BACKGROUND/AIM: Brachial artery flow-mediated dilation (FMD) is extensively used for non-invasive assessment of endothelial function. Traditionally, FMD is calculated as a percent change of arterial diameter from the baseline value at an arbitrary time point after cuff deflation (usually 60 seconds). Considerable individual differences in brachial artery temporal response to hyperemic stimulus have been observed, potentially influenced by the presence of atherosclerotic risk factors (RF). The importance of such differences for the evaluation of endothelial function has not been well established. The aim of the study was to determine the time course of maximal brachial artery endothelium-dependent dilation in healthy adults with and without RF, to explore the correlation of RF with brachial artery temporal response and to evaluate the importance of individual differences in temporal response for the assessment of endothelial function. METHODS: A total of 115 healthy volunteers were included in the study. Out of them, 58 had no RF (26 men, mean age 44 +/-14 years) and 57 had at least one RF (29 men, mean age 45 +/-14 years). High-resolution color Doppler vascular ultrasound was used for brachial artery imaging. To determine maximal arterial diameter after cuff deflation and the time-point of maximal vasodilation off-line sequential measurements were performed every 10 seconds from 0 to 240 seconds after cuff release. True maximal FMD value was calculated as a percent change of the true maximal diameter from the baseline, and compared with FMD value calculated assuming that every participant reached maximal dilation at 60 seconds post cuff deflation (FMD60). Correlation of different RF with brachial artery temporal response was assessed. RESULTS: A maximal brachial artery endothelium-dependent vasodilation occurred from 30-120 seconds after cuff release, and the mean time of endothelium-dependent dilation was 68 +/-20 seconds. Individuals without RF had faster endothelium-dependent dilation (mean time 62 +/-17 seconds), and a shorter time-span (30 to 100 seconds), than participants with RF (mean time 75 +/-21 seconds, time-span 40 to 120 seconds) (p < 0.001). Time when the maximal endothelium-dependent dilation occurred was independently associated with age, serum lipid fractions (total cholesterol, LDL and HDL cholesterol), smoking, physical activity and C-reactive protein. True maximal FMD value in the whole group (6.7 +/-3.0%) was significantly higher (p < 0.001) than FMD60 (5.2 +/-3.5%). The same results were demonstrated for individuals with RF (4.9 +/- 1.7% vs 3.1 +/- 2.3%, p < 0.001) and without RF (8.4 +/- 2.9% vs 7.2 +/- 3.2%, p < 0.05). CONCLUSION: The temporal response of endothelium-dependent dilation is influenced by the presence of coronary FR and individually heterogeneous. When calculated according to the commonly used approach, i.e. 60 seconds after cuff deflation, FMD is significantly lower than the true maximal FMD. The routinely used measurement time-points for FMD assessment may not be adequate for the detection of true peak vasodilation in individual persons. More precise evaluation of endothelial function can be achieved with sequential measurement of arterial diameter after hyperemic stimulus.

To present a 19-year experience of the prognosis of patients with acute myocardial infarction (AMI) and prior coronary artery bypass surgery (CABS), 748 patients with AMI after prior CABS (postbypass group) and a control group of 1080 patients with AMI, but without prior CABS, were analyzed. All indexes of infarct size were lower in the postbypass group. There was more ventricular fibrillation in the postbypass group. In-hospital mortality was similar (p = 0.3675). In the follow-up period, postbypass patients had more heart failure, recurrent CABS, reinfarction, and unstable angina than did control patients. Cumulative survival was better in the control group than in the postbypass group (p = 0.0403). Multiple logistic regression model showed that previous angina (p = 0.0005), diabetes (p = 0.0058), and age (p = 0.0102) were independent predictor factors for survival. Use of digitalis and diuretics, together with previous angina, also influenced survival (p = 0.0092), as well as male gender, older patients, and diabetes together (p = 0.0420). Patients with AMI after prior CABS had smaller infarct, but more reinfarction, reoperation, heart failure, and angina. Previous angina, diabetes, and age, independently, as well as use of digitalis and diuretics together with angina, and male gender, older patients, and diabetes together, influenced a worse survival rate in these patients.

BACKGROUND Stent thrombosis is potentially lethal complication with huge economic burden. The role of insufficient response to antiplatelet therapy is still unclear reason for its occurrence. CASE REPORT We presented 54-year-old man with recurrent stent thrombosis on the 4th, 9th and 12th day after the primary percutaneous coronary intervention in spite of double antiaggregation therapy (aspirin+clopidogrel). All possible procedural causes were excluded and reimplantation of intracoronary stent was insufficient to resolve the problem, so four platelet tests were performed: flow cytometry, Platelet Function Analyzer-100 test, aggregometry, and determination of gene polymorphism for P2Y12 receptor (directly involved in the mechanism of thienopyridine), and GPIIbIIIa receptor (final receptor in aggregation). The patient was the carrier of the major haplotype H1H1 for P2Y12 receptor and minor A1A2 for GPIIbIIIa receptor. The results of all the performed tests showed insufficient antiplatelet effect of aspirin and sufficient response to thienopyridin (not to clopidogrel, but to ticlopidine). CONCLUSION Performance of platelet function tests is necessary in the case of major adverse cardiac events especially stent thrombosis, after implantation of intracoronary stent.

The aim of this study was to assess the pharmacokinetics and tolerability of Biolimus A9 eluted from Nobori coronary stents.