The use of β-blockers in the treatment of patients with coronary heart disease is associated with a decrease in the frequency of angina pectoris and mortality of patients. Due to the severity of the disease and previous cardiovascular interventions, many patients with coronary artery disease (CAD) use dual antiplatelet therapy to achieve greater inhibition of platelet aggregation. The influence of β-blockers on platelet aggregation in patients using antiplatelet therapy is not well understood. To examine the effect of different β-blockers on platelet aggregation in patients on dual antiplatelet therapy. The study included 331 patients who were treated at the Department of Cardiology, Clinical Center Kragujevac during 2011. Patients were divided into 4 groups depending on the type of β-blockers that were used (bisoprolol, nebivolol, metoprolol, and carvedilol). Platelet aggregation was measured using the multiplate analyzer and expressed through the value of adenosine diphosphate (ADP) test (to assess the effect of clopidogrel), ASPI test (to assess the effect of acetyl salicylic acid), TRAP test (to assess baseline platelet aggregation), and the ratio of ADP/TRAP and ASPI/TRAP ASPI/TRAP (ASPI - aranchidonic acid induced aggregation, TRAP - thrombin receptor activating peptide) representing the degree of inhibition of platelet aggregation compared to the basal value. In consideration were taken the representation of demographic, clinical characteristics, laboratory parameters, and cardiovascular medications between the groups. Patients who used nebivolol had a significantly lower value of the ratio of ADP/TRAP (0.39 ± 0.30) compared to patients who used bisoprolol (0.48 ± 0.26; P = .038), and trend toward the lower values of ADP test (328.0 ± 197.3 vs 403.7 ± 213.2; P = .059), while there was no statistically significant difference in values of other laboratory parameters of platelet function between other groups. Patients with CAD on dual antiplatelet therapy who used nebivolol had significantly lower levels of residual ADP-induced platelet aggregation compared to baseline than patients who used bisoprolol.

Dual antiplatelet therapy is recommended after acute coronary syndrome or after percutaneous coronary intervention with coronary stent implantation. Many of the patients on dual antiplatelet therapy receive β-blockers; some of them could have antiaggregatory effect. Bisoprolol is a highly selective adrenoceptor-blocker, which is often used in the settings of percutaneous coronary intervention or acute coronary syndrome in patients on dual antiplatelet therapy. Its antiaggregative effect has not been extensively studied. Therefore, the aim of this study is to investigate the effect of bisoprolol on ADP-induced platelet aggregation in patients on dual antiplatelet therapy. Platelet aggregability has been measured in 100 patients on dual antiplatelet therapy with multiplate analyzer using ADP test in blood samples anticoagulated with heparin. ADP test values have been expressed by arbitrary units/minute. In univariate and multivariate regression analyses, we have investigated the influence of bisoprolol and its dose and also different factors, such as risk factors, concomitant drugs and their dosage, laboratory findings, on ADP test values. Univariate regression analysis showed significant correlation between the bisoprolol dose and the ADP test value (P=0.046, B=52.55, 95% confidence interval 0.87–104.23), which was also shown in the multivariate regression analysis (P=0.018; B=57.011; 95% confidence interval 10.455–103.567). We have identified a positive correlation between bisoprolol dose and ADP-induced platelet aggregability in patients on dual antiplatelet therapy.

(1) Background: The aim of our study was to determine the role of oxidative stress (OS) during early evaluation of acute ST-elevated myocardial infarction (STEMI) and non-ST-elevated myocardial infarction (NSTEMI) patients in order to define the role of redox balance in profiling the development of myocardial infarction (MI). (2) Methods: This prospective observational case-control study included 40 consecutive STEMI and 39 NSTEMI patients hospitalized in the coronary care unit of the cardiology clinic at the Kragujevac Clinical Center, Serbia, between 1 January 2016 and 1 January 2017. Blood samples were collected from all patients for measuring cardio-specific enzymes at admission and 12 h after admission to evaluate systemic oxidative stress biomarkers and the activity of antioxidant enzymes. (3) Results: In this study, participants were predominately female (52%), with a mean age of 56.17 ± 1.22 years old in the STEMI group and 69.17 ± 3.65 in the non-STEMI group. According to the Killip classification, the majority of patients (>50%) were at the second and third level. We confirmed the elevation of superoxide anion radicals in the non-STEMI group 6 h after admission in comparison with the STEMI and CTRL groups, but levels had decreased 12 h after admission. Levels of hydrogen peroxide were statistically significantly increased in the NSTEMI group. A positive correlation of superoxide anion radicals and levels of troponin I at admission was observed (r = 0.955; p = 0.045), as well as an inverse correlation between reduced glutathione and levels of NT-pBNP measured 6 h after admission (r = −0.973; p = 0.027). (4) Conclusions: We confirmed that superoxide anion radicals and reduced glutathione observed together with hs-troponin I at admission and NT-pBNP during hospital treatment could be predictors of ST evolution.

Despite the wide usage of exercise ECG tests and Duke Treadmill Score (DTS) in clinical practice, no comparison between this scoring system and Fractional Flow Reserve (FFR) has yet been made, particularly in cases of angiographically verified borderline lesions. Thirty patients with single coronary lesions and angiographically assessed borderline stenosis (between 30-70%) and previously calculated intermediate values of DTS between -10 to +4 were examined using FFR. Adequate specificity and sensitivity (0.769 and 0.556, respectively) were in a more narrow range of -0.5 to -10. Sex and age did not have an influence on the DTS values. There was a correlation between the values of FFR and age (r=0.395, p=0.031) and between angiographic assessment of stenosis and quantitative coronary angiography (QCA) (r=0.648, p<0.0001). In the study population, a decision on revascularization could not be based solely on angiographic or QCA assessment of the artery or on the values of DTS

Background: An implantable loop recorder (ILR) represents the gold standard in the diagnosis of cardiac arrhythmias in patients with neurological or cardiac symptoms. Our study aimed to determine the real-world diagnostic effectiveness of ILRs in detecting arrhythmias requiring permanent pacemaker implantation. Methods: The study enrolled and followed up for two years 62 ILR recipients from the Cardiology Clinic of the Clinical Center Kragujevac, Serbia. Results: The most common indication for pacemaker implantation was pauses in cardiac activity (83%). The use of oral anticoagulants (OR: 11.80; 95% CI: 1.76, 79.4), ACE inhibitors or AT receptor blockers (OR: 3.87; 95% CI: 1.21, 12.35), and diuretics (OR: 5.29; 95% CI: 1.55, 18.04) had a statistically significant impact on the detection of pacemaker-requiring arrhythmias by an ILR. After adjustment for other factors of influence, oral anticoagulants (OR: 7.82; 95% CI: 1.08, 56.9) and diuretics (OR: 3.68; 95% CI: 1.04, 13.00) remained significant in predicting pacemaker requirement in ILR recipients. Conclusions: An ILR represents an effective diagnostic approach in detecting cardiac arrhythmias requiring permanent pacemaker implantation, especially in patients treated with oral anticoagulants or diuretics.

Atrioventricular Re‐entry Tachycardia (AVRT) occurs in patients with accessory pathways (AP) via a re‐entry circuit between the AV node and the AP. Anterograde conduction through the AP causes antidromic AVRT with wide QRS complexes, which may mimic ventricular tachycardia (VT). We report a 59‐year‐old male with ischemic cardiomyopathy (EF 35%) and recurrent wide QRS tachycardia who was referred for ICD implantation. Electrophysiology study identified a left posterolateral AP, and radiofrequency ablation successfully eliminated pre‐excitation. ICD implantation was subsequently performed without complications. Antidromic AVRT should be considered in the differential diagnosis of wide QRS tachycardia, and catheter ablation remains a safe and effective treatment.