Anna Komosa

Comparison of the antiplatelet effect of two clopidogrel bisulfate formulations: Plavix and generic-Egitromb

Abstract Due to expansion of the pharmaceutical market it seems necessary to prove the efficacy of the generic drugs. The aim of this study is to compare the effects of two clopidogrel formulations: brand-name-Plavix and generic drug – Egitromb. This is a prospective, randomized study comparing two groups of patients treated with two clopidogrel: brand-name Plavix and generic drug– Egitromb. The 53 consecutive patients with stable coronary artery disease qualifying for coronary angiography and PCI were enrolled in this trial. They were randomized into two groups. In the group A (n = 28) patients received Egitromb 300 mg at admission followed by 8 days of 75 mg Egitromb daily. In the group B (n = 25) patients received Plavix 300 mg on the admission followed by 8 days of 75 mg Plavix maintenance therapy. Blood samples for multiple electrode aggregometry testing were drawn at baseline, 5 hours and 8 days after taking the loading dose. Median values of platelet aggregation inhibition did not differ between the Plavix and Egitromb groups when assessed at baseline: 239AU/min (IQR:329) vs. 209 (IQR:406; p = 0.894), 5 hours after loading: 183 AU/min (IQR:107) vs. 165 (IQR:171; p = 0.831) or at day 8: 174 AU/min (IQR:133) vs. 211 (IQR:133; p = 0.332. The study showed no difference in the therapeutic effect of two clopidogrel formulations (Egitromb and Plavix).

Impact of common ABCB1 polymorphism on pharmacokinetics and pharmacodynamics of clopidogrel and its metabolites

The reasons of clopidogrel (CLP) resistance are still unclear. The response to CLP may be influenced by both genetic and non‐genetic factors. Among genetic factors, common polymorphisms in the gene coding glycoprotein‐P (P‐gp, MDR1 and ABCB1) are considered as potential determinants of the efficacy of CLP treatment. The aim of this study was to evaluate the influence of ABCB1 3435C>T genetic polymorphism on the pharmacokinetics and pharmacodynamics of CLP and its metabolites: diastereoisomers of thiol metabolite (the inactive H3 and the active H4) and inactive carboxylic derivative.

Platelets redox balance assessment: Current evidence and methodological considerations

Altered function of platelets can lead to cardiovascular complications in numerous disorders. Various studies aimed to investigate mechanisms triggering platelets activation cascade show a significant role of reactive oxygen species (ROS) in this matter. Moreover, ROS are known causal factor of oxidative stress that can result in DNA, lipid and protein damage. This review aims to comprehensively present the variety of methods that are potentially useful in assessment of platelets redox balance, such as intracellular concentration of particular ROS, activity of antioxidant enzymes, reduced/oxidized glutathione ratio, level of lipid peroxidation, Cu/Zn ratio, and molecular oxygen consumption. They may help to establish the platelet-related etiological factors in different disorders and to evaluate the antiplatelet therapies. The advantages and limitations of these methods are also discussed. The present paper highlights that clinicians may benefit from implementation of such tools and further encourages developing interdisciplinary evidence-based practice.

The Management of Supraventricular Tachyarrhythmias in Patients with Pulmonary Arterial Hypertension.

BACKGROUND Atrial remodelling in pulmonary arterial hypertension (PAH) may lead to higher incidence of supraventricular arrhythmias (SVA). The purpose of this study was to evaluate the efficiency and safety of various methods for treatment of SVA in this group. METHODS This was a single centre study. Forty-eight patients (33 women and 15 men) aged 19-77 years (median 49 years) were enrolled. There were 30 patients with idiopathic PAH, 10 had PAH associated with connective tissue disease, and eight with congenital heart disease. A retrospective analysis was performed to estimate the prevalence and type of supraventricular arrhythmias, as well as efficiency and safety of treatment methods. Mean follow-up period was 28.8±17.7 months. RESULTS Supraventricular arrhythmias occurred in 17 patients (35%) and appeared to be atrial fibrillation, flutter or tachycardia. Supraventricular arrhythmias coexisted with elevated mean right atrial pressure in 75%. Four patients had more than one type of SVA. A flutter-like macro-reentrant form of atrial tachycardia dependent on cavo-tricuspid isthmus was found in four cases. The treatment of SVA included typical methods: antiarrhythmic drugs, direct current cardioversion (DCC), and radiofrequency (RF) ablation. All of the therapeutic methods were effective in managing acute arrhythmia. Three patients required re-ablation. Overall mortality: 14 patients (29%) in the whole study group, including six in SVA group (35%) and eight without SVA (26%). CONCLUSIONS In patients with PAH DCC, pharmacological cardioversion and RF ablation can be applied safely and effectively. Flutter-like macro-reentrant atrial tachycardia dependent on cavo-tricuspid isthmus is observed in this group. It is more challenging, but possible, to successfully treat this arrhythmia with RF ablation.

Significance of antiplatelet therapy in emergency myocardial infarction treatment

Antiplatelet drugs play a crucial role in the treatment of patients with myocardial infarction, particularly in association with percutaneous coronary intervention. Their main advantage is the reduction of adverse ischemic incidents and the major disadvantage is the increase in the frequency of hemorrhages. Thus, the choice of appropriate drug depends on the right risk assessment of the development of these complications in individual patients. The aim of this article is to provide an update of antiplatelet therapy in emergency myocardial infarction treatment. Currently, the most important role in the process of platelet inhibition is played by ADP P2Y12 blockers: clopidogrel, prasugrel and ticagrelor. Clopidogrel and prasugrel belong to thienopyridines, and ticagrelor, a drug of irreversible action, is an analogue of adenosine triphosphate. By 2011 clopidogrel, alongside aspirin, had the highest recommendations of world cardiology associations for acute coronary syndrome treatment. The position on clopidogrel was changed following the publication of European Society of Cardiology guidelines for STEMI in 2012 which advocate the administration of acetylsalicylic acid (ASA) and ADP receptor blocker (in combination with ASA). It needs to be stressed that prasugrel and ticagrelor received class IB recommendation, while clopidogrel received only IC. However, the most recent studies aimed at introducing a new generation of antiplatelet drugs of high efficacy in prevention of ischemic incidents and of reversible action: cangrelor and elinogrel, which raise hopes for better prognosis for myocardial infarction patients.

Determinants of high on-treatment platelet reactivity and agreement between VerifyNow and Multiplate assays

Abstract Dual antiplatelet therapy with clopidogrel is a regimen used before and after drug-eluting stent (DES) implantation. Point-of-care platelet reactivity assays are easy-to-use methods to determine adequate response to the drug. The aim of this study was a comparison of the two platelet reactivity assays: Multiplate® and VerifyNow® and an identification of factors potentially influencing the results of these tests, including common genetic polymorphisms. The study included 39 patients receiving 75 mg clopidogrel daily before angioplasty with DES implantation. Platelet reactivity was measured with Multiplate and P2Y12 VerifyNow assays. Genetic polymorphisms of CYP2C19*2, ABCB1 3435C > T, and CYP3A4*1G were determined with PCR-RFLP method and CYP2C19*17 was determined by means of an allele-specific PCR. Agreement between Multiplate and VerifyNow assays was poor (Cohen’s κ = 0.056, p = .273). Hematocrit significantly negatively correlated with VerifyNow assayed platelet reactivity (r = −.487, p = .002). Female sex was significantly associated with higher VerifyNow assay results after adjustment to hematocrit (253.2 ± 47.6 PRU vs. 195.9 ± 56.9 PRU, p = .013) and the prevalence of high-on-treatment platelet reactivity (OR: 8.50; 95% CI 1.13–77.60, p = .024). Reactivity measured with Multiplate was lower in women (82.3 vs. 175.6 AU·min, p = .037) and in patients who received calcium channel blockers (74.7 vs. 191.7 AU·min, p = .002). None of the studied polymorphisms significantly influenced platelet aggregation measurements. In conclusion, different aspects modify between-patient variability of the Multiplate and VerifyNow assays and agreement between those two assays was poor.

Red Blood Cells Distribution Width as a Potential Prognostic Biomarker in Patients With Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND Red blood cells distribution width (RDW) predicts survival in cardiovascular diseases. Little is known about the variability of RDW level over time among patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). To our knowledge, RDW has never been analysed as a marker of response to specific treatment. MATERIALS AND METHODS We retrospectively analysed 77 patients for: i) RDW measured during the last hospitalisation before death or during the last follow-up (RDWlast); ii) mean RDW from all hospitalisations during the entire follow-up of the patient (RDWmean); iii) maximum RDW of all hospitalisations of each patient (RDWmax). In order to assess response to specific treatment and association with prognosis, we compared RDW levels (obtained from 56 patients) before and 3 to 6 months after introduction or intensification of treatment in both the alive and deceased group. RESULTS Twenty-eight of 77 patients died, whereas in specific drugs treatment response analysis, 22 of 56 patients died during follow-up. The cut-off values derived from the ROC analysis and assessed using the log-rank test were significant for RDWlast (p<0.0001), RDWmean (p<0.001) and RDWmax (p=0.02). A decrease in RDW levels after introduction or intensification of specific treatment was significant (p=0.015) in survivors, whereas there was no significance (p=0.29) in decrease in RDW levels in non-survivors after change of therapy. CONCLUSIONS Red blood cells distribution width might be a potential prognostic biomarker in patients with PAH and inoperable CTEPH. The decrease in RDW level after introduction or escalation of PAH-targeted and CTEPH-targeted drugs is associated with a good treatment response and better prognosis.

Routine transfusion of platelet concentrates effectively reduces reoperation rate for bleeding and pericardial effusion after elective operations for ascending aortic aneurysm

Abstract Patients with ascending aortic aneurysm undergoing complex surgical procedures are at increased risk of early postoperative excessive blood loss. The aim of this study was to analyze safety and efficacy of routine transfusions of platelet (PLT) concentrates in reduction of hemorrhagic postoperative complications. The study involved 396 consecutive patients (289 males and 107 females) with the mean age of 55.9 ± 13.6 years who underwent elective operations for aortic aneurysms. They were divided retrospectively into two groups, without (group A; n = 123) or with the routine use of PLTs (group B; n = 273). PLTs were transfused intraoperatively just after completion of cardiopulmonary bypass. Twelve patients in group A (9.8%) and 10 (3.7%) in group B required re-thoracotomy due to hemorrhage (p = 0.027). Routine transfusions of PLT concentrates reduced postoperative incidence of excessive pericardial effusion from 24.1% in group A to 2.1% in group B (p = 0.002). In a consequence, significantly less units (p < 0.0001) of red blood concentrates and fresh frozen plasma were transfused in group B than in group A. The rates of other adverse events in the early postoperative period did not differ between groups. Patients with pericardial effusion required 6.3 ± 2.7 additional days of hospitalization due to surgical re-intervention. Neither blood transfusion-related infections nor adverse reactions were noted. In conclusion, routine intraoperative transfusions of PLT concentrates in patients with ascending aortic aneurysms significantly reduced a need for re-intervention due to both early bleeding and late cardiac tamponade.

Neopterin as a Biomarker in Patients with Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension

Background: Upregulation of the immune system is regarded to play an important role in the etiopathobiology of pulmonary arterial hypertension (PAH) and inoperable chronic thromboembolic pulmonary hypertension (CTEPH). To the best of our knowledge, neopterin (NP) has never been investigated in patients with PAH and CTEPH. Objectives: The aim of the study was to evaluate the concentration of NP in blood in order to examine its impact on outcome and relationship with disease severity in that population. Methods: Serum concentration of NP was analysed prospectively in 50 patients (36 with PAH and 14 with CTEPH vs. 31 healthy controls) and assessed in relation to clinical parameters and outcome. Results: NP concentration in the PAH and CTEPH groups combined was significantly higher than in the control group (8.68, 6.39–15.03 vs. 5.14, 4.16–5.98 nmol/L, p < 0.0000001). During 9 months of follow-up, clinical deterioration occurred in 18 patients (including 8 deaths), and NP concentration in this group was higher when compared to stable patients (15.6, 8.52–25.13 vs. 7.87, 6.18–9.89, p = 0.002). The cutoff value of NP derived from ROC curve analysis was 15.3 nmol/L (p = 0.002, AUC 0.77, p = 0.0004, HR = 4.35, 95% CI 1.43–13.18, log-rank test). On Cox regression analysis, NP predicted clinical deterioration (p = 0.009, 95% CI 1.01–1.06). NP correlated positively with NT-proBNP (p < 0.001), red blood cell distribution width (p < 0.001), and right atrium area (p = 0.002) and inversely with 6-min walking test (p = 0.002) and peak oxygen consumption (p = 0.001). Conclusions: NP concentration is increased in patients with PAH and inoperable CTEPH. Elevated NP concentration is associated with adverse clinical outcomes and correlates with clinical parameters.

The altered platelet mineral ratios in pregnancy complicated with intrauterine growth restriction

Altered function of maternal platelets has been evidenced in intrauterine growth restriction (IUGR) but intraplatelet burden of trace elements, factors known to affect platelet activity, remains unknown in IUGR pregnancy. This study assessed the intraplatelet status of Ca, Cu, Mg, Na, K, P, Zn and their ratios (Ca/P, Ca/Mg, Na/K, Cu/Zn) in IUGR pregnancy (n = 35), uncomplicated pregnancy (n = 25) and in non-pregnant females (n = 25). The IUGR group was characterized by the lowest content of Ca, Mg and Zn, and Ca/P ratio (<1.0), and the highest Ca/Mg and Cu/Zn ratios. The studied parameters in non-pregnant women and in uncomplicated pregnancy were comparable except P content and Ca/Mg ratio which were significantly lower in the former group. No differences in Na and K contents, and Na/K ratio between studied groups were found. This study reports that maternal intraplatelet status of selected minerals may be altered in IUGR.