Tomasz Fabiszak

Meta-Analysis of Impact of Different Types and Doses of Statins on New-Onset Diabetes Mellitus

Recent reports indicate that statins are associated with an increased risk for new-onset diabetes mellitus (DM) compared with placebo and that this relation is dose dependent. The aim of this study was to perform a comprehensive network meta-analysis of randomized controlled trials (RCTs) investigating the impact of different types and doses of statins on new-onset DM. RCTs comparing different types and doses of statins with placebo were searched for using the MEDLINE, Embase, and Cochrane databases. A search of RCTs pertinent to this meta-analysis covering the period from November 1994 to October 2012 was conducted by 2 independent investigators using the MEDLINE, Cochrane, Google Scholar, and Embase databases as well as abstracts and presentations from major cardiovascular meetings. Seventeen RCTs reporting the incidence of new-onset DM during statin treatment and including a total of 113,394 patients were identified. The RCTs compared either a statin versus placebo or high-dose versus moderate-dose statin therapy. Among different statins, pravastatin 40 mg/day was associated with the lowest risk for new-onset DM compared with placebo (odds ratio 1.07, 95% credible interval 0.86 to 1.30). Conversely, rosuvastatin 20 mg/day was numerically associated with 25% increased risk for DM compared with placebo (odds ratio 1.25, 95% credible interval 0.82 to 1.90). The impact on DM appeared to be intermediate with atorvastatin 80 mg/day compared with placebo (odds ratio 1.15, 95% credible interval 0.90 to 1.50). These findings were replicated at moderate doses. In conclusion, different types and doses of statins show different potential to increase the incidence of DM.

Genetic determinants of platelet response to clopidogrel

Antiplatelet agents are the mainstay treatment in the prevention and management of atherothrombotic complications. However, a substantial interpatient variability in response to clopidogrel has been reported. Furthermore, patients with coronary artery disease and lesser platelet inhibition in response to clopidogrel are at increased risk for cardiovascular events. Clopidogrel after absorption requires two-step oxidation by the hepatic cytochrome P450 to generate its active metabolite. Polymorphisms of genes encoding the cytochrome enzymes and P-glycoprotein involved in clopidogrel absorption are regarded as major determinants of the interindividual variability in the clopidogrel-induced platelet inhibition. In our review we discuss the prevalence and clinical significance of various alleles of the genes: CYP2C19 and ABCB1 in the setting of coronary artery disease. Allele CYP2C19*2 is associated with excess of ischaemic events including myocardial infarction and stent thrombosis. On the other hand, CYP2C19*17 allele poses a serious threat of bleeding. Data concerning the prognostic value of genetic variant 3435C→T of ABCB1 remain inconclusive.

Overview of pleiotropic effects of platelet P2Y12 receptor inhibitors.

Dual antiplatelet therapy consisting of one of the P2Y12 receptor inhibitors in conjunction with aspirin is the mainstay of treatment for patients with acute coronary syndromes (ACS) and those undergoing percutaneous coronary interventions (PCI). In recent years, multiple extra-platelet features of P2Y12 receptor antagonists have been reported in numerous clinical trials. The aim of this review is to summarise reported pleiotropic effects of clopidogrel, prasugrel, ticagrelor and other P2Y12 receptor blockers. We included observations made both in human and in animal models, together with proposed mechanisms of action for described features. If confirmed in randomised studies and properly applied to everyday practice, the observed extra-platelet actions could enable us to improve efficacy of ACS and post-PCI treatment, as well as to confine mortality and occurrence rate of cardiovascular events.

Impact of morphine on antiplatelet effects of oral P2Y12 receptor inhibitors

Abstract Morphine and P2Y12 receptor inhibitors are both recommended in patients with acute myocardial infarction. Morphine may impede gastrointestinal absorption of several oral drugs including P2Y12 platelet receptor inhibitors. The aim of this review was to critically discuss drug–drug interactions between oral P2Y12 receptor inhibitors and morphine according to currently available knowledge based on the findings of experimental, observational and randomized clinical studies. The morphine–clopidogrel pharmacodynamic interaction has been observed in numerous trials and it has been proposed as an explanation for the negative impact of morphine on the clinical outcomes in patients with acute coronary syndromes. An analogous morphine interaction with ticagrelor and prasugrel was found in several observational studies and finally proven in randomized trials in healthy volunteers and acute myocardial infarction patients. Morphine delays and attenuates exposure and antiplatelet action of oral P2Y12 receptor inhibitors in patients with myocardial infarction. Although this interaction may have potentially harmful consequences, routine avoidance of morphine cannot be recommended until clinically powered trials are completed.

Prasugrel overcomes high on-clopidogrel platelet reactivity in the acute phase of acute coronary syndrome and maintains its antiplatelet potency at 30-day follow-up

BACKGROUND The aim of this study was to assess antiplatelet effect of prasugrel in acute coronary syndrome (ACS) patients with high on-treatment platelet reactivity (HTPR) on clopidogrel, undergoing percutaneous coronary intervention (PCI). METHODS A prospective, platelet reactivity-guided, parallel-group, open-label study including 71 patients pretreated with clopidogrel 600 mg and assigned either to prasugrel (30 mg loading dose, 10 mg maintenance dose; n = 46) or clopidogrel (150 mg maintenance dose for 6 days and thereafter 75 mg maintenance dose; n = 25) regimen, based on vasodilator-stimulated phosphoprotein (VASP)-assessed platelet reactivity index (PRI; > 50% vs. ≤ 50%) measured next morning post-PCI. RESULTS Median PRI value after switch to prasugrel sharply declined at 24 h (70.0 [61.3-75.6] vs. 11.9 [6.8-25.7]%; p < 0.000001) and slightly but significantly rose between 24 h and 30 days (27.9 [15.5-46.8]%; p < 0.0006). In contrast, median PRI values in the clopidogrel group were similar at baseline and at 24 h (25.1 [13.7-40.2] vs. 22.0 [18.4-36.8]%; p = NS) and then modestly rose at 30 days (30.3 [20.4-45.7]%; p < 0.03). The prevalence of HTPR decreased in the prasugrel group between baseline and 24 h measurements (100.0 vs. 4.3%; p < 0.0001). Rates of patients with HTPR at 24 h and 30 days were similar in both groups, so were the tendencies in patterns of platelet inhibition evaluated with multiple electrode aggregometry as compared with the VASP assay. CONCLUSIONS Our study indicates that prasugrel overcomes HTPR on clopidogrel in the acute phase of interventionally treated ACS and maintains its antiplatelet potency in 30-day follow-up. Potential clinical benefits of personalized antiplatelet prasugrel-based therapy warrant further investigation in clinical ACS trials.

Cangrelor: an emerging therapeutic option for patients with coronary artery disease

Abstract Objectives: To perform a systematic up-to-date review and critical discussion of potential clinical applications of cangrelor based on its pharmacologic properties and the main findings from randomized clinical studies. Methods: A database search (PubMed, CENTRAL and Google Scholar) by two independent investigators, including proceedings from scientific sessions of ACC, AHA, ESC, TCT and EuroPCR, from January 1998 through December 2013. Results: Cangrelor is a potent, intravenous, direct-acting P2Y12 antagonist with rapid onset and quickly reversible action. In contrast to ticagrelor, cangrelor’s interaction with thienopiridines requires termination of cangrelor infusion before switching to clopidogrel or prasugrel. According to randomized trials, a cangrelor–clopidogrel combination is relatively safe and more effective than the standard clopidogrel regimen in both urgent and elective percutaneous coronary intervention (PCI) settings, with the advantage of this drug combination fully evident when the universal definition of myocardial infarction is applied. In contrast to available antiplatelet drugs with delayed onset and offset of action, its favorable properties make cangrelor a desirable agent for ad hoc elective PCI, high risk acute coronary syndromes treated with immediate coronary stenting and for bridging those surgery patients who require periprocedural P2Y12 inhibition. Current evidence on cangrelor therapy is limited by the lack of adequately powered studies assessing cangrelor co-administration either with prasugrel or ticagrelor, suboptimal design of some of the trials favoring cangrelor, potentially attenuated benefits with modern stent design, and finally, by the lack of survival advantage. Conclusions: With its pharmacokinetic and pharmacodynamic advantages, allowing consistent and strong P2Y12 inhibition, and with its rapid onset and swift reversal of action devoid of need for an antidote, cangrelor might improve clinical outcomes in clopidogrel-treated patients by reducing ischemic events, while maintaining a favorable safety profile. However, further studies, addressing the safety and efficacy of cangrelor on top of novel oral P2Y12 inhibitors, are warranted.

High-Dose, but Not Low-Dose, Aspirin Impairs Anticontractile Effect of Ticagrelor following ADP Stimulation in Rat Tail Artery Smooth Muscle Cells

Objective. To compare effects of low- versus high-dose aspirin coadministered with ticagrelor on the reactivity of vascular smooth muscle cells (VSMCs). Methods. Wistar rats were orally administered ticagrelor (10 mg/kg) and/or aspirin (2 or 10 mg/kg) (n = 7 per each of 4 groups) or placebo (n = 9) 12 and 2 hours before experiments. Anticontractile effects of ticagrelor were assessed in perfusion solution containing ticagrelor (1 μM/L). Changes in perfusion pressure proportional to the degree of adenosine diphosphate analogue- (2-MeS-ADP-) and phenylephrine-induced constriction of rat tail arteries were evaluated. Results. Pretreatment with high- but not low-dose aspirin enhanced the reactivity of VSMCs only in endothelium-lined vessels. Suppression of 2-MeS-ADP-induced VSMC contraction by ticagrelor observed in arteries with and without endothelium was maintained in endothelialized arteries pretreated only with low-dose aspirin. For endothelium-denuded vessels and low-dose aspirin we observed a significant reduction of the maximal effect of ticagrelor with no rightward shift of the concentration-response curve for phenylephrine. With high-dose aspirin pretreatment ticagrelor exerted no anticontractile effect. Conclusion. High-dose, but not low-dose, aspirin impairs the anticontractile effect of ticagrelor on ADP-induced VSMC contraction in the rat model. Both the clinical significance and detailed underlying mechanism of our findings require further investigation.

Updated evidence on intracoronary abciximab in ST-elevation myocardial infarction: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND Intracoronary (IC) abciximab administration remains a promising approach aimed to increase a drug concentration in the target area and possibly improve clinical outcomes in the setting of ST-segment elevation myocardial infarction (STEMI). The goal of this literature review and meta-analysis is to update available knowledge comparing IC and intravenous (IV) abciximab administration in STEMI patients. METHODS A total of 7 randomized clinical trials (RCTs) with a median follow-up of 3 months were included in the meta-analysis (n = 3311). All-cause mortality was selected as the primary end point while recurrent myocardial infarction (re-MI), target vessel revascularization (TVR) and major bleeding complications were the secondary end points. RESULTS IC abciximab did not provide any benefits in terms of all-cause mortality as compared with IV abciximab (odds ratio [OR] 0.67; 95% confidence interval [CI] 0.34-1.34). However, this neutral effect was driven by the AIDA STEMI trial. The IC route was associated with a reduced rate of re-MI when compared with IV administration (OR 0.61; 95% CI 0.40-0.92) but the difference disappeared after one of the RCTs was excluded from the analysis. Both strategies were equal regarding TVR (OR 0.66; 95% CI 0.40-1.09) and major bleeding complications (OR 1.18; 95% CI 0.76-1.83). CONCLUSIONS Our updated meta-analysis shows that the clinical superiority of IC over IV abciximab administration in STEMI patients is no longer clear after the release of the AIDA STEMI trial results. Further research in high-risk STEMI patients is warranted to finally determine clinical advantages of IC vs IV abciximab administration.

Time-related changes in determinants of antiplatelet effect of clopidogrel in patients after myocardial infarction☆

Substantial variability of antiplatelet action is an important limitation of clopidogrel. The aim of this study was to evaluate time-related changes in determinants of clopidogrel responsiveness in patients after myocardial infarction. The study population comprised 191 consecutive patients treated with primary percutaneous coronary intervention for acute myocardial infarction. Follow-up visits were scheduled at 3, 6 and 9 months after discharge. ADP-induced platelet aggregation was tested with Multiplate Analyzer. Patients with ADP-PA>46.8U were defined as clopidogrel non-responders. The prevalence of clopidogrel non-responsiveness was highest during hospitalization and at 9 month follow-up visit, while it was lowest at 3 and 6 months after myocardial infarction (P=0.004). According to multivariate analysis, platelet count, mean platelet volume, concentration of hsCRP and leukocyte count influenced ADP-induced platelet aggregation in multiple assessment points. BMI, concentrations of hemoglobin, glycated hemoglobin, and BNP, hematocrit, adherence to medication, and patient׳s age were found to be independent predictors of high on-treatment ADP-induced platelet aggregation only at a single follow-up visit. Determinants of clopidogrel responsiveness in patients after myocardial infarction change within the long-term therapy. During hospitalization and early after discharge only biological factors affect ADP-induced platelet aggregation, while non-adherence to antiplatelet therapy may be a significant factor in determining clopidogrel non-responsiveness during late follow-up visits.

ACS network-based implementation of therapeutic hypothermia for the treatment of comatose out-of-hospital cardiac arrest survivors improves clinical outcomes: the first European experience

BackgroundThere is a paucity of data regarding clinical outcomes associated with the integration of a mild therapeutic hypothermia (MTH) protocol into a regional network dedicated to treatment of patients with acute coronary syndromes (ACS). Additionally, a recent report suggests that the neurological benefits of MTH therapy in interventionally managed ACS patients resuscitated from out-of-hospital cardiac arrest (OHCA) may be potentially offset by the catastrophic occurrence of stent thrombosis. The goal of this study was to share our experience with the implementation of an MTH program using a previously established ACS network in consecutive comatose OHCA survivors undergoing interventional management due to an initial diagnosis of ACS and to assess the clinical effectiveness and safety of MTH.MethodsWe conducted a retrospective historically controlled single centre study. Hospital survival with a favourable neurological outcome (Cerebral Performance Category of 1 or 2) and all-cause in-hospital mortality were the primary and secondary efficacy end points, respectively. Occurrence of definite stent thrombosis was the primary safety end point while the development of pneumonia, presence of positive blood cultures, occurrence of probable stent thrombosis, any bleeding complications, need for red blood cell transfusion and presence of rhythm and conductions disorders during hospitalisation constituted secondary safety end points.ResultsComatose OHCA survivors (n = 32) were referred to our Department based on ECG recording transmissions and/or phone consultations or admitted from the Emergency Department. Compared with controls (n = 33), they were significantly more likely to be discharged from hospital with a favourable neurological outcome (59 vs. 27%; p < 0.05; number needed to treat [NNT] = 3.11) and experienced lower all-cause in-hospital mortality (13 vs. 55%; p < 0.05; NNT = 2.38). Rates of all safety end points were similar in patients treated with and without MTH.ConclusionsOur study indicates that a regional system of care for OHCA survivors may be successfully implemented based on an ACS network, leading to an improvement in neurological status and to a reduction of in-hospital mortality in patients treated with MTH, without any excess of complications. However, our findings should be verified in large, prospective trials.