875 (53%) on new oral P2Y12 inhibitors and 38909 (47%) on intravenous P2Y12 inhibitors compared with clopidogrel. The primary efficacy endpoint was major adverse cardiac events (MACEs). The primary safety endpoint was thrombolysis in myocardial infarction (TIMI) major bleeding. New oral P2Y12 inhibitors significantly decreased MACEs (odds ratio: 0.85, p<0.0001 for the whole cohort; OR: 0.77, p=0.04 for STEMI) and all-cause death (OR: 0.88, p=0.04 for the whole cohort; OR: 0.77, p=0.01 for STEMI). Among new intravenous P2Y12 inhibitors, only cangrelor significantly decreased the risk of MACEs. An increase in TIMI major bleeding was observed only by prasugrel among the new P2Y12 inhibitors.. New oral P2Y12 inhibitors reduce ischemic events, but there is no obvious increase in major bleeding in patients with CAD, and the risk/benefit ratio is particularly favorable for STEMI patients. Moreover, only cangrelor is beneficial for ischemic events in patients on new intravenous P2Y12 inhibitors.

Topics: Acute Coronary Syndrome; Adenosine; Adenosine Monophosphate; Administration, Oral; Clopidogrel; Coronary Artery Disease; Coronary Restenosis; Fibrinolytic Agents; Hemorrhage; Humans; Injections, Intravenous; Multicenter Studies as Topic; Myocardial Infarction; Piperazines; Prasugrel Hydrochloride; Purinergic P2Y Receptor Antagonists; Quinazolinones; Randomized Controlled Trials as Topic; Stents; Stroke; Sulfonamides; Thiophenes; Thrombolytic Therapy; Ticagrelor; Ticlopidine

The efficacy with aspirin and clopidogrel treatment has been demonstrated in various clinical trials. Laboratory evaluation of platelet response in recent studies revealed that a distinctive response variability and nonresponsiveness/resistance in selected patients were associated with these antiplatelet agents. Moreover, some studies have correlated this nonresponsiveness/resistance phenomenon to the occurrence of thrombotic events. At this time there are no uniformly established methods to quantify exvivo platelet reactivity after clopidogrel and aspirin treatment of the extent of platelet inhibition by clopidogrel and aspirin. Therefore, specific treatment recommendations for patients exhibiting high platelet reactivity or poor platelet inhibition during clopidogrel or aspirin therapy are not established. A higher aspirin dose and strict compliance to therapy may overcome the occurrence of "aspirin resistance" in selected patients. A higher clopidogrel dose may be considered in patients exhibiting clopidogrel nonresponsiveness.

Topics: Adenosine; Adenosine Monophosphate; Angioplasty, Balloon, Coronary; Aspirin; Clinical Trials as Topic; Clopidogrel; Coronary Restenosis; Drug Resistance; Humans; Membrane Proteins; Myocardial Ischemia; Piperazines; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Purinergic P2 Receptor Antagonists; Receptors, Purinergic P2Y12; Thiophenes; Ticagrelor; Ticlopidine

Topics: Adenosine Monophosphate; Clopidogrel; Coronary Restenosis; Coronary Stenosis; Coronary Thrombosis; Double-Blind Method; Hemorrhage; Humans; Multicenter Studies as Topic; Myocardial Infarction; Myocardial Revascularization; Percutaneous Coronary Intervention; Platelet Aggregation Inhibitors; Purinergic P2Y Receptor Antagonists; Randomized Controlled Trials as Topic; Stents; Ticlopidine

Reperfusion therapy for myocardial infarction is limited by a significant reocclusion rate and less optimal myocardial tissue perfusion due to excessive platelet accumulation and recruitment at the sites of vascular injury. We assessed the influence of a selective P2Y(12)-receptor antagonist (AR-C69931MX), in conjunction with thrombolytic therapy, on the prevention of platelet aggregation and thrombus formation.. A canine coronary electrolytic injury thrombosis model was used. Tissue-type plasminogen activator (t-PA; 1 mg/kg in phase I, 0.5 mg/kg in phase II in the AR-C69931MX group, and 1 mg/kg in the placebo group in phase I and II) was administered 30 minutes after thrombus formation; either saline or AR-C69931MX (4 micro g x kg(-1) x min(-1)) was given to all animals intravenously 10 minutes before t-PA administration for a total of 2 hours. All animals received heparin (80 U/kg) as an intravenous bolus followed by a continuous infusion of 17 U x kg(-1) x h(-1). Myocardial tissue perfusion was evaluated by use of the colored microsphere technique and real-time myocardial contrast echocardiography. The incidences of reocclusion and cyclic flow variation were significantly decreased in the AR-C69931MX group (P<0.05). Myocardial tissue flow with AR-C69931MX treatment improved significantly at 20 and 120 minutes after reflow, whereas tissue flow with placebo remained at a level similar to that during occlusion (P<0.05).. The adjunctive administration of AR-C69931MX blocked ADP-mediated platelet aggregation and recruitment and prevented platelet-mediated thrombosis, resulting in prolongation of reperfusion time and a decrease in reocclusion and cyclic flow variations. Importantly, myocardial tissue perfusion was significantly improved in the P2Y(12) antagonist group.

Topics: Adenosine Monophosphate; Angioplasty, Balloon, Coronary; Animals; Bleeding Time; Blood Coagulation; Coronary Circulation; Coronary Restenosis; Coronary Stenosis; Disease Models, Animal; Dogs; Drug Combinations; Echocardiography; Female; Heparin; Infusions, Intravenous; Male; Membrane Proteins; Myocardial Infarction; Myocardial Reperfusion; Platelet Aggregation; Platelet Aggregation Inhibitors; Purinergic P2 Receptor Antagonists; Receptors, Purinergic P2; Receptors, Purinergic P2Y12; Thrombosis; Tissue Plasminogen Activator