Administration, Oral ; Anticoagulants/adverse effects* ; Atrial Fibrillation/drug therapy* ; Humans ; Stroke ; Vascular Calcification/drug therapy* ; Warfarin

OBJECTIVETo evaluate the factors responsible for the insufficient application of oral anticoagulation (OAC) in Chinese patients with non-valvular atrial fibrillation.

METHODSThe research is a single center registration study in a tertiary referral hospital in Beijing. The general characteristics, history of atrial fibrillation, comorbidities and anticoagulation treatment were obtained from all patients.Factors affecting the oral Walfarin use were evaluated by univariable and multivariable regression analysis.

RESULTSOAC therapy with Walfarin was applied on Only 214(39.4%) out of 576 consecutive patients with non-valvular atrial fibrillation. The OAC rate was 30.3% among non-ablation patients. Patients with persistent atrial fibrillation, diabetes, chronic heart failure, history of ischemic stroke/TIA and higher CHA2DS2-VASc score were more likely prescribed with Walfarin. Multivariable regression analysis showed that persistent fibrillation, history of chronic heart failure, ischemic stroke/TIA and non-coronary heart disease predicted the treatment with Walfarin.

CONCLUSIONSOAC use is extremely low in Chinese patients with non-valvular atrial fibrillation. More efforts are warranted to improve OAC use in these patients.

Administration, Oral ; Aged ; Anticoagulants ; administration & dosage ; therapeutic use ; Atrial Fibrillation ; drug therapy ; Female ; Humans ; Male ; Middle Aged ; Regression Analysis ; Warfarin ; administration & dosage ; therapeutic use

BACKGROUNDNon-valvular atrial fibrillation is associated with an increased risk of ischemic stroke; however, the appropriate intensity of anticoagulation therapy for Chinese patients has not been determined. The purpose of this study was to compare the safety and the efficacy of standard-intensity warfarin therapy, low-intensity warfarin therapy, and aspirin therapy for the prevention of ischemic events in Chinese patients with non-valvular atrial fibrillation (NVAF).

METHODSA total of 786 patients from 75 Chinese hospitals were enrolled in this study and randomized into three therapy groups: standard-intensity warfarin (international normalized ratio (INR) 2.1 to 2.5) group, low-intensity warfarin (INR 1.6 to 2.0) group and aspirin (200 mg per day) group. All patients were evaluated by physicians at 1, 3, 6, 9, 12, 15, 18, 21 and 24 months after randomization to obtain a patient questionnaire, physical examination and related laboratory tests.

RESULTSThe annual event rates of ischemic stroke, transient ischemic attack (TIA) or systemic thromboembolism were 2.6%, 3.1% and 6.9% in the standard-intensity warfarin, low-intensity warfarin and aspirin groups, respectively (P = 0.027). Thromboembolic event rates in both warfarin groups were significantly lower than that in the aspirin group (P = 0.018, P = 0.044), and there was no significant difference between the two warfarin groups. Severe hemorrhagic events occurred in 15 patients, 7 (2.6%) in the standard-intensity warfarin group, 7 (2.4%) in the low-intensity warfarin group and 1 (0.4%) in the aspirin group. The severe hemorrhagic event rates in the warfarin groups were higher than that in the aspirin group, but the difference did not reach statistical significance (P = 0.101). The mild hemorrhagic and total hemorrhagic event rates in the warfarin groups (whether in the standard-intensity warfarin group or low-intensity warfarin group) were much higher than that in the aspirin group with the annual event rates of total hemorrhages of 10.2%, 7.6% and 2.2%, respectively, in the 3 groups (P = 0.001). Furthermore, there was no significant difference in all cause mortality among the three study groups.

CONCLUSIONIn Chinese patients with NVAF, the warfarin therapy (INR 1.6 - 2.5) for the prevention of thromboembolic events was superior to aspirin.

Aged ; Aged, 80 and over ; Anticoagulants ; administration & dosage ; therapeutic use ; Aspirin ; administration & dosage ; therapeutic use ; Atrial Fibrillation ; drug therapy ; Female ; Humans ; Male ; Middle Aged ; Warfarin ; administration & dosage ; therapeutic use

Anticoagulation therapy is effective in preventing primary and secondary thromboembolic events due to atrial fibrillation. Warfarin, which was approved by the United States in 1954, was the only long-term oral anticoagulation therapy till the approval of dabigatran in 2010, and of rivaroxaban and other direct factor Xa inhibitors from 2011, forming a group known as novel oral anticoagulants (NOAC). NOAC have fewer food and drug interactions compared to warfarin; hence, the patient will require fewer clinic visits. However, the short half-life of NOAC means that twice-a-day dosing is needed and there is higher risk of a prothrombotic state when doses are missed. Other disadvantages are the lack of long-term data on NOAC, their high cost and the current lack of locally available antidotes.
Administration, Oral ; Anticoagulants ; administration & dosage ; Atrial Fibrillation ; drug therapy ; Cardiology ; methods ; Dabigatran ; administration & dosage ; Family ; Humans ; Professional-Patient Relations ; Rivaroxaban ; administration & dosage ; Stroke ; prevention & control ; Thromboembolism ; prevention & control ; Warfarin ; administration & dosage

OBJECTIVETo investigate the clinical application of anticoagulation treatment with warfarin after prosthetic heart valve replacement and compare the effect and safety of different anticoagulant intensities.

METHODSA total of 845 Chinese patients receiving oral warfarin for anticoagulant treatment after prosthetic heart valve replacement in Guangdong General Hospital between 2000 and 2008 were enrolled in this survey. The general data, clinical data, medications, international normalized ratio (INR) and results of echocardiogram of these patients were followed up to observe the incidence of complication of thrombo-embolism and such adverse effect as hemorrhage.

RESULTSAll the patients were of Han nationality, and Cantonese accounted for 88.04%. The daily mean maintenance dose of warfarin was 2.92∓0.88 mg in these patients with a median INR of 2.09∓0.39. Of these patients, 44.62% received low-intensity anticoagulant treatment with warfarin with the INR maintained between 1.5 and 2.0, and 56.45% had standard anticoagulant intensity with the INR maintained between 2.0 and 3.0. The total incidence of thrombo-embolism was 4.14%. Severe hemorrhage occurred in 14 cases (1.66%), most frequently in the alimentary tract. The events of hemorrhage were correlated to the type of prosthetic heart valve replacement, occurring more frequently in patients with mechanical prosthetic heart valve replacement than in those with biological ones. No significant difference was found in the incidence of thrombo-embolism and server hemorrhage between the two groups receiving low and standard intensity therapy anticoagulant.

CONCLUSIONThe effect and safety of low-intensity anticoagulant treatment are comparable to that of standard intensity treatment in Chinese Han patients, and anticoagulation treatment with warfarin is effective and safe to maintain the INR between 1.8-3.0.

Adult ; Anticoagulants ; administration & dosage ; therapeutic use ; Female ; Heart Valve Prosthesis Implantation ; methods ; Humans ; Male ; Middle Aged ; Postoperative Period ; Warfarin ; administration & dosage ; therapeutic use

BACKGROUNDObstructive sleep apnea hypopnea syndrome (OSAHS) constitutes an independent factor for high warfarin dose for patients with pulmonary embolism (PE). The aim of this study was to investigate whether the 6-month anticoagulation treatment by warfarin is enough for patients with PE complicated by OSAHS.

METHODSWe investigated 97 PE patients, 32 of them had OSAHS and 65 non-OSAHS. Warfarin was administered for 6-month if no abnormal circumstances occurred. All patients were followed up for 18 months. Adverse events (AE) included death, major bleeding, hospitalization due to heart failure or pulmonary hypertension, and recurrence or aggravation of PE (including deep vein thrombosis). Recurrence rate of PE after warfarin cessation was compared between the two groups.

RESULTSOSAHS patients required a significantly higher dose of warfarin than their non-OSAHS counterparts (4.73 mg vs. 3.61 mg, P < 0.001). During warfarin treatment, no major bleeding and aggravation of PE occurred among OSAHS patients, and the rates of various AE were not significantly different between the OSAHS and non-OSAHS groups. PE recurrence was higher in OSAHS than non-OSAHS groups after withdrawal of warfarin (21.43% vs. 6.78%, P = 0.047). Compared with non-OSAHS patients, OSAHS group had lower international normalized ratio (INR) value but higher plasminogen on baseline and INR resumed to a relatively low level after warfarin discontinuation.

CONCLUSIONSOSAHS patients may present with hypercoagulation and relatively high-risk of recurrence of PE after cessation of 6-month warfarin treatment.

Anticoagulants ; administration & dosage ; therapeutic use ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Pulmonary Embolism ; drug therapy ; Sleep Apnea, Obstructive ; complications ; Warfarin ; administration & dosage ; therapeutic use

BACKGROUND: Oral anticoagulation with warfarin requires routine monitoring of prothrombin time to maintain the international normalized ratio (INR) within the appropriate therapeutic range. Coagu- Chek XS (Roche Diagnositic, Germany) is a portable coagulometer that measures the INR. We evaluated the precision and accuracy of CoaguCheck XS by comparing it with CA-1500 (Sysmex, Japan). METHODS: We analyzed the CV and the correlation of all INR results measured in 68 samples obtained from patients treated with warfarin and 10 samples from control subjects with no history of anticoagulant therapy with CoaguChek XS and CA-1500. We compared the turn-around time between two instruments and evaluated the differences between the results obtained with venous and capillary blood samples and those obtained with different lots of the test strip. We also evaluated the precision of the two instruments in 5 repeated tests with samples of normal and increased INR. RESULTS: Mean INR values of 5 repeated tests with the same samples were similar. The correlation of INR values between two instruments was excellent (r2=0.97, P=0.001), and the difference in the values between the two instruments was mostly within the 95% limit of agreement, but was shown to increase in direct proportion to INR values. The turn-around time of CoaguChek XS was shorter than that of CA-1500. The differences between venous and capillary blood and between different lots of the test trip were not significant (P>0.05). CONCLUSIONS: CoaguChek XS showed a good precision and correlation with CA-1500 with a very short turn-around time. This instrument should be clinically useful in monitoring INR of patients with oral anticoagulation.
Administration, Oral ; Anticoagulants/administration & dosage/pharmacology/*therapeutic use ; Drug Monitoring ; Humans ; International Normalized Ratio/*instrumentation ; Prothrombin Time/*instrumentation/methods ; Reproducibility of Results ; Self Care/instrumentation/methods ; Warfarin/administration & dosage/*therapeutic use

The present study was designed to determine the effects of puerarin pre-treatment on the pharmacokinetics of the oral anticoagulant agent warfarin and the antiplatelet agent clopidogrel in rats. In the treatment group, rats was gavaged with warfarin or clopidogrel after repeated treatment with puerarin at intraperitoneal doses of 20, 60, or 200 mg·kg(-1) for 7 days, while rats in the control group were administrated only with the same dose warfarin or clopidogrel. Plasma samples were obtained at the prescribed times and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The results showed that rats treated with puerarin at all the test doses of 20, 60 and 200 mg·kg(-1) were found to affect the pharmacokinetics of warfarin, but not clopidogrel, suggesting a potential herb-drug interaction between puerarin and warfarin.
Animals ; Anticoagulants ; pharmacokinetics ; Chromatography, Liquid ; Clopidogrel ; Drug Administration Schedule ; Herb-Drug Interactions ; Injections, Intraperitoneal ; Isoflavones ; administration & dosage ; pharmacology ; Male ; Platelet Aggregation Inhibitors ; pharmacokinetics ; Rats ; Rats, Wistar ; Tandem Mass Spectrometry ; Ticlopidine ; analogs & derivatives ; pharmacokinetics ; Vasodilator Agents ; administration & dosage ; pharmacology ; Warfarin ; pharmacokinetics

Acute myocardial infarction is a rarely reported complication of amphetamine abuse. We report here on a case of a 39-year-old man who presented with cardiac enzyme patterns, a clinical history and an ECG that were all compatible with acute ST elevation myocardial infarction. This was probably the result from self administration of intravenous amphetamine. The initial coronary angiogram (CAG) showed total occlusion of the distal right coronary artery (RCA) with a large thrombus. Because the RCA was tortuous and removal of thrombus was thought not to be easy, he was treated with thrombolytic therapy and intravenous heparin followed by oral warfarin. The follow-up CAGs at 2 weeks and 10 months later showed almost complete resolution of the coronary abnormalities. In this case, the early coronary angiography was thought to be helpful to determine the relative contribution of thrombus and spasm that were associated with amphetamine abuse.
Adult ; Amphetamine* ; Amphetamine-Related Disorders* ; Coronary Angiography ; Coronary Vessels ; Electrocardiography ; Follow-Up Studies ; Heparin ; Humans ; Myocardial Infarction* ; Self Administration ; Spasm ; Thrombolytic Therapy ; Thrombosis ; Warfarin

We report a case of intolerance to warfarin dosing due to impaired drug metabolism in a patient heterozygous for the CYP2C9*3 allele. A 30-year-old woman with an artificial cardiac pacemaker was taking warfarin to prevent thromboembolism. This patient had an extremely elevated international normalized ratio (INR) of prothrombin time (PT) following standard doses of warfarin and experienced difficulties during the induction of anticoagulation. Genotyping for CYP2C9 revealed that this patient was an intermediate metabolizer with genotype CYP2C9*1/*3. This case suggests the clinical usefulness of pharmacogenetic testing for individualized dosage adjustments of warfarin.
Warfarin/administration & dosage/*adverse effects/metabolism ; Prothrombin Time ; Polymorphism, Genetic ; Humans ; Female ; Dose-Response Relationship, Drug ; DNA Mutational Analysis ; Aryl Hydrocarbon Hydroxylases/*genetics/metabolism ; Anticoagulants/administration & dosage/*adverse effects/metabolism ; Adult