Frequency of heparin/platelet factor 4-dependent platelet antibodies in patients undergoing angioplasty and stenting for cardiovascular disease and their role for on-clopidogrel platelet reactivity

Morphine interaction with prasugrel: a double-blind, cross-over trial in healthy volunteers

Background

Morphine decreases the concentrations and effects of clopidogrel, which could lead to treatment failure in myocardial infarction.

Objectives

To clarify whether more potent P2Y₁₂-inhibitors may provide an effective alternative, we examined drug–drug interactions between morphine and prasugrel.

Methods

Twelve healthy volunteers received 60 mg prasugrel with placebo or 5 mg morphine intravenously in a randomized, double-blind, placebo-controlled, cross-over trial. Pharmacokinetics were determined by liquid chromatography tandem mass spectrometry, and prasugrel effects were measured by platelet function tests.

Results

Morphine neither diminished total drug exposure (AUC), which was the primary endpoint, nor significantly delayed drug absorption of prasugrel. However, morphine reduced maximal plasma concentrations (C_max) of prasugrel active metabolite by 31 % (p = 0.019). Morphine slightly, but not significantly, delayed the onset of maximal inhibition of platelet plug formation under high shear rates (30 vs. 20 min). Whole blood aggregation was not influenced.

Conclusions

Although morphine significantly decreases the maximal plasma concentrations of prasugrel active metabolite, it does not diminish its effects on platelets to a clinically relevant degree in healthy volunteers. However, it should be considered that the observed decrease in C_max of prasugrel active metabolite caused by morphine co-administration may gain relevance in STEMI patients.

Clinical Trial Registration: NCT01369186, EUDRA-CT#: 2010-023761-22.

Investigating the role of acute mental stress on endothelial dysfunction: a systematic review and meta-analysis

Chronic stress is a known risk factor for both endothelial dysfunction and cardiovascular disease (CVD), but less is known of how acute mental stress affects the vasculature. In this systematic review and meta-analysis, we analyzed the impact of acute mental stress on flow-mediated dilation (FMD), an indicator of endothelial function. We searched the Medline, Cochrane, EMBASE, and ISI Web of Knowledge databases through May 2014, to identify publications in English-language journals. The primary outcome was the change in FMD from baseline to the time of measurement. We also assessed the risk of bias and the heterogeneity of included studies. Our search identified eight prospective studies, which displayed significant heterogeneity. Four studies measured FMD while the subject was performing the task; six measured FMD after the task had been completed. The total number of participants was 164. The pooled results indicate that FMD did not change significantly while the task was being performed (pooled difference in means: -0.853; 95 % confidence interval (CI), -3.926/2.220; P = 0.586); however, FMD measured after the task was completed was significantly less than baseline (pooled difference in means: -2.450; 95 %CI, -3.925/-0.975; P = 0.001). In conclusions, our findings provide evidence that an acute stressful experience has a delayed, negative impact on the function of the endothelium. Repeated exposure to short-term stress may lead to permanent injury of the vasculature. Therefore, assessment of patients' exposure to both repeated acute mental stress and chronic stress may be useful in determining their risk of developing CVD.