H ischemic cerebral focus by nuclear magnetic resonance), myocardial infarction or coronary artery bypass graft (n = 14), one or multiple coronary stents (n = 46, 38 coronary drug-eluting stents), and peripheral arterial disease (n = 3). Bleeding was defined according to Ben-Dor et al. [9]: alarming bleeding, internal bleeding, and nuisance bleeding. Internal bleeding included hematoma, epistaxis, vaginal bleeding, melena, hematemesis, eye bleeding, and haematuria. Nuisance bleeding included easy bruising, bleeding from small cuts, petechia, and ecchymosis andMost patients were receiving additional therapy at the time of the study: antidepressants (n = 6), antidiabetics (n = 11), anxiolytics (n = 26), beta-blockers (n = 36), ACE inhibitors (n = 23), folic acid (n = 11), PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/744568 lipid-lowering agents (n = 53), protein pump PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/21715270 inhibitor (PPI) (n = 16, 7 on omeprazol), levothyroxine (n = 7), and diuretics (n = 3). Drug-drug interaction between the PPI omeprazole and CLOP that attenuates the antiplatelet effect has been described recently but is not yet widely accepted [10-13]; the US Food and Drug Administration has alerted the public to new safety information concerning an interaction between the 2 therapies. Because of these contradicting publications and, to the best of our knowledge, the absence of any publications showing that PPI drugs affect BT, patients receiving omeprazole therapy were not excluded from the study. None of the patients were receiving anticoagulant therapy. Patients presented several comorbidities including diabetes (11 ), hypertension (57 ), and dyslipidemia (53 ); 5 had peripheral vascular disease. No patients were active smokers. The mean number of weeks on clopidogrel + aspirin was 28.3 ?10.6 weeks (max 58 weeks, min 12 weeks).Hemostasis Tests and Bleeding TimeVenous blood was drawn from the antecubital vein without stasis and mixed with 0.11 mol/L sodium citrate (1:10 v/v). PRP was obtained by centrifugation at 150 for 10 min at room temperature; platelet-poor plasma (PPP) was obtained by centrifugation of PRP at 4,4,5,5-Tetramethyl-2-(2-methylprop-1-en-1-yl)-1,3,2-dioxaborolane 900 for 15 min at 20 . The PRP was adjusted to a platelet count of 290,000-310,000/L with autologous PPP. If contamination of the PRP with erythrocytes or leukocytes was observed by light microscopy, a second centrifugation at 900 for 5 min was carried out to minimize the cell number. Plastic syringes, tubes, and pipettes were used for all tests. LTA of the PRP was performed in a double-channel Lumi-Aggregometer (Chrono-log Corp., Havertown, PA, USA). Light transmission was set at 10 for PRP and 90 for PPP. The aggregating agent (1-10 L) was added to PRP in the aggregometer at 37 with constant stirring (1000 rpm). Arachidonic acid (AA) sodium salt (0.625 mmol/L; Sigma, St. Louis, MO, USA) and adenosine diphosphate (ADP; 2, 4, and 8 mol/L; Sigma, St. Louis, MO, USA) were used as platelet agonists in the aggregation studies. The percentage IPA was expressed as 100 minus the maximal percent change in light transmission from baseline with PPP used as a reference.Altman et al. Thrombosis Journal 2012, 10:3 http://www.thrombosisjournal.com/content/10/1/Page 3 ofFor BT, a disposable Surgicutt adult device (ITC, Thoratec Co, Edison, NJ, USA) was 3-Bromo-5-chloro-2-fluoroaniline used to make a standard incision (5-mm long, 1-mm deep) on the volar surface of the forearm, perpendicular to the antecubital crease, while maintaining a pressure of 40 mmHg in a sphygmomanometer cuff. The time until complete cessation of bleeding (to the nearest 30 s).