Ethnic Differences in Oral Antithrombotic Therapy

Timing of Direct Oral Anticoagulants Resumption Following Colorectal Endoscopic Submucosal Dissection: A Nationwide Study in Japan

INTRODUCTION

With the increasing use of direct oral anticoagulants (DOACs), managing these agents around endoscopic submucosal dissection (ESD) is crucial. However, due to the need for a large number of cases, studies examining the timing of resumption are lacking, resulting in varied recommendations across international guidelines. We aimed to perform a comparative study about the resumption timing of DOACs after colorectal ESD using a nationwide database in Japan.

METHODS

We conducted a retrospective cohort study on colorectal ESD using the Diagnosis Procedure Combination database from 2012 to 2023. Patients using anticoagulants other than DOACs were excluded, and only those who resumed DOACs within 3 days were included. From eligible patients, we divided them into early (the day after ESD) and delayed (2-3 days after ESD) resumption groups. We used inverse probability of treatment weighting to assess the delayed bleeding and thromboembolic events within 30 days. Delayed bleeding was defined as bleeding requiring endoscopic hemostasis or blood transfusion after ESD.

RESULTS

Of 176,139 colorectal ESDs, 3,550 involved DOAC users, with 2,698 (76%) categorized as early resumption and 852 (24%) categorized as delayed resumption groups. After inverse probability of treatment weighting adjustment, the early resumption group did not significantly increase delayed bleeding compared with the delayed resumption group (odds ratio 1.05; 95% confidence interval 0.78-1.42; P = 0.73). However, it significantly reduced the risk of thromboembolic events (odds ratio 0.45; 95% confidence interval 0.25-0.82; P < 0.01).

DISCUSSION

Resuming DOACs the day after colorectal ESD was associated with reduced thromboembolic events without significant increase in risk of delayed bleeding.

Coronary events in elderly patients with non-valvular atrial fibrillation: a prespecified sub-analysis of the ANAFIE registry

Real-world data on coronary events (CE) in elderly patients with atrial fibrillation (AF) are lacking in the direct oral anticoagulant era. This prespecified sub-analysis of the ANAFIE Registry, a prospective observational study in > 30,000 Japanese patients aged ≥ 75 years with non-valvular AF (NVAF), investigated CE incidence and risk factors. The incidence and risk factors for new-onset CE (a composite of myocardial infarction [MI] and cardiac intervention for coronary heart diseases other than MI), MI, and cardiac intervention for coronary heart diseases other than MI during the 2-year follow-up were assessed. Bleeding events in CE patients were also examined. Among 32,275 patients, the incidence rate per 100 patient-years was 0.48 (95% confidence interval (CI): 0.42-0.53) for CE during the 2-year follow-up, 0.20 (0.16-0.23) for MI, and 0.29 (0.25-0.33) for cardiac intervention for coronary heart diseases other than MI; that of stroke/systemic embolism was 1.62 (1.52-1.73). Patients with CE (n = 287) likely had lower creatinine clearance (CrCL) and higher CHADS2 and HAS-BLED scores than patients without CE (n = 31,988). Significant risk factors associated with new-onset CE were male sex, systolic blood pressure of ≥ 130 mmHg, diabetes mellitus (glycated hemoglobin ≥ 6.0%), CE history, antiplatelet agent use, and CrCL < 50 mL/min. Major bleeding incidence was significantly higher in patients with new-onset CE vs without CE (odds ratio [95% CI], 3.35 [2.06-5.43]). In elderly patients with NVAF, CE incidence was lower than stroke/systemic embolism incidence. New-onset CE (vs no CE) was associated with a higher incidence of major bleeding.Trial registration: UMIN000024006.

Aspirin-free antiplatelet strategies after percutaneous coronary interventions

Dual antiplatelet therapy (DAPT) with aspirin and a platelet P2Y12 receptor inhibitor is the standard antithrombotic treatment after percutaneous coronary interventions (PCI). Several trials have challenged guideline-recommended DAPT after PCI by testing the relative clinical effect of an aspirin-free antiplatelet approach-consisting of P2Y12 inhibitor monotherapy after a short course (mostly 1-3 months) of DAPT-among patients undergoing PCI without a concomitant indication for oral anticoagulation (OAC). Overall, these studies have shown P2Y12 inhibitor monotherapy after short DAPT to be associated with a significant reduction in the risk of bleeding without an increase in thrombotic or ischaemic events compared with continued DAPT. Moreover, the effects of the P2Y12 inhibitor monotherapy without prior DAPT or following a very short course of DAPT after PCI are being investigated in emerging studies, of which one has recently reported unfavourable efficacy results associated with the aspirin-free approach compared with conventional DAPT. Finally, P2Y12 inhibitor alone has been compared with aspirin alone as chronic therapy after DAPT discontinuation, thus challenging the historical role of aspirin as a standard of care for secondary prevention following PCI. A thorough understanding of study designs, populations, treatments, results, and limitations of trials testing P2Y12 inhibitor monotherapy vs. DAPT or vs. aspirin is required to consider adopting this treatment in clinical practice. This review addresses the use of aspirin-free antiplatelet strategies among patients undergoing PCI without a concomitant indication for OAC, providing an overview of clinical evidence, guideline indications, practical implications, ongoing issues, and future perspectives.

Enoxaparin as an Anticoagulant in a Multipara with a Mechanical Mitral Valve: A Case Report

Patients who have undergone mechanical valve replacement require anticoagulation therapy with warfarin to prevent thromboembolism. However, administering warfarin to pregnant patients increases their risk of warfarin embryopathy or central nervous system disorders. Consequently, safer alternatives, such as heparin or low-molecular-weight heparin injection, are substituted for warfarin. However, limited research has been conducted on this subject, with no large-scale studies and particularly few investigations involving multiparous patients. A patient who had previously undergone mechanical mitral valve replacement for atrial septal defect and mitral stenosis received anticoagulant therapy with enoxaparin during 2 pregnancies. Upon confirmation of pregnancy, warfarin was replaced with subcutaneously injected enoxaparin with a dosage of 1 mg/kg at 12-hour intervals. The enoxaparin dosage was controlled using an anti-factor Xa assay, with a target range of 0.3-0.7 IU/mL. Intravenous heparin injections were administered starting 3 days prior to the expected delivery date and were continued until delivery, after which warfarin was resumed. No complications were observed during the deliveries.

Real-world data emulating randomized controlled trials of non-vitamin K antagonist oral anticoagulants in patients with venous thromboembolism

BACKGROUND

Emulating randomized controlled trials (RCTs) by real-world evidence (RWE) studies would benefit future clinical and regulatory decision-making by balancing the limitations of RCT. We aimed to evaluate whether the findings from RWE studies can support regulatory decisions derived from RCTs of non-vitamin K antagonist oral anticoagulants (NOACs) in patients with venous thromboembolism (VTE).

METHODS

Five landmark trials (AMPLIFY, RE-COVER II, Hokusai-VTE, EINSTEIN-DVT, and EINSTEIN-PE) of NOACs were emulated using the South Korean nationwide claims database (January 2012 to August 2020). We applied an active comparator and new-user design to include patients who initiated oral anticoagulants within 28 days from their VTE diagnoses. The prespecified eligibility criteria, exposure (each NOAC, such as apixaban, rivaroxaban, dabigatran, and edoxaban), comparator (conventional therapy, defined as subcutaneous heparin followed by warfarin), and the definition of outcomes from RCTs were emulated as closely as possible in each separate emulation cohort. The primary outcome was identical to each trial, which was defined as recurrent VTE or VTE-related death. The safety outcome was major bleeding. Propensity score matching was conducted to balance 69 covariates between the exposure groups. Effect estimates for outcomes were estimated using the Mantel-Haenszel method and Cox proportional hazards model and subsequently compared with the corresponding RCT estimates.

RESULTS

Compared to trial populations, real-world study populations were older (range: 63-69 years [RWE] vs. 54-59 years [RCT]), with more females (55-60.5% vs. 39-48.3%) and had a higher prevalence of active cancer (4.2-15.4% vs. 2.5-9.5%). The emulated estimates for effectiveness outcomes showed superior effectiveness of NOAC (AMPLIFY: relative risk 0.81, 95% confidence interval 0.70-0.94; RE-COVER II: hazard ratio [HR] 0.60, 0.37-0.96; Hokusai-VTE: 0.49, 0.31-0.78; EINSTEIN-DVT: 0.54, 0.33-0.89; EINSTEIN-PE: 0.50, 0.34-0.74), when contrasted with trials that showed non-inferiority. For safety outcomes, all emulations except for AMPLIFY and EINSTEIN-DVT yielded results consistent with their corresponding RCTs.

CONCLUSIONS

This study revealed the feasibility of complementing RCTs with RWE studies by using claims data in patients with VTE. Future studies to consider the different demographic characteristics between RCT and RWE populations are needed.

Comparison of Clinical Outcomes Between Ticagrelor and Clopidogrel in East-Asian Patients with Acute Coronary Syndrome: Large Cohort Study

AIM

A high risk of bleeding is observed in East Asian patients with acute coronary syndrome (ACS). Therefore, the choice between two antiplatelet therapy drugs, ticagrelor and clopidogrel, remains controversial in this population with ACS. This study aimed to use a large cohort database to assess the clinical outcomes of ticagrelor and clopidogrel therapy, including major bleeding, recurrent ACS, and mortality, in this population.

METHODS

Between January 2009 and December 2019, 43,696 patients were diagnosed with ACS based on the medical history (International Classification of Diseases [ICD] code) of the Chang Gung Research Database. After excluding patients without percutaneous coronary intervention, with concurrent medical problems, and on non-standard dual antiplatelet therapy (DAPT) or a single antiplatelet agent, 18,046 patients were recruited for analysis. Ticagrelor- and clopidogrel-based DAPT were administered to 3666 patients and 14,380 patients, respectively. Baseline characteristics and clinical outcomes were compared between the two groups. A total of 4225 patients were defined as a high-bleeding-risk subgroup according to Academic Research Consortium for High Bleeding Risk (ARC-HBR) score (met one major or two minor criteria), of which 466 and 3759 patients received ticagrelor- and clopidogrel-based DAPT, respectively.

RESULTS

Before propensity score matching (PSM), younger age, higher prevalence of male sex, and higher body mass index were noted in the ticagrelor-based DAPT group in the whole cohort and high-bleeding-risk subgroup. After PSM, no difference in baseline characteristics and comorbidities between ticagrelor-based and clopidogrel-based DAPT groups in the whole cohort and high-bleeding-risk subgroup was noted. The Kaplan-Meier curves of recurrent ACS and major bleeding were significantly lower in the ticagrelor-based DAPT group than in the clopidogrel-based DAPT group, and that of cardiovascular (CV) and all-cause mortality showed no significant differences. After PSM, in the high-bleeding-risk subgroup, the Kaplan-Meier curve of recurrent ACS was significantly lower in the ticagrelor-based DAPT group than in the clopidogrel-based DAPT group, and that of major bleeding, CV, and all-cause mortality showed no significant differences.

CONCLUSION

In this large cohort study, patients receiving ticagrelor-based DAPT were at lower risk of recurrent ACS compared to those receiving clopidogrel-based DAPT, especially in the patients with myocardial infarction. Ticagrelor-based DAPT did not result in a higher risk of major bleeding in the whole ACS population and high-bleeding-risk subgroup. The rate of CV and all-cause mortality were similar between both the groups.

Comparison of De-escalation of DAPT Intensity or Duration in East Asian and Western Patients with ACS Undergoing PCI: A Systematic Review and Meta-analysis

BACKGROUND

 Guideline-recommended dual antiplatelet therapy (DAPT; aspirin plus prasugrel/ticagrelor) for 12 months in acute coronary syndrome (ACS) patients increases bleeding, with East Asians (EAs) exhibiting higher bleeding and lower ischemic risk, compared with non-East Asians (nEAs). We sought to compare DAPT "de-escalation" strategies in EA and nEA populations.

METHODS

 A systematic review and meta-analysis of randomized controlled trials assessing reduction of DAPT intensity or duration in ACS patients undergoing percutaneous coronary intervention, in EA and nEA, was performed using a random-effects model.

RESULTS

 Twenty-three trials assessed reduction of DAPT intensity (n = 12) or duration (n = 11). Overall, reduced DAPT intensity attenuated major bleeding (odds ratio [OR]: 0.78, 95% confidence interval [CI]: 0.65-0.94, p = 0.009), without impacting net adverse cardiovascular events (NACE) or major adverse cardiovascular events (MACE). In nEA, this increased MACE (OR: 1.20, 95% CI: 1.09-1.31, p < 0.0001) without impacting NACE or bleeding; while in EA, it reduced major bleeding (OR: 0.71, 95% CI: 0.53-0.95, p = 0.02) without affecting NACE or MACE. Overall, abbreviation of DAPT duration reduced NACE (OR: 0.90, 95% CI: 0.82-0.99, p = 0.03) due to major bleeding (OR: 0.69, 95% CI: 0.53-0.99, p = 0.006), without impacting MACE. In nEA, this strategy did not impact NACE, MACE, or major bleeding; while in EA, it reduced major bleeding (OR: 0.60, 95% CI: 0.4-0.91, p = 0.02) without impacting NACE or MACE.

CONCLUSION

 In EA, reduction of DAPT intensity or duration can minimize bleeding, without safety concerns. In nEA, reduction of DAPT intensity may incur an ischemic penalty, while DAPT abbreviation has no overall benefit.

Use of preinjury antiplatelet and oral anticoagulant agents on outcomes following blunt trauma in an Asian population: a 1:2 propensity score matched study

BACKGROUND

Bleeding is a feared complication of antiplatelets (APTs) and oral anti-coagulants (OACs) use. Asians are at higher risk of bleeding from APT/OAC compared to Western population. Our study aims to investigate the impact of preinjury APT/OAC use on outcomes of moderate to severe blunt trauma.

METHODS

This is a retrospective cohort study from Jan 2017 - Dec 2019 of all patients with moderate to severe blunt trauma. A 1:2 propensity score matching (PSM) analysis was performed to address for confounding factors. Our primary outcome was in-hospital mortality. Our secondary outcomes were severity of head injury and need for emergency surgery within the first 24 hours.

RESULTS

There were 592 patients (APT/OAC n=72, no APT/OAC n=520) included in our study. The median age was 74 years in APT/OAC and 58 years in no APT/OAC. PSM resulted in 150 patients (APT/OAC n=50, no APT/OAC n=100). In the PSM cohort, more patients with APT/OAC use had ischemic heart disease (76% vs 0%, P<0.001). APT/OAC use was independently associated with higher in-hospital mortality (22.0% vs 9.0%, Odds ratio (OR) 3.00, 95% Confidence interval (CI): 1.05, 8.56, P=0.040) Severity of head injury (abbreviated injury scale in APT/OAC: 3.33 ± 1.53, vs 2.97 ± 1.43, P=0.380) and need for emergency surgery (APT/OAC 16.2% vs 11.0%, P=0.434) was comparable between APT/OAC and no APT/OAC.

CONCLUSIONS

Preinjury APT/OAC use was associated with higher in-hospital mortality. Severity of head injury and need for emergency surgery within 24 hours from admission were comparable between APT/OAC use and no APT/OAC use.

Pharmacokinetics and bioequivalence evaluation of omeprazole and sodium bicarbonate dry suspensions in healthy Chinese volunteers

Omeprazole and sodium bicarbonate dry suspension are effective treatments for acid-related disorders. This study compared the bioequivalence and safety of the two formulations of omeprazole and sodium bicarbonate powder and assessed how CYP2C19 gene polymorphisms affect pharmacokinetics (PK). A single-center, randomized, single-dose, 2-sequence and 2-period crossover method was performed in forty healthy Chinese subjects. Blood samples were collected after a single dose for PK (AUC0-∞, AUC0-t, and Cmax) analysis. The concentrations of Omeprazole in human plasma were determined by HPLC-MS/MS. Besides, the gene polymorphisms of CYP2C19 were assessed by Sanger sequencing. The geometric mean ratios (90% confidence interval) [GMR (95% CI)] of Test/Reference preparation for Cmax: 95.2% (88.48%, 102.43%), AUC0-t: 97.47% (94.4%, 101.02%), AUC0-∞: 97.68% (94.27%, 101.21%) were within the range of 80.00-125.00%. The non-parametric test showed no statistical difference in Tmax between the two groups (p > 0.05). All drugs were well tolerated, no severe adverse reactions occurred, and no significant differences in adverse events between the two drugs. For CYP2C19 gene polymorphisms, the results showed that of 40 subjects, 12 subjects were extensive metabolizers, 24 were intermediate metabolizers, and 4 were poor metabolizers, the frequency of metabolic genotypes were 30%, 60%, and 10%. And the allele distributions for CYP2C19 were *1, *2, and *3 at 60%, 38.75%, and 1.25%. Both the CYP2C19 alleles and metabolic genotypes were consistent with other studies in Chinese. The results of PK parameters showed that different genotypes of CYP2C19 lead to significant differences in t1/2, AUC0-t, AUC0-∞ and Cmax, but no significant differences in Tmax in each group. At the same time, we confirmed that the PK parameters of the test and reference had no differences between the males and females. This study has shown that the pharmacokinetic parameters of the two formulations are not significantly different, which showed bioequivalence and exemplary safety. CYP2C19 gene polymorphism significantly differed in the PK parameters of omeprazole sodium bicarbonate powder.

Percutaneous Patent Foramen Ovale Closure After Stroke

Percutaneous patent foramen ovale (PFO) closure in patients with a prior PFO-associated stroke showed a risk reduction of the stroke recurrence compared to the medical therapy alone in recent several studies. Nevertheless, optimal patient selection for PFO closure has not been clarified. In this paper, we discuss the characteristics of PFO-associated strokes and discuss the recently published evidence and patient selection for PFO closure in patients with ischemic stroke. The lesions characteristics of PFO-associated stroke are associated with multiple scattered lesion, small sized cerebral cortical lesion, or posterior circulation. Overcoming the failure of early studies in CLOSURE I, PC, and RESPECT trials, PFO closure showed a significant reduction in recurrent stroke in recently published REDUCE, CLOSE, DEFENSE-PRO trials, and long-term follow-up data of RESPECT study. However, considering that PFO closure cannot completely prevent stroke recurrence and that complications including atrial fibrillation, we should be selectively performed in patients with high-risk PFO.

Antiplatelet regimens after ischemic stroke or transient ischemic attack: a systematic review and updated network meta-analysis

Background

It is still uncertain which antiplatelet regimen had the greatest net clinical benefit in patients who have suffered a transient ischemic attack or non-cardioembolic ischemic stroke, and it is necessary to choose the optimal regimen according to the clinical situation.

Methods

We utilized 3 databases of Medline, Embase, and the Cochrane Central Register of Controlled Trials to find randomized controlled trials that met our criteria, and performed network meta-analyses in recurrent stroke, composite outcomes, major bleeding events, recurrent ischemic stroke, and all bleeding events. Three-dimensional clustered rank plots were used to obtain the net clinical benefit. Subgroup analyses were performed according to the symptom-onset-to-treatment time (<72 and >72 h), stroke subtypes (large artery atherosclerosis and small vessel occlusion), and dual antiplatelet agent treatment duration.

Results

A total of 69 trials were enrolled. Cilostazol was associated with a lower risk of recurrent stroke, major bleeding events, composite outcomes, recurrent ischemic stroke, and all bleeding events compared to low to medium dose aspirin. The three-dimensional rank plot showed that cilostazol had the highest net clinical benefit. The combination of aspirin plus clopidogrel had greater efficacy in the <72 h after stroke onset and large artery atherosclerosis subgroups, and when it was restricted to1 month of use major bleeding risk was not higher than aspirin. The combination of aspirin plus dipyridamole had greater efficacy and safety comparable to aspirin in terms of small vessel occlusion.

Conclusions

The efficacy and safety profiles among antiplatelet regimens may differ according to clinical situation, although cilostazol, aspirin plus clopidogrel, and aspirin plus dipyridamole may be considered as preferable options.

Thrombotic vs. Bleeding Events of Interruption of Dual Antiplatelet Therapy within 12 Months among Patients with Stent-Driven High Ischemic Risk Definition following PCI

BACKGROUND

There is a paucity of real-world data regarding the clinical impact of dual antiplatelet therapy (DAPT) interruption (temporary or permanent) among patients at high ischemic risk. The aim of this study was to assess the risk of cardiovascular events after interruption of DAPT in high-risk PCI population.

METHODS

This study used data from the Fuwai PCI registry, a large, prospective cohort of consecutive patients who underwent PCI. We assessed 3,931 patients with at least 1 high ischemic risk criteria of stent-related recurrent ischemic events proposed in the 2017 ESC guidelines for focused update on DAPT who were free of major cardiac events in the first 12 months. The primary ischemic endpoint was 30-month major adverse cardiac and cerebrovascular events, and the key safety endpoints were BARC class 2, 3, or 5 bleeding and net adverse clinical events.

RESULTS

DAPT interruption within 12 months occurred in 1,122 patients (28.5%), most of which were due to bleeding events or patients' noncompliance to treatment. A multivariate Cox regression model, propensity score (PS) matching, and inverse probability of treatment weighting (IPTW) based on the propensity score demonstrated that DAPT interruption significantly increased the risk of primary ischemic endpoint compared with prolonged DAPT (3.9% vs. 2.2%; Cox-adjusted hazard ratio (HR): 1.840; 95% confidence interval (CI): 1.247 to 2.716; PS matching-HR: 2.049 [1.236-3.399]; IPTW-adjusted HR: 1.843 [1.250-2.717]). This difference was driven mainly by all-cause death (1.8% vs. 0.7%) and MI (1.3% vs. 0.5%). Furthermore, the rate of net adverse clinical events (4.9% vs. 3.2%; Cox-adjusted HR: 1.581 [1.128-2.216]; PS matching-HR: 1.639 [1.075-2.499]; IPTW-adjusted HR: 1.554 [1.110-2.177]) was also higher in patients with DAPT interruption (≤12 months), whereas no significant differences between groups were observed in terms of BARC 2, 3, or 5 bleeding. These findings were consistent across various stent-driven high-ischemic risk subsets with respect to the primary ischemic endpoints, with a greater magnitude of harm among patients with diffuse multivessel diabetic coronary artery disease.

CONCLUSIONS

In patients undergoing high-risk PCI, interruption of DAPT in the first 12 months occurred infrequently and was associated with a significantly higher adjusted risk of major adverse cardiovascular events and net adverse clinical events. 2017 ESC stent-driven high ischemic risk criteria may help clinicians to discriminate patient selection in the use of long-term DAPT when the ischemic risk certainly overcomes the bleeding one.

Ethnic Difference of Thrombogenicity in Patients with Cardiovascular Disease: a Pandora Box to Explain Prognostic Differences

Arterial and venous atherothrombotic events are finely regulated processes involving a complex interplay between vulnerable blood, vulnerable vessel, and blood stasis. Vulnerable blood ('thrombogenicity') comprises complex interactions between cellular components and plasma factors (inflammatory, procoagulant, anticoagulant, and fibrinolytic factors). The extent of thrombogenicity may determine the progression of atheroma and the clinical manifestation of atherothrombotic events, with the highest thrombogenicity in African Americans and lowest in East Asians. Inherent thrombogenicity may influence clinical efficacy and safety of specific antithrombotic treatments in high-risk patients, which may in part explain the observation that East Asian patients have reduced anti-ischemic benefits and elevated bleeding risk with antithrombotic therapy compared to Caucasian patients. In this review, we discuss available evidence regarding the racial differences in thrombogenicity and its impact on clinical outcomes among patients with atherosclerotic cardiovascular disease.