Atrial fibrillation and stroke: Four treatment controversies

Opinion statement Atrial fibrillation is an important cause of disabling ischemic stroke, and adjusteddose warfarin is highly effective for prevention and remains the therapy of choice for high-risk patients. Ximelagatran, a novel oral anticoagulant, is clinically equivalent to warfarin for preventing stroke in patients with atrial fibrillation, but concerns about potential hepatic toxicity have precluded US Food and Drug Administration approval. Many patients with low-risk atrial fibrillation do not benefit substantially from anticoagulation, and these patients can be reliably identified using the CHADS2 stroke risk stratification scheme. A target International Normalized Ratio (INR) range of 2 to 3 is usually recommended for anticoagulation of patients with atrial fibrillation, but a lower INR target (2, range 1.6–2.5) may be a reasonable benefit/risk trade-off for primary prevention in those aged older than 75 years. Adding aspirin to adjusted-dose anticoagulation increases bleeding (including central nervous system bleeding), is of uncertain value, and should only be done after careful consideration and with vigorous efforts to control blood pressure.     

Therapeutic aspects of cerebral ischemia

ACUTE STROKE: At the acute stage of cerebral ischemia, the treatment consists of:--general non-specific rules, such as treating a vital emergency, keeping biological parameters within normal limits and preventing complications;--admission in a stroke unit, to decrease mortality without increasing dependence or recurrence risks;--intravenous administration of rt-PA within 3 hours of stroke onset in eligible patients;--in patients who are not eligible for rt-PA, aspirin (160 to 300 mg) to reduce early recurrence and death, even in atrial fibrillation;--decompressive surgery in patients with raised intracranial pressure. SECONDARY PROPHYLAXIS: Secondary prevention consists of:--treatment of risk factors for stroke;--aspirin (75 to 325 mg), or clopidogrel, or the association aspirin-dipyridamole in high-risk subjects without cardiopathy, or warfarin in patients with high-risk cardiopathies;--carotid surgery in patients selected by clinical and imaging criteria.     

Thromboembolic complications after mitral valve replacement with Hancock xenograft

Case histories of 140 patients who had mitral valve replacement with the Hancock xenograft were reviewed according to the incidence of thromboembolic complications. There were 16 patients with preoperative and/or postoperative low-output syndrome (Group A.) Eight of these patients died, and six had autopsies which showed major thrombi on the heterograft valve. In 126 long-term survivors (followed 1 to 33 months) nine thromboembolic events occurred (thromboembolic incidence 5.3 percent per patient-year). All patients with emboli were in atrial fibrillation. Additional predisposing factors included a history of systemic emboli and the presence of atrial clots at the time of surgery. The majority (7/9) of emboli occurred during the first 3 postoperative months. Two emboli occurred immediately following the operation (before oral anticoagulation therapy could have been begun). Five occurred in patients who were not on anticoagulation (Group B) and two occurred under warfarin treatment (Group C). There was no thromboembolic event in patients taking aspirin (Group D). It is concluded that hemodynamically stable patients have a decreased risk of thromboembolism and do not require anticoagulation. Patients with atrial fibrillation have an increased thromboembolic risk and should be on a regimen of warfarin for 3 months postoperatively and then on aspirin therapy.     

Underutilization of aspirin in hemodialysis patients for primary and secondary prevention of cardiovascular disease

BACKGROUND: Patients on hemodialysis are at high risk for cardiovascular disease (CVD). Aspirin is an established therapy for primary and secondary prevention of CVD that may be underutilized in hemodialysis patients. To better understand the use of aspirin in hemodialysis patients, we examined the experience of an urban hemodialysis center. Guidelines for use as well as associated risks and benefits are reviewed. METHODS: Medical records for patients receiving hemodialysis treatment at our center (New York City, USA) in May 2004 were reviewed for aspirin use, presence of CVD, and potential contraindications to aspirin therapy. CVD was defined as a history of coronary artery disease, ischemic stroke, transient ischemic attack, or peripheral vascular disease. Potential contraindications to aspirin therapy included history of clinically significant bleeding or increased risk of bleeding, aspirin allergy and routine treatment with other anticoagulants. RESULTS: 176 patients were eligible for the study and 172 (98%) were included. Although 74 patients had a history of CVD, only 38 (51 %) of these were treated with aspirin. Among patients with a history of CVD who were not treated with aspirin, 19 (53%) had no identifiable contraindications to aspirin therapy for secondary prevention of CVD. Ninetyeight patients had no history of CVD, and 18 (18%) of these were treated with aspirin. Of patients without a history of CVD who were not treated with aspirin, 57 (71%) had no identifiable contraindications to aspirin therapy for primary prevention of CVD. CONCLUSIONS: Aspirin is underutilized in hemodialysis patients for the primary and secondary prevention of CVD. Given the high risk of CVD in hemodialysis patients, therapy with aspirin may be of significant benefit and prospective studies of aspirin therapy are needed.     

Prevention of atrial fibrillation after cardiac surgery

Atrial fibrillation is the most common arrhythmia occurring after heart surgery. Its prevalence after coronary artery bypass surgery is 17-33%. Atrial fibrillation requires additional treatment, lengthens hospitalization and increases the overall expenses of cardiac surgery. Atrial fibrillation can cause hemodynamic problems, predispose to congestive heart failure and increase the risk of stroke. Beta-blockers have been shown to effectively prevent atrial fibrillation, and beta-blockers should be a part of the medication of every patient undergoing cardiac surgery, if there are no contraindications. Amiodarone therapy can also be considered for especially high-risk patients.     

Prevention of thromboembolism using aspirin after mitral valve replacement with porcine bioprosthesis

The thromboembolic rate of 768 patients who were treated only with aspirin after mitral valve replacement or mitral plus aortic valve replacement with porcine bioprostheses was evaluated. We analyzed the thromboembolic rate for the whole series and for subgroups of patients categorized by atrial fibrillation, giant left atrium, left atrial thrombosis, and dosage of aspirin (1 gm daily or 0.5 gm every 48 hours). The total embolic rate was 1.4% (11/768). No patient in sinus rhythm had an embolic event. The embolic rate for patients in atrial fibrillation was 1.9% (11/583). There were no embolic events in 31 patients with a giant atrium. An embolic event occurred in 1 of 42 patients with atrial thrombosis (2.4%). Patients treated with 1 gm of aspirin daily had a 3% embolic rate (9/295) while the incidence was 0.4% (2/473) in those treated with 0.5 gm every 48 hours (p less than 0.01). Administration of aspirin after mitral valve replacement with a bioprosthesis is a very effective treatment for prevention of thromboembolism. In our experience, this treatment provides protection equal to or better than that offered by oral anticoagulants for patients in atrial fibrillation as well as for patients with a giant atrium or atrial thrombosis at operation. The dosage and timing of aspirin administration may markedly affect the result of this type of treatment. Oral anticoagulation with coumarin derivatives may not be appropriate after mitral valve replacement with a bioprosthesis, and platelet antiaggregates should be used for this purpose in the future.     

Does preoperative atrial fibrillation reduce survival after coronary artery bypass grafting?

BACKGROUND: Preoperative atrial fibrillation has been identified as a risk factor for reduced long-term survival after coronary artery bypass grafting. This study sought to determine whether atrial fibrillation is merely a marker for high-risk patients or an independent risk factor for time-related mortality. METHODS: From 1972 to 2000, 46,984 patients underwent primary isolated coronary artery bypass grafting; 451 (0.96% prevalence) had electrocardiogram-documented preoperative atrial fibrillation (n = 411) or flutter (n = 40). Characteristics of patients with and without atrial fibrillation were contrasted by multivariable logistic regression to form a propensity score. With this, comparable groups with and without atrial fibrillation were formed by pairwise propensity-matching to assess survival. RESULTS: Patients with preoperative atrial fibrillation were older (67 +/- 9.0 versus 59 +/- 9.8 years, p < 0.0001), had more left ventricular dysfunction (66% versus 52%, p < 0.0001) and hypertension (73% versus 59%, p < 0.0001), but less severe angina (39% moderate or severe versus 49%, p < 0.0001). Many of these factors are themselves predictors of increased time-related mortality. In propensity-matched patients, survival at 30 days and at 5 and 10 years for patients with versus without atrial fibrillation was 97% versus 99%, 68% versus 85%, and 42% versus 66%, respectively, a survival difference at 10 years of 24%. Median survival in patients with atrial fibrillation was 8.7 years versus 14 years for those without it. CONCLUSIONS: Atrial fibrillation in patients undergoing coronary artery bypass grafting is a marker for high-risk patients; in addition, atrial fibrillation itself substantially reduces long-term survival. Thus, if patients in atrial fibrillation require surgical revascularization, it is appropriate to consider performing a concomitant surgical ablation procedure.     

Neurosurgical complications of direct thrombin inhibitors--catastrophic hemorrhage after mild traumatic brain injury in a patient receiving dabigatran

Dabigatran etexilate is an oral anticoagulant that acts as a direct, competitive thrombin inhibitor. Large randomized clinical trials have shown higher doses of dabigatran (150 mg taken twice daily) to be superior to warfarin in terms of stroke and systemic embolism rates in patients with nonvalvular atrial fibrillation. As a result, in 2010 the US FDA approved the use of dabigatran for the prevention of stroke and systemic embolism in patients with atrial fibrillation. Dabigatran is especially attractive in the outpatient setting because patients do not require routine monitoring with prothrombin times or international normalized ratios. To date, no effective reversal agent for dabigatran in the event of catastrophic hemorrhage has been identified. The authors report a case of an elderly patient, being treated with dabigatran for atrial fibrillation, who presented with a rapidly expanding intracranial hemorrhage after a ground-level fall. This case highlights an impending neurosurgical quandary of complications secondary to this new anticoagulation agent and suggests potential options for management.     

术后房颤危险因素的研究进展

术后房颤是一种常见的术后并发症,虽有一定自限性,但是会给患者带来严重的危害。术后房颤可能使患者继发心血管疾病、急性肾损伤、脑卒中,甚至死亡,增加患者医疗负担。术后房颤的早期预防在疾病发展环节中十分重要。本文收集了近年来关于术后房颤的研究文献,以详细阐述术后房颤危险因素的最新研究进展,为早期识别术后房颤高危患者提供理论支持,并通过分析围术期药物对术后房颤的影响,为围术期早期预防术后房颤提供参考。     

The effect of insulin cardioplegia on atrial fibrillation after high-risk coronary bypass surgery: a double-blinded, randomized, controlled trial

Atrial fibrillation after coronary bypass (CABG) surgery is an important cause of morbidity and increased resource utilization. Insulin-enhanced cardioplegia may reduce postoperative arrhythmias by improving aerobic myocardial metabolism and mitigating the deleterious effects of ischemia. We performed a double-blinded, randomized, controlled clinical trial to determine if insulin-enhanced cardioplegia decreases the risk of post-CABG atrial fibrillation in a high-risk patient population. We randomized 501 patients undergoing urgent CABG to receive insulin-enhanced (Humulin R 10 IU/L, Insulin group, n = 243) or standard (Control group, n = 258) blood cardioplegia during cardiopulmonary bypass. Patients were monitored by using continuous electrocardiography for a minimum of 3 days postoperatively. All standard cardiac medications, including beta-adrenergic blockers, were continued postoperatively. Insulin-enhanced cardioplegia did not result in a significant reduction in postoperative atrial fibrillation. Furthermore, we failed to detect a difference in the incidence of conduction defects, ventricular tachycardia, or pacemaker requirements between insulin and placebo patients. Atrial fibrillation was the most common arrhythmia, occurring in 31% of all patients. Independent predictors of atrial fibrillation were elderly age, preoperative atrial fibrillation, and renal insufficiency. Right bundle branch block was the most common conduction abnormality. Predictors of right bundle branch block were elderly age, female sex, and circumflex coronary artery disease. The incidence of postoperative ventricular tachycardia, left bundle branch block, and permanent pacemaker requirement was small. We conclude that insulin-enhanced cardioplegia does not reduce the incidence of postoperative atrial fibrillation in high-risk CABG patients. IMPLICATIONS: We conducted a double-blinded, randomized, placebo-controlled trial of insulin-enhanced cardioplegia in 501 patients undergoing urgent coronary bypass surgery. Insulin did not decrease the incidence of postoperative atrial fibrillation when compared with placebo. We also failed to demonstrate a difference in the incidence of other postoperative arrhythmias between the two groups of patients.     

Aspirin or Coumadin as the Drug of Choice for Valve Replacement with Porcine Bioprosthesis

Eight hundred twenty-four patients who had cardiac valve replacement with a porcine bioprosthesis were given either Coumadin (sodium warfarin) or aspirin. No patient in sinus rhythm no matter what valve or valves were replaced had thromboembolism whether treated with Coumadin (124 patients) or aspirin (260 patients). One hundred fifty-one patients who had mitral valve replacement, were in atrial fibrillation, and were treated with Coumadin had seven embolic events (4.6%), while 135 similar patients treated with aspirin had five embolic events (3.7%). Fifty-one patients who had double-valve replacement, were in atrial fibrillation, and were treated with Coumadin had three embolic episodes (5.9%), while 86 similar patients treated with aspirin had three embolic events (3.5%).No statistical difference was found in the incidence of thromboembolism between similar groups of patients whether treated with Coumadin or aspirin (p > 0.05). Hemorrhagic complications were higher and reached statistical significance (p < 0.001) for the group treated with Coumadin. This study shows that aspirin prevents thromboembolic complications as well as Coumadin in patients having cardiac valve replacement with a bioprosthesis, and results in a lower rate of complications.     

New onset postoperative atrial fibrillation and early anticoagulation after cardiac surgery

Objectives. New onset postoperative atrial fibrillation (POAF) after cardiac surgery is associated with increased risk for thromboembolic complications. Compliance with anticoagulation treatment is prerequisite for successful outcome after POAF. We hypothesized that a disciplined anticoagulation protocol initiated instantly after POAF secures a long-term outcome. Design. A total of 519 consecutive patients undergoing cardiac surgery were retrospectively analyzed. Patients received anticoagulation using warfarin whenever POAF lasted longer than five min. Postoperative outcome including mortality, myocardial infarction and stroke were compared with patients on sinus rhythm (non-POAF). Results. Mean age of the study cohort was 64.3?±?9.0 years and median follow-up time was 76 months. There were 177 (34%) POAF and 342 (66%) non-POAF patients. At discharge, 144 (81%) POAF patients complied with warfarin, while 82 (24%) non-POAF patients received warfarin for non-rhythm causes (p?p?=?.03). After adjustment for comorbidities, major adverse clinical events (MACE)- including a combination of late cardiovascular mortality, myocardial infarction, stroke and late atrial fibrillation- was independently associated with POAF (OR 2.73, 95%CI 1.69-4.45, p?Conclusions. POAF after cardiac surgery was associated with high risk of MACE. Early anticoagulation may be justified in POAF patients to secure a long-term outcome after cardiac surgery.     

Low-dose oral amiodarone prophylaxis reduces atrial fibrillation after pulmonary resection

BACKGROUND: Atrial fibrillation after pulmonary resection increases morbidity and costs. To evaluate the efficacy of low-dose oral amiodarone (LDOA) as prophylaxis for atrial fibrillation after pulmonary resection, we reviewed all patients 60 years or older having pulmonary resections by thoracotomy in a 30-month period. METHODS: We identified 31 patients who received prophylactic LDOA (200 mg by mouth every 8 hours) while hospitalized and 52 patients who received no prophylactic treatment. The groups were comparable for sex, age, comorbidities, and surgical procedure. RESULTS: Twenty of 83 patients (24%) had postoperative atrial fibrillation: 17 of 52 patients (33%) without prophylaxis and 3 of 31 (9.7%) with prophylaxis (odds ratio, 0.221; 95% confidence interval, 0.059 to 0.829; p = 0.0253). The median total hospital charge was $30,800 (range, $20,400-$96,900) for 50 patients without prophylaxis and $26,700 (range, $11,000-$55,900) for 31 patients with prophylaxis (p = not significant). Patients receiving LDOA had lower accumulated charges per day of hospital stay (p = 0.0011). CONCLUSIONS: LDOA prophylaxis significantly reduces the incidence of atrial fibrillation after pulmonary resection. Its use in this population may be cost-effective. Results of this pilot study provide a rationale for a prospective randomized trial.     

高龄冠心病合并心房颤动患者行非体外循环冠状动脉旁路移植术中左心耳处理的回顾性队列研究

目的 本文旨在探讨左室射血分数(LVEF)降低的高龄冠心病合并心房颤动(房颤)患者在非体外循环冠状动脉旁路移植术(OPCABG)中同期处理左心耳的手术技巧及效果评价.方法 纳入2013～ 2018年,84例OPCABGLVEF降低(＜50％)的高龄(年龄≥70岁)冠心病合并房颤患者在我科行非体外循环冠脉搭桥术.男54例...     

Antithrombotic Secondary Prevention After Stroke

Opinion statement In patients with transient ischemic attack (TIA) or ischemic stroke of noncardiac origin, antiplatelet drugs are able to decrease the risk of stroke by 11% to 15%, and decrease the risk of stroke, myocardial infarction (MI), and vascular death by 15% to 22%. Aspirin leads to a moderate but significant reduction of stroke, MI, and vascular death in patients with TIA and ischemic stroke. Low doses are as effective as high doses, but are better tolerated in term of gastrointestinal side effects. The recommended aspirin dose, therefore, is between 50 and 325 mg. Bleeding complications are not dose-dependent, and also occur with the lowest doses. The combination of aspirin (25 mg twice daily) with slow release dipyridamole (200 mg twice daily) is superior compared with aspirin alone for stroke prevention. Ticlopidine is effective in secondary stroke prevention in patients with TIA and stroke. For some endpoints, it is superior to aspirin. Due to its side effect profile (neutropenia, thrombotic thrombocytopenic purpura [TTP]), ticlopidine should be given to patients who are intolerant of aspirin. Prospective trials have not indicated whether ticlopidine is suggested for patients who have recurrent cerebrovascular events while on aspirin. Clopidogrel has a better safety profile than ticlopidine. Although not investigated in patients with TIA, clopidogrel should also be effective in these patients assuming the same pathophysiology than in patients with stroke. Clopidogrel is second-line treatment in patients intolerant for aspirin, and first-line treatment for patients with stroke and peripheral arterial disease or MI. A frequent clinical problem is patients who are already on aspirin because of coronary heart disease or a prior cerebral ischemic event, and then suffer a first or recurrent TIA or stroke. No single clinical trial has investigated this problem. Therefore, recommendations are not evidencebased. Possible strategies include the following: continue aspirin, add dipyridamole, add clopidogrel, switch to ticlopidine or clopidogrel, or switch to anticoagulation with an International Normalized Ratio (INR) of 2.0 to 3.0. The combination of lowdose warfarin and aspirin was never studied in the secondary prevention of stroke. In patients with a cardiac source of embolism, anticoagulation is recommended with an INR of 2.0 to 3.0. At the present time, anticoagulation with an INR between 3.0 and 4.5 can not be recommended for patients with noncardiac TIA or stroke. Anticoagulation with an INR between 3.0 and 4.5 carries a high bleeding risk. Whether anticoagulation with lower INR is safe and effective is not yet known. Treatment of vascular risk factors should also be performed in secondary stroke prevention.     

Vitamin K Antagonists: Beyond Bleeding

Warfarin is the most widely used oral anticoagulant in clinical use today. Indications range from prosthetic valve replacement to recurrent thromboembolic events due to antiphospholipid syndrome. In hemodialysis (HD) patients, warfarin use is even more frequent than in the nonrenal population due to increased cardiovascular comorbidities. The use of warfarin in dialysis patients with atrial fibrillation requires particular caution because side effects may outweigh the assumed benefit of reduced stroke rates. Besides increased bleeding risk, coumarins exert side effects which are not in the focus of clinical routine, yet they deserve special consideration in dialysis patients and should influence the decision of whether or not to prescribe vitamin K antagonists in cases lacking clear guidelines. Issues to be taken into consideration in HD patients are the induction or acceleration of cardiovascular calcifications, a 10‐fold increased risk of calciphylaxis and problems related to maintaining a target INR range. New anticoagulants like direct thrombin inhibitors are promising but have not yet been approved for ESRD patients. Here, we summarize the nontraditional side effects of coumarins and give recommendations about the use of vitamin K antagonists in ESRD patients.     

Use of Warfarin in People with Low Glomerular Filtration Rate or on Dialysis

Atrial fibrillation, venous thromboembolism, and access malfunction are common clinical problems in dialysis patients that prompt consideration of warfarin therapy. Atrial fibrillation appears to be more common in people with low glomerular filtration rate (GFR) or on dialysis than in the general population, but the risk of stroke in this population is not known. No randomized trials have addressed the safety and efficacy of warfarin in these patients. Deep venous thrombosis and pulmonary embolism are also more common in this population and, again, no randomized trials have addressed the safety and efficacy of warfarin in this group. Pending such information, we suggest an approach that generalizes from large randomized controlled trials in the general population, modifying the assessment of risks and benefits for individual patients using the CHADS₂ and HEMORR₂HAGES scores. A single randomized trial reported a clinically important benefit in prevention of catheter malfunction from warfarin and low-molecular weight heparin started within 12 hours of catheter insertion, in the prevention of catheter thrombosis, in people treated with ticlopidine. Trials of low-intensity anticoagulation for people with grafts and of fixed 1 mg daily warfarin dosing in people with catheters showed no benefit. Warfarin substantially increases the risk of bleeding in patients on dialysis. It is possible that it may contribute also to accelerated vascular calcification. Large randomized studies are needed to assess the risk–benefit ratio of warfarin in people with low GFR or on dialysis for a range of indications.     

Is it safe to stop anticoagulants after successful surgery for atrial fibrillation?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was: is it safe to stop anticoagulants after successful surgery for atrial fibrillation? Altogether, 177 papers were found using the reported search, of which 14 were selected that represented the best evidence to answer the clinical question. Selection criteria included study relevance, primary outcome, size of study population and length of follow-up. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The weight of evidence, including over 10,000 patient-years of follow-up, supports the discontinuation of warfarin following atrial fibrillation correction procedures as being safe, with an associated annual thromboembolic stroke rate of 0-3.8% off warfarin, in studies where warfarin was stopped at a mean of 3.6 months (range 0-8 months) after the procedure. However, the confidence of this conclusion suffers from a paucity of high-quality randomized controlled trials in the field, with the main body of evidence coming instead from observational non-randomized studies. The stroke rate also varies with the exact procedure performed; pulmonary vein isolation procedures are the most extensively evaluated and carry the lowest stroke rate following warfarin discontinuation (0-0.4% per annum when performed as an isolated procedure). By contrast, left atrial appendage occlusion by insertion of a transcatheter device has an associated annual stroke rate of 0-3.8% off warfarin. Thus, discontinuation of warfarin following such transcatheter procedures cannot be recommended at this time. Concomitant heart surgeries, such as mitral valve repair have been shown to increase the thromboembolic rate both unpredictably and dramatically, and this review thus identifies concomitant mitral valve surgery as a potentially substantial risk factor for late thromboembolic stroke in patients undergoing corrective surgeries for atrial fibrillation. This review finds in favour of warfarin discontinuation in selected patients at three months post-procedure, emphasizing consideration of the patient's individual risk-factor profile as paramount. This recommendation is in line with the 2010 guidelines for the management of atrial fibrillation produced by the European Society of Cardiology.     

Anticoagulation strategy in patients with atrial fibrillation after carotid endarterectomy

Aim: Carotid artery stenosis and atrial fibrillation are diseases of the aging patient population. Literature lacks precise anticoagulation treatment protocols for patients with atrial fibrillation following carotid endarterectomy. We present our experiences with anticoagulation strategy in this particular patient population.

Patients and methods: Between June 2001–September 2017, 165 patients with chronic or paroxysmal atrial fibrillation out of 1594 cases from three different institutions whom received Coumadin and aspirin and required carotid endarterectomy were reviewed, respectively. Mean age was 63.4?±?7.9 years. Male/female ratio was 102/63. There were 67 diabetic and 138 hypertensive cases.

Results: Patients are followed a mean of 64.4?±?16.9 months. Early mortality occurred in two patients due to intracranial bleeding and heart failure. Another patient was lost due to intracerebral hemorrhage and 16 other patients died due to various causes in the late follow-up. Three patients required exploration against bleeding.

Conclusion: Combination of warfarin with an aim to keep the INR value between 2 and 3, and aspirin at a dosage of 100?mg per day seemed feasible and in our modest patient cohort. Further studies including multicenter larger data are warranted in order to establish a precise anticoagulation treatment protocol for patients with atrial fibrillation after carotid endarterectomy.     

Impact of the maze procedure on the stroke rate in patients with atrial fibrillation.

OBJECTIVE: The incidence of stroke associated with atrial fibrillation, even in high-risk patients, can be reduced significantly by adequate anticoagulation. However, anticoagulation does not abolish the stroke rate, and unfortunately only 40% of patients with atrial fibrillation actually receive anticoagulant therapy, even in areas where adequate health care is available. METHODS: During the past 11.5 years, we have performed the maze procedure for the treatment of medically refractory atrial fibrillation in 306 patients, 58 of whom presented with a history of having had a stroke (n = 40) or transient ischemic attack (n = 18) before surgery. All patients with atrial fibrillation are at an increased risk for these complications, but they are especially prevalent in those patients with previous thromboembolic events and those with other recognized risk factors. RESULTS: Among the 306 patients who had surgery, there were only 2 perioperative strokes (0. 7%), and in the 265 patients followed for up to 11.5 years after the maze procedure, there has been only 1 late minor stroke that has now completely resolved. CONCLUSIONS: The ability of the maze procedure to decrease the risk of stroke associated with atrial fibrillation so dramatically is likely due to the restoring of sinus rhythm and atrial transport function in combination with surgical removal or obliteration of the left atrial appendage, where most thrombi associated with atrial fibrillation develop.