Optimized Methodology to Produce Platelet-Rich Plasma and Perform Platelet Aggregation in Patients With Coronary Artery Disease.

BACKGROUND:  Inter-individual differences in clopidogrel metabolism and platelet counts within platelet-rich plasma (PRP) intrigued us to optimize light transmittance aggregometry (LTA) assay in coronary artery disease (CAD) patients administered with clopidogrel and ticagrelor. The objective of the study was to optimize PRP preparation using separating gel PRP tubes to perform LTA among CAD patients on clopidogrel and ticagrelor. METHODOLOGY:  Initially, we optimized PRP preparation and platelet aggregation (PA) on healthy controls. To validate the protocol, we recruited 10 healthy controls and 28 CAD patients, comprising 16 on clopidogrel and 12 on ticagrelor regimen. Bio-X, India, supplied PRP tubes (9 mL) with 3.2% sodium citrate. PRP and autologous platelet-poor plasma (PPP) were prepared by centrifugation at 151 g for seven minutes and 3,780 g for 10 minutes, respectively. LTA was performed using platelet aggregometer TA-4V (Stago, Asnières-sur-Seine, France). Adenosine diphosphate (ADP) (10 µM) was used as an agonist. RESULTS:  The mean maximum platelet aggregation (MPA) among controls, clopidogrel patients, and ticagrelor patients were 55.161±13.69%, 53.17±22%, and 35.84±20.79% (p=0.042), respectively. The mean platelet volumes among groups were 9.34±2.51 fL, 7.60±0.85 fL, and 10.99±1.62 fL (p≤0.01), respectively. CONCLUSION:  We successfully optimized PRP preparation for the LTA assay using a PRP tube. Its application to measure PA routinely in a cardiology clinic seems propitious.

Role of ticagrelor in the peri-thrombolytic phase for patients with ST-segment elevation myocardial infarction: a comprehensive review.

Recent years have seen ticagrelor, a potent P2Y12 inhibitor, emerge as a significant advancement in the peri-thrombolytic management of patients with ST-segment elevation myocardial infarction (STEMI), offering a promising alternative to traditional antiplatelet drugs like clopidogrel. This review critically examines the efficacy and safety of ticagrelor during the peri-thrombolytic phase in STEMI patients, drawing on evidence from key clinical trials such as TREAT and MIRTOS, as well as other relevant studies. These investigations underscore ticagrelor's superior platelet inhibition capabilities, which are crucial for minimizing thrombotic complications post-thrombolysis without increasing bleeding risks. Despite its potential, clopidogrel remains the guideline-recommended choice for such patients, leaving the appropriateness of ticagrelor in this context open to debate. By summarizing the current evidence and identifying gaps in our understanding, this study advocates for targeted research to clarify the long-term benefits and optimal deployment of ticagrelor, highlighting its evolving significance in cardiovascular care.

Switching from cangrelor to oral P2Y12 inhibitors: a focused review on drug-drug interactions.

INTRODUCTION: . Cangrelor, the only intravenous platelet P2Y12 receptor inhibitor, is characterized by a prompt and potent platelet inhibition, with a rapid offset of action. Large-scale clinical trials have shown that cangrelor reduce peri-procedural thrombotic events among patients undergoing percutaneous coronary interventions and not pre-treated with an oral P2Y12 receptor inhibitor. However, high P2Y12 receptor occupancy provided by cangrelor raises concerns for drug-drug interactions (DDIs) when transitioning to oral P2Y12 inhibitors. AREAS COVERED: An understanding of the pharmacology of cangrelor and oral P2Y12 inhibitors is essential to define the optimal approach to transition to oral P2Y12 inhibitors without incurring the risk of DDIs. This review, based on a thorough literature search in major scientific databases (PubMed, Cochrane Library, Web of Science), synthesizes the pharmacology of cangrelor and the oral P2Y12 receptor inhibitors, providing the rationale for the occurrence of DDIs and strategies to avoid such risk. EXPERT OPINION: The timing of transition from cangrelor to oral P2Y12 inhibitors plays a crucial role in the occurrence of DDIs, especially with clopidogrel and prasugrel. Currently, no evidence suggests a DDI when transitioning to ticagrelor. Adhering to product labels and guideline recommendations is crucial for optimizing safety and efficacy of cangrelor.

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.

Ticagrelor and Statins: Dangerous Liaisons?

Polypharmacy is often necessary in complex, chronic, comorbid and cardiovascular patients and is a known risk factor for potential drug-drug interaction (DDI) that can cause adverse reactions (toxicity or therapeutic failure). Anti-thrombotic drugs (largely low-dose aspirin and a platelet P2Y12 receptor inhibitor) and statins are among the most co-administered drugs in cardiovascular patients. Ticagrelor is a selective antagonist of the platelet P2Y12-receptor, highly effective in inhibiting platelet aggregation and bio-transformed by the CYP3A4 and substrate of transporters, such as the breast cancer resistance protein (BCRP). Statins have different pharmacokinetic profiles; some undergo CYP3A4-mediated metabolism; rosuvastatin is primarily metabolized by the CYP2C9; and they have different affinities for drug transporters. Rhabdomyolysis is a very rare but severe adverse event, which is specific for statins which can be triggered by DDIs that increase statin's concentrations through blockade of their biotransformation and/or elimination. Large pharmacovigilance and small observational studies reported increased rhabdomyolysis in patients treated with some statins and ticagrelor but not aspirin, clopidogrel or prasugrel. Recent studies in vitro, pharmacokinetic trials and in silico drug modelling identified and validated the BCRP inhibition by ticagrelor, as a mechanism contributing to the DDI with statins, as 'victim' drugs, leading to increased rhabdomyolysis. While the clinical impact of this DDI deserves further investigation, a careful evaluation should be advised when ticagrelor is co-prescribed with some statins.

Ticagrelor monotherapy after ≤ 1-month DAPT vs continued DAPT in patients with acute coronary syndrome treated with percutaneous coronary intervention: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Current guidelines recommend at least 12 months of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). However, DAPT prolonged use may increase the risk of bleeding complications. Therefore, we aimed to perform a meta-analysis to assess whether ticagrelor monotherapy after ≤1 month of DAPT improves clinical outcomes compared with continued DATP in acute coronary syndrome (ACS) patients post-PCI. METHODS: We systematically searched PubMed, Embase and Cochrane databases for randomized controlled trials published up to August 2024. All-cause and cardiovascular death, overall and major bleeding events, myocardial infarction (MI), stroke, target vessel revascularization (TVR) and stent thrombosis within 1-2 years post-procedure were evaluated. Statistical analysis was performed using Review Manager 5.1.7. RESULTS: Three studies and 13,737 patients were included, of whom 6861 (49.95 %) received ticagrelor alone. When compared with DAPT, ticagrelor monotherapy significantly reduced the risk of overall (2.0 % vs 4.5 %; RR 0.44; 95 % Cl 0.33-0,59; p < 0.00001) and major (1.4 % vs 2.5 %; RR 0.49; 95 % Cl 0.29-0.83; p = 0.04) bleeding events. Both antiplatelet regimens had similar rates of mortality, MI, stroke, TVR or stent thrombosis. CONCLUSION: This meta-analysis suggests that ticagrelor alone after ≤1 month of DAPT post-PCI in ACS patients reduces bleeding complications without increasing major adverse events compared with traditional DAPT for 12 months.

The effect of gene polymorphism on ticagrelor metabolism: an in vitro study of 22 CYP3A4 variants in Chinese Han population.

Background: Ticagrelor is a novel oral antiplatelet agent which can selectively inhibit P2Y12 receptor. Bleeding and dyspnea are common adverse reactions of ticagrelor in clinic. The side effects of ticagrelor are correlated with the plasma concentration of ticagrelor. Objective: This study aimed to evaluate the catalytic characteristics of 22 CYP3A4 alleles identified in the Chinese Han population on the metabolism of ticagrelor in vitro, focusing on the effect of CYP3A4 polymorphism on ticagrelor metabolism. Methods: In this study, insect cells were used to express 22 CYP3A4 variants, which were then incubated with 1-50 µM ticagrelor at 37 °C for 30 minutes to obtain the metabolite (AR-C124910XX). AR-C124910XX was detected by UHPLC-MS/MS to calculate the kinetic parameters, including Km, Vmax and CLint. Results: Compared to the wild-type, most CYP3A4 alleles exhibited significant differences in intrinsic clearance. The intrinsic clearance of CYP3A4*11, *18 and *33 was much higher than that of wild-type; four variants exhibited similar intrinsic clearance values as the wild-type enzyme; The remaining 14 variants showed significantly reduced intrinsic clearance values, ranging from 1.48% to 75.11% of the wild-type; CYP3A4*30 displayed weak or no activity. Conclusion: This study conducted a comprehensive assessment of the effect of CYP3A4 variants on ticagrelor's metabolism. The results suggested that there is allele-specific activity towards ticagrelor in vitro. These findings can provide some insights and predictions for treatment strategies and risk assessments associated with ticagrelor in clinical practice.

Randomised Placebo-Controlled Pilot Trial Evaluating the Anti-Anginal Efficacy of Ticagrelor in Patients with Angina with Nonobstructive Coronary Arteries and Coronary Slow Flow Phenomenon.

Background: The coronary slow flow phenomenon (CSFP) is an angiographic finding characterised by the delayed passage of contrast through the coronary arteries, despite the absence of obstructive coronary artery disease (defined as less than 50% narrowing of the vessel lumen). Patients with the CSFP experience recurrent angina, for which there are limited evidence-based therapies. Ticagrelor may serve as an effective anti-anginal therapy for these patients by increasing adenosine levels, which could alleviate coronary microvascular dysfunction and its associated angina due to its vasodilatory properties. This study aimed to determine the anti-anginal efficacy of ticagrelor 90 mg taken twice daily on spontaneous angina episodes in patients with refractory angina (i.e., episodes ≥3/week despite two anti-anginals) and documented CSFP. Methods: In a randomised, double-blind, placebo-controlled, cross-over trial, the anti-anginal efficacy of a 4-week ticagrelor therapy regimen was evaluated in 20 patients with refractory angina (mean age 61.5 ± 10.5 years; 40% women) who had documented slow coronary flow. The primary endpoint was the frequency of angina episodes, recorded using an angina diary. Secondary endpoints included the duration and severity of angina episodes, consumption of short-acting nitrates, and health status evaluations using the Seattle Angina Questionnaire (SAQ) and the Short Form-36 (SF-36) indices. Results: During the four weeks of therapy, ticagrelor did not significantly improve angina symptoms compared to the placebo (placebo 25.7 (16.7)) vs. ticagrelor 19.8 (18.1), p > 0.05). Furthermore, it did not impact other patient-related outcome measures, including angina severity, duration, frequency of prolonged angina episodes, nitrate consumption, or the SAQ/SF-36 health outcome indices. No serious adverse events related to the study drug were observed. Conclusions: In patients with documented CSFP who were unresponsive to standard anti-anginal therapy, ticagrelor did not reduce the frequency of spontaneous angina episodes or the consumption of nitrates. Further confirmation of the potential benefits of this therapy may be obtained through a larger clinical trial.

Strategies to optimize initial P2Y12 inhibitor therapy in STEMI patients.

INTRODUCTION: Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is the standard of care for patients who undergo percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI). Though this regimen reduces rates of ischemic events in patients with STEMI, the optimal strategy for P2Y12 administration in STEMI patients is still evolving. PURPOSE: The purpose of this review is to summarize current evidence on optimal use of ticagrelor and prasugrel in the acute phase of STEMI. SUMMARY: Due to high platelet activity in the acute setting of STEMI and PCI, adequate and rapid platelet inhibition is important. Strategies of increased ticagrelor/prasugrel loading dose or earlier administration in STEMI have not been successful in closing this platelet inhibition gap. Potential strategies for improving ticagrelor/prasugrel use early in STEMI include bridging with intravenous antiplatelet agents or crushed or chewed administration. CONCLUSION: Oral ticagrelor/prasugrel given before or immediately after STEMI PCI is usually sufficient to prevent thrombotic complications. When faster platelet inhibition is desired, or oral administration is compromised by inability to swallow tablets, crushing/chewing ticagrelor/prasugrel tablets is an alternative to intravenous P2Y12 inhibitor therapy.

Comparison of Ticagrelor with Clopidogrel on Coronary Microvascular Dysfunction Following Acute Myocardial Infarction Using Angiography-Derived Index of Microcirculatory Resistance.

PURPOSE: This research aimed to assess the impact of ticagrelor and clopidogrel on coronary microvascular dysfunction (CMD) and prognosis following acute myocardial infarction (AMI), using the angiography-derived index of microcirculatory resistance (angio-IMR) as a non-invasive assessment tool. METHODS: In this retrospective study, angio-IMR was performed to evaluate CMD before and after dual antiplatelet therapy (DAPT) with either ticagrelor (90 mg twice daily, n = 184) or clopidogrel (75 mg once daily, n = 72). The primary endpoint is the improvement of CMD evaluated by angio-IMR (delta angio-IMR) following DAPT. Secondary endpoints included myocardial reinfarction and readmission for heart failure during 2-year follow-up. RESULTS: Compared with clopidogrel, ticagrelor exhibited a significantly higher delta angio-IMR [- 3.09 (5.14) versus - 1.99 (1.91), P = 0.008], indicating a superior improvement of CMD with ticagrelor treatment. Multivariate Cox regression indicated that ticagrelor treatment was related to a reduced risk of readmission for heart failure [8 (4.3) versus 9 (12.5), adjusted HR = 0.329; 95% CI = 0.116-0.934; P = 0.018] and myocardial reinfarction [7 (3.8) versus 8 (11.1), adjusted HR = 0.349; 95% CI = 0.125-0.975; P = 0.026]. Furthermore, ticagrelor treatment serves as an independent predictor of readmission for heart failure (HR = 0.322; 95% CI = 0.110-0.943; P = 0.039). CONCLUSION: The results of this study indicate a potential association between ticagrelor treatment and improved CMD, as well as a reduced risk of cardiovascular events, including myocardial reinfarction and readmission for heart failure in AMI patients. Further randomized controlled trials are necessary to confirm the potential benefits of ticagrelor on CMD and cardiovascular prognosis. This clinical trial was registered in www. CLINICALTRIALS: gov (NCT05978726).

Pharmacokinetics and Bioequivalence of a Generic Ticagrelor 90-mg Formulation Versus the Innovator Product in Healthy White Subjects Under Fasting Conditions.

Ticagrelor is a key antiplatelet agent used to prevent thrombotic events in patients with acute coronary syndrome. This open-label, 2-period, crossover Phase I study assessed the pharmacokinetics and bioequivalence of a generic ticagrelor 90-mg formulation compared to the innovator product under fasting conditions. Twenty-eight healthy White adults participated in the study. Each participant received a single dose of either the test or reference formulation, followed by a 7-day washout period before switching to the alternate formulation. Plasma concentrations of ticagrelor were measured using a validated high-performance liquid chromatography-tandem mass spectrometry method. Statistical analysis of primary pharmacokinetic parameters, including maximum concentration and area under the plasma concentration-time curve from time 0 to the last quantifiable concentration, showed bioequivalence with test/reference ratios of 110.9% and 107.1%, respectively, and 90% confidence intervals within the 80%-125% regulatory range. Treatment-emergent adverse events, such as headache, dysphagia, and dizziness, were moderate and transient and resolved promptly, with no significant difference in incidence between the formulations. These results confirm that the generic ticagrelor formulation is bioequivalent to the innovator product, supporting its use as an interchangeable option in clinical practice.

Ticagrelor-Related Dyspnea Beyond Adenosine: Insights into Retrotrapezoid Hyperactivity.

Ticagrelor, a P2Y12 receptor antagonist, has been demonstrated to induce dyspnea, which is not associated with cardiac or pulmonary alterations, or metabolic disturbances. The attribution of ticagrelor-related dyspnea to excess adenosine has been widely proposed, yet is not supported by experimental data. In this paper, we put forth a novel hypothesis that the hyperactivity of the retrotrapezoid nucleus, a group of ventral medullary neurons involved in respiratory modulation, is the underlying cause of ticagrelor-related dyspnea. This hypothesis offers a theoretical resolution to the discrepancies and controversies present in previous theories.

P2Y12-targeted modulation of microglial phenotypes: A novel therapeutic strategy for enhanced axonal regeneration post-spinal cord injury.

AIMS: Microglia activation after spinal cord injury (SCI) is a double-edged sword, modulation of the activated microglia populations toward pro-regenerative phenotypes highlights the potential therapeutic implications. P2Y12, a microglia-specific marker, remains underexplored in its capacity to polarize microglial activation populations in SCI repair. We aimed to explore the effects of modulating P2Y12 on microglia function after spinal cord injury, and further on axonal regeneration and motor recovery after spinal cord injury. MATERIALS AND METHODS: The study employed both in vitro and in vivo models, using BV2 cells and a mouse model of SCI, respectively. Ticagrelor, a P2Y12 antagonist, was administered via a collagen scaffold to ensure stable and sustained release. Transcriptome sequencing analysis, immunofluorescence staining, and Basso Mouse Scale (BMS) scores were used to assess microglial activation, axonal regeneration, and functional recovery. KEY FINDINGS: Herein, we observed P2Y12+ microglia localized predominantly at the lesion periphery within 3 days post injury (dpi), manifesting a pro-inflammatory phenotype, but not anti-inflammatory phenotype. In vitro investigations revealed that P2Y12 inhibition of the activated microglia curtailed pro-inflammatory differentiation while augmenting anti-inflammatory differentiation. SIGNIFICANCE: Leveraging this insight, we engineered a collagen scaffold-based delivery system for sustained release of the P2Y12 antagonist, ticagrelor, at the injury site in a mouse complete SCI model. Notably, P2Y12 suppression markedly enhanced axonal regeneration within the injured site and ameliorated lower limb motor functions in SCI mice. Collectively, our findings illuminate P2Y12-targeted microglial modulation as a promising therapeutic approach for SCI.

Efficacy and safety of ticagrelor monotherapy following a brief DAPT vs. prolonged 12-month DAPT in ACS patients post-PCI: a meta-analysis of RCTs.

BACKGROUND: As per current guidelines, acute coronary syndrome (ACS) patients who undergo percutaneous coronary intervention (PCI) should be started on dual antiplatelet therapy (DAPT) for a period of 12 months. OBJECTIVE: To assess the efficacy and safety of brief DAPT (up to 3 months) succeeded by ticagrelor monotherapy compared with a 12-month DAPT in ACS patients following PCI. METHODS: We systematically searched Cochrane, Embase, and PubMed to find relevant randomized clinical trials. Examined outcomes included the incidence of major adverse cerebrovascular and cardiovascular events (MACCE), bleeding events, and the composite incidence of net adverse clinical events (NACE). RESULTS: Our primary analysis included 21,927 ACS patients from six RCTs. Our pooled results indicate that following PCI in individuals with ACS, brief DAPT followed by ticagrelor did not increase the risk of MACCE (OR 0.92, 95% CI 0.79-1.07) but significantly reduced the risk of minor or major bleeding (OR 0.52, 95% CI 0.44-0.62) and NACE (OR 0.71, 95% CI 0.59-0.86) compared with a long-term DAPT within a follow-up of 12 months. CONCLUSION: Brief DAPT followed by ticagrelor monotherapy is superior to a 12-month DAPT in offering a net clinical advantage in ACS patients following PCI.

Abbreviated ticagrelor based dual antiplatelet therapy in acute coronary syndrome: A systematic review and meta-analysis.

BACKGROUND: Few randomized clinical trials have evaluated the safety and efficacy of abbreviated ticagrelor based dual antiplatelet therapy (DAPT) in acute coronary syndrome (ACS); however, these trials were underpowered to detect differences in hard clinical outcomes. METHODS: A systematic search of MEDLINE, Cochrane, and Scopus databases was performed through June 2024, for trials that compared abbreviated (≤3-months) versus standard 12-months ticagrelor based DAPT in ACS. The primary endpoint was all-cause mortality. Secondary endpoints included cardiovascular death, myocardial infarction, stent thrombosis, ischemic stroke, and major bleeding. Endpoints were measured at 12-months after DAPT initiation. Data were pooled using random-effects model. Effect measure utilized was risk ratio (RR). Heterogeneity was assessed via Chi-squared and Higgin's I2 test. RevMan 5.0 (Cochrane Collaboration, Oxford, United Kingdom) was utilized to perform statistical analysis. RESULTS: Five trials were included in this analysis with 21,407 patients assessed. ULTIMATE-DAPT, T-PASS, and GLOBAL LEADERS-ACS assessed 1-month DAPT duration while TICO and TWILIGHT-ACS assessed 3-months DAPT duration. The average age was 62.7 years and 22.7 % were women. ACS presentations included non-ST elevation myocardial infarction (40.1 %), unstable angina (35.2 %), and ST-segment elevation myocardial infarction (31.5 %). Abbreviated ticagrelor based DAPT was associated with lower risk of all-cause mortality (RR 0.78; 95 % Confidence Interval (CI) 0.62-0.98, I2 = 0 %) compared with standard duration DAPT. There was no difference between groups in cardiovascular death (RR 0.65; 95 % CI 0.41-1.03, I2 = 0 %), myocardial infarction (RR 1.04; 95 % CI 0.85-1.27, I2 = 0 %), stent thrombosis (RR 0.97; 95 % CI 0.64-1.45, I2 = 0 %), or ischemic stroke (RR 0.90; 95 % CI 0.62-1.30, I2 = 0 %). Abbreviated DAPT was associated with lower risk of major bleeding (RR 0.50; 95 % CI 0.38-0.66, I2 = 46 %). CONCLUSION: Our analysis includes the totality of randomized data evaluating the merits of abbreviated ticagrelor based DAPT after ACS. The salient study finding was the observed reduced risk of all-cause mortality and major bleeding with abbreviated DAPT approach.

How to undertake procedures while on antiplatelet agents: a hematologist's view.

Cardiovascular diseases (CVDs) are the leading cause of mortality globally while also contributing to excess health system costs. Significant advancements have been made in the understanding and prevention of deaths from CVD. In addition to risk factor modifications, one of the key developments in this area is the appropriate prescribing of antiplatelet medications for secondary prevention of CVD. With the advent of vascular devices, there has been an increased use of potent antiplatelet agents to mitigate thrombosis risk. A well-recognized, albeit rare complication of antiplatelet drugs is the heightened risk of bleeding. This adverse effect is particularly relevant when a patient receiving these medications may require an urgent surgery. In addition, for elective surgeries, although these drugs can be withheld, there may be some situations when interruption of antiplatelet agents, even for short duration, may lead to thrombotic events. There are no robust guidelines on how to manage these clinical scenarios, although there have been some important studies published recently in this area. In this review, we provide our approach to patients on antiplatelet drugs who may require urgent surgeries or surgical interventions.

Supporting appropriate use of extended dual antiplatelet therapy post-myocardial infarction based on an innovative 12-month ticagrelor virtual service.

Purpose: Extended dual antiplatelet therapy (DAPT) with ticagrelor and aspirin is recommended in selected cases after myocardial infarction (MI) but not widely deployed in practice. This study assessed an innovative, cardiology pharmacist-led virtual service for determining eligibility for extended DAPT among patients completing 12 months of initial DAPT in primary care following MI. Methods: Within this model, potentially eligible individuals are reviewed virtually by a cardiology pharmacist for suitability for extended DAPT with reduced-dose ticagrelor [60 mg twice daily (BD)] for up to 3 years. Eligibility is guided by the PEGASUS-TIMI 54 trial criteria (aged ≥50 years and having ≥1 high-risk feature for further ischaemic events). This is balanced against potential ineligibility driven primarily by bleeding risk, assessed using PRECISE-DAPT score. The final recommendation is sent to primary care to action. The present work is a retrospective evaluation of patients referred to the service between July 2018 and December 2021. Results: A total of 200 patients were included [n = 131 (65.5%) male; mean age: 69.4 ± 9.5 years]. Of these, 79 (39.5%) were recommended for extended DAPT based on the balance of risks for further ischaemic events vs. bleeding. Sixty-three patients on high-dose DAPT (ticagrelor 90 mg BD)-which is inappropriate beyond 12 months-were reassigned to reduced-dose DAPT or aspirin monotherapy. Conclusions: This virtual clinic played a key role in medicines optimisation, enabling appropriate patients to benefit from extended DAPT while offsetting bleeding risk. The model could be adapted locally for use elsewhere.

An interesting case series of ticagrelor induced long QTc.

This case series explores three patients who underwent percutaneous coronary intervention (PCI) and experienced prolonged QT intervals under treatment with Ticagrelor. The first case was a female who presented with chest pain and received a Xience stent. The second case involved a male patient who received two Xience stents. The third case was that of a male patient with LAD stenosis. All three patients received Ticagrelor and exhibited prolonged QTc intervals on their electrocardiograms (ECGs), which was resolved after switching to Clopidogrel. Thus far, the potential impact of Ticagrelor on QT prolongation has not been adequately addressed in the literature. It is hypothesized that Ticagrelor can block adenosine uptake by red blood cells, which may explain QTc prolongation. The results of this case series indicate that Ticagrelor may prolong QTc intervals. Consequently, it is imperative that clinicians are aware of this previously unlisted side effect and that patients are closely monitored while seeking alternative medications to manage the condition.

Temporal Effect of CYP3A4/5 Induction on Ticagrelor's Pharmacodynamic Effects: A Case Series.

Ticagrelor is contraindicated in combination with cytochrome P450 3A4 and 3A5 enzyme (CYP3A4/5) inducers due to increased clearance, causing diminished antiplatelet effects. The emergent nature of acute coronary syndromes (ACS) may preclude scrutinization of home medications before P2Y12 inhibitor administration. The purpose of this case series is to establish the temporal impact of CYP3A4/5 enzyme induction on ticagrelor's pharmacodynamic effect by utilizing VerifyNow platelet aggregation studies. This was a retrospective case series of three patients who were taking a CYP3A4/5-inducing medication and loaded with ticagrelor for ACS. The duration of ticagrelor's antiplatelet effect was dramatically shortened in the presence of background CYP3A4/5 induction. The offset of antiplatelet effect, defined by platelet reactivity units (PRU), was 10-24 hours in the presence of CYP3A4/5 enzyme induction compared to the anticipated 36-48 hours. This was consistent across CYP3A4/5-inducing medications including carbamazepine, phenobarbital, and phenytoin. This study demonstrates rapid return of platelet function after a ticagrelor loading dose in the presence of CYP3A4/5-inducing medications. Monitoring of PRU every 6-12 hours with subsequent loading with clopidogrel or prasugrel should be considered. Larger scale studies are warranted to confirm these results.

Ticagrelor monotherapy in ST-elevation myocardial infarction: An individual patient-level meta-analysis from TICO and T-PASS trials.

BACKGROUND: Patients with ST-elevation myocardial infarction (STEMI) tend to be excluded or under-represented in randomized clinical trials evaluating the effects of potent P2Y12 inhibitor monotherapy after short-term dual antiplatelet therapy (DAPT). METHODS: Individual patient data were pooled from randomized clinical trials that included STEMI patients undergoing drug-eluting stent (DES) implantation and compared ticagrelor monotherapy after short-term (≤3 months) DAPT versus ticagrelor-based 12-month DAPT in terms of centrally adjudicated clinical outcomes. The co-primary outcomes were efficacy outcome (composite of all-cause death, myocardial infarction, or stroke) and safety outcome (Bleeding Academic Research Consortium type 3 or 5 bleeding) at 1 year. FINDINGS: The pooled cohort contained 2,253 patients with STEMI. The incidence of the primary efficacy outcome did not differ between the ticagrelor monotherapy group and the ticagrelor-based DAPT group (1.8% versus 2.0%; hazard ratio [HR] = 0.88; 95% confidence interval [CI] = 0.49-1.61; p = 0.684). There was no difference in cardiac death between the groups (0.6% versus 0.7%; HR = 0.89; 95% CI = 0.32-2.46; p = 0.822). The incidence of the primary safety outcome was significantly lower in the ticagrelor monotherapy group (2.3% versus 4.0%; HR = 0.56; 95% CI = 0.35-0.92; p = 0.020). No heterogeneity of treatment effects was observed for the primary outcomes across subgroups. CONCLUSIONS: In patients with STEMI treated with DES implantation, ticagrelor monotherapy after short-term DAPT was associated with lower major bleeding without an increase in the risk of ischemic events compared with ticagrelor-based 12-month DAPT. Further research is necessary to extend these findings to non-Asian patients. FUNDING: This study was funded by Biotronik (Bülach, Switzerland).