持续性与阵发性心房颤动导管射频消融肺静脉电隔离的抗凝治疗

目的探讨持续性心房颤动(简称房颤)患者导管射频消融肺静脉电隔离前后的抗凝治疗。方法2004年7月到2006年1月连续收治行射频消融治疗的持续性房颤64例,导管射频消融前需华法林抗凝治疗的阵发性房颤患者84例。所有患者术前华法林抗凝治疗使国际标准比率2.0~3.0维持至少3周。术中完成房间隔穿刺后,静脉给予肝素5000~8000U或75~100U/kg,以后每小时追加1000U或12U/kg。术后华法林抗凝治疗至少3个月。结果持续性房颤患者中1例术中心腔内超声发现消融时消融导管顶端血栓形成,术后无血栓栓塞表现,3例术后出现血栓栓塞表现,血栓栓塞发生率4.7%。阵发性房颤患者中未见血栓形成和栓塞表现。两组病例血栓形成和栓塞比较有显著差异(4/64vs0/84,P=0.033)。结论持续性房颤患者行导管射频消融肺静脉电隔离术易血栓形成和栓塞,应加强术中及术后肝素抗凝治疗。     

高龄心房颤动患者导管消融围术期不同抗凝方案的对比观察

目的：观察大于75岁的高龄心房颤动（房颤）患者围导管消融期三种抗凝方案的安全有效性。方法选取2011年7月到2013年12月行房颤导管消融治疗的高龄（＞75岁）房颤患者85例,术前常规华法林抗凝后经食管超声检查排除左心耳血栓,分为三组：传统抗凝组30例,消融前停用华法林,以低分子肝素桥接,术中用普通肝素抗凝,术后桥接低分子肝素联合华法林过渡到单用华法林;华法林持续使用组32例,围消融期正常使用华法林,术中使用普通肝素抗凝;新型口服抗凝药物组23例（达比加群组12例,利伐沙班组11例）,术前、术中同传统抗凝组,术后4h开始服用达比加群或利伐沙班抗凝。比较三组抗凝方案围术期到术后3个月的出血和栓塞事件发生率及其他并发症。结果传统抗凝组住院期间新发脑梗死1例,下肢血肿7例,假性动脉瘤1例,出院后3个月内内脏出血1例,小出血事件6例;华法林持续使用组院内下肢血肿4例,出院后3个月内小出血事件4例;新型口服抗凝药物院内下肢血肿2例,出院后无小出血事件。结论高龄房颤患者行导管消融治疗,总体安全有效。与传统抗凝治疗方案对比,持续使用华法林方案或采用新型口服抗凝药物能进一步降低出血并发症风险,并未增加血栓栓塞的风险。     

心房颤动导管消融患者围术期口服抗凝治疗概况

经导管射频消融术已成为有症状心房颤动(简称房颤)患者节律控制的有效治疗手段,传统抗凝方案为肝素桥接,目前不中断华法林及新型口服抗凝药也已在临床广泛应用。但房颤消融围术期血栓栓塞及出血事件的风险仍存在,围术期口服抗凝治疗策略尚无统一意见。     

磺达肝癸钠用于心房颤动导管消融术围术期的抗凝疗效观察

目的评估皮下注射磺达肝癸钠用于心房颤动（房颤）导管消融术围术期抗凝治疗的疗效及安全性、对华法林的起效时间有无影响及在局部注射部位瘀斑的形成是否优于依诺肝素及达肝素。方法将射频导管消融术治疗房颤的患者随机分为依诺肝素组24例,达肝素组20例及磺达肝癸钠组50人。消融术前皮下注射依诺肝素、达肝素或磺达肝癸钠5-10d,消融术后皮下注射至少3-5d（同时应用华法林治疗）,待国际标准化比率（INR）上升至1-8-2．0时停用。结果（1）三组患者基线特征的比较差异无统计学意义（P〉0．05）。（2）三组疗效性及安全性的比较：依诺肝素组、达肝素组、磺达肝癸钠组血栓栓塞事件发生率分别为0／24、0／20、1／50人,比较三组血栓栓塞率差异无统计学意义;三组均无大出血事件发生。（3）三组药物在华法林INR不同的达标时间例数上差异无统计学意义（P〉0．051。（4）三组患者注射部位瘀斑情况比较：用药7天时,磺达肝癸钠注射部位皮下瘀斑的发生率明显降低（磺达肝癸钠组、依诺肝素组、达肝素组无瘀斑患者所占比例分别为：0．66,0．21,0．15,P〈0．05）,瘀斑长径明显减小（磺达肝癸钠组、依诺肝素组、达肝素组瘀斑长径分别为：0．7,2．3,3．3cm,P〈0．05）,且优于依诺肝素及达肝素。结论与依诺肝素和达肝素组相比,磺达肝癸钠用于房颤射频导管消融术围术期抗凝治疗未增加严重出血及血栓栓塞,也不影响INR的达标时间,但可以减少注射部位皮下瘀斑的发生率和范围。     

高龄持续性心房纤颤患者不同剂量阿司匹林与华法林抗栓疗效及安全性比较

目的观察在持续性心房纤颤（房颤）的高龄患者中,不同剂量阿司匹林及华法林的疗效和安全性。方法选取年龄≥75岁的持续性房颤患者217例,分为4组,华法林高抗凝组『2．0〈国际标准化比率（international normalized ratio,INR）≤3．0154例,华法林低抗凝组（1．6≤INR≤2．0）53例,阿司匹林组（325mg／d）47例,阿司匹林组（200mg／d）63例,观察各组中血栓栓塞和出血事件的发生率。结果华法林高抗凝组与低抗凝组血栓栓塞发生率明显低于阿司匹林组（325mg／d）,差异有统计学意义（矿=6．487,P=O．011;矿=7．929,P=O．005;r=6．354,P=O．012;r=7．771,P=O．005）;华法林高抗凝组出血发生率明显高于低抗凝组和阿司匹林组（200mg／d）,差异有统计学意义（14.8％＇US．0m0,P〈0．05）;华法林高抗凝组与阿司匹林组（325mg／d）出血发生率比较,差异无统计学意义（P〉O．05）。结论对于年龄≥75岁的老年持续性房颤患者,低抗凝强度华法林（1．6≤INR≤2．0）安全有效,其疗效优于阿司匹林。     

围手术期不同抗凝策略对病窦综合征合并心房颤动患者起搏器植入术后囊袋相关并发症及血栓栓塞事件的影响

目的观察围手术期不同抗凝策略对病窦综合征(SSS)合并心房颤动(AF)患者起搏器植入术后囊袋相关并发症及血栓栓塞事件的影响。方法将84例应用华法林抗凝的SSS合并AF需要接受起搏器植入的患者分为3组。A组:围手术期不中断华法林;B组:停用华法林,低分子肝素桥接治疗;C组:停用华法林。观察术后1年内囊袋相关并发症及血栓栓塞事件的发生情况。结果 A组出现囊袋血肿2例;B组出现囊袋血肿3例,其中1例囊袋破溃并拔除起搏系统;C组囊袋血肿2例。A、B组均无血栓栓塞事件发生;C组围手术期出现急性脑梗塞2例。结论 SSS合并持续性AF卒中中高危患者起搏器植入不停用华法林未明显增加囊袋相关并发症,未出现明显血栓栓塞事件。     

心房颤动射频消融术中经验性抗凝方案评价

目的 观察心房颤动(房颤)射频导管消融术中经验性抗凝活化凝血时间(ACT)达标情况及短期术后血栓并发症发生情况.方法 顺序入选2011年我院行射频导管消融治疗的阵发性或持续性房颤患者87例,术中均依据经验肝素抗凝(即首次穿刺房间隔后予负荷量肝素100 U/kg,术中每小时追加1000 U),术中定时监测ACT,如ACT≥250 s即为抗凝达标,ACT≥300 s则抗凝效果较好.观察ACT达标情况.随访终点:术后1个月脑卒中及严重出血情况(颅内出血、穿刺口血肿、皮肤黏膜出血).结果 87例患者测定ACT总体达标率为74.1％,未达标25.9％.ACT全程达标患者共45例,达标率为51.7％.术中术后无血栓及出血事件发生.结论 虽然房颤消融术中经验性抗凝多数患者可以全程达标抗凝,但仍有部分患者部分时间ACT未达到抗凝标准,存在潜在血栓及出血不良事件发生风险,建议遵循指南进行术中ACT监测指导抗凝.大体重的阵发性房颤患者,术中经验性抗凝不易达标,需要加强抗凝,提高达标率.     

心房颤动消融术后应用达比加群酯和华法林抗凝疗效观察

目的研究达比加群酯在心房颤动(简称房颤)射频消融术后抗凝治疗的有效性及安全性。方法选择已行导管射频消融术治疗的房颤患者,按应用口服抗凝药物的不同分为华法林组和达比加群酯组。收集所有患者的年龄、性别、房颤类型、凝血及肝肾功能等基本指标。所有患者符合入选及排除标准,均于射频消融术后应用达比加群酯或华法林行抗凝治疗。对患者进行3个月随访,以血栓性终点与安全性终点为研究终点,对比两组患者的临床疗效和出血风险。结果华法林组133例,达比加群酯组98例。两组间性别、年龄、房颤类型、伴随疾病及吸烟史等无差异。与华法林组比较,达比加群酯组血栓栓塞事件发生率无差异(4.08%vs 4.51%,P0.05)。严重出血事件更低(1.02%vs 6.77%,P0.05)。达比加群酯组及华法林组均有少量出血事件发生,两组发生率无差异(31.63%vs 33.08,P0.05)。结论达比加群酯对房颤射频消融术后抗凝治疗的效果与华法林相当,但安全性更高。     

华法林、达比加群酯和低分子肝素对心房颤动射频导管消融术中活化凝血时间达标情况及潜在血栓形成风险的影响

目的：评价目前心房颤动（房颤）射频导管消融术中抗凝方案的有效性和不同抗凝药对术中凝血状态的影响。方法：筛选2015年12月至2017年3月于我院行房颤射频导管消融术的患者163例,其中158例术前接受有效抗凝治疗的患者均纳入研究。根据患者服用不同药物分为三组：华法林组86例、达比加群酯组51例和低分子肝素（LMWH）组21例。分析患者房间隔穿刺后首剂肝素后活化凝血时间（ACT）达标率（First-ACT达标率）、穿间隔后1 h ACT达标率（1 h-ACT达标率）;比较三组间基础ACT值、First-ACT达标率、1 h-ACT达标率、ACT首次达标耗时、术中肝素总量情况。结果：158例患者中基础ACT结果：华法林组最接近有效范围,且三组间比较差异有统计学意义（P<0.001）;与达比加群酯组及LMWH组比较,华法林组的First-ACT达标率及1 h-ACT达标率明显升高,而ACT首次达标耗时和术中肝素总量明显减低,差异均有统计学意义（P均<0.05）;达比加群酯组及LMWH组比较差异无统计学意义（P>0.05）。结论：目前临床上参考体重和ACT监测给予肝素的术中抗...     

高龄心房颤动患者导管消融治疗围术期抗凝方案的研究

目的 探讨高龄心房颤动(房颤)患者行导管消融治疗围术期有效而安全的抗凝方案.方法 选取射频消融治疗的高龄(＞75岁)房颤患者15例(高龄组),术前服用华法林;同期＜75岁射频消融治疗房颤患者15例(非高龄组),根据栓塞风险服用华法林或阿司匹林治疗.术中均用肝素抗凝;高龄组术后以低分子肝素过渡,第3天开始服用华法林,非高龄组术后从第1天开始华法林与低分子肝素重叠应用3d;院外两组服用华法林抗凝3个月.3个月后根据CHADS2评分服用阿司匹林或华法林治疗.门诊随访至少12个月,比较两组凝血酶原时间-国际标准化比值(PT-INR)、6个月内出血和栓塞事件发生率及术后3、6、12个月24 h动态心电图记录心律失常情况.结果 术前高龄组与非高龄组PT-INR值(1.58±0.32对1.37±0.44,P＞0.05),术后INR达标天数[(11.73±3.29)d对(9.71±3.63)d,P＞0.05];左心房内自发显影情况[3例(20.00％)对4例(26.67％),P＞0.05];出血并发症(0对6.67％,P=0.05)、栓塞事件发生率(6.67％对0,P=0.05)差异无统计学意义.两组间术后3、6、12个月心律失常复发情况差异无统计学意义.结论 高龄房颤患者行导管消融治疗术前需严格抗凝并排除心房血栓;术中抗凝与常规用药相同;术后延迟加用华法林治疗同样安全有效.     

The safety of low-molecular weight heparins for the prevention of thromboembolic events after cardioversion of atrial fibrillation

Transesophageal echocardiography (TEE) guided early cardioversion (CV) in conjunction with short-term anticoagulation has been shown to be safe, and an alternative to prolonged conventional anticoagulation therapy. Recently, low molecular weight heparins (LMWHs) have been used successfully as an alternative to standard heparin therapy obviating the need for hospitalization and APTT monitoring. The aim of this study was to determine the feasibility and safety of TEE guided early cardioversion in conjunction with short-term LMWH use in patients with nonvalvular atrial fibrillation (NVAF). The study group consisted of 172 consecutive patients with NVAF. Before TEE, 90 patients received LMWH (Dalteparin 2 x 5,000U) and 82 patients received standard heparin (UFH) (5,000U bolus followed by infusion to raise APTT to 1.5 times control). TEE was performed and the left atrium and left atrial appendage were examined thoroughly for the presence of thrombus. One patient from each group was excluded due to detection of a left atrial thrombus by TEE. Immediately after TEE, CV was attempted and warfarin was initiated. All patients received warfarin for one month after CV. In the LMWH group, 89 of 90 patients (98.9%) were successfully cardioverted. CV was successful in 97.5% of the patients in the UFH group. None of the patients experienced thromboembolic events during the four weeks after CV. TEE guided early CV in conjunction with short-term LMWH treatment is as safe as UFH for the prevention of thromboembolic events after CV.     

Periprocedural thromboprophylaxis in patients receiving chronic anticoagulation therapy

Patients receiving chronic anticoagulation therapy pose a clinical challenge when therapy needs to be interrupted for surgical or invasive procedures. Maintaining anticoagulation places them at risk for serious bleeding complications, whereas discontinuing anticoagulation puts them at risk of thromboembolic complications. Most patients can undergo dental procedures, cataract surgery, and diagnostic endoscopy without discontinuing anticoagulation. The main patient groups that may require a periprocedural alternative to oral anticoagulation (periprocedural thromboprophylaxis or bridging) include patients with prosthetic heart valves, atrial fibrillation, and hypercoagulable states and patients with chronic venous thrombosis who are undergoing surgery. Currently, there is little consensus on the appropriate perioperative treatment of patients on long-term warfarin therapy. There are an increasing number of studies that evaluate the benefits of periprocedural bridging with low-molecular-weight heparin (LMWH) in place of unfractionated heparin (UFH). An advantage of LMWH over UFH is that perioperative conversion from warfarin therapy with LMWH can be carried out in the outpatient setting, which is more convenient for patients and is cost effective. As with the use of UFH, there are reports of maternal thromboembolic complications with LMWHs in pregnant women with mechanical heart valves. This review brings together the available data on periprocedural bridging to assess the available options for patients on long-term warfarin therapy who are undergoing surgical procedures. It provides a rationale for using LMWHs while individualizing the risks versus benefits in a given patient population.     

Pulmonary vein antrum isolation for atrial fibrillation on therapeutic coumadin: special considerations

Pulmonary vein antrum isolation (PVAI) has emerged as an effective treatment for drug-refractory atrial fibrillation (AF). However, thromboembolic events are important complications of this approach. Management of anticoagulation is essential to prevent thromboembolic complications and avoid bleeding complications. The purpose of this review is to outline the general principles followed at our AF centers to address the important issue of pre-, peri-, and postprocedural anticoagulation strategies during PVAI of AF. We initiate warfarin therapy prior to the ablation procedure and continue it through the procedure. Prior work has demonstrated that continuation of therapeutic warfarin during the radiofrequency catheter ablation reduces the risk of periprocedural stroke/transient ischemic attack without increasing the risk of hemorrhagic events. In fact, a strategy that interrupts warfarin anticoagulation may increase the risk of stroke, even with bridging with enoxaparin. Data from our work have shown that minor bleeding was more frequent in the patients bridged with heparin or enoxaparin. There was no significant difference in incidence of major bleeding complications among the patients with a therapeutic level of international normalized ratio (INR) compared with patients for whom bridging therapy was used. Furthermore, the strategy of ablation during a therapeutic INR could be more economical compared with bridging therapy with enoxaparin. Continuation of therapeutic warfarin during ablation of AF may be the best strategy, especially in patients with nonparoxysmal AF, patients with higher thromboembolic risk scores, and patients who require extensive ablation during PVAI of AF.     

Low–Molecular-Weight-Heparins as Periprocedural Anticoagulation for Patients on Long-Term Warfarin Therapy: A Standardized Bridging Therapy Protocol

Background: Over 2 million patients in North America are on warfarin anticoagulation therapy for prevention of thromboembolism. Suspension of warfarin therapy is often required to prepare patients for invasive procedures or surgeries. To protect these patients against thromboembolism while they are off warfarin, shorter-acting parenteral agents such as low-molecular-weight heparins (LMWHs) are often used. We conducted a retrospective observational study of our anticoagulation clinic patients to assess the safety and efficacy of LMWHs using a standardized protocol for periprocedural anticoagulation therapy.Methods: We included 69 consecutive patients who required interruption of their long-term warfarin therapy between August 2001 and August 2002, and were deemed by the treating physician to be at high enough risk for perioperative thromboembolism to justify bridging anticoagulation. We used a standard bridging therapy protocol in our anticoagulation clinic. Sixty-six patients received enoxaparin and three patients received tinzaparin for a mean duration of 7.7 days postoperatively. Outcomes were assessed for 30 days post-procedure. Safety outcomes included major bleeding and minor bleeding. Efficacy outcomes included thromboembolic event or death.Results: There were two major bleeding events, one minor bleeding event, and no cases of thromboembolism. Twelve patients experienced some bruising around the injection site.Conclusions: LMWH administration using our standard outpatient bridging protocol for perioperative anticoagulation appears to be relatively safe and efficacious, offering an alternative to inpatient administration of intravenous unfractionated heparin (UFH). Our study provides additional evidence to the limited published observational data regarding the safety and efficacy of LMWH as bridging therapy in the perioperative and periprocedural setting. Large, multicenter, randomized controlled trials are necessary to fully assess the safety and efficacy of LMWH for perioperative anticoagulation.Abbreviated Abstract We conducted a retrospective observational study of 69 consecutive anticoagulation clinic patients on warfarin between August 2001 and August 2002, who were undergoing a procedure or surgery. The study was done to assess the safety and efficacy of an outpatient LMWH bridging protocol. Sixty-six patients received enoxaparin and three patients received tinzaparin for a mean duration of 3 days preoperatively and 7.7 days postoperatively. Outcomes were assessed for 30 days post-procedure. Safety outcomes included major bleeding and minor bleeding. Efficacy outcomes included thromboembolic event or death. There were two major bleeding events, one minor bleeding event, and no cases of thromboembolism. Twelve patients experienced some bruising around the injection site.     

Low molecular weight heparin versus unfractionated heparin in the colonoscopy peri-procedure period: a cost modeling study

OBJECTIVE: The aim of this study was to compare the economic outcomes of peri-procedure anticoagulation approaches for elective colonoscopy. METHODS: Decision analysis was used to model the economic outcomes of five peri-procedure anticoagulation options: outpatient low molecular weight heparin (LMWH), inpatient unfractionated heparin infusion (UFHi), continuous warfarin (with probability of a repeat procedure using LMWH or UFHi), and discontinuation of anticoagulation therapy. The model's base-case scenario assumed drug therapy options for high-risk patients were equally effective in preventing a thromboembolic event (0.1% risk), with a higher probability for the no anticoagulation strategy (0.4%); event costs were based on published data and adjusted to 1997 dollars. Drug costs reflected 1997 average wholesale price. Medical costs for other variables were estimated based on local hospital charges. Indirect costs were not considered. Risk probabilities and LMWH drug cost were tested in sensitivity analysis. RESULTS: In the base-case scenario, costs for the options evaluated were $1436/patient, $1792/patient, $1848/patient, $2629/patient, and $5196/patient for no anticoagulation, continuous warfarin/repeat LMWH, LMWH as outpatient, continuous warfarin/repeat UFHi, and UFHi as inpatient respectively ($1997). Discontinuing anticoagulation was the least costly approach but involved the greatest thromboembolic risk. The cost of continued warfarin anticoagulation/repeat LMWH was minimally less than the LMWH option, but assumes 25% of patients would require a second procedure. The traditional approach (UFHi) requires an extended hospitalization and is the most costly option. Varying risk category or LMWH cost in sensitivity analysis had a negligible impact on overall costs. CONCLUSION: Within the model's assumptions, LMWH offers a novel, convenient, and economical solution to the problem of peri-procedure anticoagulation for elective colonoscopy.     

Warfarin Is Not Needed in Low-Risk Patients Following Atrial Fibrillation Ablation Procedures

Background: The recently published HRS/EHRA/ECAS AF Ablation Consensus Statement recommended that warfarin should be used for at least 2 months following an AF ablation in all patients regardless of stroke risk factors. The objective of the study was to assess outcomes based upon anticoagulation practice after atrial fibrillation (AF) ablation to determine relative risk of a strategy of aspirin only in low-risk patients.
Methods: A total of 630 consecutive patients who underwent 934 ablation procedures using an open irrigated tip catheter for symptomatic AF were evaluated. Outcomes were compared between patients treated with warfarin (goal INR: 2–3) versus aspirin only (325 mg/day) in CHADS2 0–1 patients after ablation.
Results: Of the 690 patients, 123 (20%) were treated with aspirin and 507 (80%) with warfarin. Prevalences of the CHADS2 scores of patients on aspirin were (0: 40.7%, 1: 59.3%) and on warfarin (0: 13.6%, 1: 31.6%, ≥2: 54.8%), P < 0.0001. Patients in the warfarin group were older, had on average a lower ejection fraction, and had higher rates persistent/permanent AF, repeat ablations, hypertension, prior stroke/TIA, and diabetes. The 1-year survival free of AF for the total study population was 71.6%. There were no strokes/TIA in the aspirin group and 4 events (4 strokes, 0 TIAs) in the warfarin group. Two patients in the warfarin group died of fatal hemorrhage (1 intracranial, 1 gastrointestinal).
Conclusion: Select low-risk patients with a low CHADS2 (0–1) score who undergo left atrial ablation with an aggressive anticoagulation strategy with heparin and use of an open irrigated tip catheter with low CHADS2 scores can safely be discharged following their procedure on aspirin alone.     

The effect of excessive anticoagulation on mortality and morbidity in hospitalized patients with anticoagulant-related major hemorrhage

BACKGROUND: We aimed to determine the effect of excessive anticoagulation on morbidity and mortality in hospitalized patients with major anticoagulant-associated hemorrhage. METHODS: We prospectively identified 101 consecutive inpatients admitted to Brigham and Women's Hospital with major bleeding occurring during administration of warfarin sodium, unfractionated heparin (UFH), or low-molecular-weight heparin (LMWH). RESULTS: Fifty patients had excessive and 51 had nonexcessive anticoagulation. The overall mortality at 60 days was 26% (13/50) in the excessive group compared with 10% (5/51) in the nonexcessive group (P =.03). Excessive warfarin therapy was associated with an increased 60-day mortality (P =.049), in contrast to excessive anticoagulation with UFH or LMWH alone (P =.27) or UFH or LMWH as a "bridge" to warfarin therapy (P =.10). Multivariate regression identified excessive anticoagulation as an independent predictor of 60-day mortality (adjusted hazard ratio [HR], 4.17; 95% confidence interval [CI], 1.39-12.49; P =.01), along with intracranial hemorrhage (adjusted HR, 6.16; 95% CI, 1.75-21.67; P =.005) and active cancer (adjusted HR, 3.79; 95% CI, 1.13-12.70; P =.03). Excessive anticoagulation was also a significant predictor of the combined nonfatal end point of stroke, myocardial infarction, hypotension, critical anemia, and surgical or angiographic intervention at 30 days (HR, 2.17; 95% CI, 1.25-3.78; P =.006). CONCLUSION: In a cohort of patients with anticoagulation-associated hemorrhage, excessive anticoagulation contributed independently to increased morbidity and mortality.