Correlations among different platelet aggregation pathways in a group of healthy volunteers.

Platelet aggregation is a complicated process mediated by different signaling pathways. As the process is highly complex and apparently redundant, the relationships between these pathways are not yet fully known. The aim of this project was to study the interconnections among seven different aggregation pathways in a group of 53 generally healthy volunteers aged 20 to 66 years. Platelet aggregation was induced with thrombin receptor activating peptide 6 (TRAP), arachidonic acid (AA), platelet activating factor 16 (PAF), ADP, collagen, thromboxane A2 analogue U46619 or ristocetin (platelet agglutination) ex vivo in fasting blood samples according to standardized timetable protocol. Additionally, some samples were pre-treated with known clinically used antiplatelet drugs (vorapaxar, ticagrelor or acetylsalicylic acid (ASA)). Significant correlations among all used inducers were detected (Pearson correlation coefficients (rP): 0.3 to 0.85). Of all the triggers, AA showed to be the best predictor of the response to other inducers with rP ranging from 0.66 to 0.85. Interestingly, the antiplatelet response to ticagrelor strongly predicted the response to unrelated drug vorapaxar (rP = 0.71). Our results indicate that a response to one inducer can predict the response for other triggers or even to an antiplatelet drug. These data are useful for future testing but should be also confirmed in patients.

What is the context?• Platelet activation is a complicated process with multiple signaling cascades involved.• A total of seven common platelet triggers (ADP, collagen, TRAP-6, PAF, arachidonic acid/AA/, ristocetin and U46619) were tested.• The process is dependent on many factors including sex, age, concomitant disease(s), pharmacotherapy.What is new?• There were significant correlations between all tested aggregatory cascades.• AA has the highest rate of response predictability in our heterogeneous generally healthy volunteer group.• There was no correlation between impedance aggregometry in whole blood and turbidimetric measurement with platelet-rich plasma.What is the impact?• The effect of antiplatelet drugs can be assessed from the reaction to different trigger(s) at least in this group of healthy patients.• Future studies must test these relationships in patients with different diseases.

My journey on the path to understanding IgA nephropathy: From bench to bedside.

When Berger et al. first reported IgA nephropathy in 1968, the prognosis was generally thought to be benign. However, as more case data were accumulated, it became evident that not all patients with IgA nephropathy necessarily had a good prognosis. IgA nephropathy has a significant morbidity, culminating in end-stage kidney disease (ESKD) in about 40% of patients without treatment within 20 years of the diagnosis. Although almost 20% of patients remain stable in their renal function, 30%-40% of patients develop ESKD from its onset. The important factors of renal outcome in patients with IgA nephropathy is the severity of histopathological findings, heavy proteinuria, long duration of proteinuria, haematuria and hypertension.

Application of Antithrombotic Drugs in Patients with Acute Type B Aortic Dissection Underwent Thoracic Endovascular Aortic Repair.

This study aimed to evaluate the safety and necessity of antithrombotic drugs for acute type B aortic dissection (TBAD) treated with thoracic endovascular aortic repair (TEVAR).The patients of acute TBAD treated with TEVAR were retrospectively enrolled from January 2007 to October 2022 in General Hospital of Northern Theater Command. The primary outcomes such as mortality and aortic adverse events [stroke, paraplegia, limb ischemia, organ failure (renal and intestinal tract), endoleak, redissection, aortic rupture, reintervention, and mortality] were recorded and evaluated at 1 month (early term) and 18 months (late term).The 697 patients of TBAD treated with TEVAR were divided into the antithrombotic (AT) group (n = 208) and nonantithrombotic (NAT) group (n = 489). The incidence of early mortality, early aortic adverse events, and the 18 months of cumulative freedom from all-cause mortality and aortic adverse events were not significantly different between the AT and NAT groups (2.4% versus 1.4%, 2.9% versus 4.5%, 94.7% versus 96.5% and 88.4% versus 89.9%, respectively). Log-rank tests also indicated that there were no significant differences. In multivariate Cox regression models, only pleural effusion, partially thrombosed of false lumen, maximum diameter of false lumen, and branch involvement were independent predictors of mortality, whereas the systolic blood pressure (SBP), pleural effusion, partially thrombosed of false lumen, true lumen compression, maximum diameter of false lumen, branch involvement were independent predictors of adverse aortic events.The antithrombotic drug for acute TBAD treated with TEVAR does not influence the mortality and aortic events in the early and late terms.

Relationship between antithrombotic drugs and postoperative outcomes in patients with gastric cancer after gastrectomy: a propensity matching analysis.

BACKGROUND: As there is no consensus on the impact of antithrombotic drugs on post-gastrectomy outcomes in gastric cancer patients, this study aimed to investigate the impact of antithrombotic drugs on postoperative outcomes in these patients after gastrectomy. METHODS: Patients with Stage I-III primary gastric cancer who underwent radical gastrectomy between April 2005 and May 2022 were included. We performed propensity score matching to adjust for patient background and compared bleeding complications. Multivariate analysis with logistic regression analysis was performed to identify risk factors associated with bleeding complications. RESULTS: Of the 6798 patients, 310 (4.6%) were in the antithrombotic group and 6488 (95.4%) were in the non-antithrombotic group. Twenty-six patients (0.38%) experienced bleeding complications. After matching, the number of patients in each group was 300, with insignificant differences in any factor. A comparison of postoperative outcomes showed no difference in bleeding complications (P = 0.249). In the antithrombotic group, 39 (12.6%) continued drugs, and 271 (87.4%) discontinued them before surgery. After matching, there were 30 and 60 patients, respectively, with no differences in patient background. A comparison of postoperative outcomes showed no differences in bleeding complications (P = 0.551). In multivariate analysis, antithrombotic drug use and continuation of antiplatelet agents were not risk factors for bleeding complications. CONCLUSION: Antithrombotic drugs and its continuation may not worsen bleeding complications in patients with gastric cancer after radical gastrectomy. Bleeding complications were rare, and further studies are needed on risk factors for bleeding complications in larger databases.

Adiponectin receptor agonist AdipoRon modulates human and mouse platelet function.

Adiponectin, an adipokine secreted by adipocytes, has anti-atherosclerotic and antithrombotic activities. AdipoRon is synthetic small molecule adiponectin receptor agonist. In this study, we investigated the effect of AdipoRon on platelet activation and thrombus formation. Washed human platelets were prepared from the peripheral blood of healthy donors. In a series of in vitro platelet functional assays, pre-treatment with AdipoRon (10, 20, 40 µg/mL) dose-dependently inhibited the aggregation, granule secretion and spreading of washed human platelets. We showed that AdipoRon (20, 40 µg/mL) significantly inhibited AMPK, Syk, PLCγ2, PI3K, Akt, p38-MAPK and ERK1/2 signalling pathways in washed human platelets. In addition, we demonstrated that the phosphorylation of CKII at Tyr255 was an important mechanism of the integrin αIIbß3-mediated platelet activation. Meanwhile, AdipoR1 deficiency impaired the inhibitory effect of AdipoRon on mouse platelets. In ferric chloride-induced carotid injury model, injection of AdipoRon (5 or 12.5 mg/kg, iv) significantly attenuated arterial thrombosis. In conclusion, AdipoRon attenuates platelet function via the AdipoR1/AMPK/CKII/PI3K/AKT signalling pathways, while exerting a protective effect against arterial thrombosis. This study offers new insights into the fields of cardiovascular disease and antiplatelet drug discovery.Schematic model of AdipoRon regulating platelet activation. (BioRender.com).

Safety outcomes of anti-platelet therapy post coronary artery bypass graft surgery: A systematic review and network meta-analysis of randomized control trials.

BACKGROUND: Antiplatelet therapy is used to decrease the risk of graft failure post coronary artery bypass graft surgery. We aimed to compare dual antiplatelet therapy (DAPT) with monotherapy along with a comparison of Aspirin, Ticagrelor, Aspirin+Ticagrelor (A+T) and Aspirin+Clopidogrel (A+C) to determine the major and minor bleeding risk, risk of postoperative myocardial infarction (MI), stroke, and all-cause mortality (ACM). METHODS: Randomized Controlled Trials comparing the four groups were included. Odds ratio (OR) and Absolute Risk (AR) were employed to assess the mean and standard deviation (SD) with 95% confidence intervals (CI). The Bayesian random-effects model was used for statistical analysis. Risk difference and Cochran Q tests were used to calculate rank probability (RP) and heterogeneity, respectively. RESULTS: We included 10 trials, consisting of 21 arms and 3926 patients. For the risk of major and minor bleed, A + T and Ticagrelor showed the lowest mean value of 0.040 (0.043) and 0.067 (0.073), respectively, and the highest RP of being the safest group. While a direct comparison between DAPT and monotherapy resulted in an OR of 0.57 [0.34, 0.95] for the risk of minor bleed. A + T was found to have the highest RP and the lowest mean value in terms of ACM, MI, and stroke. CONCLUSION: No significant difference was found between monotherapy or dual-antiplatelet therapy for the major bleeding risk safety outcome, however DAPT was found to have a significantly higher rate of minor bleeding complications post-CABG. DAPT should be considered as the antiplatelet modality of choice post-CABG.

Eptifibatide, an Older Therapeutic Peptide with New Indications: From Clinical Pharmacology to Everyday Clinical Practice.

Therapeutic peptides are oligomers or short polymers of amino acids used for various medical purposes. Peptide-based treatments have evolved considerably due to new technologies, stimulating new research interests. They have been shown to be beneficial in a variety of therapeutic applications, notably in the treatment of cardiovascular disorders such as acute coronary syndrome (ACS). ACS is characterized by coronary artery wall damage and consequent formation of an intraluminal thrombus obstructing one or more coronary arteries, leading to unstable angina, non-ST elevated myocardial infarction, and ST-elevated myocardial infarction. One of the promising peptide drugs in the treatment of these pathologies is eptifibatide, a synthetic heptapeptide derived from rattlesnake venom. Eptifibatide is a glycoprotein IIb/IIIa inhibitor that blocks different pathways in platelet activation and aggregation. In this narrative review, we summarized the current evidence on the mechanism of action, clinical pharmacology, and applications of eptifibatide in cardiology. Additionally, we illustrated its possible broader usage with new indications, including ischemic stroke, carotid stenting, intracranial aneurysm stenting, and septic shock. Further research is, however, required to fully evaluate the role of eptifibatide in these pathologies, independently and in comparison to other medications.

Platelet function assessed by ROTEM®platelet in patients receiving antiplatelet therapy during cardiac and vascular surgery.

Patients undergoing coronary artery bypass graft (CABG) surgery or carotid endarterectomy (CEA) continue antiplatelet therapy perioperatively, which may increase bleeding risk. We aimed to investigate whether Rotational thromboelastometry (ROTEM®) platelet, a newly marketed platelet function analysis, would detect antiplatelet therapy in CABG and CEA patients; whether detection of reduced platelet function was associated with increased bleeding; and whether ex vivo desmopressin increased platelet function. We included 20 CABG patients continuing aspirin and 20 CEA patients continuing clopidogrel (n = 1) or clopidogrel and aspirin (n = 19). Platelet function was analyzed with ROTEM®platelet and light transmission aggregometry (LTA). According to the lower reference limit, ROTEM®platelet managed to detect aspirin, but clopidogrel detection was inadequate compared to LTA. Using a previously published cut-off for bleeding risk, 6 (30%) patients receiving aspirin and 4 (21%) patients receiving both clopidogrel and aspirin demonstrated platelet function below this cut-off. One of the four CEA patients below the cut-off died from intracerebral hemorrhage postoperatively. CABG patients below (n = 6) and above (n = 14) the cut-off did not differ in chest tube output (median [range]: 373 ml [250-900] vs. 368 ml [195-820]). Ex vivo addition of desmopressin did not increase platelet function. In conclusion, ROTEM®platelet does reveal aspirin treatment whereas clopidogrel treatment is most often overlooked. Due to low bleeding in the study population, it was not possible to conclude on the association with bleeding risk.

Antithrombotic therapies in aortic and peripheral arterial diseases in 2021: a consensus document from the ESC working group on aorta and peripheral vascular diseases, the ESC working group on thrombosis, and the ESC working group on cardiovascular pharmacotherapy.

The aim of this collaborative document is to provide an update for clinicians on best antithrombotic strategies in patients with aortic and/or peripheral arterial diseases. Antithrombotic therapy is a pillar of optimal medical treatment for these patients at very high cardiovascular risk. While the number of trials on antithrombotic therapies in patients with aortic or peripheral arterial diseases is substantially smaller than for those with coronary artery disease, recent evidence deserves to be incorporated into clinical practice. In the absence of specific indications for chronic oral anticoagulation due to concomitant cardiovascular disease, a single antiplatelet agent is the basis for long-term antithrombotic treatment in patients with aortic or peripheral arterial diseases. Its association with another antiplatelet agent or low-dose anticoagulants will be discussed, based on patient's ischaemic and bleeding risk as well therapeutic paths (e.g. endovascular therapy). This consensus document aims to provide a guidance for antithrombotic therapy according to arterial disease localizations and clinical presentation. However, it cannot substitute multidisciplinary team discussions, which are particularly important in patients with uncertain ischaemic/bleeding balance. Importantly, since this balance evolves over time in an individual patient, a regular reassessment of the antithrombotic therapy is of paramount importance.

Prasugrel-related hepatotoxicity.

Prasugrel is usually preferred over Clopidogrel to reduce the risk of recurrent coronary thrombosis in patients who undergo percutaneous coronary interventions during an acute coronary syndrome owing to its more potent and more rapid antithrombotic activation. Little is known about Prasugrel-induced hepatotoxicity, although mild-to-moderate alanine transaminase (ALT) and gamma glutamyl transpeptidase (GGT) elevations have been noticed in post-marketing surveillance. Herein, we report the case of a patient with Prasugrel-related hepatotoxicity that was reverted after switching from Prasugrel to Ticagrelor.

Dual versus Single Antiplatelet Therapy in Medically Treated Acute Myocardial Infarction Patients with Baseline Thrombocytopenia - Insights from a Multi-Institute Cohort Study.

Background: The safety and efficacy of dual antiplatelet therapy (DAPT) in medically treated acute myocardial infarction (AMI) patients with baseline thrombocytopenia (platelet count < 150 × 103/uL) are unclear. Methods: In this multi-institute retrospective cohort study, we included 468 patients with medically treated AMI with baseline thrombocytopenia and separated them into single antiplatelet therapy (SAPT) and DAPT groups according to the discharge anti-thrombotic strategy. The primary outcome was net clinical adverse events (NACEs), defined as a composite of death, ischemic events (myocardial infarction, ischemic stroke, and transient ischemic attack), and major bleeding within 30 days. Results: There were 168 patients in the SAPT group (100 taking aspirin and 68 taking clopidogrel) and 300 in the DAPT group. A primary outcome occurred in 35 (24.11 per 100 patient-months) patients in the SAPT group and 39 (14.26 per 100 patient-months) patients in the DAPT group [adjusted hazard ratio (HR): 0.67; 95% confidence interval (CI): 0.40-1.10; p = 0.1145]. Kaplan-Meier curves showed favorable results in the DAPT group (log-rank p = 0.0243). Bleeding events occurred in 18 (10.71 per 100 patient-months) patients in the SAPT group and 18 (6.40 per 100 patient-months) patients in the DAPT group (adjusted HR: 0.66; 95% CI: 0.32-1.36; p = 0.2573). Conclusions: DAPT versus SAPT as discharge anti-thrombotic strategy in thrombocytopenic patients with medically treated AMI did not significantly improve NACEs at 30 days. However, there was a trend towards favorable outcomes in the DAPT group. These results should be interpreted carefully with respect to the relatively limited trial population and study design.

Cilostazol Addition to Aspirin could not Reduce the Neurological Deterioration in TOAST Subtypes: ADS Post-Hoc Analysis.

BACKGROUND: Our previous trial acute dual study (ADS) reported that dual antiplatelet therapy (DAPT) using cilostazol and aspirin did not reduce the rate of short-term neurological worsening in non-cardioembolic stroke patients. Present post-hoc analysis investigated whether the impact of combined cilostazol and aspirin differed among stroke subtypes and factors associated with neurological deterioration and/or stroke recurrence. METHODS: Using the ADS registry, the rate of neurological deterioration, defined as clinical worsening and/or recurrent stroke, including transient ischemic attack was calculated. Stroke subtypes included large-artery atherosclerosis (LAA), small vessel occlusion (SVO), other determined etiology (Others), and undetermined etiology of stroke (Undetermined). RESULTS: Data of 1022 patients were analyzed. Deterioration was seen in 104 (10%) patients, and the rates were not markedly different between patients treated with DAPT vs. aspirin in any stroke subtypes: LAA, 19% vs. 11%, (p=0.192); SVO, 10% vs. 10% (p=1.000); Others, 6% vs. 6% (p=1.000); Undetermined, 11% vs. 8% (p=0.590). Diabetes mellitus was the independent factor associated with deterioration (odds ratio 4.360, 95% confidence interval 1.139-16.691, p=0.032) in the LAA group. Age (1.030 [1.004-1.057], p=0.026), systolic blood pressure (1.012 [1.003-1.022], p=0.010), and infarct size (2.550 [1.488-4.371], p=0.001) were associated with deterioration in SVO group, and intracranial stenosis/occlusion was associated with it in the Undetermined group (3.744 [1.138-12.318], p=0.030). CONCLUSIONS: Combined cilostazol and aspirin did not reduce the rate of short-term neurological deterioration in any clinical stroke subtype. The characteristics of patients whose condition deteriorates in the acute period may differ based on the stroke subtypes.

Effects of Antithrombotic Treatment on Bleeding Complications of EBUS-TBNA.

Background and Objectives: The application of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been markedly increased over the past decade. EBUS-TBNA is known to be a very safe and accurate procedure; however, the incidence of bleeding complications in patients who are taking antithrombotic agents (ATAs) is not well established. Materials and Methods: We conducted a retrospective analysis of a prospectively registered EBUS-TBNA cohort in a single tertiary hospital from May 2009 to December 2016. The patients were divided into two groups: an insufficient discontinuation group, defined as having a prescription for ATAs on the procedure day or only interrupting them for a short period of time, and a sufficient discontinuation group, defined as having prescription for ATAs during 30 days prior to the procedure and interrupting them for a sufficient period of time. Results: During the study period, a total of 4271 patients, after excluding 3773 patients who did not take ATAs at all, 498 patients were classified into the insufficient discontinuation group (n = 102) and the sufficient discontinuation group (n = 396). The baseline characteristics of patients and examined lesions between two groups were not significantly different, except insufficient discontinuation group had longer prothrombin times than the sufficient discontinuation group. In the insufficient discontinuation group, the most common reasons for prescriptions of ATAs were ischemic heart disease (48.0%) and cerebral vascular disease (28.4%), and half of the patients were taking two or more ATAs. Eventually, only one bleeding complication in the insufficient discontinuation group (1/102, 1.0%) and one event in the sufficient discontinuation group (1/396, 0.3%) occurred (p = 0.368). Conclusions: EBUS-TBNA is considered a safe procedure in terms of bleeding complications, even in patients with insufficient stopping of ATAs.

Frequency and clinical outcomes of CYP2C19 genotype-guided escalation and de-escalation of antiplatelet therapy in a real-world clinical setting.

PURPOSE: To evaluate the frequency and clinical impact of switches in antiplatelet therapy following implementation of CYP2C19 genotyping after percutaneous coronary intervention (PCI). METHODS: The frequency of escalation (clopidogrel switched to prasugrel/ticagrelor) and de-escalation (prasugrel/ticagrelor switched to clopidogrel) was evaluated in 1063 PCI patients who underwent CYP2C19 genotyping. Risk of major adverse cardiovascular or cerebrovascular (MACCE) and bleeding events over one year was evaluated. RESULTS: Antiplatelet therapy switches were common (19%), with escalation (101/115: 88%) and de-escalation (77/84: 92%) occurring predominantly in patients with and without a CYP2C19 nonfunctional allele, respectively. Nonfunctional allele carriers initiated and continued on clopidogrel had a significantly higher risk of experiencing either a MACCE or bleeding event compared with those escalated to prasugrel/ticagrelor (52 vs. 19 events/100 patient-years; adjusted hazard ratio [HR] 2.89 [1.44-6.13], p = 0.003). Patients without a nonfunctional allele de-escalated to clopidogrel had no difference in risk compared with those initiated and continued on prasugrel/ticagrelor (21 vs. 19 events/100 patient-years; adjusted HR 1.13 [0.51-2.34], p = 0.751). CONCLUSION: CYP2C19-guided escalation and de-escalation is common in a real-world setting. Continuation of clopidogrel in nonfunctional allele carriers is associated with adverse outcomes. De-escalation to clopidogrel in patients without a nonfunctional allele appears safe and warrants prospective study.

Acquired Factor V Inhibitor with Hemorrhagic Symptoms after Prasugrel Hydrochloride Treatment.

Acquired factor V inhibitor (AFVI) is a rare coagulopathy. It may be triggered by specific antigens such as antibiotics. We herein report the first case of AFVI after treatment with prasugrel hydrochloride (prasugrel) in an 80-year-old male who underwent percutaneous coronary intervention because of angina pectoris 6 years ago and was initiated on aspirin and ticlopidine hydrochloride. He was switched from ticlopidine hydrochloride to prasugrel before undergoing percutaneous coronary intervention for myocardial infarction. Fifteen days later, he developed sudden nasal hemorrhage, hematuria, and systemic purpura. Coagulation tests revealed prolonged prothrombin time-international normalized ratio (11.35) and activated partial thromboplastin time (170 s). The coagulation factor profile revealed a decreased FV activity (1%). The Bethesda assay for FV inhibitor was positive. AFVI was diagnosed; prasugrel was immediately discontinued, and administration of recombinant activated factor VII and prednisolone were initiated. Hemorrhagic symptoms immediately disappeared; FV activity improved, and the FV inhibitor titer was normalized.

CYP2C19 Polymorphism is Associated With Amputation Rates in Patients Taking Clopidogrel After Endovascular Intervention for Critical Limb Ischaemia.

OBJECTIVE: Clopidogrel is a pro-drug requiring cytochrome P450 (CYP) 2C19 enzyme to be oxidised to its active form. This study evaluated the association between the CYP 2C19 genetic polymorphism and clinical outcomes in patients with critical limb ischaemia (CLI) taking clopidogrel after endovascular therapy (EVT). METHODS: This was a retrospective study. Patients with CLI who had undergone EVT between August 2014 and January 2017 were included. The study subjects were divided into three groups according to the loss of function (LOF) CYP2C19 alleles: (1) extensive metaboliser (EM); (2) intermediate metaboliser (IM); and (3) poor metaboliser (PM). All patients underwent a platelet function test (VerifyNow). Amputation free survival and all cause mortality were estimated using the Kaplan-Meier method. The association between baseline characteristics and clinical outcomes was assessed with the Cox proportional hazard model. RESULTS: A total of 278 CLI patients (EM: 153, IM: 79, PM: 46) who underwent EVT were included. There were 180/278 (64.7%, EM: 107, IM: 45, PM: 28) patients who completed the 12 month follow up examination. Carriers of at least one CYP2C19 LOF allele (44.9%, 125/278) had diminished pharmacodynamic responses to clopidogrel as measured using VerifyNow (174 ± 27 platelet reactivity units (PRU), 216 ± 21 PRU, and 245 ± 35 PRU for patients with EM, IM, and PM CYP2C19 profiles, respectively; EM vs. IM, p < .0001 and EM vs. PM, p < .0001). The estimated amputation free 12 month survival rates were EM 82.1%, IM 66.1.0%, and PM 56.6% with significant differences between groups (log-rank test p = .0006, p for trend <.0001). The estimated all cause 12 month mortality rates were EM 83.7%, IM 72.2%, and PM 71.3% (log rank test p = .01, p for trend p = .007). The combined group consisting of IM and PM was associated with amputation free survival and all cause mortality based on a univariable analysis (hazard ratio [HR] = 2.23 [1.97-2.46], p = .011; HR = 1.43 [1.05-1.85], p = .043) and remained significant in a multivariable Cox analysis (HR = 2.65 [2.1-2.9], p = .009; HR = 1.39 [1.07-1.74], p = .037). CONCLUSION: CYP2C19 genetic profiles can significantly influence clinical outcomes (in both amputation free survival and all cause mortality) in CLI patients who are taking only clopidogrel after EVT.

Characteristics of ß-oxidative and reductive metabolism on the acyl side chain of cinnamic acid and its analogues in rats.

Cinnamic acid and its analogues (pyragrel and ozagrel) undergo chain-shortened (ß-oxidative) and reductive metabolism on acyl side chain. In this study, we characterized the ß-oxidative and reductive metabolism on acyl side chain of cinnamic acid and its analogues using primary rat hepatocytes, hepatic mitochondrial, and microsomal systems. A compartmental model including parent compounds and metabolites was developed to characterize in vivo ß-oxidative and reductive metabolism following an intravenous dose of parent compounds to rats. The fitted total in vivo clearance values were further compared with the in vitro values predicted by the well-stirred model. We showed that hepatic microsomal CYP450s did not catalyze ß-oxidative or reductive metabolism of the three compounds. Similar to ß-oxidation of fatty acids, ß-oxidative metabolism on their acyl side chain occurred mainly in mitochondria, which was highly dependent on ATP, CoA and NAD+. Fatty acids and NADH inhibited the ß-oxidative metabolism. Reductive metabolism occurred in both mitochondria and microsomes. Reduction in mitochondria was ATP-, CoA-, and NAD(P)H-dependent and reversible, which was suppressed by enoyl reductase inhibitor triclosan. Reduction in microsomes was ATP-, CoA-, and NADPH-dependent but little affected by triclosan. Both plasma concentrations of ß-oxidative metabolites and reductive metabolites were successfully fitted using the compartmental model. The estimated total in vivo clearance values were consistent with those predicted from hepatocytes and organelles, implicating significance of in vitro kinetics. These findings demonstrate the roles of hepatic mitochondria and microsomes in ß-oxidative and reductive metabolism on acyl side chain of cinnamic acid and its analogues along with their metabolic characteristics.

Epidemiology and secondary prevention of ischemic stroke in patients on antiplatelet drug: a retrospective cohort study.

One-third to one-half of ischemic strokes occurred in patients taking antiplatelet drugs. The optimal therapeutic strategy for antithrombotic drugs remains uncertain and guidelines provide scarse recommendation. Therefore, aims of our study were to: (i) estimate the prevalence of patients who develop an ischemic stroke while on antiplatelet drugs, (ii) investigate potential factors associated with this phenomenon, (iii) describe management strategies in daily clinical practice. Consecutive adult patients admitted for acute ischemic stroke at the academic hospital of Varese, Italy, from January 2010 till December 2011 were included. Patients were retrospectively identified by searching the administrative database of the hospital. Odds ratios (ORs) and their 95% confidence intervals (CI) for identifying factors associated with dependent variable were estimated using univariate logistic regression. Any variable with a p value < 0.2 at univariate analysis was included in a multivariate model. A total of 419 patients were included. Patients with ischemic stroke while on antiplatelet drugs were 49.6%. The following baseline characteristics were associated with the occurrence of ischemic stroke in patients taking antiplatelet drugs: diabetes mellitus (DM), history of ischemic heart disease (IHD), age > 65 years and previous stroke or transient ischemic stroke (TIA). The following variables were significantly associated with a change of antithrombotic therapy at discharge: DM, history of IHD and previous stroke or TIA. Our study confirms that the occurrence of ischemic stroke during antiplatelet treatment is common and management of antithrombotic therapy is heterogeneous. Factors that may explain therapeutic failure include undetected cardioembolic sources, drug resistance, poor compliance, or the presence of diabetes, atherothrombotic disease, and advanced age. Randomized controlled trials are warranted to assess the optimal antithrombotic strategy for ischemic stroke occurred in patients taking antiplatelet drugs.

Bioequivalence Study of 100-mg Cilostazol Tablets in Healthy Thai Adult Volunteers.

BACKGROUND: Cilostazol is a vasodilator with anticoagulant effect for treatment of peripheral vascular disease. Cilostazol 100-mg tablet was shown to increase walking distance in this patient population. OBJECTIVE: The aim of this study was to investigate and compare the pharmacokinetic profiles and safety of Bestazol 100-mg tablet (Berlin Pharmaceutical Industry Co Ltd, Bangkok, Thailand), which is a generic formulation of cilostazol, with the original brand Pletaal 100-mg tablet (Korea Otsuka Pharmaceutical Co Ltd, Seoul, South Korea) in healthy Thai adult volunteers. METHODS: The pharmacokinetic profiles of Bestazol (test) and Pletaal (reference) 100-mg tablets were compared in a single-dose, open-label, 2-treatment, 2-period, 2-sequence, randomized crossover study in healthy Thai adult volunteers. This study was conducted at the Siriraj Clinical Research Center, Siriraj Hospital, Mahidol University, Bangkok, Thailand. Each volunteer was initially treated according to either the test-reference or the reference-test sequence, after which each volunteer was switched to the other study sequence after a 2-week washout period. Pharmacokinetic analysis was performed using log-transformed ratios for Cmax, AUC0-last, AUC0-∞, Tmax, t1/2, and λZ for both cilostazol and 3,4-dehydro-cilostazol (its active metabolite) with 90% CI. Physical examination, clinical laboratory data, vital signs, and adverse events were assessed in all participants. FINDINGS: A total of 28 volunteers were included in the final analysis. The ratios of the geometric mean and the 90% CI compared test to reference of cilostazol formulations and were 101.86% (90% CI, 91.88%-112.92%), 107.78% (90% CI, 99.67%-116.56%), and 110.46% (90% CI, 102.68%-118.82%) for Cmax, AUC0-last, and AUC0-∞, respectively. The ratios of the geometric mean and the 90% CI compared test to reference of 3,4-dehydro-cilostazol and were 106.72% (95% CI, 95.31%-119.50%), 110.54% (95% CI, 101.92%-119.89%), and 107.37% (95% CI, 96.74%-119.16%) for Cmax, AUC0-last, and AUC0-∞, respectively. No significant difference was observed between formulations for Tmax. The most common adverse event was headache (51.85%), with no significant difference in incidence between the test and reference groups. No serious adverse events related to the studied drugs were reported. The findings of this study indicate these 2 cilostazol tablet formulations to be bioequivalent. CONCLUSIONS: Bestazol 100-mg tablet was bioequivalent to Pletaal 100-mg tablet. Thus, the formulations can be used interchangeably in clinical practice.

Current Status, Time Trends and Outcomes of Combination Therapy With Oral Anticoagulant and Antiplatelet Drug in Patients With Atrial Fibrillation　- The Fushimi AF Registry.

BACKGROUND: The combination of oral anticoagulant (OAC) and antiplatelet drug (APD) increases the bleeding risk in atrial fibrillation (AF). Non-vitamin K antagonist OAC (NOAC) have been increasingly used since 2011. We investigated current status, time trends and outcomes of AF patients using combination therapy in 2011-2017. Methods and Results: The Fushimi AF Registry is a community-based prospective survey of AF patients in Fushimi-ku, Kyoto, Japan. Of 2,378 patients with OAC at enrollment, 521 (22%) received combination therapy, while 1,857 (78%) received OAC alone. When compared with OAC alone, combination therapy patients had more comorbidities, but approximately 30% had no atherosclerotic disease. From 2011 to 2017, the prevalence of combination therapy decreased from 26% to 14%. The prevalence of NOAC increased in those on combination therapy. Off-label under-dosing of NOAC increased year by year, especially in combination therapy. During follow-up, the incidence of major bleeding (hazard ratio [HR], 1.42; 95% CI: 1.03-1.95) and stroke/systemic embolism (HR, 1.48; 95% CI: 1.09-2.00) was higher in the combination therapy than in the OAC alone group. CONCLUSIONS: In Japanese AF patients receiving OAC, the prevalence of combination therapy decreased, with the proportion of NOAC use increasing in 2011-2017. Many patients, however, received off-label NOAC under-dosing, especially in the combination therapy group. Patients with combination therapy had higher incidences of major bleeding as well as stroke/systemic embolism, compared with OAC monotherapy.