Increased symmetric dimethyl-arginine is a predictor factor of decreased platelet reactivity and increased bleeding risk in patients with acute coronary syndrome

Background

One of the promising biomarkers in CVD are asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), which are products of L-arginine methylation and are both involved in endothelial dysfunction. ADMA, SDMA and L-homoarginine, have emerged as biomarkers linked to cardiovascular outcomes [1].

Purpose

To investigate the association of SDMA with platelet reactivity and bleeding risk in patients with acute coronary syndrome (ACS) treated with potent P2Y12 inhibitors prasugrel and ticagrelor.

Methods

Our prospective observational study enrolled 292 patients with ACS undergoing percuteneus coronary intervention [2]. Plasma concentrations of SDMA were measured during the hospitalization for ACS. Impedance aggregometry was used. The primary study endpoint was the concentration of metabolites and platelet reactivity. The primary clinical outcome endpoint was the incidence of Thrombolysis in Myocardial Infarction (TIMI) bleeding events (major, minor and minimal). The efficacy endpoint was the composite of major adverse cardiac events (MACE: stent thrombosis, myocardial infarction, stroke and cardiac death).

Results

There was an inverse correlation between SDMA serum levels and platelet reactivity (r=−0.25; p<0.000). The ADP+PGE1-induced platelet reactivity was 33% lower among patients with the highest SDMA quartile (4th) as compared to those with the 1–3rd SDMA quartile (8 [0–29] vs 12 [0–126] U; p<0.001). The AA-induced platelet reactivity was 56% lower among patients with the highest SDMA quartile (4th) as compared to those with the 1–3rd SDMA quartile (4 [0–48] vs 9 [0–133]; p<0.001). In a multivariate model, the highest SDMA (4th) quartile was found to be an independent predictor of the lowest ADP+PGE1 and AA induced platelet aggregation (OR: 2.666, 95% CI [1.184–5.999], p=0.018).

Conclusions

Our study shows that high plasma concentration of SDMA, but not ADMA, is independently associated with low platelet reactivity to ADP and AA and is associated with major and minor bleeding events in patients with ACS on potent antiplatelet therapies. Therefore, SDMA might have a potential to be further evaluated as a blood biomarker for individualization of duration and potency of antiplatelet therapies in an ACS population at high risk of bleeding complications.

Acknowledgment

I-COMET research team

Funding Acknowledgement

Type of funding sources: None. Figure 1Table 1

High concentrations of plasma trimethylamine-n-oxide is associated with long-term cardiovascular mortality in patients with acute coronary syndrome

Background

Acute coronary syndrome (ACS) remains a leading cause of mortality worldwide [1]. Patients who experienced ACS are at high risk of future cardiovascular events and death [2–4]. Identification of reliable predictive tools could potentially improve the risk stratification [5]. Numerous studies revealed that intestinal microbial organisms (microbiota) and its metabolites, as TMAO (trimethylamine-N-oxide) may play a pathogenic role in a cardiovascular disease (CVD) and ACS [6]. Elevated concentration of circulating TMAO has been associated with increased risk of CVD and major adverse cardiac events (MACE), including myocardial infarction (MI), stroke, major bleeding and all-cause mortality [7].

Purpose

To investigate the association of liver metabolite TMAO with cardiovascular disease (CV)-related and all-cause mortality in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention.

Methods

Our prospective observational study enrolled 292 patients with ACS. Plasma concentrations of TMAO were measured during the hospitalization for ACS. Observation period lasted 7 years in the median. Adjusted Cox-regression analysis was used for prediction of mortality.

Results

ROC curve analysis revealed that increasing concentrations of TMAO levels assessed at the time point of ACS significantly predicted the risk of CV mortality (c-index=0.78, p<0.001). The cut-off value of >4 μmol/L, labeled as high TMAO level (23% of study population), provided the greatest sum of sensitivity (85%) and specificity (80%) for the prediction of CV mortality and was associated with a positive predictive value of 16% and a negative predictive value of 99%. A multivariate Cox regression model revealed that high TMAO level was a strong and independent predictor of CV death (HR=11.62, 95% CI: 2.26–59.67; p=0.003). High TMAO levels as compared with low TMAO levels were associated with the highest risk of CV death in a subpopulation of patients with diabetes mellitus (27.3% vs 2.6%; p=0.004). Although increasing TMAO levels were also significantly associated with all-cause mortality, their estimates for diagnostic accuracy were low.

Conclusions

High TMAO level is a strong and independent predictor of long-term CV mortality among patients presenting with ACS. TMAO concentration of 4 μmol/L may be a cut-off value for prognosis of ACS patients.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Kaplan-Meier curvesTable 1

P668Aspirin for primary prevention of cardiovascular disease

Background

Platelet inhibition by aspirin reduces ischemic events but increases the risk of bleeding events. Yet, the role of aspirin in primary prevention of cardiovascular disease remains unclear.

Purpose

To produce a clinically relevant benefit-risk assessment of aspirin for primary prevention of cardiovascular disease.

Methods

We performed a meta-analysis of aspirin effects in primary prevention of cardiovascular disease comprising 13 randomized-controlled trials in 164.225 patients comparing aspirin versus placebo/control during a mean follow-up period of 6.4 years. Using a random effect model, relative risks and 95% confidence intervals were calculated for each outcome.

Results

Aspirin reduced the relative risk of ischemic stroke by 10% (RR: 0.90; 95% CI: 0.82–0.99), myocardial infarction by 14% (RR: 0.86; 95% CI: 0.77–0.95) and the major adverse cardiovascular events by 9% (RR: 0.91; 95% CI: 0.86–0.95) but was associated with a 46% relative risk increase of major bleeding events (RR: 1.46; 95% CI: 1.30–1.64). Aspirin did not reduce the risk of cardiovascular mortality (RR: 0.99; 95% CI: 0.90–1.08), all-cause mortality (RR: 0.98; 95% CI: 0.93–1.02) or cancer (RR 1.05; 95% CI, 0.87–1.26). Aspirin use did not translate into a net clinical benefit adjusted for event-associated mortality risk (mean 0.034%; 95% CI: −0.18 to 0.25%).

Forest plot of major outcomes.

Conclusions

Aspirin use in primary prevention is associated with a reduced risk of stroke and myocardial infarction, but at a cost of an increased risk of major bleeding.

Acknowledgement/Funding

None

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

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).

Clinical implications of drug-drug interactions with P2Y12 receptor inhibitors

Polypharmacy in patients undergoing coronary artery stenting or in those presenting with an acute coronary syndrome is common. Nevertheless, the risk of drug-drug interactions in patients treated simultaneously with P2Y12 receptor inhibitors is less well considered in routine clinical practice. Whereas the irreversible P2Y12 receptor inhibitors clopidogrel and prasugrel are prodrugs requiring cytochrome P450 (CYP) enzymes for metabolic activation, such activation is not necessary for the direct-acting reversible P2Y12 receptor inhibitor ticagrelor. Several drugs frequently used in cardiology have been shown to interact with the metabolism of P2Y12 receptor inhibitors in pharmacodynamic studies. Whereas several drug-drug interactions have been described for clopidogrel and ticagrelor, prasugrel seems to have a low potential for drug-drug interactions. The clinical implications of these interactions have raised concern. In general, concomitant administration of P2Y12 receptor antagonists and strong inhibitors or inducers of CYP3A/CYP2C19 should be performed with caution in patients treated with clopidogrel/ticagrelor. Under most circumstances, clinicians have the option of prescribing alternative drugs with less risk of drug-drug interactions when used concomitantly with P2Y12 receptor inhibitors.

Phenotyping vs. genotyping for prediction of clopidogrel efficacy and safety: the PEGASUS-PCI study

BACKGROUND

Prognostic values of genotyping and phenotyping for assessment of clopidogrel responsiveness have been shown in independent studies.

OBJECTIVES

To compare different assays for prediction of events during long-term follow-up.

METHODS

In this prospective cohort study polymorphisms of CYP2C19*2 and CYP2C19*17 alleles, vasodilator-stimulated phosphoprotein phosphorylation (VASP) assay, multiple electrode aggregometry (MEA), cone and platelet analyser (CPA) and platelet function analyser (PFA-100) were performed in 416 patients undergoing percutaneous coronary intervention. The rates of events were recorded during a 12-month follow-up.

RESULTS

Platelet aggregation by MEA predicted stent thrombosis (2.4%) better (c-index = 0.90; P < 0.001; sensitivity = 90%; specificity = 83%) than the VASP assay, CPA or PFA-100 (c-index < 0.70; P > 0.05; sensitivity < 70%; specificity < 70% for all) or even the CYP2C19*2 polymorphism (c-index < 0.56; P > 0.05; sensitivity = 30%; specificity = 71%). Survival analysis indicated that patients classified as poor responders by MEA had a substantially higher risk of developing stent thrombosis or MACE than clopidogrel responders (12.5% vs. 0.3%, P < 0.001, and 18.5% vs. 11.3%, P = 0.022, respectively), whereas poor metabolizers (CYP2C19*1/*2 or *2/*2 carriers) were not at increased risks (stent thrombosis, 2.7% vs. 2.5%, P > 0.05; MACE, 13.5% vs. 12.1%, P = 0.556). The incidence of major bleedings (2.6%) was numerically higher in patients with an enhanced vs. poor response to clopidogrel assessed by MEA (4% vs. 0%) or in ultra-metabolizers vs. regular metabolizers (CYP2C19*17/*17 vs. CYP2C19*1/*1; 9.5% vs. 2%). The classification tree analysis demonstrated that acute coronary syndrome at hospitalization and diabetes mellitus were the best discriminators for clopidogrel responder status.

CONCLUSIONS

 Phenotyping of platelet response to clopidogrel was a better predictor of stent thrombosis than genotyping.

Low-molecular-weight heparins vs. unfractionated heparin in the setting of percutaneous coronary intervention for ST-elevation myocardial infarction: a meta-analysis

BACKGROUND

The aim of the current study was to perform two separate meta-analyses of available studies comparing low-molecular-weight heparins (LMWHs) vs. unfractionated heparin (UFH) in ST-elevation myocardial infarction (STEMI) patients treated (i) with primary percutaneous coronary intervention (pPCI) or (ii) with PCI after thrombolysis.

METHODS

All-cause mortality was the pre-specified primary endpoint and major bleeding complications were recorded as the secondary endpoints. Relative risk (RR) with a 95% confidence interval (CI) and absolute risk reduction (ARR) were chosen as the effect measure.

RESULTS

Ten studies comprising 16,286 patients were included. The median follow-up was 2 months for the primary endpoint. Among LMWHs, enoxaparin was the compound most frequently used. In the pPCI group, LMWHs were associated with a reduction in mortality [RR (95% CI) = 0.51 (0.41-0.64), P < 0.001, ARR = 3%] and major bleeding [RR (95% CI) = 0.68 (0.49-0.94), P = 0.02, ARR = 2.0%] as compared with UFH. Conversely, no clear evidence of benefits with LWMHs was observed in the PCI group after thrombolysis. Meta-regression showed that patients with a higher baseline risk had greater benefits from LMWHs (r = 0.72, P = 0.02).

CONCLUSIONS

LMWHs were associated with greater efficacy and safety than UFH in STEMI patients treated with pPCI, with a significant relationship between risk profile and clinical benefits. Based on this meta-analysis, LMWHs may be considered as a preferred anticoagulant among STEMI patients undergoing pPCI.

Effect of proton pump inhibitors on clinical outcome in patients treated with clopidogrel: a systematic review and meta-analysis

To investigate whether proton pump inhibitors (PPIs) negatively affect clinical outcome in patients treated with clopidogrel. Systematic review and meta-analysis. Outcomes evaluated were combined major adverse cardiac events (MACE), myocardial infarction (MI), stent thrombosis, death and gastrointestinal bleeding. Studies included were randomized trials or post-hoc analyzes of randomized trials and observational studies reporting adjusted effect estimates. Twenty five studies met the selection criteria and included 159 138 patients. Administration of PPIs together with clopidogrel corresponded to a 29% increased risk of combined major cardiovascular events [risk ratio (RR) = 1.29, 95% confidence intervals (CI) = 1.15-1.45] and a 31% increased risk of MI (RR = 1.31, 95%CI = 1.12-1.53). In contrast, PPI use did not negatively influence the mortality (RR = 1.04, 95%CI = 0.93-1.16), whereas the risk of developing a gastrointestinal bleed under PPI treatment decreased by 50% (RR = 0.50, 95% CI = 0.37-0.69). The presence of significant heterogeneity might indicate that the evidence is biased, confounded or inconsistent. The sensitivity analysis, however, yielded that the direction of the effect remained unchanged irrespective of the publication type, study quality, study size or risk of developing an event. Two studies indicate that PPIs have a negative effect irrespective of clopidogrel exposure. In conclusion, concomitant PPI use might be associated with an increased risk of cardiovascular events but does not influence the risk of death. Prospective randomized trials are required to investigate whether a cause-and-effect relationship truly exists and to explore whether different PPIs worsen clinical outcome in clopidogrel treated patients as the PPI-clopidogrel drug-drug interaction does not seem to be a class effect.

Effect of proton pump inhibitors on clinical outcome in patients treated with clopidogrel: a systematic review and meta-analysis

To investigate whether proton pump inhibitors (PPIs) negatively affect clinical outcome in patients treated with clopidogrel. Systematic review and meta-analysis. Outcomes evaluated were combined major adverse cardiac events (MACE), myocardial infarction (MI), stent thrombosis, death and gastrointestinal bleeding. Studies included were randomized trials or post-hoc analyzes of randomized trials and observational studies reporting adjusted effect estimates. Twenty five studies met the selection criteria and included 159 138 patients. Administration of PPIs together with clopidogrel corresponded to a 29% increased risk of combined major cardiovascular events [risk ratio (RR) = 1.29, 95% confidence intervals (CI) = 1.15-1.45] and a 31% increased risk of MI (RR = 1.31, 95%CI = 1.12-1.53). In contrast, PPI use did not negatively influence the mortality (RR = 1.04, 95%CI = 0.93-1.16), whereas the risk of developing a gastrointestinal bleed under PPI treatment decreased by 50% (RR = 0.50, 95% CI = 0.37-0.69). The presence of significant heterogeneity might indicate that the evidence is biased, confounded or inconsistent. The sensitivity analysis, however, yielded that the direction of the effect remained unchanged irrespective of the publication type, study quality, study size or risk of developing an event. Two studies indicate that PPIs have a negative effect irrespective of clopidogrel exposure. In conclusion, concomitant PPI use might be associated with an increased risk of cardiovascular events but does not influence the risk of death. Prospective randomized trials are required to investigate whether a cause-and-effect relationship truly exists and to explore whether different PPIs worsen clinical outcome in clopidogrel treated patients as the PPI-clopidogrel drug-drug interaction does not seem to be a class effect.

Effect of proton pump inhibitors on clinical outcome in patients treated with clopidogrel: a systematic review and meta-analysis

To investigate whether proton pump inhibitors (PPIs) negatively affect clinical outcome in patients treated with clopidogrel. Systematic review and meta-analysis. Outcomes evaluated were combined major adverse cardiac events (MACE), myocardial infarction (MI), stent thrombosis, death and gastrointestinal bleeding. Studies included were randomized trials or post-hoc analyzes of randomized trials and observational studies reporting adjusted effect estimates. Twenty five studies met the selection criteria and included 159 138 patients. Administration of PPIs together with clopidogrel corresponded to a 29% increased risk of combined major cardiovascular events [risk ratio (RR) = 1.29, 95% confidence intervals (CI) = 1.15-1.45] and a 31% increased risk of MI (RR = 1.31, 95%CI = 1.12-1.53). In contrast, PPI use did not negatively influence the mortality (RR = 1.04, 95%CI = 0.93-1.16), whereas the risk of developing a gastrointestinal bleed under PPI treatment decreased by 50% (RR = 0.50, 95% CI = 0.37-0.69). The presence of significant heterogeneity might indicate that the evidence is biased, confounded or inconsistent. The sensitivity analysis, however, yielded that the direction of the effect remained unchanged irrespective of the publication type, study quality, study size or risk of developing an event. Two studies indicate that PPIs have a negative effect irrespective of clopidogrel exposure. In conclusion, concomitant PPI use might be associated with an increased risk of cardiovascular events but does not influence the risk of death. Prospective randomized trials are required to investigate whether a cause-and-effect relationship truly exists and to explore whether different PPIs worsen clinical outcome in clopidogrel treated patients as the PPI-clopidogrel drug-drug interaction does not seem to be a class effect.

Tacrolimus-eluting carbon-coated stents versus sirolimus-eluting stents for prevention of symptom-driven clinical end points

BACKGROUND

Coating of stents has been shown to minimize the interactions between platelets, stent surface and vascular response following stent implantation. The aim of our study was to compare the tacrolimus-eluting carbon-coated JANUS(®) stent with sirolimus-eluting CYPHER(®) stent for the prevention of symptom-driven clinical end points in a real world clinical setting.

METHODS

This prospective registry with a follow-up period of 24 months was conducted in 90 consecutive patients undergoing coronary artery stenting receiving CYPHER(®) (n = 48) or JANUS(®) (n = 42) stents. The primary end point was a composite of death from cardiovascular causes, nonfatal myocardial infarction and target vessel revascularisation, and the secondary end point was clinically driven in-stent restenosis.

RESULTS

The primary combined endpoint occurred in 38% of patients (n = 16) in the JANUS(®) group compared to 10% (n = 5) in the CYPHER(®) group. The relative risk increase of the composite end point was therefore 63% higher in patients receiving JANUS(®) stents compared to the CYPHER(®) stents (crude HR = 1.63, 95% CI = 1.17-2.28, p = 0.004; adjusted HR = 1.79, CI = 1.26-2.55, p = 0.001). Interestingly, 75% of events in the JANUS(®) group occurred during the first 6 months after stent implantation. Similarly, the rate of clinically driven in-stent restenosis was higher in patients receiving JANUS(®) stent (n = 10, 2%) compared to the CYPHER(®) stent (n = 2, 4%). Concordantly, the relative risk for clinically driven in-stent restenosis was 81% higher in the JANUS(®) group compared to the CYPHER(®) group (crude HR = 1.81, 95% CI = 1.08-3.02, p = 0.02; adjusted HR = 2.24, CI = 1.26-3.96, p = 0.006).

CONCLUSION

The use of tacrolimus-eluting carbon coated JANUS(®) stent was associated with worse clinical outcome compared to the sirolimus-eluting CYPHER(®) stent in clinical routine use.

Multiple electrode aggregometry predicts stent thrombosis better than the vasodilator-stimulated phosphoprotein phosphorylation assay

BACKGROUND AND AIM

The prognostic value of the vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay and multiple electrode aggregometry (MEA) for thrombotic adverse events has been shown in independent studies. As no direct comparison between the two methods has been made so far, we investigated which laboratory approach has a better predictive value for stent thrombosis.

METHODS

The VASP phosphorylation assay and MEA were performed in 416 patients with coronary artery disease undergoing percutaneous coronary intervention. The rate of stent thrombosis was recorded during a 6-month follow-up.

RESULTS

Definite stent thrombosis occurred in three patients (0.7%) and probable stent thrombosis in four (1%). Receiver operating characteristic (ROC) analysis demonstrated that MEA distinguishes between patients with or without subsequent stent thrombosis better than the VASP phosphorylation assay: the area under the ROC curve was higher for MEA (0.92; P=0.012) than for the VASP phosphorylation assay (0.60; P=0.55). At equal levels of sensitivity (100%), the specificity was greater for MEA than for the VASP phosphorylation assay (86% vs. 37%). Stent thrombosis occurred in 9% of patients with platelet hyperreactivity in MEA, who were simultaneously clopidogrel non-responders in the VASP phosphorylation assay. Interestingly, clopidogrel non-responders in the VASP phosphorylation assay without platelet hyperreactivity in MEA did not suffer from stent thrombosis.

CONCLUSIONS

Platelet hyperreactivity in MEA might be a better risk predictor for stent thrombosis than the assessment of the specific clopidogrel effect with the VASP phosphorylation assay.