Paraoxonase-1 as a Cardiovascular Biomarker in Caribbean Hispanic Patients Treated with Clopidogrel: Abundance and Functionality.

Clopidogrel, a prescription drug to reduce ischemic events in cardiovascular patients, has been extensively studied in mostly European individuals but not among Caribbean Hispanics. This study evaluated the low abundance and reduced activity of paraoxonase-1 (PON1) in clopidogrel-resistant patients as a predictive risk biomarker of poor responders and disease severity in this population. Thirty-six patients on clopidogrel (cases divided into poor and normal responders) were enrolled, along with 11 cardiovascular patients with no clopidogrel indications (positive control) and 13 healthy volunteers (negative control). Residual on-treatment platelet reactivity unit (PRU), PON1 abundance by Western blotting, and PON1 activity by enzymatic assays were measured. PON1 genotyping and computational haplotype phasing were performed on 512 DNA specimens for two genetic loci (rs662 and rs854560). No statistical differences in mean relative PON1 abundance were found among the groups (p > 0.05). However, a significantly lower enzymatic activity was found in poor responders (10.57 ± 6.79 µU/mL) when compared to controls (22.66 ± 8.30 µU/mL and 22.21 ± 9.66 µU/mL; p = 0.004). PON1 activity among carriers of the most prevalent PON1 haplotype (AA|AA) was significantly lower than in wild types (7.90 µU/mL vs. 22.03 µU/mL; p = 0.005). Our findings suggested that PON1 is a potential biomarker of cardiovascular disease severity in Caribbean Hispanics.

Aspirin Desensitization and Percutaneous Coronary Intervention in a Patient with Aspirin Hypersensitivity and Acute Coronary Syndrome: A Case Report.

Hypersensitivity to aspirin is rare disorder occurring in 1.88% of the patients. Aspirin-hypersensitive patients requiring single antiplatelet agent may be treated with clopidogrel, an alternative antiplatelet agent. However, aspirin desensitization is more cost-effective than the usage of clopidogrel in these patients. Furthermore, aspirin desensitization is of greater value in patients requiring dual antiplatelet therapy, for example following procedures like percutaneous transluminal coronary angioplasty (PTCA) instead of using non-aspirin-based combinations. Herein, we report a 74-year-old hypertensive male presented with features of acute coronary syndrome and planned for percutaneous transluminal coronary angioplasty of RCA followed by dual antiplatelet therapy. Since he had aspirin allergy, desensitization was done using rapid desensitization protocol for which he responded well. This case highlights the importance of aspirin-desensitization in patients with aspirin allergy instead of choosing non-aspirin based antiplatelet agents.

Cost analysis of CYP2C19 genetic testing in percutaneous coronary intervention patients.

CYP2C19 loss of function (LOF) carriers undergoing percutaneous coronary intervention (PCI) have an increased risk of ischemic events when treated with clopidogrel. PCI patients in TAILOR-PCI were randomized to clopidogrel or genotype-guided (GG) therapy in which LOF carriers received ticagrelor and non-carriers clopidogrel. Direct medical costs associated with a GG approach have not been described before. TAILOR-PCI participants for whom direct medical costs were available for the duration from the date of PCI to one-year post PCI were included. Primary cost estimates were obtained from the Mayo Clinic Cost Data Warehouse. There were no differences in direct medical costs between the GG and clopidogrel groups (mean $20,682 versus $19,747, p = 0.11) however total costs were greater in the GG group (mean $21,245 versus $19,891, p = 0.02) which was primarily driven by ticagrelor costs. In conclusion the increased expense of a GG strategy post PCI as compared to clopidogrel for all is primarily driven by the cost of ticagrelor.

Antiplatelet Strategy for Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: A Systematic Review and Network Meta-Analysis.

BACKGROUND: Optimal duration and choice of antiplatelet therapy in patients with acute coronary syndrome undergoing percutaneous coronary intervention remain controversial. METHODS AND RESULTS: Digital databases (PubMed, Cochrane, and Embase) were queried to select all randomized controlled trials on a post-percutaneous coronary intervention population with acute coronary syndrome. Dual-antiplatelet therapy (DAPT) with aspirin and clopidogrel for 12 months was compared with 4 major strategies: high-potency, high- to low-potency, low-dose, and short-duration DAPT. A network meta-analysis was performed to compare the safety and efficacy of different antiplatelet strategies. This study was the second updated manuscript under the International Prospective Register of Systematic Review registration (CRD42021286552). Thirty-two randomized controlled trials comprising 103 459 (51 750 experimental, 51 709 control) patients were included. Compared with DAPT with aspirin and clopidogrel for 12 months, high- to low-potency DAPT (risk ratio [RR], 0.69 [95% CI, 0.52-0.92]) and aspirin+prasugrel containing DAPT for 12 months (RR, 0.84 [95% CI, 0.72-0.98]) had a significantly lower, whereas DAPT for 1 month followed by clopidogrel only (RR, 1.59 [95% CI, 1.06-2.39]) had a higher, incidence of major adverse cardiovascular events at 1 year (median follow-up). Prasugrel (RR, 1.35 [95% CI, 1.09-1.66]) and ticagrelor (RR, 1.38 [95% CI, 1.17-1.62]) containing DAPT for 12 months had significantly higher rates, whereas high- to low-potency DAPT (RR, 0.85 [95% CI, 0.63-1.15]) had no significant risk of major bleeding. CONCLUSIONS: Aspirin and ticagrelor for 3 months, followed by aspirin and clopidogrel for the remaining duration, can be considered the optimal strategy for treating post-percutaneous coronary intervention patients with acute coronary syndrome because of a significantly reduced risk of major adverse cardiovascular events without increasing the risk of bleeding.

Platelet Function, Platelet Size and Content of Reticulated Platelets: Interactions in Patients Receiving Dual Antiplatelet Therapy.

Increased platelet activity is a risk factor of thrombotic events in cardiovascular patients. We studied the relationship between platelet function, platelet size, and the content of reticulated platelets (RP) in patients with coronary heart disease (CHD, n = 55) and acute coronary syndrome (ACS, n = 95) receiving acetylsalicylic acid + clopidogrel or ticagrelor, respectively. The control group consisted of patients with risk factors for CHD, but with no CHD/ACS and free of antiplatelet drugs (n = 66). Platelet function was evaluated by the exposure of activated glycoprotein (GP) IIb-IIIa and P-selectin. In the control group, platelets were activated by TRAP (Thrombin Receptor Activating Peptide) 10 µM, and ADP 20, 5, 2.5 µM, and in the CHD/ACS groups, by TRAP 10 µM, and ADP 20 5 µM (±epinephrine 20 µM). Platelet size was assessed by the mean volume, % large forms, and forward scattering. RP were stained by thiazole orange. In the control group, activated GP IIb-IIIa and P-selectin correlated with platelet size and RP content after platelet activation by all agonists. Despite the decrease in platelet activity by antiplatelet drugs, most correlations (primarily for activated GP IIb-IIIa) were preserved in the CHD/ACS patients. In conclusion, increased platelet size and RP content are associated with increased platelet activity and the reduced efficacy of antiplatelet therapy.

Predictive value of the systemic immune-inflammation index for periprocedural complications in flow diverter treatment for patients with intracranial aneurysms.

Flow-diverter devices (FDs) are effective in treating intracranial aneurysms (IAs) but carry substantial periprocedural risks, particularly ischemic complications. This study aimed to determine if elevated Systemic Immune-Inflammation Index (SII) can independently predict these risks and assess the impact of age and dual antiplatelet therapy on this association. We conducted a retrospective analysis of patients treated with FDs between February 2016 and August 2023, using blood samples taken within six days before surgery to calculate SII. Logistic regression and decision tree analyses assessed the link between SII and periprocedural complications, with subgroups exploring influencing factors. Multivariable analysis identified high SII as an independent predictor of periprocedural complications (OR = 5.306, 95% CI: 1.367-18.455; P = 0.009). The decision tree model confirmed SII > 0.437 as a critical threshold. Subgroup analysis showed a pronounced association of SII with periprocedural complications in patients ≥ 65 years (OR = 36.979, 95% CI: 2.103-650.134; P = 0.014) and in those on clopidogrel plus aspirin therapy (OR = 16.921, 95% CI: 2.733-104.746; P = 0.002). An elevated Systemic Immune-Inflammation Index (SII) > 0.437 significantly correlates with increased periprocedural complications (6.5% vs. 1.8%, P = 0.017). Although not statistically significant, higher SII is associated with a greater rate of ischemic events (3.9% vs. 0.9%). Elevated preoperative SII independently predicts periprocedural complications, particularly ischemic events, in patients undergoing FDs treatment for intracranial aneurysms. This association is particularly pronounced in older patients (> 65 years) and those receiving dual therapy with clopidogrel plus aspirin. Trial Registration: ClinicalTrials.gov (NCT06446778). Registered on May 22, 2024.

Time to treatment and disability attributed to index stroke in the POINT trial.

BACKGROUND: In the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial, dual antiplatelet therapy (DAPT) was associated with reduced disability attributable to the index stroke compared to antiplatelet monotherapy. However, it is unknown whether earlier treatment with DAPT versus aspirin is associated with greater benefit. METHODS: We analyzed patients enrolled in POINT with minor ischemic stroke who had available data recording the treatment initiation time and modified Rankin Scale (mRS) at 90 days. Patients were randomized to DAPT (aspirin plus clopidogrel) vs. aspirin alone within 12 h of symptom onset. We estimated the effect of DAPT on disability (defined as mRS>1) ascribed to the index event and major hemorrhage at 90 days, stratified by tertiles of time from symptom onset-to-treatment-initiation. RESULTS: A total of 2559 patients were included; median onset-to-treatment-initiation time was 8.3 h (IQR:5.8-11.0). Comparing DAPT to aspirin, the rate of disability attributed to the index event at 90-day follow-up was 5.1 % vs. 8.6 % (OR 0.57; 95 % CI:0.33-0.99) in patients treated <6.7 h, 7.5 % vs. 9.9 % (OR 0.74; 95 % CI:0.45-1.19) in those treated 6.7-10.0 h, and 8.6 % vs. 10.6 % (OR 0.80; 95 % CI:0.50-1.26) in those treated >10.0 h after symptom onset (p for interaction=0.65). There was no difference in major hemorrhage across time strata. CONCLUSIONS: While not statistically significant, these results suggest the possibility of greater efficacy at reducing disability ascribed to minor stroke with earlier treatment with DAPT compared to aspirin. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Identifier: NCT00991029.

Comparison of clinical outcomes between ticagrelor and clopidogrel in patients with acute coronary syndrome and left ventricle dysfunction undergoing percutaneous coronary intervention: An observational study.

Patients with acute coronary syndrome (ACS) and left ventricular (LV) dysfunction undergoing percutaneous coronary intervention (PCI) need adequate antithrombotic protection. We aim to compare the clinical outcomes between ticagrelor and clopidogrel in these patients. In total, 336 patients with ACS and LV dysfunction who undergoing PCI were included in this retrospective observational study. Of these, 137 received clopidogrel and 199 received ticagrelor. There was a 6-month follow-up period during which clinical outcomes were monitored. The incidence of the composite endpoint (23.1% vs 13.9%, P = .041) and bleeding events (6.5% vs 1.5%, P = .027) in the ticagrelor group were significantly higher compared to the clopidogrel group. Multivariate logistic regression analysis revealed that age (P = .006), hypertension (P = .007), liver insufficiency (P = .022), previous MI (P = .014) and ticagrelor (P = .044) were independent risk factors that affect the efficacy outcome. Age (P = .027) and ticagrelor (P = .016) were the independent risk factors for the safety outcome. Furthermore, in Cox survival regression analysis model, the survival rate of the efficacy endpoint in the clopidogrel group was seemingly higher than in the ticagrelor group (HR = 1.68, 95% CI: 0.97-2.90, P = .065). The survival rate of the bleeding endpoint in the clopidogrel group was higher than in the ticagrelor group (HR = 2.00, 95% CI: 1.17-3.40, P = .011). Compared to clopidogrel, ticagrelor showed increased risk of efficacy outcome and major bleeding events during 6-month follow-up in patients with ACS and LV dysfunction undergoing PCI.

A retrospective study of the safety and efficacy of clopidogrel versus aspirin monotherapy one year after coronary stent implantation.

BACKGROUND: The ideal single antiplatelet therapy for long-term maintenance after coronary stenting remains uncertain. In a head-to-head comparison, we aimed to evaluate the efficacy and safety profile of aspirin and clopidogrel as monotherapies in this patient cohort. METHOD: We reviewed 1044 patients who underwent percutaneous coronary intervention (PCI) with drug-eluting stents (DES) at the Department of Cardiovascular Medicine, Jinshan Hospital of Fudan University, between January 2019 and December 2021 and completed a 12-month Dual Antiplatelet Therapy (DAPT) treatment. They were divided into two groups: 582 were assigned to the aspirin group (100 mg/day) and 422 to the clopidogrel group (75 mg/day). The primary endpoint was the composite cardiac death, ischemic stroke, myocardial infarction, and Bleeding Academic Research Consortium (BARC) bleeding type 3 or greater. Secondary endpoint events included all-cause death, ischemic stroke, myocardial infarction, bleeding (defined as a BARC type ≥ 2 bleeding), and gastrointestinal complications. RESULTS: After a mean observation period of 25 ± 8.4 months, the primary endpoint event occurred in 29 (6.8%) patients in the clopidogrel group and 30 (5.1%) in the aspirin group, with no difference between the two groups (P = 0.253). In BARC type 2 or greater bleeding events, there were 9 (1.5%) in the aspirin group compared to 7 (1.7%) in the clopidogrel group, with no difference between the two groups (P = 0.160). CONCLUSION: After 12-month DAPT in Chinese patients undergoing DES implantation, aspirin monotherapy versus clopidogrel monotherapy showed no significant difference between the two drugs in terms of safety and efficacy in terms of hemorrhage, myocardial infarction, ischemic stroke, cardiac death, and bleeding with BARC type 2 or greater.

The prognostic difference study on the individualized clopidogrel administration in Hmong and Dong patients based on the CYP2C19 gene polymorphism after percutaneous coronary intervention.

This study explored the distribution characteristics of CYP2C19 gene polymorphism among Hmong and Dong patients in the Qiandongnan region of Guizhou province after percutaneous coronary intervention (PCI). The aim was to assess the clinical impact of individualized clopidogrel administration based on CYP2C19 genotypes. A total of 208 patients were classified into ultra-fast, fast, intermediate, and slow metabolic groups. They were randomly assigned to clopidogrel individualized administration (IA) or conventional treatment (CA) groups. Patients were followed for 6 months to evaluate major adverse cardiovascular events (MACE) and adverse reactions. The CYP2C19 genotype distribution was in Hardy-Weinberg equilibrium, showing consistency in the population. While no significant ethnic differences were found in genotype and metabolic distribution, allele distribution varied, with Hmong patients exhibiting a higher proportion of CYP2C19*1 alleles than Dong patients. Following individualized administration, the IA group demonstrated lower incidences of non-fatal myocardial infarction and emergency revascularization compared to the CA group. Bleeding events were higher in the IA group, but the total MACE incidence was lower. No statistical difference in MACE and adverse drug reactions (ADR) was observed in the CA group across metabolic types, but MACE incidence was higher in intermediate and slow metabolic groups. In the IA group, no significant difference in MACE was noted among metabolic types, but ADR incidence varied significantly, particularly in dyspnea. The study highlighted significant CYP2C19 allele distribution differences between Hmong and Dong patients post-PCI in Qiandongnan. Patients with slow metabolic profiles demonstrated higher MACE incidence with conventional clopidogrel dosage, whereas CYP2C19-guided therapy reduced MACE without increasing bleeding risk. These findings supported clinical individualized clopidogrel administration in post-PCI patients in the Qiandongnan region, contributing to rational clopidogrel use.

Duration of Benefit and Risk of Dual Antiplatelet Therapy up to 72 Hours After Mild Ischemic Stroke and Transient Ischemic Attack.

BACKGROUND AND OBJECTIVES: Clopidogrel-aspirin initiated within 72 hours of symptom onset is effective in patients with mild ischemic stroke or transient ischemic attack (TIA) in the Intensive Statin and Antiplatelet Therapy for Acute High-risk Intracranial or Extracranial Atherosclerosis (INSPIRES) trial. Uncertainties remain about the duration of the treatment effect. This study aimed to assess duration of benefit and risk of clopidogrel-aspirin in these patients. METHODS: The INSPIRES trial was a 2*2 factorial placebo-controlled randomized trial conducted in 222 hospitals in China. The 2 treatments did not interact and were evaluated separately. In this study, we performed secondary analyses based on antiplatelet treatment. All patients with mild stroke or TIA of presumed atherosclerotic cause within 72 hours of symptom onset enrolled in the trial were included. Patients were randomly assigned to receive clopidogrel-aspirin on days 1-21 followed by clopidogrel on days 22-90 or aspirin alone for 90 days. The primary efficacy outcome was major ischemic event which included the composite of ischemic stroke and nonhemorrhagic death. The primary safety outcome was moderate-to-severe bleeding. We estimated the risk difference between the 2 treatments for each stratified week. RESULTS: All 6,100 patients in the trial were included (3,050 in each group). The mean age was 65 years, and 3,915 patients (64.2%) were men. Compared with aspirin alone, the reduction of major ischemic events by clopidogrel-aspirin mainly occurred in the first week (absolute risk reduction [ARR] 1.42%, 95% CI 0.53%-2.32%) and remained in the second week (ARR 0.49%, 95% CI 0.09%-0.90%) and the third week (ARR 0.29%, 95% CI -0.05% to 0.62%). Numerical higher risk of moderate-to-severe bleedings in the clopidogrel-aspirin group was observed in the first 3 weeks (absolute risk increase 0.05% [95% CI -0.10% to 0.20%], 0.10% [95% CI -0.09% to 0.29%], and 0.18% [95% CI -0.03% to 0.40%] in the first, second, and third weeks, respectively). CONCLUSIONS: Among patients with mild ischemic stroke or high-risk TIA of presumed atherosclerotic cause, the net benefit of clopidogrel-aspirin initiated within 72 hours of symptom onset was pronounced in the first week and continued to a lesser degree in the following 2 weeks, outweighing the low, but ongoing hemorrhagic risk. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT03635749. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that among patients with mild ischemic stroke or high-risk TIA of presumed atherosclerotic cause, the net benefit of clopidogrel-aspirin initiated within 72 hours of symptom onset was pronounced in the first week and continued to a lesser degree in the following 2 weeks, outweighing the low but ongoing hemorrhagic risk.

Elevated High-Sensitivity C-Reactive Protein Level Enhances the Impact of Lipoprotein(a) on Platelet Reactivity in PCI Patients Treated with Clopidogrel.

BACKGROUND: Recently, the effect of Lipoprotein(a) [Lp(a)] on thrombogenesis has aroused great interest, while inflammation has been reported to modify the Lp(a)-associated risks through an unidentified mechanism. PURPOSE: This study aimed to evaluate the association between platelet reactivity with Lp(a) and high-sensitivity C-reactive protein (hs-CRP) levels in percutaneous intervention (PCI) patients treated with clopidogrel. METHODS: Data were collected from 10,724 consecutive PCI patients throughout the year 2013 in Fuwai Hospital. High on-treatment platelet reactivity (HTPR) and low on-treatment platelet reactivity (LTPR) were defined as thrombelastography (TEG) maximum amplitude of adenosine diphosphate-induced platelet (MAADP) > 47 mm and < 31 mm, respectively. RESULTS: 6615 patients with TEG results were finally enrolled. The mean age was 58.24 ± 10.28 years and 5131 (77.6%) were male. Multivariable logistic regression showed that taking Lp(a) < 30 mg/dL and hs-CRP < 2 mg/L as the reference, isolated Lp(a) elevation [Lp(a) ≥ 30 mg/dL and hs-CRP < 2 mg/L] was not significantly associated with HTPR (P = 0.153) or LTPR (P = 0.312). However, the joint elevation of Lp(a) and hs-CRP [Lp(a) ≥ 30 mg/dL and hs-CRP ≥ 2 mg/L] exhibited enhanced association with both HTPR (OR:1.976, 95% CI 1.677-2.329) and LTPR (OR:0.533, 95% CI 0.454-0.627). CONCLUSIONS: The isolated elevation of Lp(a) level was not an independent indicator for platelet reactivity, yet the concomitant elevation of Lp(a) and hs-CRP levels was significantly associated with increased platelet reactivity. Whether intensified antiplatelet therapy or anti-inflammatory strategies could mitigate the risks in patients presenting combined Lp(a) and hs-CRP elevation requires future investigation.

Comparison of uric acid elevation between aspirin-ticagrelor and aspirin-clopidogrel during dual antiplatelet therapy.

OBJECTIVE: This study investigated whether serum uric acid levels are more elevated in the aspirin-ticagrelor group than in the aspirin-clopidogrel group. Materials and Materials and methods: We conducted a retrospective cohort study with patients between 2013 and 2020. Baseline and maximum serum uric acid levels within a 6-month follow-up period were analyzed to determine the increase in both groups. RESULTS: A total of 41,877 patients were enrolled. A statistically significant elevation of serum uric acid levels was found in the aspirin-ticagrelor group compared to the aspirin-clopidogrel group (odds ratio (OR; 95% confidence interval (CI)) = 1.36 (1.15 - 1.60), p < 0.001). Kidney dysfunction and diuretic use were also identified as risk factors for uric acid elevation. CONCLUSION: Monitoring serum uric acid levels is recommended during aspirin-ticagrelor therapy, especially in patients with kidney dysfunction or those using diuretics.

Association of Clopidogrel with Interstitial Lung Disease: Gaining Insight Through the Japanese Pharmacovigilance Database.

Background: The P2Y12 receptor inhibitors clopidogrel and prasugrel are widely used. Clopidogrel and prasugrel have different metabolic pathways, but whether their adverse event (AE) profiles differ significantly is unclear. Objective: This study aimed to compare the possible AEs induced by clopidogrel and prasugrel and to assess the rank-order of their AEs submitted to a spontaneous reporting database. Materials and Methods: Data were extracted from the Japanese Adverse Drug Event Report database (JADER). Reports of AEs associated with clopidogrel and prasugrel were analyzed to calculate the reporting odds ratios (RORs) and 95% confidence intervals (CIs). Results: Based on 5869 reports for clopidogrel (69.6%, men) and 513 reports for prasugrel (74.1%, men), 703 and 135 different AEs were identified, respectively. Bleeding complications including hemorrhage were commonly reported for both clopidogrel and prasugrel. As for AEs related to clopidogrel, unexpected AEs such as interstitial lung disease (227 reports; ROR, 1.77; 95% CI, 1.49-2.10), abnormal hepatic function (137 reports; ROR, 1.27; 95% CI, 1.07-1.51), and hepatocellular injury (96 reports; ROR, 120.0; 95% CI, 94.9-151.8) ranked at relatively high positions based on the number of occurrences, unlike prasugrel. Conclusion: This analysis of the national pharmacovigilance database highlights distinct AE profiles for clopidogrel and prasugrel. Unexpected AEs associated with clopidogrel were identified, providing valuable insights for clinical monitoring and patient safety.

Genetic Determinants of Response to P2Y12 Inhibitors and Clinical Implications.

The CYP2C19 enzyme metabolizes clopidogrel, a prodrug, to its active form. Approximately 30% of individuals inherit a loss-of-function (LoF) polymorphism in the CYP2C19 gene, leading to reduced formation of the active clopidogrel metabolite. Reduced clopidogrel effectiveness has been well documented in patients with an LoF allele following an acute coronary syndrome or percutaneous coronary intervention. Prasugrel or ticagrelor is recommended in those with an LoF allele as neither is affected by CYP2C19 genotype. Although data demonstrate improved outcomes with a CYP2C19-guided approach to P2Y12 inhibitor selection, genotyping has not yet been widely adopted in clinical practice.

Outcomes of Ticagrelor Versus High-dose Clopidogrel in CYP2C19 Intermediate Metabolizer Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndromes.

ABSTRACT: Guidelines on antiplatelet recommendation for CYP2C19 intermediate metabolizer (IM) have not come to an agreement. This study aimed to evaluate the clinical benefit of ticagrelor when compared with high-dose clopidogrel in CYP2C19 IM after percutaneous coronary intervention for acute coronary syndromes. Patients were enrolled according to CYP2C19 genotype and individual antiplatelet therapy. Patient characteristics and clinical outcomes were collected through electronic medical record system. The primary outcome was major adverse cardiac and cerebrovascular event (MACCE), namely a composite of death from cardiovascular causes, myocardial infarction, stroke, and stent thrombosis within 12 months. The secondary outcome was Bleeding Academic Research Consortium scale bleeding events within 12 months. The Cox proportional hazards regression model was performed, with inverse probability treatment weighting (IPTW) adjusting for potential confounders. A total of 532 CYP2C19 IM were enrolled in this retrospective single-center study. No statistically significant difference in incidence rate of MACCE was found between patients receiving ticagrelor versus clopidogrel (7.01 vs. 9.52 per 100 patient-years; IPTW-adjusted hazard ratio 0.71; 95% confidence interval: 0.32-1.58; adjusted log-rank P = 0.396), but the incidence rate of Bleeding Academic Research Consortium type 2, 3, or 5 bleeding events was statistically higher in the loss of function-ticagrelor group than in the loss of function-clopidogrel group (13.53 vs. 6.16 per 100 patient-years; IPTW-adjusted hazard ratio: 2.29; 95% confidence interval: 1.10-4.78; adjusted log-rank P = 0.027). Ticagrelor treatment in CYP2C19 IM resulted in a statistically higher risk of bleeding compared with high-dose clopidogrel, whereas a clear association between treatments and MACCE warrants further investigations.

Evaluation of pharmacogenetic automated clinical decision support for clopidogrel.

Aim: Clopidogrel requires CYP2C19 activation to have antiplatelet effects. Pharmacogenetic testing to identify patients with impaired CYP2C19 function can be coupled with clinical decision support (CDS) alerts to guide antiplatelet prescribing. We evaluated the impact of alerts on clopidogrel prescribing.Materials & methods: We retrospectively analyzed data for 866 patients in which CYP2C19-clopidogrel CDS was deployed at a single healthcare system during 2015-2023.Results: Analyses included 2,288 alerts. CDS acceptance rates increased from 24% in 2015 to 63% in 2023 (p < 0.05). Adjusted analyses also showed higher acceptance rates when clopidogrel had been ordered for a percutaneous intervention (OR: 28.7, p < 0.001) and when cardiologists responded to alerts (OR: 2.11, p = 0.001).Conclusion: CDS for CYP2C19-clopidogrel was effective in reducing potential drug-gene interactions. Its influence varied by clinician specialty and medication indications.

[Box: see text].

Neutrophil count as a risk factor for cardiovascular diseases: how can we manage it?

Neutrophils activation plays a pivotal role in the pathogenesis of atherosclerotic plaque formation, progression and rupture. An association between the leukocyte count and the risk of developing myocardial infarction has been well known for many years; however, only recently did Mendelian randomization studies show that a high neutrophil count is a causal risk factor for atherosclerotic cardiovascular disease. On the other hand, experimental studies show that depletion of circulating neutrophils impairs plaque development. Clopidogrel, an antiplatelet agent, is widely used in combination with aspirin to reduce the incidence of ischemic events in patients treated with coronary stenting. Chronic treatment with this drug reduces inflammatory markers and neutrophil numbers, rarely causing severe leukopenia. The purpose of this review is to present recent evidence showing the link between neutrophil number and the development of cardiovascular diseases and to discuss how the clopidogrel-induced reduction in the neutrophil count may be a beneficial off-target effect of this drug.

Clinical and cost-effectiveness of clopidogrel resistance genotype testing after ischaemic stroke or transient ischaemic attack: a systematic review and economic model.

Background: Stroke or transient ischaemic attack patients are at increased risk of secondary vascular events. Antiplatelet medications, most commonly clopidogrel, are prescribed to reduce this risk. Factors including CYP2C19 genetic variants can hinder clopidogrel metabolism. Laboratory-based or point-of-care tests can detect these variants, enabling targeted treatment. Objective: To assess the effectiveness of genetic testing to identify clopidogrel resistance in people with ischaemic stroke or transient ischaemic attack. Specific objectives: Do people tested for clopidogrel resistance, and treated accordingly, have a reduced risk of secondary vascular events? Do people with loss-of-function alleles associated with clopidogrel resistance have a reduced risk of secondary vascular events if treated with alternative interventions compared to clopidogrel? Do people with loss-of-function alleles associated with clopidogrel resistance have an increased risk of secondary vascular events when treated with clopidogrel? What is the accuracy of point-of-care tests for detecting variants associated with clopidogrel resistance? What is the technical performance and cost of CYP2C19 genetic tests? Is genetic testing for clopidogrel resistance cost-effective compared with no testing? Design: Systematic review and economic model. Results: Objective 1: Two studies assessed secondary vascular events in patients tested for loss-of-function alleles and treated accordingly. They found a reduced risk, but confidence intervals were wide (hazard ratio 0.50, 95% confidence interval 0.09 to 2.74 and hazard ratio 0.53, 95% confidence interval 0.24 to 1.18). Objective 2: Seven randomised controlled trials compared clopidogrel with alternative treatment in people with genetic variants. Ticagrelor was associated with a lower risk of secondary vascular events than clopidogrel (summary hazard ratio 0.76, 95% confidence interval 0.65 to 0.90; two studies). Objective 3: Twenty-five studies compared outcomes in people with and without genetic variants treated with clopidogrel. People with genetic variants were at an increased risk of secondary vascular events (hazard ratio 1.72, 95% confidence interval 1.43 to 2.08; 18 studies). There was no difference in bleeding risk (hazard ratio 0.98, 95% confidence interval 0.68 to 1.40; five studies). Objective 4: Eleven studies evaluated Genomadix Cube accuracy; no studies evaluated Genedrive. Summary sensitivity and specificity against laboratory reference standards were both 100% (95% confidence interval 94% to 100% and 99% to 100%). Objective 5: Seventeen studies evaluated technical performance of point-of-care tests. Test failure rate ranged from 0.4% to 19% for Genomadix Cube. A survey of 8/10 genomic laboratory hubs revealed variation in preferred technologies for testing, and cost per test ranging from £15 to £250. Most laboratories expected test failure rate to be < 1%. Additional resources could enhance testing capacity and expedite turnaround times. Objective 6: Laboratory and point-of-care CYP2C19 testing strategies were cost-saving and increase quality-adjusted life-years compared with no testing. Both strategies gave similar costs, quality-adjusted life-years and expected net monetary benefit. Conclusions: Our results suggest that CYP2C19 testing followed by tailored treatment is likely to be effective and cost-effective in both populations. Future work: Accuracy and technical performance of Genedrive. Test failure rate of Genomadix Cube in a National Health Service setting. Value of testing additional loss-of-function alleles. Appropriateness of treatment dichotomy based on loss-of-function alleles. Limitations: Lack of data on Genedrive. No randomised 'test-and-treat' studies of dipyramidole plus aspirin. Study registration: This study is registered as PROSPERO CRD42022357661. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Evidence Synthesis programme (NIHR award ref: NIHR135620) and is published in full in Health Technology Assessment; Vol. 28, No. 57. See the NIHR Funding and Awards website for further award information.

The most common type of stroke occurs when the supply of blood to the brain is cut off. Symptoms of stroke happen suddenly and vary depending on which part of the brain is affected. They usually include problems with movement, speech, vision and the face drooping on one side. A 'transient ischaemic attack' is a milder related condition. There are around 100,000 strokes and 60,000 transient ischaemic attacks every year in the UK. People who have a stroke or transient ischaemic attack are at greater risk of having another stroke. To reduce the chances of this happening, doctors will often prescribe medication. The most common medication used is called 'clopidogrel'. However, clopidogrel does not work for everyone. One reason for this is having specific variations of a gene called the CYP2C19 gene. Around one in three people in the UK have this variation. We wanted to know whether introducing genetic testing to identify variations in the CYP2C19 gene for people who have had a stroke or transient ischaemic attack can help doctors prescribe a treatment that will work for them, reducing the risk of having another stroke. We also wanted to know if doing this test would be a good use of NHS money. Doing a genetic test to identify variations in the CYP2C19 gene, and prescribing an alternative medication for people with these variations, may reduce the chances of having a new stroke. It is likely that a genetic test for variations of the CYP2C19 gene would represent value for money for the NHS.