观察华法林及阿司匹林分别对非瓣膜性心房颤动患者血栓栓塞的影响

目的观察华法林及阿司匹林对非瓣膜性心房颤动患者血栓栓塞事件的影响。方法80例非瓣膜性心房颤动患者分为华法林组及阿司匹林组,阿司匹林组每天服用阿司匹林100 mg,华法林组根据国际标准化比值(INR)调整华法林用量,随访时间为2 a。结果阿司匹林组死亡2例,1例为缺血性卒中,另1例为心力衰竭;华法林组1例为猝死。阿司匹林组发生栓塞事件共8例,出血并发症3例;华法林组发生栓塞事件共3例,出血并发症7例。结论华法林可明显降低非瓣膜性房颤患者血栓栓塞事件,但出血并发症稍增多,关键是要严密随访INR。     

某三甲医院心房颤动患者华法林规范化抗凝治疗现状调查分析

目的：了解心房颤动患者抗凝治疗现状,为心房颤动规范化抗凝治疗提供参考。方法：选取皖南医学院弋矶山医院2013年1月~2014年12月非瓣膜性心房颤动患者200例,采用CHA2DS2-VASc和HAS-BLED评分系统对纳入人群进行血栓危险分层和出血风险评估,并依据《2010年欧洲心脏病学会（ESC）心房颤动治疗指南》评价其规范化抗凝情况。结果：CHA2DS2-VASc和HAS-BLED评分分别为（2.73±2.10）分和（1.57±1.13）分。183例（91.5%）患者接受抗血栓治疗,使用华法林抗凝治疗的有74例（37%）,而血栓高危组125例患者中,接受华法林抗凝治疗50例（40%）。华法林抗凝治疗时间（5.78±4.73） d,累积给药剂量为（19.46±18.19） mg,55例（74.32%）患者出院前监测国际标准化比值（INR）,INR达标率为30.9%。结论：心房颤动以华法林抗凝治疗现状不容乐观,应采取有效的干预措施,提高心房颤动患者抗凝治疗规范化程度。     

住院心房颤动患者抗凝治疗现状分析

目的了解住院心房颤动（房颤）患者抗凝治疗中存在的问题,为更加安全的抗凝治疗提供依据。方法收集2013年1月1日至8月31日在江苏省苏北人民医院心内科住院治疗的所有非瓣膜性房颤患者病历资料进行回顾性分析。根据2010年《欧洲心脏病学会（ESC）心房颤动治疗指南》,采用CHADS2-VASc评分和HAS—BLED评分分别对患者进行血栓栓塞危险程度分层和出血风险评估。主要分析指标为接受不同房颤治疗方案（室率控制,节律控制）患者的血栓栓塞危险分层,出血风险评分,抗凝药物应用情况、国际标准化比值（INR）、出血合并症、血栓栓塞事件、患者用药依从性等。结果纳入分析的患者共134例,男性69例,女性67例;年龄20～91岁,平均（67±14）岁,CHA2DS2-VASe评分为0、1和≥2分者分别为11、23和100例,HAS—BELD评分≥3分者13例。接受室率控制和节律控制治疗者分别为85和49例。接受室率控制治疗的85例患者中CHA2DS2-VASe评分为0、1、≥2分者分别为1、12、72例。0分者1例使用阿司匹林。1分者12例中2例应用华法林,2例未行抗凝治疗（1例有禁忌证）,8例使用抗血小板药物（阿司匹林、氯吡格雷单用或二药联用）,其中2例单用氯吡格雷患者头颅CT检查均有多发性缺血灶。≥2分者72例中33例应用华法林,35例应用抗血小板药物,4例未行抗凝治疗。接受华法林抗凝治疗的患者出院时25例INR〈2．0,7例INR为2．0～3．0,1例INR〉3．0。接受节律控制治疗的49例患者CHA2DS2-VASe评分平均为（2．3±1．8）,HAS—BLED评分平均为（1．3±1．1）,其中25例应用华法林,出院时17例INR〈2．0,5例INR为2．0～3．0,2例INR〉3．0。1例患者未监测INR。134例患者中有15例（11．2％）出现脑梗死,其中8例（53．3％）应用华法林抗凝治疗,患者出院时INR均未达标。结论住院房颤患者抗凝治疗中存在的主要问题是采用华法林抗凝的比例较低,采用华法林治疗的部分患者抗凝强度不足。临床医师过分担心发生出血合并症是抗凝治疗不规范的主要原因。     

门诊应用华法林安全性的分析

目的探讨具有高卒中和栓塞风险的房颤患者门诊应用华法林的安全性。方法选择根据CAH2DS2VASc评分标准≥2分的32例高危房颤患者门诊应用华法林的回顾性分析。结果 32例房颤患者,1例出现牙龈出血,未有严重的出血和血栓栓塞事件。结论门诊应用华法林是安全有效的。     

不同抗凝强度华法林治疗非瓣膜性房颤的安全性及缺血性脑卒中发生的危险因素评估

目的 评估华法林不同抗凝强度治疗非瓣膜性房颤的安全性,以及缺血性脑卒中发生的危险因素。方法 纳入2012年1月—2013年12月收治的130例非瓣膜性房颤患者,根据华法林抗凝治疗的强度分为中强度组：华法林中等强度抗凝治疗,国际标准化比率(international normalized ratio,INR)控制在2.0＜INR≤3.0;低强度组：华法林低等强度抗凝,INR控制在1.6≤INR≤2.0,记录2组患者治疗和随访期间缺血性脑卒中、出血栓塞等不良反应的发生率,ROC曲线法分析INR诊断抗凝出血风险,多因素Logistic回归分析患者缺血性脑卒中的危险因素。结果 中强度组缺血性脑卒中、短暂性脑缺血发作和外周动脉栓塞发生率分别为6.70%,3.45%和1.72%,与低强度组的8.33%,4.17%和4.17%比较,无统计学差异(P>0.05);中强度组华法林用量(3.13±0.45)mg·d^-1,INR值2.61±0.32,出血发生率为24.14%;低强度组华法林用量(2.63±0.32)mg·d^-1,INR值 1.84±0.30,出血发生率为9.72%。采用INR诊断患者出血风险,ROC曲线下面积为0.858(95%CI：0.791~0.924),INR的cut-off值2.85,该值下判断出血敏感性为81.1%,特异性为67.2%;多因素logistic回归分析发现年龄、合并高血压、糖尿病、心力衰竭、脑卒中病史、INR、治疗窗内时间、卒中危险评分是非瓣膜性房颤患者缺血性脑卒中发生的独立危险因素(P<0.05)。结论 中、低强度华法林抗凝治疗均有较好的抗凝效果,非瓣膜性心房颤动患者伴有血栓栓塞危险因素应尽早应用华法林抗凝治疗,严密监测INR,INR值控制在1.6≤INR≤2.0,降低和避免出血并发症。     

华法林在低栓塞风险的心房颤动患者射频消融术后的应用

目的探讨消融治疗获得成功的持续性心房颤动患者,特别是栓塞风险低的个体,术后是否需要继续应用华法林抗凝治疗。方法入选低危栓塞风险的持续性心房颤动患者107例,射频消融术后随机分为华法林治疗组(55例)和非华法林组(52例),华法林治疗组患者术后服用华法林治疗至少3个月,抗凝治疗强度为INR2.0～3.0;非华法林组只服用阿司匹林,每日100mg。所有患者术后均进行随访,观察比较两组患者血栓栓塞和出血事件发生率的差异。结果所有患者均成功完成射频消融术,即刻成功率为100%。两组患者术中均未发生栓塞或出血事件。随访6～18个月,华法林组发生血栓栓塞事件2例(3.6%),非华法林组发生2例(3.7%),两组患者栓塞发生率无统计学差异,P>0.1。华法林组有3例(5.5%)出血事件,非华法林组无出血事件发生。结论对于射频消融取得成功的低危心房颤动患者,可以考虑不应用华法林抗凝,而只服用阿司匹林。     

新型口服抗凝药在伴有慢性肾脏疾病的非瓣膜性房颤患者中抗凝的研究进展

心房颤动是常见的心律失常疾病,持续48 h即可形成血栓,血栓脱落可导致动脉栓塞,其中90%是缺血性脑卒中,而慢性肾脏疾病可进一步增加房颤患者的卒中和出血风险。因此,在伴有慢性肾脏疾病的非瓣膜性房颤患者中的抗凝尤为重要。华法林用于肾功能不全的房颤患者虽可减少血栓栓塞的发生率,但是随着肾功能的恶化,华法林可增加出血的风险,且维持国际标准化比值（INR）在目标范围的时间非常困难。与华法林相比,新型口服抗凝药物能显著地降低卒中、颅内出血和死亡风险。然而新型口服抗凝药物在轻度、中度、重度,甚至血液透析房颤患者的应用仍存在争议。     

华法林对中国人心房颤动患者抗栓的安全性和有效性研究

本文通过回顾性分析心房颤动(房颤)患者的抗栓治疗,初步探讨中国人华法林国际标准化率(INR)的合理范围(目前公认的华法林抗凝标准为INR2 .0～3.0 ) ,文章调查4 35例房颤患者应用华法林抗凝及INR监测情况,分析出血和血栓栓塞事件的危险因素及与INR的关系。结果显示:华法林疗程时间中位数7个月,平均剂量为(2 .77土0 .83) mg。共发生出血事件31例(7.11% ) ,其中严重出血5例,轻微出血2 6例。多因素分析中INR≥3为预测出血的独立危险因素(OR=3.74 )。血栓栓塞事件37(17.4 7% )例,发生缺血性卒中或栓塞的危险随INR下降明显增加。本研究显…     

非瓣膜病房颤患者不同强度抗凝的疗效分析

目的分析非瓣膜病房颤患者不同强度抗凝的治疗效果。方法把我院2005年1月到2011年10月有效随访的236例非瓣膜病房颤患者,分成四组,第一组61例,采用阿司匹林(100mg/d)抗凝治疗;第二组54例,采用华法林(INR1.5-2.0)抗凝治疗;第三组63例,采用华法林(INR2.01-2.5)抗凝治疗;第四组58例,采用华法林(INR2.51-3.0)抗凝治疗。最后对四组患者在随访期内的血栓事件及出血事件进行比较。结果第一组患者的栓塞事件发生率为13.1%,高于其他各组,差异有显著性(P<0.05),第四组栓塞事件发生率为1.7%,低于其他组,差异有显著性(P<0.05)。第四组严重血事件发生率10.3%,高于其他各组(P<0.05),而第一组无严重出血事件发生,低于其他组,差异有显著性(P<0.05),但在总出血发生率上四组比较差异无显著性(P>0.05)。结论在非瓣膜病房颤患者抗凝治疗中,华法林预防栓塞疗效优于阿司匹林,随INR强度上升栓塞事件发生降低,但严重出血风险升高,INR1.5-2.5时有效且安全,推荐国人采用。     

非瓣膜性房颤患者规范化抗凝治疗的临床应用效果分析

目的研究低强度华法林治疗非瓣膜性房颤及其并发症的临床应用效果。方法选取收治于笔者所在医院的非瓣膜性房颤患者137例,随机分为低强度组及对照组。低强度组66例,对照组71例,所有患者均服用抗凝药华法林,低强度组使其INR值控制在1.5~2.0之间,对照组使其INR值控制在2.0~3.0之间。随访1年,观察用药期间脑栓塞及全身出血情况。结果低强度组治疗期间脑栓塞发生率为7.6%,对照组发生率为4.2%,略低于低强度组,但其差异无统计学意义(P>0.05);出血事件发生率两组相近,分别为4.5%和5.6%,差异无统计学意义(P>0.05)。结论低强度华法林和标准强度华法林对于非瓣膜性房颤的治疗差异不显著,对于非瓣膜性房颤的抗凝治疗要注重其个体差异性,理想的国际标准化比率(INR)值是要为每一例患者制定个性化指标。     

Secondary prevention of stroke in patients with nonvalvular atrial fibrillation: optimal intensity of anticoagulation

Nonvalvular atrial fibrillation (NVAF) is frequently seen in elderly people and has become a main cause of cardioembolic stroke. The efficacy of anticoagulation for primary prevention of stroke or transient ischaemic attacks (TIAs) in patients with NVAF has been established by prospective, randomised and controlled trials. Warfarin decreased the frequency of all strokes by 68% and the rate of the combined outcome of stroke, systemic embolism or death by 48%. Anticoagulation with warfarin using international normalised ratios (INRs) ranging from 2.0 to 3.0 is recommended for patients with NVAF, who have any of the risk factors identified by the Atrial Fibrillation Investigators (AFI) [previous stroke or TIA, history of hypertension, diabetes mellitus, advanced age (> or = 65 years old), congestive heart failure and coronary artery disease], the American College of Chest Physicians (ACCP) [increased age (> 75 years old), prior stroke, hypertension and heart failure], or the Stroke Prevention in Atrial Fibrillation (SPAF) investigators [women > 75 years old, prior stroke, systolic blood pressure > 160mm Hg, recent heart failure, and fractional shortening < 25% on echocardiography]. For the secondary prevention of stroke, the efficacy of adjusted-dose warfarin therapy has been demonstrated by 2 major randomised trials. SPAF III (INR 2.0 to 3.0) demonstrated a lower incidence of ischaemic stroke or systemic embolism (3.4 %/year) compared with low fixed-dose warfarin plus aspirin (acetylsalicylic acid) [11.9%]. The European Atrial Fibrillation Trial [EAFT] (INR 2.5 to 4.0) showed a lower incidence of all stroke (4.0 %/year) with adjusted-dose warfarin compared with placebo (12.0 %/year). The incidence of major bleeding in the adjusted-dose warfarin group in SPAF III and EAFT was 2.4 and 2.8 %/year, respectively. EAFT incidence rates for the occurrence of a first ischaemic or haemorrhagic complication analysed by INR range indicated that the rate was lowest at INRs of 2.0 to 2.9, and higher with INRs of 3.0 to 3.9. Therefore, the optimal intensity of anticoagulation for prevention of recurrent stroke seems to be an INR of between 2.0 and 3.0, as for primary prevention. Retrospective and prospective studies from Japan reported that in the elderly, haemorrhagic complications occur frequently with INRs above 2.6 and major ischaemic events cannot be prevented at INRs below 1.6. Therefore, an INR target between 1.6 and 2.6 may be an alternative for secondary prevention of stroke in elderly patients with NVAF who have a potential risk of bleeding, to avoid both major ischaemic and haemorrhagic events. Antiplatelets may be administered in patients who are unable to manage taking warfarin properly or who have a high risk of falling and subsequently sustaining a head injury, although the efficacy of antiplatelets for secondary prevention of stroke in NVAF has not yet been established.     

亚洲人群心房颤动华法林抗凝治疗预防脑栓塞的最佳INR值

国内外大量的流行病学调查均显示心房颤动（房颤）的发病率呈明显升高趋势,华法林目前仍是治疗非瓣膜性心房颤动及预防脑栓塞的主要药物。欧美指南建议75岁以下房颤患者对血栓栓塞事件的一级预防及二级预防国际标准化比值（INR）应控制在2．0～3．0,75岁以上房颤患者的出血风险增加,INR应控制在1．6—2．6。亚洲人群华法林肝脏代谢酶活性与西方人群存在明显差异,且相关临床研究显示中等抗凝强度仍能取得与高抗凝强度相同的临床结局,因此华法林剂量应调低。国内初步研究显示,华法林抗凝治疗将INR控制在1．7-2．5范围内是安全有效的,其预防非瓣膜性房颤患者发生血栓栓塞事件的疗效明显优于阿司匹林,但仍需进一步大量临床试验及循证医学提供证据。     

非瓣膜性房颤抗凝治疗临床观察

目的：探讨抗凝治疗非瓣膜性房颤（NVAF）的临床效果及药物选择。方法回顾性分析本院近5年内科住院治疗的NVAF患者96例,随机分为华法令组32例,予华法令1.25~5 mg/d,维持国际标准化比值（INR）2.0~3.0;通心络胶囊联合阿司匹林组32例,予通心络胶囊0.78 g,3次/d,阿司匹林片100 mg/d;阿司匹林组32例,予阿司匹林片100 mg/d。观察和比较三组患者脑栓塞及出血等并发症发生率,随访2年。结果脑栓塞年发病率华法令组（3.33%）与通心络胶囊联合阿司匹林组（5.0%）比较差异无统计学意义（P〉0.05）;阿司匹林组（17.2%）与通心络胶囊联合阿司匹林组比较差异有统计学意义（P〈0.05）;华法令组与阿司匹林组比较差异有统计学意义（P〈0.01）。华法令组有1例脑出血;通心络胶囊联合阿司匹林组有4例出现上腹痛、恶心,1例出现牙龈肿痛;阿司匹林组有3例出现上腹痛、恶心。结论通心络胶囊联合阿司匹林预防NVAF患者脑栓塞的效果和华法令比较差异无统计学意义,优于单用阿司匹林,无严重不良反应发生,且不需要监测凝血酶原时间（PT）和INR。不愿意接受华法令治疗的NVAF患者,给予通心络胶囊联合阿司匹林预防脑栓塞并发症是安全有效的。     

Thromboembolic consequences of subtherapeutic anticoagulation in patients stabilized on warfarin therapy: the low INR study

STUDY OBJECTIVE: To quantify the absolute risk of thromboembolism associated with a significant subtherapeutic international normalized ratio (INR) in patients with previously stable anticoagulation while receiving warfarin. DESIGN: Retrospective, matched cohort analysis. SETTING: Centralized anticoagulation service in an integrated health care delivery system. PATIENTS: A total of 2597 adult patients receiving warfarin from January 1998-December 2005; 1080 patients were in the low INR cohort and were matched to 1517 patients in the therapeutic INR cohort based on index INR date, indication for warfarin, and age. MEASUREMENTS AND MAIN RESULTS: Stable, therapeutic anticoagulation was defined as two INR values, measured at least 2 weeks apart, within or above the therapeutic range. The low INR cohort included patients with a third INR value of 0.5 or more units below their therapeutic range. The therapeutic INR cohort included patients with a third therapeutic INR value and no INR value 0.2 or more units below their target INR range in the ensuing 90 days. The primary outcome was anticoagulation-related thromboembolism during the 90 days after the index INR. Secondary outcomes were times to the first occurrence of anticoagulation-related complications (bleeding, thromboembolism, or death) in the 90 days after the index INR. Four thromboembolic events (0.4%) occurred in the low INR cohort and one event (0.1%) in the therapeutic INR cohort (p=0.214). The differences in the proportions of thromboembolism, bleeding, or death were not significant between the cohorts (p>0.05). No significant differences were noted in the hazard of thromboembolism, bleeding, or death between the cohorts (p>0.05). CONCLUSION: Patients with stable INRs while receiving warfarin who experience a significant subtherapeutic INR value have a low risk of thromboembolism in the ensuing 90 days. The risk was similar to that observed in a matched control population in whom therapeutic anticoagulation was maintained. These findings do not support the practice of anticoagulant bridge therapy for patients stabilized on warfarin therapy to reduce their risk for thromboembolism during isolated periods of subtherapeutic anticoagulation.     

Stroke risk reduction outweighed bleeding risk increase from vitamin K antagonist treatment among nonvalvular atrial fibrillation patients with high stroke risk and low bleeding risk

Objective: Warfarin is widely used for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). We compared the rates of stroke and major bleeding in NVAF patients with a high stroke risk and low bleeding risk profile during warfarin treated (W+) and warfarin untreated (W?) periods.

Method: Insurance claims from six commercial, Medicaid or Medicare databases were analyzed from 2000 to 2014. NVAF patients treated with warfarin, with a CHADS₂/CHA₂DS₂-VASc score ≥2, and an ATRIA score ≤3 at baseline were identified. Incidence rate ratios (IRRs) of stroke and major bleeding were calculated for W?+?versus W? episodes of person-time, as well as for first 30 days versus beyond 30 days of W?+?episodes.

Results: Among 316,145 patients, anticoagulant prophylaxis with warfarin significantly reduced stroke risk, with IRRs ranging from 0.48 (95% CI: 0.46–0.51) to 0.80 (95% CI: 0.70–0.91), and increased major bleeding risk, with IRRs ranging from 1.13 (95% CI: 1.10–1.15) to 1.95 (95% CI: 1.10–3.45). Stroke and major bleeding rates were higher during the first 30 days of W?+?than beyond.

Conclusion: In NVAF patients at high risk for stroke and low risk for bleeding, our data confirm the effectiveness of anticoagulation for stroke prevention. The decrease in stroke risk of anticoagulation may outweigh the risk of major bleeding events, particularly among elderly patients. Potential risks of warfarin during initiation warrant attention, especially among patients who stop and start therapy repeatedly.     

不同华法林抗凝治疗强度治疗冠心病并非瓣膜性房颤的效果

目的 探讨不同华法林抗凝治疗强度治疗冠心病并非瓣膜性房颤(NVAF)的效果.方法 238例冠心病并非瓣膜性房颤患者,根据随机数字表法分为对照组(59例)、低强度组(58例)、标准强度组(65例)、高强度组(56例).对照组采取阿司匹林抗凝治疗,低强度组采用国际标准化比值(INR)1.5～2.0华法林进行抗凝治疗,标准强...     

农村偏远地区心脏瓣膜置换术后的抗凝治疗

目的观察农村偏远地区心脏瓣膜置换术后的抗凝治疗,为农村偏远地区换瓣患者提供一种简单可行的抗凝方法。方法近3年30名农村偏远地区换瓣患者（观察组）与31名城镇换瓣患者（对照组）术后抗凝,口服华法林片,剂量根据凝血酶原时间（PT）、国际标准化比（INR）调整,观察组的抗凝监测间隔时间较对照组延长,抗凝强度一样。同时进行抗凝的宣教。结果 61例患者中测得INR共742次,其中观察组329次,对照组413次,INR控制在1.5-2.0的596次。住院期间两组患者无严重出血及栓塞并发症,出院后观察组1例1月后出现感染性心内膜炎死亡,2例牙龈出血,4例月经过多。对照组2例牙龈出血,3例月经过多。结论采用INR 1.5-2.0抗凝治疗强度是安全可靠的,通过加强抗凝的宣教,适当延长检测间隔时间的方法并不影响换瓣术后中短期抗凝效果。     

Use of oral anticoagulants in older patients

Recently published American and British guidelines have comprehensively reviewed the indications for long term anticoagulation. The best evidence currently available supports the use of long term oral anticoagulants in patients with nonvalvular atrial fibrillation (NVAF), venous thromboembolic disease, ischaemic heart disease, mural thrombi, and mechanical heart valves. Selected patients with valvular heart disease, cerebral vascular disease, and peripheral arterial disease may also benefit from the use of these drugs. When no specific contraindications are present, elderly patients with either paroxysmal or persistent NVAF should be considered candidates for treatment with anticoagulants. Pooled analyses of the results from 9 randomised trials demonstrate that warfarin significantly reduces the risk of ischaemic stroke in patients with NVAF, particularly those in a 'high risk' category defined by the presence of additional clinical or echocardiographic risk factors. Long term anticoagulation does not appear to be justified in patients with NVAF considered to be at 'low risk' for stroke. Because the prevalence of NVAF and most other cardiovascular conditions increases with advancing age, many elderly patients will be candidates for thromboprophylaxis. The potential benefit of long term anticoagulation must be carefully weighed against the risk of serious haemorrhage in such patients. Bleeding complications with anticoagulant drugs appear to occur more frequently in older patients than in younger individuals. Advanced age (>75 years), intensity of anticoagulation [International Normalised Ratio (INR) >4.0], history of cerebral vascular disease (recent or remote), and concomitant use of drugs that interfere with haemostasis [aspirin (acetylsalicylic acid) or nonsteroidal anti-inflammatory drugs] are among the most important variables in determining an individual's risk for major bleeding with anticoagulants. Older patients often display increased sensitivity to the effects of warfarin, both in the early induction phase and during the long term maintenance phase of therapy. Conditions such as congestive heart failure, malignancy, malnutrition, diarrhoea and unsuspected vitamin K deficiency, enhance the prothrombin time response. The decision to interrupt anticoagulant therapy before elective surgery in elderly patients should evaluate the thrombotic risk of such a manoeuvre versus the risk of bleeding if anticoagulants are continued. In non-surgical patients, excessively elevated INRs without associated haemorrhage can usually be managed by simply witholding one or several doses of warfarin. If more rapid reversal is needed, small doses of phytomenadione (vitamin K1) can be administered safely without overcorrection or the development of vitamin K-induced warfarin resistance.     

Guidelines for stroke prevention in patients with atrial fibrillation

Atrial fibrillation (AF) is a major independent risk factor for stroke. AF is most commonly associated with nonvalvular cardiovascular disease and is especially frequent among the elderly. The annual risk for stroke in patients with AF is approximately 5% with a wide range depending on the presence of additional risk factors. For patients who cannot successfully be converted and maintained in normal sinus rhythm (NSR), antithrombotic therapy is an effective method for preventing stroke. The 2 drugs which are indicated for stroke prophylaxis in patients with AF are warfarin and aspirin. For primary prevention, warfarin reduces the risk of stroke approximately 68%. Aspirin therapy is less effective, resulting in a 20 to 30% risk reduction. Combination therapy with aspirin and low intensity warfarin adjusted to an International Normalised Ratio (INR) of 1.2 to 1.5 has not been shown to be superior to standard intensity warfarin with a target INR of 2.0 to 3.0. In patients with AF and a prior history of stroke or transient ischaemic attack (TIA), the absolute risk reduction with warfarin is even greater because of the high risk of stroke in this population. In contrast, aspirin has not been shown to significantly reduce the risk of stroke in patients with AF when used for secondary prevention. When appropriately managed, warfarin is associated with a low risk of major bleeding. In controlled trials of highly selected patients, the annual rate of intracranial haemorrhage (ICH) with warfarin was approximately 0.3%. Studies have shown that specialty anticoagulation clinics can achieve similar low rates of major bleeding. However, these results cannot be extrapolated to the general population. Factors which have been identified as predictors of bleeding include advanced age, number of medications and most importantly, the intensity of anticoagulation. INR values above 4.0 have been associated with an increased risk of major bleeding while values below 2.0 have been associated with thrombosis. Slow careful dosage titration, regular laboratory monitoring and patient education can substantially reduce the risk of complications. In patients with AF, antithrombotic therapy has been shown to be cost effective. For high risk patients, warfarin is the most cost-effective therapy, provided the risks for bleeding are minimised. In contrast, aspirin is the most cost-effective agent for low risk patients. Current practice guidelines for stroke prophylaxis recommend warfarin (target INR 2.5: range 2.0 to 3.0) for AF patients at high risk for stroke including those over 75 years of age or younger patients with additional risk factors. Aspirin should be reserved for low risk patients or those unable to take warfarin. Although these recommendations are strongly supported by the clinical trial evidence, studies show that many patients are not receiving appropriate antithrombotic therapy. In particular, warfarin is underutilised in high risk elderly patients. Additional studies are needed to identify barriers that prevent implementation of the clinical trial findings into clinical practice.