Residual platelet reactivity to predict long-term clinical outcomes after clopidogrel loading in patients with acute coronary syndromes: comparison of different cutoff values by light transmission aggregometry from the responsiveness to clopidogrel and stent thrombosis 2-acute coronary syndrome (RECLOSE 2-ACS) study

The aim of this study was the identification of the optimal cutoff value of high residual platelet reactivity (HRPR) assessed by light transmission aggregometry (LTA) in the responsiveness to clopidogrel and stent thrombosis 2-acute coronary syndrome (RECLOSE 2-ACS) patient cohort to discriminate patients with and without major adverse cardiac events (MACE) and cardiac death at 2 years. The RECLOSE 2-ACS study included 1,789 patients with ACS who underwent LTA after clopidogrel loading. A post hoc cutoff value for HRPR was defined with the ROC curve and the Youden index and compared with the protocol-defined cutoff of 70 %. By ROC analysis, 63 % resulted the optimal cutoff value to predict both MACE and cardiac death at 2 years follow-up. A significant sensitivity improvement for the ROC-based cutoff value was noted (p < 0.001), at the price of lower specificity and predictive accuracy. The latter were 81 % for MACE and 85 % for cardiac death with the 70 % cutoff, while the respective figures were 73 and 75 % with the 63 % cutoff. The areas under the curve were virtually identical with the 70 and 63 % cutoffs both for MACE (0.71) and cardiac death (0.79). A residual platelet reactivity cutoff of 70 % by LTA, compared to the ROC-based cutoff of 63 %, allows for the identification of a subset of patients at very high risk of adverse ischemic events, making LTA-ADP test more acceptable in clinical practice for the identification of subjects at risk than other platelet function assays with broader definitions of HRPR.

Apolipoprotein(a) Kringle-IV Type 2 Copy Number Variation Is Associated with Venous Thromboembolism

In addition to the established association between high lipoprotein(a) [Lp(a)] concentrations and coronary artery disease, an association between Lp(a) and venous thromboembolism (VTE) has also been described. Lp(a) is controlled by genetic variants in LPA gene, coding for apolipoprotein(a), including the kringle-IV type 2 (KIV-2) size polymorphism. Aim of the study was to investigate the role of LPA gene KIV-2 size polymorphism and single nucleotide polymorphisms (SNPs) (rs1853021, rs1800769, rs3798220, rs10455872) in modulating VTE susceptibility. Five hundred and sixteen patients with VTE without hereditary and acquired thrombophilia and 1117 healthy control subjects, comparable for age and sex, were investigated. LPA KIV-2 polymorphism, rs3798220 and rs10455872 SNPs were genotyped by TaqMan technology. Concerning rs1853021 and rs1800769 SNPs, PCR-RFLP assay was used. LPA KIV-2 repeat number was significantly lower in patients than in controls [median (interquartile range) 11(6–17) vs 15(9–25), p<0.0001]. A significantly higher prevalence of KIV-2 repeat number ≤7 was observed in patients than in controls (33.5% vs 15.5%, p<0.0001). KIV-2 repeat number was independently associated with VTE (p = 4.36 x10^-9), as evidenced by the general linear model analysis adjusted for transient risk factors. No significant difference in allele frequency for all SNPs investigated was observed. Haplotype analysis showed that LPA haplotypes rather than individual SNPs influenced disease susceptibility. Receiver operating characteristic curves analysis showed that a combined risk prediction model, including KIV-2 size polymorphism and clinical variables, had a higher performance in identifying subjects at VTE risk than a clinical-only model, also separately in men and women.

Ndufc2 Gene Inhibition Is Associated With Mitochondrial Dysfunction and Increased Stroke Susceptibility in an Animal Model of Complex Human Disease

BACKGROUND

The genetic basis of stroke susceptibility remains to be elucidated. STR1 quantitative trait locus (STR1/QTL) was identified on rat chromosome 1 of stroke-prone spontaneously hypertensive rat (SHRSP) upon Japanese-style stroke-permissive diet (JD), and it contributes to 20% of the stroke phenotype variance.

METHODS AND RESULTS

Nine hundred eighty-six probe sets mapping on STR1 were selected from the Rat RAE230A array and screened through a microarray differential expression analysis in brains of SHRSP and stroke-resistant SHR (SHRSR) fed with either regular diet or JD. The gene encoding Ndufc2 (NADH dehydrogenase [ubiquinone] 1 subunit), mapping 8 Mb apart from STR1/QTL Lod score peak, was found significantly down-regulated under JD in SHRSP compared to SHRSR. Ndufc2 disruption altered complex I assembly and activity, reduced mitochondrial membrane potential and ATP levels, and increased reactive oxygen species production and inflammation both in vitro and in vivo. SHRSR carrying heterozygous Ndufc2 deletion showed renal abnormalities and stroke occurrence under JD, similarly to SHRSP. In humans, T allele variant at NDUFC2/rs11237379 was associated with significant reduction in gene expression and with increased occurrence of early-onset ischemic stroke by recessive mode of transmission (odds ratio [OR], 1.39; CI, 1.07-1.80; P=0.012). Subjects carrying TT/rs11237379 and A allele variant at NDUFC2/rs641836 had further increased risk of stroke (OR=1.56; CI, 1.14-2.13; P=0.006).

CONCLUSIONS

A significant reduction of Ndufc2 expression causes complex I dysfunction and contributes to stroke susceptibility in SHRSP. Moreover, our current evidence may suggest that Ndufc2 can contribute to an increased occurrence of early-onset ischemic stroke in humans.

On-treatment platelet reactivity: State of the art and perspectives

High on-clopidogrel platelet reactivity (HcPR) during dual-antiplatelet therapy is a marker of vascular risk, in particular stent thrombosis, in patients with acute coronary syndromes (ACS). Genetic determinants (CYP2C19*2 polymorphism), advanced age, female gender, diabetes and reduced ventricular function are related to a higher risk to develop HcPR. In addition, inflammation and increased platelet turnover, as revealed by the elevated percentage of reticulated platelets in patients' blood, that characterize the acute phase of acute coronary syndromes, are associated with HcPR. To overcome the limitation of clopidogrel, new antiplatelet agents (prasugrel and ticagrelor) were developed and the demonstration of their superiority over clopidogrel was obtained in the two randomized trials, TRITON TIMI 38 and PLATO. Emerging evidence is accumulating on the role of high-on aspirin platelet reactivity (HaPR), especially in the clinical context of diabetes. Finally, the presence of new, potent antiplatelet drugs has shifted the focus from thrombotic to bleeding risk. Recent data document that low on-treatment platelet reactivity (LPR) is associated with a significantly higher bleeding risk. Due to the current possibility to choose between multiple antiplatelet strategies, the future perspective is to include in the management of ACS, in addition to clinical data and classical risk factors, the definition of platelet function during treatment in order to set a tailored therapy.

Genetic Contributions to the Development of Complications in Preterm Newborns

Aim

We aimed to identify specific polymorphisms of genes encoding for vascular endothelial growth factor A (VEGFA), endothelial nitric oxide synthase (eNOS), renin-angiotensin system (angiotensinogen gene [AGT], angiotensinogen type 1 receptor [AGTR1], angiotensin-converting enzyme [ACE]), and heme oxygenase-1 (HMOX-1) in a cohort of preterm infants and correlate their presence with the development of respiratory distress syndrome (RDS) requiring mechanical ventilation (MV), bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) and retinopathy of prematurity (ROP).

Study Design

We carried out a retrospective study to evaluate the allele frequency and genotype distribution of polymorphisms of VEGFA, eNOS, AGT, AGTR1, ACE, and HMOX-1 in a population of preterm neonates (n=342) with a gestational age ≤28 weeks according to the presence or absence of RDS requiring MV, BPD, IVH, or ROP. Moreover, we evaluated through the haplotype reconstruction analysis whether combinations of the selected polymorphisms are related to the occurrence of RDS, BPD, IVH and ROP.

Results

In our population 157 infants developed RDS requiring MV, 71 BPD, 70 IVH, and 43 ROP. We found that TC+CC rs2070744 eNOS (41.7 vs. 25.4%, p=0.01) and GT+TT rs1799983 eNOS (51.8 vs. 35.2%, p=0.01) polymorphisms are independent risk factors for BPD. Haplotype reconstruction showed that haplotypes in VEGF and eNOS are significantly associated with different effects on RDS, BPD, IVH, and ROP in our population.

Conclusions

We found that TC+CC rs2070744 eNOS and GT+TT rs1799983 eNOS polymorphisms are independent predictors of an increased risk of developing BPD. Haplotypes of VEGFA and eNOS may be independent protective or risk markers for prematurity complications.

Unbalanced Metalloproteinase-9 and Tissue Inhibitors of Metalloproteinases Ratios Predict Hemorrhagic Transformation of Lesion in Ischemic Stroke Patients Treated with Thrombolysis: Results from the MAGIC Study

Background

Experimentally, metalloproteinases (MMPs) play a detrimental role related to the severity of ischemic brain lesions. Both MMPs activity and function in tissues reflect the balance between MMPs and tissue inhibitors of metalloproteinases (TIMPs). We aimed to evaluate the role of MMPs/TIMPs balance in the setting of rtPA-treated stroke patients.

Methods

Blood was taken before and 24-h after rtPA from 327 patients (mean age 68 years, median NIHSS 11) with acute ischemic stroke. Delta median values of each MMP/TIMP ratio [(post rtPA MMP/TIMP-baseline MMP/TIMP)/(baseline MMP/TIMP)] were analyzed related to symptomatic intracranial hemorrhage (sICH) according to NINDS criteria, relevant hemorrhagic transformation (HT) defined as confluent petechiae within the infarcted area or any parenchymal hemorrhage, stroke subtypes (according to Oxfordshire Community Stroke Project) and 3-month death. The net effect of each MMP/TIMP ratio was estimated by a logistic regression model including major clinical determinants of outcomes

Results

Adjusting for major clinical determinants, only increase in MMP9/TIMP1 and MMP9/TIMP2 ratios remained significantly associated with sICH (odds ratio [95% confidence interval], 1.67 [1.17–2.38], p = 0.005; 1.74 [1.21–2.49], p = 0.003, respectively). Only relative increase in MMP9/TIMP1 ratio proved significantly associated with relevant HT (odds ratio [95% confidence interval], 1.74 [1.17–2.57], p = 0.006) with a trend toward significance for MMP9/TIMP2 ratio (p = 0.007).

Discussion

Our data add substantial clinical evidence about the role of MMPs/TIMPs balance in rtPA-treated stroke patients. These results may serve to generate hypotheses on MMPs inhibitors to be administered together with rtPA in order to counteract its deleterious effect.

Characterization and identification of hidden rare variants in the human genome

Background

By examining the genotype calls generated by the 1000 Genomes Project we discovered that the human reference genome GRCh37 contains almost 20,000 loci in which the reference allele has never been observed in healthy individuals and around 70,000 loci in which it has been observed only in the heterozygous state.

Results

We show that a large fraction of this rare reference allele (RRA) loci belongs to coding, functional and regulatory elements of the genome and could be linked to rare Mendelian disorders as well as cancer. We also demonstrate that classical germline and somatic variant calling tools are not capable to recognize the rare allele when present in these loci. To overcome such limitations, we developed a novel tool, named RAREVATOR, that is able to identify and call the rare allele in these genomic positions. By using a small cancer dataset we compared our tool with two state-of-the-art callers and we found that RAREVATOR identified more than 1,500 germline and 22 somatic RRA variants missed by the two methods and which belong to significantly mutated pathways.

Conclusions

These results show that, to date, the investigation of around 100,000 loci of the human genome has been missed by re-sequencing experiments based on the GRCh37 assembly and that our tool can fill the gap left by other methods. Moreover, the investigation of the latest version of the human reference genome, GRCh38, showed that although the GRC corrected almost all insertions and a small part of SNVs and deletions, a large number of functionally relevant RRAs still remain unchanged. For this reason, also future resequencing experiments, based on GRCh38, will benefit from RAREVATOR analysis results. RAREVATOR is freely available at http://sourceforge.net/projects/rarevator.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1481-9) contains supplementary material, which is available to authorized users.

Bicuspid aortic valve syndrome and fibrillinopathies: potential impact on clinical approach

Bicuspid aortic valve (BAV) is a common heterogeneous disorder whose natural history is determined by hemodynamic<br />valvular impairment and/or increased prevalence of aortic abnormalities ranging from dilatation to aneurysm and dissection.<br />BAV-related aortopathy is frequently associated with relevant aortic pathologic changes leading to structural alterations,<br />characteristic degenerative lesions and histological changes of the aorta very similar to those identified and described in<br />patients with Marfan syndrome (MFS), an inherited connective tissue disorder associated with mutations in fibrillin 1 (FBN1)<br />gene in more than 90% of patients. Recently, a 4-fold increase in the prevalence of BAV in MFS patients has been reported.<br />Subsequently, pathogenetic FBN1 mutations in patients with BAV and aortic dilatation/aneurysm in whom MFS and other<br />more severe type 1 fibrillinopathies were clinically excluded have been identified. In this review we discuss how this evidence,<br />together with that of the wide heterogeneity in pathogenetic mechanisms of BAV-related aortopathy, may impact the clinical<br />management of BAV.

EXCAVATOR: detecting copy number variants from whole-exome sequencing data

We developed a novel software tool, EXCAVATOR, for the detection of copy number variants (CNVs) from whole-exome sequencing data. EXCAVATOR combines a three-step normalization procedure with a novel heterogeneous hidden Markov model algorithm and a calling method that classifies genomic regions into five copy number states. We validate EXCAVATOR on three datasets and compare the results with three other methods. These analyses show that EXCAVATOR outperforms the other methods and is therefore a valuable tool for the investigation of CNVs in largescale projects, as well as in clinical research and diagnostics. EXCAVATOR is freely available at http://sourceforge.net/projects/excavatortool/.

Abstract T P59: Inflammatory Mediators and Metalloproteinase Profile Predict Poor Outcome in Ischemic Stroke Patients Treated with Thrombolysis: Results from the MAGIC Study

Background: Experimentally inflammatory mediators and metalloproteinases (MMPs) play a detrimental role related to severity of an ischemic brain lesion. MMPs activity is also induced by the inflammatory response after an ischemic attack. This study aimed to evaluate the role of a large panel of circulating molecules in the setting of tPA treated stroke patients

Methods: Blood was taken before and 24-hours after tPA from 327 patients (mean age 68 years, median NIHSS 11) with acute ischemic stroke. Baseline values and delta median values [(post tPA-baseline)/baseline] of each parameters were analyzed related to 3-month death and 3-month Rankin scale (mRs) score 3-6. The net effect of each biomarker was estimated by a logistic regression model including the major clinical determinants.

Results: 1) Death vs survival: significant for baseline alpha 2-macroglobulin (A2M), deltaMMP9, and deltaTIMP1 [OR (95%CI): A2M 2.52(1.14-5.55); MMP9 1.58(1.11-2.26), TIMP1 2.59(1.44 - 4.66)]. 2) mRs 3-6 vs 0-2: significant for deltaMMP9, deltaIL6, and deltaCRP [OR (95%CI): MMP9 1.35(1.01 - 1.81); IL6 1.07(1.01-1.13); CRP 1.03(1.01-1.06)]. ROC analysis demonstrated that the addition of baseline A2M and deltaMMP9 (model 2) to a model including factors known to affect the outcome (model 1) significantly improved the area under the curve for mortality [model 1: AUC=0.82 (95%CI 0.75-0.90); model 2: AUC=0.88 (95%CI 0.83-0.93), p<0.05]. Discussion: Our data add substantial clinical evidence about the detrimental role of inflammatory mediators and MMPs profile, in particular A2M and MMP9, in tPA treated stroke patients.

Association of rs1466535 LRP1 but not rs3019885 SLC30A8 and rs6674171 TDRD10 gene polymorphisms with abdominal aortic aneurysm in Italian patients

OBJECTIVE

Recently, a large genome-wide association study in patients with abdominal aortic aneurysm (AAA) and control subjects identified nine loci associated with AAA. Besides the significant association of the rs1466535 single nucleotide polymorphism in the low-density lipoprotein receptor-related protein 1 gene (LRP1), two of eight remaining loci, rs6674171 in the tudor domain containing protein 10 (TDRD10) and rs3019885 in solute carrier family 30 zinc transporter member 8 (SLC30A8) gene, showed a weakly significant association with AAA requiring further attention. Therefore, the aim of our study was to evaluate the role of these three polymorphisms in conferring AAA genetic susceptibility.

METHODS

We studied these three polymorphisms in 423 patients and 423 sex- and age-comparable control subjects from Italy. All subjects were genotyped with the use of the real-time TaqMan approach. Multiple logistic regression analysis adjusted for traditional cardiovascular risk factor and chronic obstructive pulmonary disease was used to estimated odds ratios and 95% confidence intervals for AAA risk.

RESULTS

The prevalence of carriers of the rs3019885 SLC30A8 G allele was higher in control subjects (67.8%) than in patients (60.3%, P = .022), suggesting a protective effect for AAA. The prevalence of carriers of the rs1466535 LRP1 T allele was higher in patients (51.8%) than in control subjects (39.7%, P = .0004), suggesting a risk effect for AAA. rs6674171 polymorphism genotype distribution did not differ between AAA patients and control subjects. In the multiple logistic regression analysis adjusted for traditional AAA risk factors, only the rs1466535 polymorphism remained significantly associated with AAA (odds ratio, 1.85; 95% confidence interval, 1.2-2.84; P = .01).

CONCLUSIONS

Our findings confirm the role as significant and independent susceptibility factor for AAA of the rs1466535 LRP1 polymorphism (T allele) in an Italian population. Nevertheless, our findings consistently differed from previous published data because in the genome-wide association study, the risk allele was the most frequent rs1466535 C allele. Our findings are consistent with literature data of LRP1 knock-out mice developing atherosclerotic lesions and aortic dilatation and association of the T allele with reduced LRP1 gene expression in humans.

CLINICAL RELEVANCE

Our work supports the evidence that the T allele of the rs1466535 LRP1 polymorphism is an independent risk factor for abdominal aortic aneurysm. Our findings are consistent with literature data of Lrp1 knock-out mice developing atherosclerotic lesions and aortic dilatation, and association of the T allele with reduced LRP1 gene expression in humans. These data could have a crucial role for developing future diagnostic or prognostic scores based on biohumoral, clinical, genetic, proteomic, and imaging data to be applied in everyday clinical practice in order to improve the management of these high-risk patients in consideration of their characteristics and pathophysiological complexity.

MMP9 variation after thrombolysis is associated with hemorrhagic transformation of lesion and death

BACKGROUND AND PURPOSE

Experimentally, matrix metalloproteinases (MMPs) play a detrimental role related to hemorrhagic transformation and severity of an ischemic brain lesion. Tissue-type plasminogen activator (tPA) enhances such effects. This study aimed to expand clinical evidence in this connection.

METHODS

We measured MMPs 1, 2, 3, 7, 8, 9, and tissue inhibitors of metalloproteinases 1, 2, 4 circulating level in blood taken before and 24 hours after tPA from 327 patients (mean age, 68.9±12.1 years; median National Institutes of Health Stroke Scale, 11) with acute ischemic stroke. Delta median values ([24 hours post tPA-pre tPA]/pre tPA) of each MMP or tissue inhibitors of metalloproteinase were analyzed across subgroups of patients undergoing symptomatic intracerebral hemorrhage, 3-month death, or 3-month modified Rankin Scale score 3 to 6.

RESULTS

Adjusting for major clinical determinants, only matrix metalloproteinase-9 variation proved independently associated with death (odds ratio [95% confidence interval], 1.58 [1.11-2.26]; P=0.045) or symptomatic intracerebral hemorrhage (odds ratio [95% confidence interval], 1.40 [1.02-1.92]; P=0.049). Both matrix metalloproteinase-9 and tissue inhibitors of metalloproteinase-4 changes were correlated with baseline, 24 hours, and 7 days National Institutes of Health Stroke Scale (Spearman P from <0.001 to 0.040).

CONCLUSIONS

Our clinical evidence corroborates the detrimental role of matrix metalloproteinase-9 during ischemic stroke treated with thrombolysis, and prompts clinical trials testing agents antagonizing its effects.

High-dose atorvastatin on the pharmacodynamic effects of double-dose clopidogrel in patients undergoing percutaneous coronary interventions: The ACHIDO (Atorvastatin and Clopidogrel HIgh DOse in stable patients with residual high platelet activity) study

OBJECTIVES

The goal of this study was to investigate the impact of high-dose atorvastatin on the pharmacodynamic (PD) effects of double-dose clopidogrel in statin-naive patients with stable coronary artery disease (CAD) and high-on-treatment platelet reactivity (HTPR) while on standard-dose clopidogrel before percutaneous coronary intervention (PCI).

BACKGROUND

Patients with HTPR are at increased risk of adverse cardiovascular events after PCI. High-dose statins improve prognosis in high-risk patients by lipid- and nonlipid-related mechanisms, including antithrombotic effects.

METHODS

The ACHIDO (Atorvastatin and Clopidogrel HIgh DOse in stable patients with residual high platelet activity) study was a randomized PD study of high-dose (80 mg) atorvastatin in addition to double-dose (150 mg) clopidogrel (atorvastatin group, n = 38) versus double-dose clopidogrel alone (control group, n = 38) in patients with HTPR. HTPR was defined as P2Y(12) reaction units (PRU) ≥235 by the VerifyNow P2Y12 assay. Platelet reactivity was evaluated immediately before PCI and at 10 and 30 days.

RESULTS

Patients randomized to atorvastatin had lower PRU values (188 ± 48 vs. 223 ± 53 PRU, p < 0.01; primary endpoint) and HTPR rates (16% vs. 42%, p < 0.01) at 30 days than patients in the control group. Statin treatment (odds ratio [OR]: 3.8, p = 0.011), baseline PRU <298 (OR: 10.7, p = 0.0001), noncarrier status of CYP2C19*2 loss-of-function allele (OR: 2.9, p = 0.043), and age (OR: 0.94, p = 0.032) were variables significantly associated with optimal PD response (PRU <235) at 30 days. No correlations were found between PRU and lipid fractions.

CONCLUSIONS

High-dose atorvastatin significantly improved the PD effects of double-dose clopidogrel in our stable CAD patients with HTPR undergoing PCI (Atorvastatin and Clopidogrel HIgh DOse in stable patients with residual high platelet activity [ACHIDO]; NCT01335048).

Desmoglein-2-integrin Beta-8 interaction regulates actin assembly in endothelial cells: deregulation in systemic sclerosis

Background

The inability of endothelial cells of patients affected by the diffuse form of Systemic sclerosis (SSc) to perform angiogenesis is a marker of the disease. We previously demonstrated that desmoglein-2 reduction is a major difference between (SSc)-microvascular endothelial cells (MVECs) and normal (N)-MVECs. Here we investigated the role of desmoglein-2 in human N-MVECs and SSc-MVECs angiogenesis.

Methodology/principal findings

Angiogenesis was studied by Matrigel invasion, capillary morphogenesis in vitro and Matrigel plug assay in vivo. Gene profiling was studied by Affymetrix technology and signal transduction by Western blotting. Colocalization was validated by immunoprecipitation and confocal microscopy. SiRNAs were used to validate the roles of specific molecules. We observed that desmoglein-2 co-localizes with integrin-beta8 in N-MVECs. This complex is required to signal through Rac, FAK, SMAD1/5 and MAP-kinases, promoting an angiogenic program. Inhibition of desmoglein-2 by DSG2-siRNA impaired actin stress fibres formation, capillary morphogenesis in vitro and angiogenesis in vivo. Transcriptome profiling after DSG2 inhibition revealed alterations of several genes involved in actin organization. siRNA inhibition of integrin-beta8 and RAC2 also resulted into capillary morphogenesis impairment in N-MVECs, due to reduced expression of the same actin-assembly genes that were down-regulated by DSG2 silencing. SSc-MVECs showed down-regulation of the same genes in DSG2-siRNA treated N-MVECs, suggesting that impairment of desmoglein-2/integrin-beta8 complex contributes to angiogenesis derangement in SSc. Transfection of DSG2 in SSc-MVEC partially restored their angiogenic properties in vitro.

Conclusions/significance

We have shown that impairment of actin assembly as a result of desmoglein-2/integrin-beta8 complex formation is a major factor contributing to angiogenesis deregulation in Systemic sclerosis.

Antiplatelets in acute coronary syndrome: personal perspectives

High platelet reactivity (HPR) during dual-antiplatelet therapy is a marker of vascular risk, in particular stent thrombosis, in patients with acute coronary syndromes. Genetic determinants (CYP2C19*2 polymorphism), advanced age, female gender, diabetes and reduced ventricular function are related to a higher risk to develop HPR. In addition, inflammation and increased platelet turnover, as revealed by the elevated percentage of reticulate platelets in patients' blood, that characterize the acute phase of acute coronary syndrome are associated with HPR. To overcome the limitation of clopidogrel, new antiplatelet agents (prasugrel and ticagrelor) were developed and the demonstration of their superiority over clopidogrel was obtained in the two randomized trials, TRITON TIMI 38 and PLATO. Due to the current possibility not a choice between multiple antiplatelet strategies, the future prospect is to include, in addition to clinical data and classical risk factors, the definition of platelet function during treatment in order to set a tailored therapy.