Effects of genetic variants on platelet reactivity and one-year clinical outcomes after percutaneous coronary intervention: A prospective multicentre registry study

A novel machine learning model to predict high on-treatment platelet reactivity on clopidogrel in Asian patients after percutaneous coronary intervention

BACKGROUND

Various genetic and nongenetic variables influence the high on-treatment platelet reactivity (HTPR) in patients taking clopidogrel.

AIM

This study aimed to develop a novel machine learning (ML) model to predict HTPR in Chinese patients after percutaneous coronary intervention (PCI).

METHOD

This cohort study collected information on 507 patients taking clopidogrel. Data were randomly divided into a training set (90%) and a testing set (10%). Nine candidate Machine learning (ML) models and multiple logistic regression (LR) analysis were developed on the training set. Their performance was assessed according to the area under the receiver operating characteristic curve, precision, recall, F1 score, and accuracy on the test set. Model interpretations were generated using importance scores by transforming model variables into scaled features and representing in radar plots. Finally, we established a prediction platform for the prediction of HTPR.

RESULTS

A total of 461 patients (HTPR rate: 19.52%) were enrolled in building the prediction model for HTPR. The XGBoost model had an optimized performance, with an AUC of 0.82, a precision of 0.80, a recall of 0.44, an F1 score of 0.57, and an accuracy of 0.87, which was superior to those of LR. Furthermore, the XGBoost method identified 7 main predictive variables. To facilitate the application of the model, we established an XGBoost prediction platform consisting of 7 variables and all variables for the HTPR prediction.

CONCLUSION

A ML-based approach, such as XGBoost, showed optimum performance and might help predict HTPR on clopidogrel after PCI and guide clinical decision-making. Further validated studies will strengthen this finding.

High Platelet Reactivity Combined with CYP2C19 Genotype in Predicting Outcomes in East Asian Patients Undergoing Percutaneous Coronary Intervention

Loss-of-function (LoF) alleles of cytochrome P450 2C19 (CYP2C19), which are prevalent in East Asians, are linked to high platelet reactivity (HPR) phenotype and poor prognosis. We aimed to investigate the incremental predictive value of HPR combined with CYP2C19 genotype in predicting outcomes after drug-eluting stent (DES) implantation. The patients treated with platelet function and genotype-related long-term prognosis in drug-eluting stent (PTRG-DES) consortium enrolled a total of 13,160 Korean patients treated with DES who had platelet function test (PFT) or CYP2C19 genotype, of which, 6,717 patients with PFT and genotype together were categorized. HPR was defined as VerifyNow ≥ 252 P2Y12 reaction unit. The primary outcome was the incidence of major adverse cardiac and cerebrovascular event (MACCE) 5 years after treatment. The patients with both HPR and CYP2C19 LoF/LoF had the highest MACCE rates (6.2%) and increased MACCE risk (adjusted hazard ratio: 1.89, 95% confidence interval: 1.20-2.91, P = 0.006) compared with those without both HPR and CYP2C19 LoF/LoF. There was no effect of interaction between HPR and CYP2C19 genotype on the primary outcome (P = 0.424). Adding combined HPR and CYP2C19 genotype to the conventional model had an incremental influence in predicting MACCE and stent thrombosis. Compared to the model including HPR or CYP2C19 genotype alone, a combination model significantly improved the risk stratification for stent thrombosis but not MACCE. In DES-treated East Asian patients, the combined evaluation of PFT results and CYP2C19 genotyping might improve risk prediction of ischemic events during clopidogrel treatment.

Platelet Function and Genotype after DES Implantation in East Asian Patients: Rationale and Characteristics of the PTRG-DES Consortium

PURPOSE

Platelet function test (PFT) results and genotype hold unique prognostic implications in East Asian patients. The aim of the PTRG-DES (Platelet function and genoType-Related long-term proGnosis in Drug-Eluting Stent-treated Patients with coronary artery disease) consortium is to assess the clinical impact thereof on long-term clinical outcomes in Korean patients with coronary artery disease during dual antiplatelet therapy (DAPT) including clopidogrel.

MATERIALS AND METHODS

Searching publications on the PubMed, we reviewed clopidogrel treatment studies with PFT and/or genotype data for potential inclusion in this study. Lead investigators were invited to share PFT/genotype results, patient characteristics, and clinical outcomes to evaluate relationships among them.

RESULTS

Nine registries from 32 academic centers participated in the PTRG-DES consortium, contributing individual patient data from 13160 patients who underwent DES implantation between July 2003 and August 2018. The PTRG-PFT cohort was composed of 11714 patients with available VerifyNow assay results. Platelet reactivity levels reached 218±79 P2Y12 reaction units (PRU), and high on-clopidogrel platelet reactivity based on a consensus-recommended cutoff (PRU >208) was observed in 55.9%. The PTRG-Genotype cohort consisted of 8163 patients with candidate genotypes related with clopidogrel responsiveness. Of those with cytochrome P450 (CYP) 2C19 genotype, frequencies of carrying one and two loss-of-function allele (s) (^*2 or ^*3) were 47.9% (intermediate metabolizers) and 14.2% (poor metabolizers), respectively.

CONCLUSION

The PTRG-DES consortium highlights unique values for on-clopidogrel platelet reactivity and CYP2C19 phenotype that may be important to developing optimal antiplatelet regimens in East Asian patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04734028.

Differences in Optimal Platelet Reactivity after Potent P2Y12 Inhibitor Treatment in Acute Coronary Syndrome Patients Undergoing Percutaneous Coronary Intervention

Background: East Asian patients receiving treatment with the potent P2Y12 inhibitors prasugrel or ticagrelor experience more potent platelet inhibition than with clopidogrel. Methods: This study investigated differences in OPR rates with reduced doses of prasugrel (n = 38) or ticagrelor (n = 40) for maintenance therapy in 118 Korean ACS patients who had undergone PCI, in comparison to conventional-dose clopidogrel (n = 40). We assessed drug responses at one- and three-months post-PCI with VerifyNow and multiple electrode aggregometry assays. Results: At the one-month period, patients receiving standard-dose prasugrel or ticagrelor had lower platelet reactivity as determined by the three assays than those receiving the conventional dose of clopidogrel (VN: p = 0.000; MEA: p = 0.000; LTA: p = 0.000). At the 3-month point, platelet reactivity was lower in those receiving reduced-dose prasugrel or ticagrelor than the clopidogrel-treated patients (VN: p = 0.000; MEA: p = 0.012; LTA: p = 0.002). Prasugrel resulted in significantly lower platelet inhibition than ticagrelor as determined by VN and LTA (VN: p = 0.000; LTA: p = 0.003). At three months, there was a significant overall difference in OPR among the three groups when measured by VN (p < 0.001), but not when measured by MEA (p = 0.596). OPR in the reduced-dose prasugrel group was not significantly different to the clopidogrel group at three months (VN: p = 0.180; MEA: p = 0.711). OPR in the reduced-dose ticagrelor group was similar to clopidogrel as determined by MEA at three months, but was different when assessed by VN (VN: p = 0.000; MEA: p = 0.540). Compared to standard-dose, the reduced-dose prasugrel OPR rate was significantly increased (VN: p = 0.008; MEA: p = 0.020). Conclusions: OPR values for reduced-dose prasugrel and conventional-dose clopidogrel at three months were similar but higher than for reduced-dose ticagrelor as determined by VN, but no differences were noted by MEA. The MEA assay might have less sensitivity and consistency than the VN assay. Further studies are needed to explore this discrepancy.

Impact of renal function on residual platelet reactivity and clinical outcomes in patients with acute coronary syndrome treated with clopidogrel

BACKGROUND

Chronic kidney disease (CKD) is a common comorbidity in patients with acute coronary syndrome (ACS) and may potentially influence platelet function.

HYPOTHESIS

We explored the influence of renal function on platelet reactivity to investigate whether high residual platelet reactivity (HRPR) is associated with cardiovascular events.

METHODS

ACS patients treated with aspirin and clopidogrel were prospectively enrolled. Patients were categorized into two groups on the basis of baseline estimated glomerular filtration rate (eGFR): non-CKD (eGFR ≥60 mL/min/1.73 m2 ) and CKD (eGFR <60 mL/min/1.73 m2 ). Platelet function was measured by thromboelastography ≥5 days after maintenance dual antiplatelet therapy. Major adverse clinical events (MACEs) were collected at 1 year after discharge.

RESULTS

There were 282 non-CKD patients and 212 CKD patients. A significant difference in median MAADP value was observed between the two groups (15.0 mm vs. 31.3 mm, p < .001). HRPR was more prevalent in the CKD group than the non-CKD group (27.4% vs 9.6%, p < .001). At 1-year follow-up, the incidence of MACEs was significantly higher for those with both CKD and HRPR compared with those with either CKD or HRPR (37.9% vs. 18.5%, p < .001). The relationship between HRPR and MACEs was consistent across CKD strata without evidence of interaction. Adding platelet reactivity to eGFR improved the model with area under the curve increasing from 0.703 to 0.734.

CONCLUSION

In patients with ACS, the risk of HRPR increased with declining eGFR. Both CKD and HRPR were associated with MACEs at 1-year follow-up.

Impact of genetic variants on clinical outcome after percutaneous coronary intervention in elderly patients

Elderly patients treated with percutaneous coronary intervention (PCI) have a higher risk of both ischemic and bleeding complications than younger patients. However, few studies have reported how genetic information of elderly patients treated with PCI affects clinical outcomes. We investigated the impact of genetic variants on clinical outcomes in elderly patients. Correlations between single-nucleotide polymorphisms (CYP2C19 and P2Y12 receptor gene G52T polymorphism) and clinical outcomes were analyzed in 811 elderly patients (≥75 years of age) from a prospective multicenter registry. The primary endpoint was a composite of myocardial infarction and death. Secondary endpoints were an individual event of death, cardiac death, myocardial infarction, stent thrombosis, target lesion revascularization, stroke, and major bleeding (Bleeding Academic Research Consortium ≥3). Regarding CYP2C19, patients with poor metabolizers had a significantly higher risk for the primary endpoint (hazard ratio [HR] 2.43; 95% confidence interval [95% CI] 1.12–5.24; p=0.024) and secondary endpoints (death and cardiac death). Regarding P2Y12 G52T, the TT group had a significantly higher occurrence of major bleeding than the other groups (HR 3.87; 95% CI 1.41–10.68; p=0.009). In conclusion, poor metabolizers of CYP2C19 and TT groups of P2Y12 G52T may be significant predictors of poor clinical outcomes in elderly patients.

Pharmacodynamic Profile and Prevalence of Bleeding Episode in East Asian Patients with Acute Coronary Syndromes Treated with Prasugrel Standard-Dose versus De-escalation Strategy: A Randomized A-MATCH Trial

Compared with Caucasian patients, East Asian patients have the unique risk-benefit trade-off and different responsiveness to antithrombotic regimens. The aim of this study was to compare pharmacodynamic profile in East Asian patients with acute coronary syndromes (ACSs) treated with prasugrel standard-dose versus a de-escalation strategy. Before discharge, ACS patients with age <75 years or weight ≥60 kg (n = 255) were randomly assigned to the standard-dose (10-mg group) or de-escalation strategy (5-mg group or platelet function test [PFT]-guided group). After 1 month, VerifyNow P2Y12 assay-based platelet reactivity (P2Y12 reaction unit [PRU]) and bleeding episodes were evaluated. Primary endpoint was the percentage of patients with the therapeutic window (85 ≤ PRU ≤ 208). The 250 patients completed 1-month treatment. The percentage of patients within the therapeutic window was significantly lower in the 10-mg group (n = 85) compared with the 5-mg (n = 83) and PFT-guided groups (n = 82) (35.3 vs. 67.5 vs. 65.9%) (odds ratio [OR]: 3.80 and 3.54; 95% confidence interval [CI]: 2.01-7.21 and 1.87-6.69, respectively). Compared with the 10-mg group, the bleeding rate was tended to be lower with de-escalation strategies (35.3 vs. 24.1% vs. 23.2%) (hazard ratio [HR]: 0.58 and 0.55; 95% CI: 0.30-1.14 and 0.28-1.09, respectively). "PRU < 127" was the optimal cut-off for predicting 1-month bleeding events (area under the curve: 0.616; 95% CI: 0.543-0.689; p = 0.005), which criteria was significantly associated with early discontinuation of prasugrel treatment (HR: 2.00; 95% CI: 1.28-3.03; p = 0.001). In conclusion, compared with the standard-dose prasugrel, the prasugrel de-escalation strategy in East Asian patients presented with ACS showed a higher chance within the therapeutic window and a lower tendency toward bleeding episodes. REGISTRATION:  URL: https://clinicaltrials.gov. Unique identifier:NCT01951001.

The East Asian Paradox: An Updated Position Statement on the Challenges to the Current Antithrombotic Strategy in Patients with Cardiovascular Disease

East Asian patients have reduced anti-ischemic benefits and increased bleeding risk during antithrombotic therapies compared with Caucasian patients. As potent P2Y₁₂ receptor inhibitors (e.g., ticagrelor and prasugrel) and direct oral anticoagulants are commonly used in current daily practice, the unique risk-benefit trade-off in East Asians has been a topic of emerging interest. In this article, we propose updated evidence and future directions of antithrombotic treatment in East Asian patients.

The Pharmacogenetics of Rituximab: Potential Implications for Anti-CD20 Therapies in Multiple Sclerosis

There are a broad range of disease-modifying therapies (DMTs) available in relapsing-remitting multiple sclerosis (RRMS), but limited biomarkers exist to personalise DMT choice. All DMTs, including monoclonal antibodies such as rituximab and ocrelizumab, are effective in preventing relapses and preserving neurological function in MS. However, each agent harbours its own risk of therapeutic failure or adverse events. Pharmacogenetics, the study of the effects of genetic variation on therapeutic response or adverse events, could improve the precision of DMT selection. Pharmacogenetic studies of rituximab in MS patients are lacking, but pharmacogenetic markers in other rituximab-treated autoimmune conditions have been identified. This review will outline the wider implications of pharmacogenetics and the mechanisms of anti-CD20 agents in MS. We explore the non-MS rituximab literature to characterise pharmacogenetic variants that could be of prognostic relevance in those receiving rituximab, ocrelizumab or other monoclonal antibodies for MS.

Risk of major adverse cardiovascular events of CYP2C19 loss-of-function genotype guided prasugrel/ticagrelor vs clopidogrel therapy for acute coronary syndrome patients undergoing percutaneous coronary intervention: a meta-analysis

The most effective antiplatelet treatments for acute coronary syndrome (ACS) patients carrying CYP2C19 loss-of-function (LoF) alleles undergoing percutaneous coronary intervention (PCI) is still debating and conflicting. It was aimed to compare the efficacy and safety endpoints for these patients treated with alternative P2Y12 receptor blockers (e.g. prasugrel or ticagrelor) against clopidogrel. Literature was searched in PubMed, Cochrane library, Synapse and 1000 Genomes databases following PRISMA guidelines for identifying relevant studies. Aggregated risk was estimated by RevMan software using either fixed/random-effects models where P values<0.05 (two-sided) were considered statistically significant. Nine studies comprising 16,132 ACS patients undergoing PCI were included in this analysis in which 2,746 and 2,640 patients were in the CYP2C19 LoF clopidogrel and alternatives treatment group, respectively. It was demonstrated that patients treated with prasugrel or ticagrelor significantly reduced the risk of MACEs (RR 0.58; 95% CI 0.45-0.76; P<0.0001) as compared to patients with clopidogrel where both groups carrying CYP2C19 LoF alleles. Subgroup analysis showed that prasugrel or ticagrelor significantly reduced the risk of cardiovascular death (RR 0.44; 95% CI: 0.25-0.74; P=0.002) and MI (RR 0.60; 95% CI: 0.44-0.81; P=0.0008) while other clinical outcomes were not found statistically significant between these two groups; stroke (RR 0.77; 95% CI: 0.43-1.38; P =0.39), stent thrombosis (RR 0.67; 95% CI: 0.38-1.18; P =0.17), unstable angina (RR 0.55; 95% CI: 0.13-2.33; P =0.42), revascularisation (RR 0.79; 95% CI: 0.28-2.24; P=0.66). Bleeding events were not found significantly different between these groups (RR 1.06; 95% CI: 0.88-1.28; P=0.55). Considering efficacy and safety, alternative antiplatelets (e.g. prasugrel or ticagrelor) may be regarded as better treatment option as compared to clopidogrel for ACS patients undergoing PCI.

1-year results after PCI with the COMBO stent in all-comers in Asia versus Europe: Geographical insights from the COMBO collaboration

BACKGROUND

The COMBO drug-eluting stent combines sirolimus-elution from a biodegradable polymer with an anti-CD34+ antibody coating for early endothelialization.

OBJECTIVE

We investigated for geographical differences in outcomes after percutaneous coronary intervention (PCI) with the COMBO stent among Asians and Europeans.

METHODS

The COMBO Collaboration is a pooled patient-level analysis of the MASCOT and REMEDEE registries of all-comers undergoing attempted COMBO stent PCI. The primary outcome was 1-year target lesion failure (TLF), composite of cardiac death, target vessel myocardial infarction (TV-MI) and target lesion revascularization (TLR).

RESULTS

This study included 604 Asians (17.9%) and 2775 Europeans (82.1%). Asians were younger and included fewer females, with a higher prevalence of diabetes mellitus but lower prevalence of other comorbidities than Europeans. Asians had a higher prevalence of ACC/AHA C type lesions and received longer stent lengths. More Asians than Europeans were discharged on clopidogrel (86.5% vs 62.8%) rather than potent P2Y₁₂ inhibitors. One-year TLF occurred in 4.0% Asians and 4.1% of Europeans, p = 0.93. The incidence of cardiac death was higher in Asians (2.8% vs. 1.3%, p = 0.007) with similar rates of TV-MI (1.5% vs. 1.2%, p = 0.54) and definite stent thrombosis (0.3% vs. 0.5%, p = 0.84) and lower incidence of TLR than Europeans (1.0% vs. 2.5%, p = 0.025). After adjustment, differences for cardiac death and TLR were no longer significant.

CONCLUSIONS

In the COMBO collaboration, although 1-year TLF was similar regardless of geography, Asians experienced higher rates of cardiac death and lower TLR than Europeans, while incidence of TV-MI and ST was similar in both regions. Adjusted differences did not reach statistical significance. CLINICALTRIAL.

GOV IDENTIFIER-NUMBERS

NCT01874002 (REMEDEE Registry), NCT02183454 (MASCOT registry).

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.

Association of PON1 gene promoter DNA methylation with the risk of Clopidogrel resistance in patients with coronary artery disease

BACKGROUND AND AIMS

The failure of therapeutic response to clopidogrel in platelet inhibition, which is called clopidogrel resistance (CR), is more likely to cause cardiovascular events. We aimed to study the contribution of promoter DNA methylation of paraoxonase 1 (PON1) to the risk of clopidogrel poor response.

METHODS

Through VerifyNow P2Y12 assay, patient' platelet functions were measured. Among 57 non-CR and 49 CR patients, the levels of DNA methylation in four CpG dinucleotides on the PON1 promoter were tested using bisulfite pyrosequencing technology. Besides, the relative expression of PON1 mRNA was analyzed by quantitative real-time PCR. Logistic regression was applied to investigate the interaction of PON1 methylation and clinical factors in CR.

RESULTS

In the subgroup with dyslipidemia, we discovered that higher CpG4 levels of the PON1 promoter indicated a poorer clopidogrel response (cases versus controls (%): 51.500 ± 14.742 vs 43.308 ± 10.891, P = 0.036), and the PON1 mRNA expression was reduced in CR patients. Additionally, the logistic regression indicated that higher level of albumin and the index of ALT were related to a lower risk of CR, and the index of AST as well as the quantity of stent may be positively associated with CR.

CONCLUSIONS

The DNA methylation of CpG4 in the PON1 promoter would lead to a low expression of PON1 mRNA, which might induce clopidogrel resistance in the patients with dyslipidemia, and the number of stents might be a risk for CR.

2018 update of expert consensus statement on antiplatelet therapy in East Asian patients with ACS or undergoing PCI

East Asians are the most populous race in the world and their health status is an important global issue. Compared with Caucasian populations, East Asian patients have a different benefit/risk ratio when using antithrombotic treatment. Despite this observation, treatment strategies in East Asian patients are mostly based on the American and European guidelines. Despite a lower platelet inhibitory response to clopidogrel, East Asian patients show a similar or even a lower rate of ischemic event occurrence and higher bleeding risk compared with Caucasian patients. For potent P2Y₁₂ inhibitors (ticagrelor and prasugrel), East Asian patients have shown less favorable net clinical benefits compared with Caucasian patients, which may be related to differences in pharmacokinetic/pharmacodynamic profiles and therapeutic zone of antiplatelet effect. This updated consensus mainly focuses on state-of-the-art and current controversies in the East Asian population. In addition, when East Asian patients are administered potent P2Y₁₂ receptor inhibitors, the strategies and ongoing trials to overcome the related hurdles are discussed.

Clopidogrel-associated genetic variants on inhibition of platelet activity and clinical outcome for acute coronary syndrome patients

Acute coronary syndrome (ACS) has become a vital disease with high mortality worldwide. A combined antiplatelet therapy (aspirin and a P2Y₁₂ antagonist) is commonly used to prevent re-infarction in ACS patients who have undergone percutaneous coronary intervention (PCI). Clopidogrel, a P2Y₁₂ antagonist, plays an important role in the inhibition of platelet aggregation (IPA). However, it is a pro-drug requiring biotransformation by cytochrome P450 (CYP450). The aim of this study is to unravel the effect of clopidogrel-associated genetic variants on inhibition of platelet activity and clinical outcomes in ACS patients. In our study, a total of 196 patients with metabolic gene polymorphism of clopidogrel were enrolled, and their antiplatelet effect as well as their cardiovascular events were collected. Approximately 2 mL of venous blood samples were used for genotype detection and another 4 mL were collected for platelet reactivity with thrombelastography. The primary clinical end-point was defined as a combination of cardiovascular mortality and revascularization for targeted vascular lesion. Based on the results of IPA, the prevalence of high on-treatment platelet reactivity (HPR) was 17.3% and the majority of patients (82.7%) obtained normal on-treatment platelet reactivity (NPR). The HPR group had significantly higher body mass index (BMI) and lower arachidonic acid (AA) induced IPA (P < 0.05). Therapy including Glycoprotein (GP) IIb/IIIa antagonist increased IPA (P < 0.05). ADP-induced IPA effect was lower with the presence of CYP2C19*2, *3 and paraoxonase (PON)1 Q192R loss-of-function (LOF) alleles, respectively (P < 0.05). Multivariate logistic regression analysis demonstrated that aspirin resistance (AA-induced IPA < 50%) had a greater risk of the occurrence of major adverse cardiovascular events (MACE) (OR = 3.817; 95% CI: 1.672-8.700; P = 0.002). CYP2C19*2 LOF alleles were associated with high risk of MACE in 1-year post PCI operations (OR = 2.571; 95% CI: 1.143-5.780; P = 0.030). For the ACS patients, the presence of CYP2C19*2 and PON1 Q192R LOF alleles were the major drivers of HPR.

Using Pharmacogenetic Testing or Platelet Reactivity Testing to Tailor Antiplatelet Therapy: Are Asians different from Caucasians?

All studies to date involving platelet reactivity and gene testing document singular interventions and their associations with outcomes. The East Asian paradox has been well documented - Asians who have had a percutaneous coronary intervention (PCI) are at a lower risk of ischaemic events even though they have a higher platelet reactivity. Asians who have had a PCI also have a higher risk of bleeding. This article covers the differences in outcomes between Caucasians and Asians, and explores the impact of outcomes, highlighting differences between the two patient populations. Given the high prevalence of loss-of-function alleles in Asia, treatment strategies will differ for different populations. It is plausible that both platelet reactivity and gene testing should be used to inform holistic decision-making for all patients - Caucasian or Asian - with acute coronary syndrome who are undergoing PCI.