Thrombotic thrombocytopenic purpura (TTP) is a rare variant of thrombotic microangiopathy. We report a case of TTP in a Nigerian chronic kidney disease (CKD) patient who was previously on clopidogrel. The features of TTP resolved soon after clopidogrel was withdrawn. Clopidogrel is a cardio-protective anti-platelet drug used in CKD patients at risk of dyspepsia. However, its potential to cause TTP should be recognized and considered in acute kidney injury (AKI) patients previously on clopidogrel.

Dual antiplatelet therapy (DAPT) is standard treatment for endoluminal stent insertion, and complete resistance to DAPT is rare. A case of in-stent thrombosis occurring 3 hours after stent-assisted coiling of internal carotid artery aneurysm is presented despite compliance with DAPT. Platelet function tests (PFTs) revealed complete clopidogrel and prasugrel resistance.

暂无摘要。

BACKGROUND: Geriatric hip fracture patients receiving clopidogrel are a surgical challenge. In China, most of these patients undergo delayed surgical treatment after clopidogrel withdrawal for at least 5 to 7 days. However, delayed surgery is associated with increased complications and mortality in the older adults. This retrospective paralleled comparison study investigated the safety of early surgery for geriatric hip fracture patients within 5 days of clopidogrel withdrawal.
METHODS: Acute hip fracture patients (≥65 years) who were hospitalized in the orthogeriatric co-management ward of Beijing Jishuitan Hospital between November 2016 and April 2018 were retrospectively reviewed. Sixty patients taking clopidogrel before injury and discontinued <5 days before surgery constituted the clopidogrel group. The control group constituted 60 patients not taking antiplatelet or anticoagulant drugs and matched 1:1 with the clopidogrel group for sex, fracture type, operative procedure, and time from injury to operation (±10 h). The primary outcome was perioperative blood loss and the secondary outcomes were transfusion requirement, complications, and mortality. The Student\'s t test or Wilcoxon signed rank sum test was used for continuous variables and the Chi-square test was used for categorical variables.
RESULTS: Age, body mass index, American Society of Anesthesiologists score, and percentage undergoing general anesthesia were comparable between the groups (P > 0.050). The percentages of patients with coronary heart disease (61.7% vs. 18.3%; P < 0.001) and cerebrovascular disease (45.0% vs. 15.0%; P < 0.010) were significantly higher in the clopidogrel vs. control groups, respectively. The median clopidogrel discontinuation time before operation was 73.0 (range: 3.0-120.0) h. There was no significant difference in the estimated perioperative blood loss between the clopidogrel group (median: 745 mL) and control group (median: 772 mL) (P = 0.866). The intra-operative transfusion rate was higher in the clopidogrel group (22/60, 36.7%) than that in the control group (12/60, 20.0%) (P < 0.050). However, there was no significant difference in the blood transfusion rate during the entire perioperative period (26/60, 43.3% vs. 20/60, 33.3%; clopidogrel group vs. control group, respectively; P > 0.050). There was no significant difference in perioperative complications, and 30-day and 1-year mortality rates between the groups.
CONCLUSIONS: Early hip fracture surgery is safe for elderly patients within 5 days of clopidogrel withdrawal, without increased perioperative blood loss, transfusion requirement, complications, and mortality compared with patients not taking antiplatelet drugs.

患者老年男性，因“发作性出汗、心悸22d”就诊，否认严重肝、肾功能不全病史，否认外源性胰岛素用药史，否认胰腺占位及手术史，有氯吡格雷服药史。多次查随机血浆葡萄糖<2.8 mmol/L，血清胰岛素>1 000 mIU/L，胰岛素自身抗体（IAA）（+）。人类白细胞抗原分型：DRB1*0403与0701，DQB1*0302与0202。停用氯吡格雷，调节饮食结构，口服阿卡波糖后低血糖症状逐渐缓解，出院5个月后复查血清胰岛素及C-肽明显下降，IAA转阴，遂停用阿卡波糖，减少进餐次数，发作性出汗及心悸未再发生。.

In real-world practice settings, there is insufficient evidence on the efficacy of antiplatelet drugs, including clopidogrel, aspirin, and ticlopidine, in stroke prevention.
To compare the efficacies between aspirin and clopidogrel and aspirin and ticlopidine in stroke prevention.
This population-based case-cohort study utilized the data obtained from a randomized sample of one million subjects in the Taiwan National Health Insurance Research Database. Patients who were hospitalized owing to the primary diagnosis of ischemic stroke from January 1, 2000 to December 31, 2010 and treated with aspirin, ticlopidine, or clopidogrel were included in the study. Propensity score matching with a 1:4 ratio was performed to compare aspirin with ticlopidine and clopidogrel. The criteria for inclusion were the use of one of the three antiplatelet drugs for more than 14 days within the first month after the stroke and then continued use of the antiplatelet drugs until the study endpoint of recurrent stroke.
During the 3-year follow-up period, the recurrent stroke rates were 1.62% (42/2585), 1.48% (3/203), and 2.55% (8/314) in the aspirin, ticlopidine, and clopidogrel groups, respectively. Compared with the patients treated with aspirin, those treated with clopidogrel and ticlopidine showed competing risk-adjusted hazard ratios of recurrent stroke of 2.27 (1.02-5.07) and 0.62 (0.08-4.86), respectively.
Compared with the patients treated with aspirin, those treated with clopidogrel were at a higher risk of recurrent stroke. For stroke prevention, aspirin was superior to clopidogrel whereas ticlopidine was not inferior to aspirin.

It is unclear whether cilostazol instead of aspirin in combination with clopidogrel could prevent in-stent thrombosis in patients with a history of gout undergoing vertebral artery origin stenting. Three men (age range, 58-74 years) were diagnosed with acute ischaemic stroke or transient ischaemic attack. Vertebral artery origin stenosis was visible by computed tomographic angiography or digital subtraction angiography. Four bare metal stents were placed in the vertebral artery origin. The patients were administered 100 mg cilostazol orally twice a day and 75 mg clopidogrel orally once a day perioperatively and 100 mg cilostazol orally twice day was administered indefinitely after 3 months. No in-stent stenosis was observed in all of these patients during a follow-up period up to 19 months. Cilostazol plus clopidogrel has the potential to become an alternative to standard dual antiplatelet therapy in vertebral artery origin stenting. A high-quality clinical trial is needed to verify these preliminary findings.

OBJECTIVE: Clopidogrel has become the mainstay oral antiplatelet regimen for recurrent ischemic event prophylaxis after acute coronary syndromes or stent placement. Stent thrombosis is considered a multifactorial problem that mostly occurs due to clopidogrel resistance. We report a case of subacute stent thrombosis in a CYP2C19*2 reduced-function allele carrier.
METHODS: A 56-year-old Chinese male diabetic patient suffered from acute myocardial infarction and underwent successful percutaneous coronary intervention (PCI) of the left anterior descending coronary artery (LAD) with two drug eluting stents (DESs). He was treated with a loading dose of aspirin 300 mg and ticagrelor 180 mg before stent placement. Ticagrelor was switched to clopidogrel of 75 mg maintenance dose, after emergency PCI. Stent thrombosis appeared 8 days after stent placement. The patient was found to be a CYP2C19*2 reduced-function allele carrier with type 2 diabetes. After intravenous administration of tirofiban, balloon angioplasty was performed, resulting in thrombolysis in myocardial infarction (TIMI) III antegrade flow.
CONCLUSIONS: The present case demonstrates that both diabetes mellitus and carriage of CYP2C19*2 allele are associated with a reduced response to clopidogrel in the setting of this standard dose of clopidogrel and a high risk of stent thrombosis. CYP2C19 genetic testing seems to be helpful for identifying patients-at-risk, and optimal antiplatelet regimen should be considered in these fragile populations.

BACKGROUND: Stent thrombosis (ST) remains a thorny issue in spite of dual antiplatelet treatment with aspirin plus clopidogrel after stent-assisted coiling (SAC). We report a first case of acute ST after SAC in an intracranial aneurysm (IA) patient who carries two reduced-function CYP2C19 alleles.
METHODS: A 43-year-old Chinese male carrying two reduced-function CYP2C19 alleles was treated with a loading dose of clopidogrel 300 mg and aspirin 300 mg before SAC. Unfortunately, life-threatening ST appeared 0.5 h later after SAC.
METHODS: A total of 100000U of urokinase was used to dissolve ST. Meanwhile, tirofiban and nodroparin was also administrated to prevent recurrent thrombotic events.
RESULTS: A repeated angiography demonstrated a successful reperfusion after thrombolytic treatment.
CONCLUSIONS: The present case demonstrates that CYP2C19 allele carriers may lead to a suppressed antiplatelet effect of clopidogrel and a high risk of ST in the meantime. Therefore, CYP2C19 genetic testing seems to be able to identify patients-at-risk and optimal antiplatelet treatment should be considered in these fragile populations.

BACKGROUND: Among atrial fibrillation patients with high risk of bleeding, left atrial appendage occlusion has emerged as an alternative to long-term oral anticoagulation therapy for stroke prevention. Device-related thrombus remains a major concern because it may result in recurrent embolic events. To date, there is no consensus on the optimal method of treating device-related-thrombus.
METHODS: A 78-year-old man with atrial fibrillation had an episode of intracranial hemorrhage while taking warfarin. He subsequently underwent percutaneous placement of a 30-mm Watchman device to the left atrial appendage. He was prescribed dual anti-platelet therapy with aspirin and clopidogrel.
METHODS: Reassessment echocardiography 3 months later found device-related thrombus.
METHODS: The antithrombotic regimen was switched from dual antiplatelet therapy to apixaban.
RESULTS: Reassessment echocardiography 3 months later revealed complete resolution of the device-related thrombus. Apixaban was stopped. He had dual antiplatelet therapy for 6 more months followed by life-long aspirin. There was no bleeding complication since implantation of Watchman device.
CONCLUSIONS: We demonstrated successful treatment of device-related thrombus with a short course of apixaban with complete resolution of thrombus. Further randomized controlled trials are required to determine the choice and duration of drug therapy for device-related thrombus.