Increased Risk in Patients With High Platelet Aggregation Receiving Chronic Clopidogrel Therapy Undergoing Percutaneous Coronary Intervention Is the Current Antiplatelet Therapy Adequate?

ObjectivesWe sought to determine whether patients receiving chronic clopidogrel therapy undergoing nonemergent stenting who display high on-treatment preprocedural platelet aggregation measured by standard light transmittance aggregometry and thrombelastography (TEG) will be at increased risk for poststenting ischemic events.BackgroundPatients exhibiting heightened platelet reactivity to adenosine diphosphate (ADP) might be at increased risk for recurrent ischemic events after coronary stenting.MethodsA total of 100 consecutive patients receiving chronic antiplatelet therapy consisting of aspirin (325 mg qd) and clopidogrel (75 mg qd) were studied before undergoing nonemergent stenting. Patients were followed for 1 year after coronary stenting for the occurrence of death, myocardial infarction, stent thrombosis, stroke, or ischemia requiring a hospital stay.ResultsAll patients were aspirin responsive. Patients with ischemic events (23 of 100, 23%) within 1 year had greater on-treatment prestent ADP-induced platelet aggregation than patients without ischemic events by aggregometry and TEG (p < 0.001 for both measurements). Of patients with an ischemic event, 70% and 87% displayed high on-treatment platelet reactivity at baseline by aggregometry and TEG, respectively. High on-treatment platelet reactivity as measured by aggregometry and TEG were the only variables significantly related to ischemic events (p < 0.001 for both assays). The administration of eptifibatide reduced periprocedural elevation in platelet reactivity, with no significant differences in bleeding events.ConclusionsPatients receiving chronic clopidogrel therapy undergoing nonemergent percutaneous coronary intervention who exhibit high on-treatment ADP-induced platelet aggregation are at increased risk for postprocedural ischemic events. These findings might have implications for the alteration in clopidogrel maintenance dose and use of glycoprotein IIb/IIIa inhibitors in selected patients

Acetylsalicylic acid and clopidogrel hyporesponsiveness following acute coronary syndromes

This review discusses the response variability to acetylsalicylic acid (ASA) and particularly to clopidogrel, and their relation to adverse recurrent ischaemic events in patients with arterial diseases. The higher rate of ASA resistance reported in the literature may be mainly due to the cyclooxygenase-1 non-specific assays, non-compliance, and underdosing. Clopidogrel response variability and non-responsiveness are established concepts. Moreover, high platelet reactivity (HPR) to adenosine diphosphate during clopidogrel therapy is now a known risk factor for recurrent ischaemic events in high-risk percutaneous coronary intervention/acute coronary syndrome patients. Variable active metabolite generation is the primary explanation for clopidogrel response variability and non-responsivenes. Variable levels of active metabolite generation following clopidogrel administration could be mainly explained by functional variability in hepatic cytochrome (CYP)P450 isoenzyme activity that is influenced by drug–drug interactions and single nucleotide polymorphisms of specific genes encoding CYP450 isoenzymes. Treatment with more potent P2Y12 receptor blockers, such as prasugrel and ticagrelor are credible alternative strategies to overcome HPR during clopidogrel therapy

PAR1 (Protease-Activated Receptor 1) Pepducin Therapy Targeting Myocardial Necrosis in Coronary Artery Disease and Acute Coronary Syndrome Patients Undergoing Cardiac Catheterization: A Randomized, Placebo-Controlled, Phase 2 Study

OBJECTIVE: Arterial thrombosis leading to ischemic injury worsens the prognosis of many patients with cardiovascular disease. PZ-128 is a first-in-class pepducin that reversibly inhibits PAR1 (protease-activated receptor 1) on platelets and other vascular cells by targeting the intracellular surface of the receptor. The TRIP-PCI (Thrombin Receptor Inhibitory Pepducin in Percutaneous Coronary Intervention) trial was conducted to assess the safety and efficacy of PZ-128 in patients undergoing cardiac catheterization with intent to perform percutaneous coronary intervention. Approach and Results: In this randomized, double-blind, placebo-controlled, phase 2 trial, 100 patients were randomly assigned (2:1) to receive PZ-128 (0.3 or 0.5 mg/kg), or placebo in a 2-hour infusion initiated just before the start of cardiac catheterization, on top of standard oral antiplatelet therapy. Rates of the primary end point of bleeding were not different between the combined PZ-128 doses (1.6%, 1/62) and placebo group (0%, 0/35). The secondary end points of major adverse coronary events at 30 and 90 days did not significantly differ but were numerically lower in the PZ-128 groups (0% and 2% in the PZ-128 groups, 6% and 6% with placebo, p=0.13, p=0.29, respectively). In the subgroup of patients with elevated baseline cardiac troponin I, the exploratory end point of 30-day major adverse coronary events + myocardial injury showed 83% events in the placebo group versus 31% events in the combined PZ-128 drug groups, an adjusted relative risk of 0.14 (95% CI, 0.02-0.75); P=0.02. CONCLUSIONS: In this first-in-patient experience, PZ-128 added to standard antiplatelet therapy appeared to be safe, well tolerated, and potentially reduced periprocedural myonecrosis, thus providing the basis for further clinical trials. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02561000

Incidence of Dyspnea and Assessment of Cardiac and Pulmonary Function in Patients With Stable Coronary Artery Disease Receiving Ticagrelor, Clopidogrel, or Placebo in the ONSET/OFFSET Study

ObjectivesWe prospectively assessed cardiac and pulmonary function in patients with stable coronary artery disease (CAD) treated with ticagrelor, clopidogrel, or placebo in the ONSET/OFFSET (A Multi-Centre Randomised, Double-Blind, Double-Dummy Parallel Group Study of the Onset and Offset of Antiplatelet Effects of AZD6140 Compared With Clopidogrel and Placebo With Aspirin as Background Therapy in Patients With Stable Coronary Artery Disease) study.BackgroundTicagrelor reduces cardiovascular events more effectively than clopidogrel in patients with acute coronary syndromes. Dyspnea develops in some patients treated with ticagrelor, and it is not known whether this is associated with changes in cardiac or pulmonary function.MethodsIn all, 123 stable aspirin-treated CAD patients randomly received either ticagrelor (180 mg load, then 90 mg twice daily; n = 57), clopidogrel (600 mg load, then 75 mg daily; n = 54), or placebo (n = 12) for 6 weeks in a double-blind, double-dummy design. Electrocardiography, echocardiography, serum N-terminal pro-brain natriuretic peptide, and pulmonary function tests were performed before (baseline) and 6 weeks after drug administration and/or after development of dyspnea.ResultsAfter drug administration, dyspnea was reported by 38.6%, 9.3%, and 8.3% of patients in the ticagrelor, clopidogrel, and placebo groups, respectively (p < 0.001). Most instances were mild and/or lasted <24 h, although 3 patients discontinued ticagrelor because of dyspnea. Eight of 22 and 17 of 22 ticagrelor-treated patients experiencing dyspnea did so within 24 h and 1 week, respectively, after drug administration. In all treatment groups, and in ticagrelor-treated patients with dyspnea, there were no significant changes between baseline and 6 weeks in any of the cardiac or pulmonary function parameters.ConclusionsDyspnea is commonly associated with ticagrelor therapy, but was not associated in this study with any adverse change in cardiac or pulmonary function. (A Multi-Centre Randomised, Double-Blind, Double-Dummy Parallel Group Study of the Onset and Offset of Antiplatelet Effects of AZD6140 Compared With Clopidogrel and Placebo With Aspirin as Background Therapy in Patients With Stable Coronary Artery Disease [ONSET/OFFSET]; NCT00528411

Drug-coated balloons in treatment of in-stent restenosis: a meta-analysis of randomised controlled trials

Background Drug-coated balloons (DCBs) have been developed for the percutaneous treatment of coronary artery disease. An initial focus has been the management of in-stent restenosis (ISR) but randomised controlled trials (RCTs) have been small and powered only for angiographic endpoints. Objective The aim of the work was to assess the clinical and angiographic outcomes of patients treated for ISR with DCB versus control (balloon angioplasty or drug-eluting stents) by a meta-analysis of RCTs. Methods A comprehensive search was performed of RCTs where patients with ISR were randomly assigned to either DCB or alternative coronary intervention. Outcome measurements were death, myocardial infarction (MI), target lesion revascularisation (TLR), binary definition of restenosis and in-lesion late luminal loss (LLL). Results Four studies were identified that fulfilled the inclusion criteria. Pooled odds ratios (ORs) were calculated for patients treated for ISR (n = 399). Mean follow-up duration was 14.5 months. DCBs were associated with lower rates of TLR [8.8 vs. 29.7 % OR (95 % confidence interval, CI) 0.20 (0.11–0.36), p\0.0001], binary restenosis [10.3 vs. 41.3 % OR (95 % CI) 0.13 (0.07–0.24), p\0.00001] and MI [0.5 vs. 3.8 %, OR (95 % CI) 0.21 (0.04–1.00), p = 0.05]. No significant heterogeneity was identified. Conclusion Drug-coated balloons appear to be effective versus control in reducing TLR and possibly MI versus balloon angioplasty or drug-eluting stents in the management of ISR