The effect of clopidogrel on platelet activity in patients with and without type-2 diabetes mellitus: a comparative study

Prevalence of CYP2C19*2 and CYP2C19*3 Allelic Variants and Clopidogrel Use in Patients with Cardiovascular Disease in Trinidad & Tobago

INTRODUCTION

Trinidad & Tobago has the highest prevalence of cardiovascular disease (CVD) in the Caribbean and clopidogrel is a ubiquitously used treatment. Yet, the extent of genetically mediated clopidogrel resistance is unknown. To determine this, we investigated whether the association between CYP2C19*2 and CYP2C19*3 genetic variants and clopidogrel resistance holds, and calculated the frequencies of these in the Trinidadian CVD population.

METHODS

Demographic data, clinical data, and a saliva sample were collected under informed consent from 22 patients with CVD on dual anti-platelet therapy whose biochemical resistance to clopidogrel is known, and a further 162 patients accessing the main public CVD clinic in Trinidad and who are either currently being treated or are likely to be treated with clopidogrel. A polymerase chain reaction (PCR) and restriction enzyme digestion procedure was used to genotype each patient for the CYP2C19*2 and CYP2C19*3 allelic variants. Genotype was compared to known clopidogrel resistance in the 22 patients, and to disease status and clopidogrel usage in the larger cohort.

RESULTS

CYP2C19*2 genotype was concordant with clopidogrel resistance. CYP2C19*2 was detected in 61.1% (99/162) of patients and CYP2C19*3 was undetected. Clopidogrel was the most prescribed antiplatelet therapy (42%). A total of 120 people presented with coronary artery disease (CAD) and 52.5% of these (n = 63/120) are currently prescribed clopidogrel. 63.5% (40/63) of patients with CAD who are prescribed clopidogrel carry the CYP2C19*2 allele; ten homozygous and 30 heterozygous. Indian patients comprised 65% of the cohort and were four times more likely to carry the CYP2C19*2 allele than African patients.

CONCLUSIONS

A large proportion of Trinidadian patients with CVD who are prescribed or may be prescribed clopidogrel carry genetic variants associated with clopidogrel resistance. These results emphasize the clinical need for further investigation into whether CYP2C19*2 genotype should guide clopidogrel use for the cardiovascular disease population in Trinidad & Tobago. A slide deck is available for this article.

NT-proBNP and cardiovascular event risk in individuals with prediabetes undergoing cardiovascular evaluation

AIMS

Cardiovascular risk assessment beyond traditional risk factors in subjects with prediabetes is not well-established. Here, we evaluated the utility of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in predicting incident adverse cardiovascular outcomes in prediabetic subjects.

METHODS

NT-proBNP was analyzed in 3,235 stable subjects with prediabetes undergoing cardiovascular risk evaluation and followed for both 3-year major adverse cardiac events (MACE; death, myocardial infarction, stroke), and 5-year all-cause mortality.

RESULTS

Using Cox proportional hazard models, we found that plasma NT-proBNP was associated with incident (3-year) MACE risk (Q4 vs Q1, HR 6.04 [95%CI 4.17-8.76], P < 0.001) and 5-year mortality risk (HR 8.64 [95%CI 5.78-12.9], P < 0.001). These associations remained significant after adjustments for traditional cardiovascular risk factors, multiple indices of glycemic control, cardiovascular disease (CVD), left ventricular ejection fraction (LVEF), and medication (e.g. diuretic) use (adjusted HR for 3-year MACE 2.65 [95% CI 1.16-6.05], P < 0.05; and adjusted HR for 5-year mortality 3.45 [95% CI 1.42-8.39], P < 0.01). NT-proBNP significantly improved the clinical prognostic value (C-statistic, NRI, IDI) for both 3-year MACE and 5-year death when added to models.

CONCLUSIONS

NT-proBNP independently predicts increased long-term MACE and mortality risks in prediabetic subjects, and may help identify those for whom more aggressive global preventive efforts are indicated.

Being Overweight or Obese Is Associated with an Increased Platelet Reactivity Despite Dual Antiplatelet Therapy with Aspirin and Clopidogrel

PURPOSE

Obese patients exhibit an overall increased platelet reactivity and a reduced sensitivity to antiplatelet therapy. The aim of this study is to evaluate the platelet reactivity measured by impedance aggregometry in overweight and obese patients and chronic coronary syndrome (CCS) that were treated with dual antiplatelet therapy (DAPT).

METHODS

Platelet aggregation was assessed by impedance aggregometry in patients with CCS receiving DAPT (aspirin plus clopidogrel). We compared the platelet reactivity in patients with a normal weight versus overweight or obese patients. Furthermore, the correlation between the body mass index (BMI) and adenosine diphosphate- (ADP-) or thrombin receptor-activating peptide- (TRAP-) dependent platelet aggregation was analyzed.

RESULTS

64 patients were included in the study of which 35.9% were patients with normal weight. A higher ADP- and TRAP-dependent platelet reactivity was observed in overweight and obese patients (ADP: median 27 units (U) [IQR 13-39.5] vs. 7 U [6-15], p < 0.001 and TRAP: 97 U [73-118.5] vs. 85 U [36-103], p = 0.035). Significant positive correlations were observed between agonist-induced platelet reactivity and BMI.

CONCLUSION

Despite the use of DAPT, a higher platelet reactivity was found in overweight and obese patients with CCS. If these patients will benefit from treatment with more potent platelet inhibitors, it needs to be evaluated in future clinical trials.

Clinically important alterations in pharmacogene expression in histologically severe nonalcoholic fatty liver disease

Polypharmacy is common in patients with nonalcoholic fatty liver disease (NAFLD) and previous reports suggest that NAFLD is associated with altered drug disposition. This study aims to determine if patients with NAFLD are at risk for altered drug response by characterizing changes in hepatic mRNA expression of genes mediating drug disposition (pharmacogenes) across the histological NAFLD severity spectrum. We utilize RNA-seq for 93 liver biopsies with histologically staged NAFLD Activity Score (NAS), fibrosis stage, and steatohepatitis (NASH). We identify 37 significant pharmacogene-NAFLD severity associations including CYP2C19 downregulation. We chose to validate CYP2C19 due to its actionability in drug prescribing. Meta-analysis of 16 independent studies demonstrate that CYP2C19 is significantly downregulated to 46% in NASH, to 58% in high NAS, and to 43% in severe fibrosis. Our data demonstrate the downregulation of CYP2C19 in NAFLD which supports developing personalized medicine approaches for drugs sensitive to metabolism by the CYP2C19 enzyme.

Impact of type 2 diabetes on in vivo activities and protein expressions of cytochrome P450 in patients with obesity

Previous studies have not accounted for the close link between type 2 diabetes mellitus (T2DM) and obesity when investigating the impact of T2DM on cytochrome P450 (CYP) activities. The aim was to investigate the effect of T2DM on in vivo activities and protein expressions of CYP2C19, CYP3A, CYP1A2, and CYP2C9 in patients with obesity. A total of 99 patients from the COCKTAIL study (NCT02386917) were included in this cross-sectional analysis; 29 with T2DM and obesity (T2DM-obesity), 53 with obesity without T2DM (obesity), and 17 controls without T2DM and obesity (controls). CYP activities were assessed after the administration of a cocktail of probe drugs including omeprazole (CYP2C19), midazolam (CYP3A), caffeine (CYP1A2), and losartan (CYP2C9). Jejunal and liver biopsies were also obtained to determine protein concentrations of the respective CYPs. CYP2C19 activity and jejunal CYP2C19 concentration were 63% (-0.39 [95% CI: -0.82, -0.09]) and 40% (-0.09 fmol/μg protein [95% CI: -0.18, -0.003]) lower in T2DM-obesity compared with the obesity group, respectively. By contrast, there were no differences in the in vivo activities and protein concentrations of CYP3A, CYP1A2, and CYP2C9. Multivariable regression analyses also indicated that T2DM was associated with interindividual variability in CYP2C19 activity, but not CYP3A, CYP1A2, and CYP2C9 activities. The findings indicate that T2DM has a significant downregulating impact on CYP2C19 activity, but not on CYP3A, CYP1A2, and CYP2C9 activities and protein concentrations in patients with obesity. Hence, the effect of T2DM seems to be isoform-specific.

Disease Severity in Moderate-to-Severe COVID-19 Is Associated With Platelet Hyperreactivity and Innate Immune Activation

Background

Hemostasis and inflammation are both dysregulated in patients with moderate-to-severe coronavirus disease 2019 (COVID-19). Yet, both processes can also be disturbed in patients with other respiratory diseases, and the interactions between coagulation, inflammation, and disease severity specific to COVID-19 are still vague.

Methods

Hospitalized patients with acute respiratory symptoms and with severe acute respiratory syndrome coronavirus 2 (SARS-CoV2)-positive (COVpos) and SARS-CoV2-negative (COVneg) status were included. We assessed adenosine diphosphate (ADP)-, thrombin receptor activator peptide 6 (TRAP)-, and arachidonic acid (AA)-induced platelet reactivity by impedance aggregometry, as well as leukocyte subtype spectrum and platelet-leukocyte aggregates by flow cytometry and inflammatory cytokines by cytometric bead array.

Results

ADP-, TRAP-, and AA-induced platelet reactivity was significantly higher in COVpos than in COVneg patients. Disease severity, assessed by sequential organ failure assessment (SOFA) score, was higher in COVpos than in COVneg patients and again higher in deceased COVpos patients than in surviving COVpos. The SOFA score correlated significantly with the mean platelet volume and TRAP-induced platelet aggregability. A larger percentage of classical and intermediate monocytes, and of CD4pos T cells (TH) aggregated with platelets in COVpos than in COVneg patients. Interleukin (IL)-1 receptor antagonist (RA) and IL-6 levels were higher in COVpos than in COVneg patients and again higher in deceased COVpos patients than in surviving COVpos. IL-1RA and IL-6 levels correlated with the SOFA score in COVpos but not in COVneg patients. In both respiratory disease groups, absolute levels of B-cell-platelet aggregates and NK-cell-platelet aggregates were correlated with ex vivo platelet aggegation upon stimulation with AA and ADP, respectively, indicating a universal, but not a COVID-19-specific mechanism.

Conclusion

In moderate-to-severe COVID-19, but not in other respiratory diseases, disease severity was associated with platelet hyperreactivity and a typical inflammatory signature. In addition to a severe inflammatory response, platelet hyperreactivity associated to a worse clinical outcome in patients with COVID-19, pointing to the importance of antithrombotic therapy for reducing disease severity.

Illustrative and historic cases of phenoconversion

Intersubject variability in drug response, whether related to efficacy or toxicity, is well recognized clinically. Over the years, drug selection from our pharmacologic armamentarium has moved from providers' preferred choices to more personalized treatments as clinicians' decisions are guided by data from clinical trials. Since the advent of more accessible and affordable pharmacogenomic (PGx) testing, the promise of precise pharmacotherapy has been made. Results have accumulated in the literature with numerous examples demonstrating the value of PGx to improve drug response or prevent drug toxicity. Unfortunately, limited availability of reimbursement policies has dampened the enthusiasm of providers and organizations. The clinical application of PGx knowledge remains difficult for most clinicians under real-world conditions in patients with numerous chronic conditions and polypharmacy. This may be due to phenoconversion, a condition where there is a discrepancy between the genotype-predicted phenotype and the observed phenotype. This condition complicates the interpretation of PGx results and may lead to inappropriate recommendations and clinical decision making. For this reason, regulatory agencies have limited the transfer of information from PGx laboratories directly to consumers, especially recommendations about the use of certain drugs. This mini-review presents cases (mexiletine, propafenone, clopidogrel, warfarin, codeine, procainamide) from historical observations where drug response was modified by phenoconversion. The cases illustrate, from decades ago, that we are still in great need of advanced clinical decision systems that cope with conditions associated with phenoconversion, especially in patients with polypharmacy.

Gene polymorphisms of insulin secretion signaling pathway associated with clopidogrel resistance in Han Chinese population

BACKGROUND

Due to the loss of responsiveness to insulin, diabetes mellitus (DM) patients develop increased platelet reactivity and reduced response to antiplatelet agents. Nevertheless, the relationship between the single-nucleotide polymorphisms (SNP) of the signal pathway gene of insulin secretion and the effect of clopidogrel is elusive.

METHODS

Blood samples were collected from patients administered with dual-antiplatelet therapy (clopidogrel, 75 mg, once daily and aspirin, 100 mg, once daily) after 5 days and completed test within 4 h. The VerifyNow P2Y12 assay was used to measure the platelet functions, and the results were expressed as a P2Y12 reaction unit (PRU). Notably, the selected SNPs were analyzed to demonstrate the functionality of genetic variants.

RESULTS

Analysis of the study population showed that old age, lower plasma albumin (ALB) level, higher creatinine (CREA) level, higher uric acid (UA) level, lower platelet (PLT) count, and lower plateletcrit (PCT) potentially increased the risk of clopidogrel resistance. In a single-nucleotide polymorphism rs6056209 of the PCLB1 gene, the AG genotype was a risk factor for clopidogrel resistance (p < 0.05, OR = 1.574). Similarly, the CC and AG genotype in GNAS rs7121 and CCKAR rs1800857 were protective factors (p < 0.05, OR = 0.094; p <0.05, OR = 0.491). TT was a protective factor in rs10814274 of the CREB3 gene (p < 0.05, OR = 0.444). In the RAPGEF4 gene polymorphism rs17746510, TG was the protective genotype, and the TT genotype was a risk factor for clopidogrel resistance. GCG rs5645 was confirmed; there was a relationship between genotypes containing A or G and clopidogrel resistance.

CONCLUSION

Single-nucleotide polymorphisms of insulin secretion signaling pathway genes trigger clopidogrel resistance.

Prognostic value of subclinical myocardial necrosis using high-sensitivity cardiac troponin T in patients with prediabetes

BACKGROUND

Risk stratification of patients with prediabetes is an unmet clinical need. Here, we examine the utility of subclinical myocardial necrosis assessed by high-sensitivity cardiac troponin T (hs-cTnT) in predicting health outcomes in stable subjects with prediabetes.

METHODS

hs-cTnT was analyzed by a high-sensitivity assay (Roche 5th generation) in 2631 stable subjects with prediabetes (HbA1c 5.7-6.4% or fasting glucose 100-125 mg/dL without previous diagnosis of diabetes or glucose-lowering therapy) who underwent elective coronary angiography for cardiac evaluation, and followed for major adverse cardiac events (MACE; death, myocardial infarction, stroke) over 3 years and all-cause mortality over 5 years.

RESULTS

In our study cohort, hs-cTnT was highly prevalent with a median level of 13 ng/L (interquartile range 8.2-21.6 ng/L). Hs-cTnT was independently associated with incident MACE at 3 years (Q4 vs. Q1 adjusted hazard ratio (HR) 2.42 [95% CI 1.69-3.46], P < 0.001) and 5-year mortality (adjusted HR 3.8 [95% CI 2.55-5.67], P < 0.001). This association remained significant in all subsets after adjustment for traditional risk factors and multiple factors known to increase hs-cTnT levels. Moreover, hs-cTnT independently predicted event risk in primary prevention subjects (n = 557, HR 5.46 [95% CI 1.50-19.89), p < 0.01) for MACE; HR 9.53 [95% CI 2.08-43.73] for all-cause mortality) and secondary prevention subjects (n = 2074, HR 1.86 [95% CI 1.31-2.66], P < 0.001 for MACE; and 2.7 [95% CI 1.79-4.08), P < 0.001 for all-cause mortality).

CONCLUSIONS

In stable prediabetic subjects, the presence of subclinical myocardial necrosis as detected by hs-cTnT portends heightened long-term adverse cardiovascular event risk. Hs-cTnT levels may help to stratify risk and improve clinical decision making in patients with prediabetes. Trial registration ClinicalTrials.gov Identifier: NCT00590200.

The Use of Total Thrombus Formation Analysis System as a Tool to Assess Platelet Function in Bleeding and Thrombosis Risk-A Systematic Review

BACKGROUND

Today there are many devices that can be used to study blood clotting disorders by identifying abnormalities in blood platelets. The Total Thrombus Formation Analysis System is an automated microchip flow chamber system that is used for the quantitative analysis of clot formation under blood flow conditions. For several years, researchers have been using a tool to analyse various clinical situations of patients to identify the properties and biochemical processes occurring within platelets and their microenvironment.

METHODS

An investigation of recent published literature was conducted based on PRISMA. This review includes 52 science papers directly related to the use of the Total Clot Formation Analysis System in relation to bleeding, surgery, platelet function assessment, anticoagulation monitoring, von Willebrand factor and others.

CONCLUSION

Most available studies indicate that The Total Thrombus Formation Analysis System may be useful in diagnostic issues, with devices used to monitor therapy or as a significant tool for predicting bleeding events. However, T-TAS not that has the potential for diagnostic indications, but allows the direct observation of the flow and the interactions between blood cells, including the intensity and dynamics of clot formation. The device is expected to be of significant value for basic research to observe the interactions and changes within platelets and their microenvironment.

Chronic Inflammatory Status Observed in Patients with Type 2 Diabetes Induces Modulation of Cytochrome P450 Expression and Activity

Diabetes mellitus is a metabolic disease that causes a hyperglycemic status which leads, over time, to serious damage to the heart, blood vessels, eyes, kidneys and nerves. The most frequent form of diabetes is type 2 diabetes mellitus (T2DM) which is often part of a metabolic syndrome (hyperglycaemia, hypertension, hypercholesterolemia, abdominal obesity) that usually requires the use of several medications from different drug classes to bring each of these conditions under control. T2DM is associated with an increase in inflammatory markers such as interleukin-6 (IL-6) and the tumor necrosis factor alpha (TNF-α). Higher levels of IL-6 and TNF-α are associated with a downregulation of several drug metabolizing enzymes, especially the cytochrome P450 (P450) isoforms CYP3As and CYP2C19. A decrease in these P450 isoenzymes may lead to unexpected rise in plasma levels of substrates of these enzymes. It could also give rise to a mismatch between the genotypes determined for these enzymes, the predicted phenotypes based on these genotypes and the phenotypes observed clinically. This phenomenon is described as phenoconversion. Phenoconversion typically results from either a disease (such as T2DM) or concomitant administration of medications inducing or inhibiting (including competitive or non-competitive inhibition) a P450 isoenzyme used by other substrates for their elimination. Phenoconversion could have a significant impact on drug effects and genotypic-focused clinical outcomes. As the aging population is exposed to polypharmacy along with inflammatory comorbidities, consideration of phenoconversion related to drug metabolizing enzymes is of importance when applying pharmacogenomic results and establishing personalized and more precise drug regimens.

Ticagrelor and prasugrel are independent predictors of improved long-term survival in ACS patients

AIM

To investigate the long-term clinical benefit of dual antiplatelet therapy with potent P2Y12 inhibitors compared to clopidogrel in patients with acute coronary syndrome (ACS).

METHODS

In this prospective multicenter observational study, we enrolled 708 patients with ACS treated with clopidogrel (n = 137), ticagrelor (n = 260) or prasugrel (n = 311). Major adverse cardiac events (MACE; over 1 year) and long-term mortality (median: 5.6 years; interquartile range [IQR] 4.9-6.5 years) were assessed. Multiple electrode aggregometry (MEA) was used to measure adenosine diphosphate (ADP)- and arachidonic acid (AA)-induced platelet aggregation.

RESULTS

Type of P2Y12 inhibitor emerged as an independent predictor of long-term mortality and MACE: patients treated with potent platelet inhibitors prasugrel or ticagrelor were at lower risk for long-term mortality (adjusted hazard ratio [HR] = 0.44; 95% CI: 0.22-0.92; P = .028) or MACE (adjusted HR = 0.38; 95% CI: 0.20-0.73; P = .004) than those treated with clopidogrel independent from clinical risk factors. In contrast, the efficacy of clopidogrel decreased with increasing severity of ACS: platelet aggregation was 37% higher in patients with ST segment elevation myocardial infarction (STEMI) and 25% higher in patients with non-ST elevation myocardial infarction (non-STEMI) compared to patients with unstable angina (P = .039). Patients with diabetes achieved less potent ADP- and AA-induced platelet inhibition under clopidogrel, compared to patients without diabetes (P = .045; P = .030, respectively).

CONCLUSION

In the setting of ACS, treatment with ticagrelor or prasugrel reduced long-term mortality and 1-year MACE as compared to clopidogrel.

Poor glycaemic control contributes to a shift towards prothrombotic and antifibrinolytic state in pregnant women with type 1 diabetes mellitus

OJECTIVES

Thrombotic and antifibrinolytic influence of Diabetes mellitus type 1 (T1DM) on haemostasis have been well demonstrated. There has been no research assessing the influence of poor glycemic control on thrombus formation under flow conditions in vitro or in pregnant type 1 diabetic women to date.

PATIENTS/METHODS

This study compared singleton pregnant T1DM women (n = 21) and control pregnant subjects without any metabolic disease (n = 15). The T1DM group was divided into two subgroups of sufficient (SGC-DM; HbA1c ≤6,5%,n = 15) and poor glycaemic control (PGC-DM; HbA1c >6,5%,n = 6). Evaluation of the whole blood thrombogenicity we assessed using T-TAS® at a shear rate of 240 s-1 (Total-Thrombus Analysis System, Zacros, Japan).

RESULTS

Blood clot formation initiation time (T10) was significantly shortened in PGC-DM subgroup when compared to SGC-DM subgroup (p = 0,03). The area under the curve (AUC30) of blood clot time formation and the MPV (mean platelet volume) values were substantially higher in the PGC-DM subgroup in comparison to the SGC-DM group (p = 0,03). Negative correlations were noted between HbA1c and T10 values (p = 0,02) and between T10 and MPV values in the T1DM group (p = 0,04).

CONCLUSIONS

Poor glycaemic control in T1DM subjects triggers a shift towards a prothrombotic and antifibrinolytic state. This phenomenon can be detected using the novel system for quantitative assessment of the platelet thrombus formation process under flow conditions in vitro. The alteration of T-TAS values in PGC-DM subgroup proves that a poor glycemic control-related shift of the equilibrium toward thrombogenesis occurs in this group of patients. Our findings need a further elucidation in research on more massive data sets to be confirmed.

Combined impact of body mass index and glycemic control on the efficacy of clopidogrel-aspirin therapy in patients with minor stroke or transient ischemic attack

Background: A single index of body mass index (BMI) may not fully address its impact on anti-platelet therapy. We aimed to elucidate the combined impact of BMI and dysglycemia expressed by glycated albumin (GA) on efficacy of clopidogrel-aspirin therapy among minor stroke (MS) or transient ischemic attack (TIA) patients.

Results: Patients with overweight/obesity and low GA levels still benefited from clopidogrel-aspirin therapy for stroke recurrence (Hazard ratio [HR]: 0.48, 95 % confidence interval [CI]: 0.28–0.82), so did those with high GA levels but low/normal weight (HR: 0.67, 95 % CI: 0.45–0.99). However, patients with both overweight/obesity and high GA levels did not benefit from clopidogrel-aspirin therapy (HR: 0.89, 95 % CI: 0.59–1.33).

Conclusions: Compared with aspirin alone, efficacy of clopidogrel-aspirin therapy for stroke still exists in overweight/obesity patients with normal glycemic control.

Methods: In Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events trial, 3044 patients with available baseline GA were recruited. Low/normal weight and overweight/obesity were defined as BMI < 25 kg/m² and ≥ 25 kg/m², respectively. Elevated and low GA levels were defined as GA levels > 15.5 % and ≤ 15.5 %, respectively. The primary outcome was stroke recurrence during the 90-day follow-up.

Inflammatory state does not affect the antiplatelet efficacy of potent P2Y12 inhibitors in ACS

Inflammation leads to atherosclerosis and acute coronary syndromes (ACS). We performed a prospective, observational study to assess association between the concentrations of inflammatory markers (high sensitivity C-reactive protein, hsCRP; high sensitivity interleukin6, hsIL-6; soluble CD40 ligand, sCD40 L) and platelet reactivity in 338 patients with ACS treated with ticagrelor and prasugrel. We also assessed whether hsCRP, hsIL-6, and sCD40 L are associated with standard inflammatory markers (white blood cell [WBC] and fibrinogen), and whether they differ according to patient diabetic status and pre-treatment with statins. Concentrations of hsCRP and concentrations of hsIL-6 and sCD40 L were assessed using turbidimetric assay and enzyme-linked immunosorbent assay, respectively. Platelet reactivity was measured using multiple electrode aggregometry. There was only a weak inverse correlation between hsIL-6 and platelet reactivity (r≤-0.125). In contrast, concentration of hsIL6 and hsCRP positively correlated with WBC and fibrinogen (r ≥ 0.199). Insulin-dependent diabetes mellitus (IDDM) was associated with higher concentration of hsIL-6 (p = .014), whereas pre-treatment with statins - with lower concentration of hsIL-6 (p = .035). In conclusion, inflammatory state does not affect the antiplatelet efficacy of potent P2Y12 inhibitors in the acute phase of ACS, confirming the safety and efficacy of potent P2Y12 inhibitors in patients with a high inflammatory burden.

Long-term effect of clopidogrel in patients with and without diabetes: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Previous studies have shown that patients with diabetes mellitus (DM) respond poorly to clopidogrel treatment.

AIM

To systematically evaluate the efficacy of clopidogrel for the treatment of acute coronary syndromes or ischemic stroke in patients with or without DM.

METHODS

PubMed, the Cochrane Central Register of Controlled Trials, and EMBASE were searched from 1980 on 27 June 2019 to identify relevant randomized controlled trials that compared the effect of a combination of clopidogrel and aspirin with aspirin alone. A random-effects meta-analysis was used to estimate the hazard ratio (HR) and its 95% confidence interval (CI). Sensitivity analysis was performed using a fixed-effect model. The I² statistic was used to evaluate the heterogeneity of the study data.

RESULTS

Six randomized controlled trials, comprising 43352 participants (13491 with and 29861 without DM) who had received antiplatelet therapy for ≥ 3 mo, were included in the meta-analysis. Compared with aspirin alone, a combination of clopidogrel and aspirin significantly reduced the risk of any cardiovascular event in patients without DM (HR = 0.78, 95%CI: 0.71–0.86, P < 0.001; I² = 23%, P = 0.26). Clopidogrel plus aspirin also significantly reduced cardiovascular risk in patients with DM, although the effect was smaller (HR = 0.89, 95%CI: 0.81–0.99, P = 0.030; I² = 0%, P = 0.74). Nevertheless, there was no significant difference in the efficacy of clopidogrel at reducing the risk of cardiovascular events in patients with DM vs those without (P for interaction = 0.062).

CONCLUSION

Thus, the present study shows that the addition of clopidogrel to aspirin significantly lowers cardiovascular risk in patients with or without DM who have experienced ischemic cardiovascular disease. The beneficial effect of the addition of clopidogrel to aspirin for patients with DM was lower than that in patients without DM, although the modifying effect of DM did not reach significance.

Factors associated with platelet reactivity during dual antiplatelet therapy in patients with diabetes after acute coronary syndrome

Antiplatelet drugs are prescribed without considering the diabetic status of the patient. The objective of the current investigation was to determine the impact of clinical factors, CYP4F2 enzyme and 20-hydroxyeicosatetraenoic acid (20-HETE) concentrations on high on-treatment platelet reactivity in patients with diabetes treated with antiplatelet drugs following acute coronary syndromes. A total of 667 patients were included in the study. Dual antiplatelet drug loading dosages with aspirin (300 mg) and ticagrelor (180 mg) or clopidogrel (600 mg) were prescribed to all the studied patients. Testing of platelet aggregation was performed the day after loading antiplatelet drug dosages. Platelet aggregation test was done according to the classical Born method. Multivariate binary regression analysis demonstrated that insulin use and higher 20-HETE concentration increased the odds of high on-treatment platelet reactivity during the initiation of antiplatelet drug therapy (OR: 3.968, 95% CI: 1.478-10.656, p = 0.006 and OR: 1.139, 95% CI: 1.073-1.210, respectively, p < 0.001). Ticagrelor use decreased the odds of developing high on-treatment platelet reactivity (OR: 0.238, 95% CI: 0.097-0.585, p = 0.002). Data from this study revealed that high on-treatment platelet reactivity during dual antiplatelet therapy in patients with diabetes may depend on such factors as insulin prescription and 20-HETE concentration.

Vascular miR-181b controls tissue factor-dependent thrombogenicity and inflammation in type 2 diabetes

BACKGROUND

Diabetes mellitus is characterized by chronic vascular inflammation leading to pathological expression of the thrombogenic full length (fl) tissue factor (TF) and its isoform alternatively-spliced (as) TF. Blood-borne TF promotes factor (F) Xa generation resulting in a pro-thrombotic state and cardiovascular complications. MicroRNA (miR)s impact gene expression on the post-transcriptional level and contribute to vascular homeostasis. Their distinct role in the control of the diabetes-related procoagulant state remains poorly understood.

METHODS

In a cohort of patients with poorly controlled type 2 diabetes (n = 46) plasma levels of miR-181b were correlated with TF pathway activity and markers for vascular inflammation. In vitro, human microvascular endothelial cells (HMEC)-1 and human monocytes (THP-1) were transfected with miR-181b or anti-miR-181b and exposed to tumor necrosis factor (TNF) α or lipopolysaccharides (LPS). Expression of TF isoforms, vascular adhesion molecule (VCAM) 1 and nuclear factor (NF) κB nuclear translocation was assessed. Moreover, aortas, spleen, plasma, and bone marrow-derived macrophage (BMDM)s of mice carrying a deletion of the first miR-181b locus were analyzed with respect to TF expression and activity.

RESULTS

In patients with type 2 diabetes, plasma miR-181b negatively correlated with the procoagulant state as evidenced by TF protein, TF activity, D-dimer levels as well as markers for vascular inflammation. In HMEC-1, miR-181b abrogated TNFα-induced expression of flTF, asTF, and VCAM1. These results were validated using the anti-miR-181b. Mechanistically, we confirmed a miR-181b-mediated inhibition of importin-α3 (KPNA4) leading to reduced nuclear translocation of the TF transcription factor NFκB. In THP-1, miR-181b reduced both TF isoforms and FXa generation in response to LPS due to targeting phosphatase and tensin homolog (PTEN), a principal inducer for TF in monocytes. Moreover, in miR-181-/- animals, we found that reduced levels of miR-181b were accompanied by increased TF, VCAM1, and KPNA4 expression in aortic tissue as well as increased TF and PTEN expression in spleen. Finally, BMDMs of miR-181-/- mice showed increased TF expression and FXa generation upon stimulation with LPS.

CONCLUSIONS

miR-181b epigenetically controls the procoagulant state in diabetes. Reduced miR-181b levels contribute to increased thrombogenicity and may help to identify individuals at particular risk for thrombosis.

β-Amyloid and mitochondrial-derived peptide-c are additive predictors of adverse outcome to high-on-treatment platelet reactivity in type 2 diabetics with revascularized coronary artery disease

BACKGROUND AND AIMS

Increased β-amyloid and decreased mitochondrial-derived peptide (MOTS-c), are reported in diabetes. We investigated their additive value to high on-clopidogrel platelet reactivity (HPR) for adverse outcome in type 2 diabetics after recent revascularization.

PATIENTS AND METHODS

In 121 type II diabetics, treated with clopidogrel and aspirin, (93 males, mean age 67.2 years) we measured: (a) maximum platelet aggregation to adenosine diphosphate (ADP) by light transmission aggregometry (LTAmax), (b) malondialdehyde (MDA), as oxidative stress marker, (c) MOTS-c, (d) β-amyloid blood levels. Cardiac death and acute coronary syndromes (MACE) were recorded during 2 years of follow-up.

RESULTS

Out of 121 patients, 32 showed HPR (LTAmax > 48%,). At baseline, HPR was associated with β-amyloid > 51 pg/ml (p = 0.006) after adjusting clinical variables, HbA1c, MOTS-c, MDA and medication. During follow-up, 22 patients suffered a MACE. HPR, β-amyloid > 51 pg/ml and MOTS-c < 167 ng/ml were predictors of MACE (relative risk 3.1, 3.5 and 3.8 respectively, p < 0.05) after adjusting for confounders and medication. There was significant interaction between HPR and β-amyloid or MOTS-c for the prediction of MACE (p < 0.05). Patients with HPR and β-amyloid > 51 mg/dl or HPR and MOTS-c concentration < 167 ng/ml had a fourfold higher risk for MACE than patients without these predictors (relative risk 4.694 and 4.447 respectively p < 0.01). The above results were confirmed in an external validation cohort of 90 patients with diabetes and CAD.

CONCLUSIONS

Increased β-amyloid or low MOTS-c are additive predictors to high on-clopidogrel platelet reactivity for adverse outcome in diabetics with CAD during 2-years follow-up. Clinical Trial Registration-URL: https://www.clinicaltrials.gov. Unique identifier: NCT04027712.

Clinical outcomes and predictive model of platelet reactivity to clopidogrel after acute ischemic vascular events

BACKGROUND

High on-treatment platelet reactivity (HTPR) has been suggested as a risk factor for patients with ischemic vascular disease. We explored a predictive model of platelet reactivity to clopidogrel and the relationship with clinical outcomes.

METHODS

A total of 441 patients were included. Platelet reactivity was measured by light transmittance aggregometry after receiving dual antiplatelet therapy. HTPR was defined by the consensus cutoff of maximal platelet aggregation >46% by light transmittance aggregometry. CYP2C19 loss-of-function polymorphisms were identified by DNA microarray analysis. The data were compared by binary logistic regression to find the risk factors. The primary endpoint was major adverse clinical events (MACEs), and patients were followed for a median time of 29 months. Survival curves were constructed with Kaplan-Meier estimates and compared by log-rank tests between the patients with HTPR and non-HTPR.

RESULTS

The rate of HTPR was 17.2%. Logistic regression identified the following predictors of HTPR: age, therapy regimen, body mass index, diabetes history, CYP2C192, or CYP2C193 variant. The area under the curve of receiver operating characteristic for the HTPR predictive model was 0.793 (95% confidence interval: 0.738-0.848). Kaplan-Meier analysis showed that patients with HTPR had a higher incidence of MACE than those with non-HTPR (21.1% vs. 9.9%; χ = 7.572, P = 0.010).

CONCLUSIONS

Our results suggest that advanced age, higher body mass index, treatment with regular dual antiplatelet therapy, diabetes, and CYP2C192 or CYP2C193 carriers are significantly associated with HTPR to clopidogrel. The predictive model of HTPR has useful discrimination and good calibration and may predict long-term MACE.

The prognostic value of multiple electrode aggregometry and light transmittance aggregometry in stable cardiovascular patients with type 2 diabetes mellitus

AIM

Limited data are available regarding the clinical relevance of platelet function measurements in stable patients with coronary artery disease (CAD). Our aim is to evaluate the agreement between multiple electrode aggregometry (MEA) and light transmittance aggregometry (LTA) in detecting clopidogrel low responders and their prognostic value in CAD patients with type 2 diabetes mellitus (T2DM) on dual platelet inhibition.

METHODS

LTA and MEA were performed in 122 stable cardiovascular patients with T2DM. The upper quartile of patients according to maximum LTA (LTAmax) and MEA measurements were defined as clopidogrel low responders. Agreement between the two methods was evaluated by kappa statistics. We assessed the potential correlation between antiplatelet response and clinical outcome and the optimal cutoff value according to ROC analysis to predict the occurrence of major adverse cardiovascular events (MACE), during 1-year follow-up period.

RESULTS

Cohen's kappa coefficients (0.214) indicated fair agreement (70.2%) between LTA and MEA. A total of 25 MACE occurred in 108 patients (23.1%). Patients with MACE had higher LTAmax than those without (57.1 ± 16.5 vs 49.3 ± 18.3, respectively, p = 0.023). MEA measurements were similar between patients with and without MACE (30.1 ± 15.4 vs 30.6 ± 20.8, respectively; p = 0.84). Multiple logistic regression showed LTAmax response as an independent predictor of death from cardiovascular causes (Odds Ratio, adjusted:0.2;0.05-0.81). ROC analysis indicated that LTAmax cutoff of 62.5% best predicted death (AUC = 0.67, sensitivity = 78%, specificity = 61.5%).

CONCLUSIONS

The assessment of platelet responsiveness remains highly test-specific. Our results support the prognostic role of LTA, but not MEA testing, for death risk evaluation in stable cardiovascular T2DM patients.

Platelet reactivity patterns in patients treated with dual antiplatelet therapy

AIM

The aim of the present study was to investigate the patterns of platelet reactivity and discriminators of therapeutic response to dual antiplatelet therapy (DAPT) with aspirin and ticagrelor or prasugrel in patients with acute coronary syndrome (ACS).

DESIGN

In this multicentre prospective observational study, 492 patients with ACS were enrolled. Platelet aggregation was determined by multiple electrode aggregometry after stimulation with adenosine diphosphate (ADP) or arachidonic acid (AA) as agonists in the maintenance phase of treatment with prasugrel or ticagrelor.

RESULTS

Age emerged as the strongest variable influencing aspirin response status: The mean AA-induced platelet aggregation in patients <49 years of age was 49% higher than in those >49 years (13.1 U vs 8.8 U; P = 0.011). The second strongest discriminator of aspirin response was sex: Male patients had a 40% higher AA-induced platelet aggregation values than female patients (9.5 U vs 6.8 U; P = 0.026). Platelet count emerged as the only variable influencing ADP antagonists response status showing that patients with platelet count >320 g/L displayed higher ADP-induced platelet aggregation. About 12% of patients had high on-treatment platelet reactivity (HTPR) to aspirin, 3% and 4% a HTPR to prasugrel and ticagrelor, respectively, and only 2% displayed HTPR to dual antiplatelet therapy.

CONCLUSION

When potent platelet inhibitors as prasugrel and ticagrelor are administered with aspirin, HTPR to DAPT plays only a marginal role.

Oral Antiplatelet Therapy for Secondary Prevention of Acute Coronary Syndrome

Patients surviving an acute coronary syndrome (ACS) remain at increased risk of ischemic events long term. This paper reviews current evidence and guidelines for oral antiplatelet therapy for secondary prevention following ACS, with respect to decreased risk of ischemic events versus bleeding risk according to individual patient characteristics and risk factors. Specifically, data are reviewed from clinical studies of clopidogrel, prasugrel, ticagrelor and vorapaxar, as well as the results of systematic reviews and meta-analyses looking at the benefits and risks of oral antiplatelet therapy, and the relative merits of shorter versus longer duration of dual antiplatelet therapy, in different patient groups.

MicroRNA-19a contributes to the epigenetic regulation of tissue factor in diabetes

Background

Diabetes mellitus is characterized by chronic vascular disorder and presents a main risk factor for cardiovascular mortality. In particular, hyperglycaemia and inflammatory cytokines induce vascular circulating tissue factor (TF) that promotes pro-thrombotic conditions in diabetes. It has recently become evident that alterations of the post-transcriptional regulation of TF via specific microRNA(miR)s, such as miR-126, contribute to the pathogenesis of diabetes and its complications. The endothelial miR-19a is involved in vascular homeostasis and atheroprotection. However, its role in diabetes-related thrombogenicity is unknown. Understanding miR-networks regulating procoagulability in diabetes may help to develop new treatment options preventing vascular complications.

Methods and results

Plasma of 44 patients with known diabetes was assessed for the expression of miR-19a, TF protein, TF activity, and markers for vascular inflammation. High miR-19a expression was associated with reduced TF protein, TF-mediated procoagulability, and vascular inflammation based on expression of vascular adhesion molecule-1 and leukocyte count. We found plasma expression of miR-19a to strongly correlate with miR-126. miR-19a reduced the TF expression on mRNA and protein level in human microvascular endothelial cells (HMEC) as well as TF activity in human monocytes (THP-1), while anti-miR-19a increased the TF expression. Interestingly, miR-19a induced VCAM expression in HMEC. However, miR-19a and miR-126 co-transfection reduced total endothelial VCAM expression and exhibited additive inhibition of a luciferase reporter construct containing the F3 3′UTR.

Conclusions

While both miRs have differential functions on endothelial VCAM expression, miR-19a and miR-126 cooperate to exhibit anti-thrombotic properties via regulating vascular TF expression. Modulating the post-transcriptional control of TF in diabetes may provide a future anti-thrombotic and anti-inflammatory therapy.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0678-z) contains supplementary material, which is available to authorized users.

[Diabetes Mellitus, a prothrombotic disease]

In patients with acute atherothrombotic disease, diabetes or glucose intolerance is frequently found. Indeed, the number of people with diabetes in the world continues to increase and is expected to reach more than 500 million people by 2035. Diabetes is a pathology commonly associated with both microvascular and macrovascular complications. Although the mortality of coronary artery disease has decreased significantly over the past 20 years, mortality in patients with type 2 diabetes has changed little and atherothrombotic events remain the leading cause of death in diabetic patients. Although our understanding of vascular pathology has greatly evolved in recent years, the cellular and molecular mechanisms linking thrombogenicity and diabetes remain incompletely understood. Type 1 and type 2 diabetes are prothrombotic pathologies. This prothrombotic state is due to both hyperglycemia and chronic hyperinsulinism. Among the different agonists involved in the increased thrombogenicity of diabetic patients, abnormalities can be found in all phases of coagulation. Increased procoagulant factors and tissue factor associated with impaired fibrinolysis, platelet hyperreactivity, endothelial dysfunction, leukocyte activation, low-grade inflammation, and microparticle involvement, they all play a role in the establishment of this prothrombotic condition. This review sought to provide an update on the prothrombotic nature of diabetes and its consequences in therapeutics.

Induction of Diabetes Abolishes the Antithrombotic Effect of Clopidogrel in Apolipoprotein E-Deficient Mice

Patients with acute coronary syndrome with diabetes mellitus (DM) exhibit an impaired platelet inhibitory response to clopidogrel which is only partially understood. DM was induced by the administration of streptozotocin (STZ) to 9-week-old mice. The antithrombotic effects of clopidogrel (10 mg/kg/d, orally × 5 days) were determined using a FeCl ₃ -induced thrombosis model employing wild-type (WT), apolipoprotein E (apoE)-deficient, and diabetic apoE-deficient mice at 21 weeks. Antiplatelet effects were determined using flow cytometry. The antithrombotic effects of clopidogrel were similar in WT and apoE-deficient mice but were attenuated in diabetic apoE-deficient mice with the percent inhibition of thrombus area (µm ² ) by clopidogrel being 85.5% (WT mice), 75.0% (apoE-deficient mice), and 1.9% (diabetic apoE-deficient mice). The time to first occlusion and lumen stenosis also reflected a significant loss of the antithrombotic effects of clopidogrel in diabetic apoE-deficient mice. Ex vivo platelet activation, which was assessed using ADP-induced expression of activated glycoprotein IIb/IIIa, was completely inhibited by clopidogrel in these three groups of mice. In contrast, the effect of clopidogrel on the ex vivo expression of platelet P-selectin induced by protease-activated receptor 4–activating peptide was diminished in diabetic apoE-deficient mice compared with that in WT and apoE-deficient mice. These data suggest that diabetic apoE-deficient mice may serve as a useful model to better understand the impaired responses to clopidogrel in patients with DM, which may partially reflect a reduction of the effect of clopidogrel on thrombin-induced platelet activation.

Effects of Ramadan fasting on platelet reactivity in diabetic patients treated with clopidogrel

Background

The effects of Ramadan fasting (RF) on clopidogrel antiplatelet inhibition were not previously investigated. The present study evaluated the influence of RF on platelet reactivity in patients with high cardiovascular risk (CVR) in particular those with type 2 diabetes mellitus (DM).

Methods

A total of 98 stable patients with ≥2 CVR factors were recruited. All patients observed RF and were taking clopidogrel at a maintenance dose of 75 mg. Clinical findings and serum lipids data were recorded before Ramadan (Pre-R), at the last week of Ramadan (R) and 4 weeks after the end of Ramadan (Post-R). During each patient visit, nutrients intakes were calculated and platelet reactivity assessment using Verify Now P2Y12 assay was performed.

Results

In DM patients, the absolute PRU changes from baseline were +27 (p = 0.01) and +16 (p = 0.02) respectively at R and Post-R. In addition, there was a significant increase of glycemia and triglycerides levels with a significant decrease of high-density lipoprotein. In non DM patients there was no significant change in absolute PRU values and metabolic parameters. Clopidogrel resistance rate using 2 cut-off PRU values (235 and 208) did not change significantly in DM and non DM patients.

Conclusions

RF significantly decreased platelet sensitivity to clopidogrel in DM patients during and after Ramadan. This effect is possibly related to an increase of glycemia and serum lipids levels induced by fasting.

Trial registration

Clinical Trials.gov NCT02720133. Registered 24 July 2014.Retrospectively registered.

Platelets, diabetes and myocardial ischemia/reperfusion injury

Mechanisms underlying the pathogenesis of ischemia/reperfusion injury are particularly complex, multifactorial and highly interconnected. A complex and entangled interaction is also emerging between platelet function, antiplatelet drugs, coronary diseases and ischemia/reperfusion injury, especially in diabetic conditions. Here we briefly summarize features of antiplatelet therapy in type 2 diabetes (T2DM). We also treat the influence of T2DM on ischemia/reperfusion injury and how anti-platelet therapies affect post-ischemic myocardial damage through pleiotropic properties not related to their anti-aggregating effects. miRNA-based signature associated with T2DM and its cardiovascular disease complications are also briefly considered. Influence of anti-platelet therapies and different effects of healthy and diabetic platelets on ischemia/reperfusion injury need to be further clarified in order to enhance patient benefits from antiplatelet therapy and revascularization. Here we provide insight on the difficulty to reduce the cardiovascular risk in diabetic patients and report novel information on the cardioprotective role of widely used anti-aggregant drugs.

PRotective Effect on the coronary microcirculation of patients with DIabetes by Clopidogrel or Ticagrelor (PREDICT): study rationale and design. A randomized multicenter clinical trial using intracoronary multimodal physiology

Background

In diabetic patients a predisposed coronary microcirculation along with a higher risk of distal particulate embolization during primary percutaneous intervention (PCI) increases the risk of peri-procedural microcirculatory damage. However, new antiplatelet agents, in particular Ticagrelor, may protect the microcirculation through its adenosine-mediated vasodilatory effects.

Methods

PREDICT is an original, prospective, randomized, multicenter controlled study designed to investigate the protective effect of Ticagrelor on the microcirculation during PCI in patient with diabetes mellitus type 2 or pre-diabetic status. The primary endpoints of this study aim to test (i) the decrease in microcirculatory resistance with antiplatelet therapy (Ticagrelor > Clopidogrel; mechanistic effect) and (ii) the relative microcirculatory protection of Ticagrelor compared to Clopidogrel during PCI (Ticagrelor < Clopidogrel; protective effect).

Conclusions

PREDICT will be the first multicentre clinical trial to test the adenosine-mediated vasodilatory effect of Ticagrelor on the microcirculation during PCI in diabetic patients. The results will provide important insights into the prospective beneficial effect of this drug in preventing microvascular impairment related to PCI (http://www.clinicaltrials.gov No. NCT02698618).

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0543-5) contains supplementary material, which is available to authorized users.

Micro-RNA-126 Reduces the Blood Thrombogenicity in Diabetes Mellitus via Targeting of Tissue Factor

Supplemental Digital Content is available in the text.

Objective—

Diabetes mellitus involves vascular inflammatory processes and is a main contributor to cardiovascular mortality. Notably, heightened levels of circulating tissue factor (TF) account for the increased thrombogenicity and put those patients at risk for thromboembolic events. Here, we sought to investigate the role of micro-RNA (miR)–driven TF expression and thrombogenicity in diabetes mellitus.

Approach and Results—

Plasma samples of patients with diabetes mellitus were analyzed for TF protein and activity as well as miR-126 expression before and after optimization of the antidiabetic treatment. We found low miR-126 levels to be associated with markedly increased TF protein and TF-mediated thrombogenicity. Reduced miR-126 expression was accompanied by increased vascular inflammation as evident from the levels of vascular adhesion molecule-1 and fibrinogen, as well as leukocyte counts. With optimization of the antidiabetic treatment miR-126 levels increased and thrombogenicity was reduced. Using a luciferase reporter system, we demonstrated miR-126 to directly bind to the F3-3′-untranslated region, thereby reducing TF expression both on mRNA and on protein levels in human microvascular endothelial cells as well as TF mRNA and activity in monocytes.

Conclusions—

Circulating miR-126 exhibits antithrombotic properties via regulating post-transcriptional TF expression, thereby impacting the hemostatic balance of the vasculature in diabetes mellitus.

Association between insulin receptor substrate-1 polymorphisms and high platelet reactivity with clopidogrel therapy in coronary artery disease patients with type 2 diabetes mellitus

BACKGROUND

The mechanisms leading to the high on-treatment platelet reactivity in diabetes patients are not fully elucidated. The genetic factors may be associated with the diminished antiplatelet efficacy of dual antiplatelet therapy. We investigated the possible association between insulin receptor substrate-1 (IRS-1) polymorphisms and high platelet reactivity in coronary artery disease (CAD) patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 674 CAD patients with T2DM were enrolled in this study. Platelet aggregation and platelet activation were assessed with light transmission aggregometry and flow cytometry analysis, respectively. Participants were divided into high platelet reactivity (HPR) group and non-HPR group according to their maximal platelet aggregation. Genotypes were identified by polymerase chain reaction and direct sequencing of genomic DNA. The association between IRS-1 genetic variants and platelet function was assessed.

RESULTS

There were 233 participants in the HPR group and 441 participants in the non-HPR group. G allele frequencies of rs13431554 were 27.7 % for the HPR group and 18.6 % for the non-HPR group (p < 0.001). Adenosine diphosphate and arachidonic acid induced platelet aggregation were significantly higher in G allele carriers compared with non-carriers (56.8 ± 16.2 vs 52.0 ± 17.9 %, p < 0.01, 28.9 ± 18.6 vs 25.2 ± 17.8 %, p < 0.01, respectively). We observed that P-selectin expression and PAC-1 binding were higher in G allele carriers compared with non-carriers (40.8 ± 12.4 vs 36.2 ± 13.8, p = 0.01; 43.7 ± 15.9 vs 38.7 ± 19.9, p = 0.03, respectively).

CONCLUSION

The G allele of rs13431554 in the IRS-1 gene was associated with a hyperreactive platelet phenotype in the CAD patients with T2DM.

Coronary artery bypass surgery compared with percutaneous coronary interventions in patients with insulin-treated type 2 diabetes mellitus: a systematic review and meta-analysis of 6 randomized controlled trials

Background

Data regarding the long-term clinical outcomes in patients with insulin-treated type 2 diabetes mellitus (ITDM) revascularized by either coronary artery bypass surgery (CABG) or percutaneous coronary intervention (PCI) are still controversial. We sought to compare the long-term (≥1 year) adverse clinical outcomes in patients with ITDM who underwent revascularization by either CABG or PCI.

Methods

Randomized Controlled Trials (RCTs) comparing the long-term clinical outcomes in patients with ITDM and non-ITDM revascularized by either CABG or PCI were searched from electronic databases. Data for patients with ITDM were carefully retrieved. Odd Ratio (OR) with 95 % confidence interval (CI) was used to express the pooled effect on discontinuous variables and the pooled analyses were performed with RevMan 5.3.

Results

Six RCTs involving 10 studies, with a total of 1297 patients with ITDM were analyzed (639 patients from the CABG group and 658 patients from the PCI group). CABG was associated with a significantly lower mortality rate compared to PCI with OR: 0.59, 95 % CI 0.42–0.85; P = 0.004. Major adverse cardiovascular and cerebrovascular events as well as repeated revascularization were also significantly lower in the CABG group with OR: 0.51, 95 % CI 0.27–0.99; P = 0.03 and OR 0.34, 95 % CI 0.24–0.49; P < 0.00001 respectively. However, compared to PCI, the rate of stroke was higher in the CABG group with OR: 1.41, 95 % CI 0.64–3.09; P = 0.40, but this result was not statistically significant.

Conclusion

CABG was associated with significantly lower long-term adverse clinical outcomes compared to PCI in patients with ITDM. However, due to an insignificantly higher rate of stroke in the CABG group, further researches with a larger number of randomized patients are required to completely solve this issue.