Warfarin for stroke prevention in octogenarians with atrial fibrillation

The authors examined warfarin use in elderly patients with atrial fibrillation. Medical records were abstracted from a random sample of Medicare beneficiaries with atrial fibrillation who were discharged from Kansas hospitals. Data were analyzed for warfarin and aspirin use and risk factors for stroke or bleeding in patients 65–79 years of age or 80 years and older. Stroke risk factors other than age and atrial fibrillation were seen in 98% of 142 patients less than 80 years of age and 100% of 141 octogenarians. Warfarin use was similar in the younger and older age groups (50% vs. 45%, respectively; p= ns) and was not associated with the number of stroke or bleeding risk factors. Compared to patients less than 80 years of age, octogenarians were less likely to receive aspirin (38% vs. 27%, respectively; p< 0.05). Anticoagulation rates for high-risk patients with atrial fibrillation were low and poorly explained by stroke or bleeding risks.     

Survey of atrial fibrillation and thromboembolism in the elderly: a multicenter cooperative study. Research Group for Antiarrhythmic Drug Therapy

A multicenter, retrospective study was undertaken to survey the prevalence of thromboembolism complicated with atrial fibrillation and the efficacy of treatment in both elderly and younger patients. The primary prevention group consisted of 1,810 patients without prior cerebral thromboembolism, and was divided into the elderly patient group (> or = 65 years old, 588 patients) and younger patient group (< 65 years old, 1,222 patients). The elderly group had higher prevalences of chronic atrial fibrillation (65.3% vs 56.4%, p < 0.001) and ischemic heart disease and hypertension (16.8% vs 9.3% and 34.2% vs 24.4%, respectively, p < 0.001) and lower prevalence of treatment with warfarin (9.2% vs 20.1%, p < 0.001). Elderly patients with mitral valve disease and hypertension had lower prevalence of treatment with warfarin as compared with younger patients (p < 0.001). This was also true for the secondary prevention group of 147 patients with prior history of cerebral infarction (p < 0.001). During the mean follow-up period of 4.6 years, patients with underlying cardiac diseases had a higher risk of thromboembolism compared with those without cardiac diseases for both the elderly (12.1% vs 6.1%, p < 0.05) and younger (7.5% vs 3.6%, p < 0.02) groups. Treatment with antiplatelets or warfarin could reduce the risk of thromboembolism in the elderly group (p < 0.1) and the younger group (p < 0.001). The risk of major hemorrhagic complication, i.e., gastrointestinal tract or intracranial hemorrhage, was quite low in patients receiving antithrombotic drugs. The present study indicates that the attitude toward the use of warfarin for prevention of thromboembolism is conservative and the risk of thromboembolism is higher in elderly patients with atrial fibrillation in Japan. Our attitude to the use of antithrombotic drugs in elderly patients with atrial fibrillation needs to be modified.     

Effect of warfarin on outcomes in septuagenarian patients with atrial fibrillation

Anticoagulation has been shown to decrease ischemic stroke in atrial fibrillation (AF). However, concerns remain regarding their safety and efficacy in those ≥70 years of age who constitute most patients with AF. Of the 4,060 patients (mean age 65 years, range 49 to 80) in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, 2,248 (55% of 4,060) were 70 to 80 years of age, 1,901 of whom were receiving warfarin. Propensity score for warfarin use, estimated for each of the 2,248 patients, was used to match 227 of the 347 patients not on warfarin (in 1:1, 1:2, or 1:3 sets) to 616 patients on warfarin who were balanced in 45 baseline characteristics. All-cause mortality occurred in 18% and 33% of matched patients receiving and not receiving warfarin, respectively, during up to 6 years (mean 3.4) of follow-up (hazard ratio [HR] when warfarin use was compared to its nonuse 0.58, 95% confidence interval [CI] 0.43 to 0.77, p <0.001). All-cause hospitalization occurred in 64% and 67% of matched patients receiving and not receiving warfarin, respectively (HR associated with warfarin use 0.93, 95% CI 0.77 to 1.12, p = 0.423). Ischemic stroke occurred in 4% and 8% of matched patients receiving and not receiving warfarin, respectively (HR associated with warfarin use 0.57, 95% CI 0.31 to 1.04, p = 0.068). Major bleeding occurred in 7% and 10% of matched patients receiving and not receiving warfarin, respectively (HR associated with warfarin use 0.73, 95% CI 0.44 to 1.22, p = 0.229). In conclusion, warfarin use was associated with decreased mortality in septuagenarian patients with AF but had no association with hospitalization or major bleeding.     

Warfarin use among ambulatory patients with nonvalvular atrial fibrillation: the anticoagulation and risk factors in atrial fibrillation (ATRIA) study

BACKGROUND: Warfarin dramatically reduces the risk for ischemic stroke in nonvalvular atrial fibrillation, but its use among ambulatory patients with atrial fibrillation has not been widely studied. OBJECTIVE: To assess the rates and predictors of warfarin use in ambulatory patients with nonvalvular atrial fibrillation. DESIGN: Cross-sectional study. SETTING: Large health maintenance organization. PATIENTS: 13428 patients with a confirmed ambulatory diagnosis of nonvalvular atrial fibrillation and known warfarin status between 1 July 1996 and 31 December 1997. MEASUREMENTS: Data from automated pharmacy, laboratory, and clinical-administrative databases were used to determine the prevalence and determinants of warfarin use in the 3 months before or after the identified diagnosis of atrial fibrillation. RESULTS: Of 11082 patients with nonvalvular atrial fibrillation and no known contraindications, 55% received warfarin. Warfarin use was substantially lower in patients who were younger than 55 years of age (44.3%) and those who were 85 years of age or older (35.4%). Only 59.3% of patients with one or more risk factors for stroke and no contraindications were receiving warfarin. Among a subset of "ideal" candidates to receive warfarin (persons 65 to 74 years of age who had no contraindications and had previous stroke, hypertension, or both), 62.1% had evidence of warfarin use. Among our entire cohort, the strongest predictors of receiving warfarin were previous stroke (adjusted odds ratio, 2.55 [95% CI, 2.23 to 2.92]), heart failure (odds ratio, 1.63 [CI, 1.51 to 1.77]), previous intracranial hemorrhage (odds ratio, 0.33 [CI, 0.21 to 0.52]), age 85 years or older (odds ratio, 0.35 [CI, 0.31 to 0.40]), and previous gastrointestinal hemorrhage (odds ratio, 0.47 [CI, 0.40 to 0.57]). CONCLUSIONS: In a large, contemporary cohort of ambulatory patients with atrial fibrillation who received care within a health maintenance organization, warfarin use was considerably higher than in other reported studies. Although the reasons why physicians did not prescribe warfarin could not be elucidated, many apparently eligible patients with atrial fibrillation and at least one additional risk factor for stroke, especially hypertension, did not receive anticoagulation. Interventions are needed to increase the use of warfarin for stroke prevention among appropriate candidates.     

AFFIRM and RACE Trials: Implications for the Management of Atrial Fibrillation

The Atrial Fibrillation (AF) Follow-up Investigation of Rhythm Management (AFFIRM) and Rate Control versus Electrical Cardioversion for Persistent Atrial Fibrillation Study (RACE) Trials evaluated strategies of rate control or rhythm control in atrial fibrillation. AFFIRM enrolled patients with recent onset AF, and at entry over half of all patients were in sinus rhythm. At any point in the trial, the achieved difference in cardiac rhythm was likely only about 30%. In RACE all patients were entered in AF, and at the end of the study, sinus rhythm was present in 10% vs 39%. The strategy of rate control was non-inferior to the rhythm control strategy in both trials, and permits consideration of rate control as primary therapy. However, the actual differences in rhythm were relatively small, and do not allow the conclusion that maintenance of sinus rhythm is inferior to non-maintenance.Current guidelines recommend that patients with paroxysmal AF receive warfarin if they have risk factors for stroke. This is supported by data from AFFIRM. Most strokes in AFFIRM occurred either during subtherapeutic INR, or after cessation of warfarin. Since more patients in the rhythm control arm of AFFIRM discontinued warfarin, it is possible that asymptomatic recurrences of paroxysmal AF fostered clot development and embolization. We cannot answer from the data available whether or not it is safe to discontinue anticoagulation if all episodes of AF are suppressed.Among the reasons that AF is associated with increased mortality may be that it encourages development of congestive heart failure or progressive left ventricular dysfunction. Congestive heart failure occurrence was monitored in both trials, and occurred at a rate of 2-5% without significant differences between rate and rhythm arms. In patients with heart failure at entry, a mortality trend in AFFIRM favored the rhythm control arm. The issue of survivorship and rhythm control in AF in congestive heart failure is undergoing further testing.     

Outcomes of late atrial tachyarrhythmias in adults after the Fontan operation

OBJECTIVES: The purpose of this study was to compare the clinical and echocardiographic features of adults who developed atrial tachyarrhythmias (ATs) late after a Fontan procedure with those who have remained free of arrhythmias. BACKGROUND: Atrial tachyarrhythmias are a frequent complication of the Fontan operation. However, the outcomes in adult patients with AT who have had the Fontan operation have not been well defined. METHODS: We reviewed the outcomes of 94 consecutive patients who underwent the Fontan operation between 1977 and 1994 and were followed as adults at the University of Toronto Congenital Cardiac Centre for Adults. Sixty patients had an atriopulmonary connection, 21 patients had an atrioventricular connection, and 13 patients received a lateral tunnel connection. RESULTS: Thirty-nine patients (41%) had sustained AT (atrial fibrillation, atrial flutter or supraventricular tachycardia) after their Fontan procedure. Compared with patients who did not develop AT, those who did were more likely to develop heart failure (46% vs. 13%, p = 0.003) and right atrial thrombus (31% vs. 4%, p = 0.006), exhibit left atrial enlargement (mean [+/-SD] diameter: 44 +/- 10 vs. 37 +/- 9 mm, p = 0.002), exhibit right atrial enlargement (mean [+/-SD] volume: 139 +/- 149 vs. 76 +/- 54 ml, p = 0.040) and have moderate-to-severe systemic valve regurgitation (31% vs. 7%, p = 0.010). The mean survival time was not significantly different between the arrhythmia group and the arrhythmia-free group (21.2 +/- 1.3 and 18.0 +/- 0.7 years, respectively; p = 0.900). CONCLUSIONS: Systemic atrioventricular valvular regurgitation and biatrial enlargement are commonly observed in patients who develop AT after the Fontan procedure. These patients are more likely to develop right atrial thrombus and heart failure.     

Risk factors for thromboembolism in patients with atrial fibrillation during treatment with aspirin: a multicenter, cooperative retrospective study. Research Group for Antiarrhythmic Drug Therapy

Warfarin is effective in preventing thromboembolism in patients with atrial fibrillation, but aspirin is frequently used as an alternative treatment. A multicenter, retrospective study was undertaken to identify patients at risk for thromboembolism during treatment with aspirin. The study group consisted of 470 patients (318 males, 152 females, mean age 59.9 +/- 11.8 years at initial examination) with atrial fibrillation who were treated with aspirin. Thirty-seven percent of patients had paroxysmal atrial fibrillation and 65% of patients received aspirin at a daily dose of 81 mg. Thromboembolism occurred in 31 patients (6.6%) during the follow-up period, resulting in cerebral infarction in 19 patients, transient ischemic attack in 7, and embolism of peripheral arteries in 5. Patients with thromboembolism had lower prevalence of New York Heart Association (NYHA) functional class I (52% vs 72%, p < 0.02) and paroxysmal atrial fibrillation (23% vs 38%, p = 0.085) compared with patients without thromboembolism. Multivariate analysis with the Cox proportional hazard model determined age (> or = 65 years, relative risk 2.29, p = 0.032) as an independent risk factor. NYHA functional class (> or = class II) tended to indicate an increased risk of thromboembolic events (relative risk 1.90, p = 0.076). These results suggest that aspirin has limited efficacy for prevention of thromboembolism in patients with atrial fibrillation who are old (> or = 65 years) or have symptomatic heart failure.     

Does intensity of rate-control influence outcome in atrial fibrillation? An analysis of pooled data from the RACE and AFFIRM studies.

AIMS: The AFFIRM and RACE studies showed that rate control is an acceptable treatment strategy for atrial fibrillation (AF). We examined whether strict rate control offers benefit over more lenient rate control. METHODS AND RESULTS: We compared the outcome of patients enrolled in the rate-control arms of AFFIRM and RACE, using data from patients who met a composite of overlapping inclusion and exclusion criteria. We evaluated 1091 patients, 874 from AFFIRM and 217 from RACE. In AFFIRM, the rate-control strategy aimed for a resting heart rate < or =80 bpm and heart rate during daily activity of < or =110 bpm. In RACE, a more lenient approach was taken: resting heart rate <100 bpm. Primary endpoint was a composite of mortality, cardiovascular hospitalization, and myocardial infarction. Mean heart rate across all follow-up visits for patients in AF was lower in AFFIRM (76.1 vs. 83.4 bpm). Event-free survival for the occurrence of the primary endpoint did not differ (64% in AFFIRM vs. 66% in RACE). Patients with mean heart rates during AF within the AFFIRM (< or =80) or RACE (<100) criteria had a better outcome than patients with heart rates > or =100 (hazard ratios 0.69 and 0.58, respectively, for < or =80 and <100 compared with > or =100 bpm). CONCLUSION: Stringency of the approach to rate control, based on the comparison of the AFFIRM and RACE studies, was not associated with an important difference in clinical events.     

Oral anticoagulation in patients with atrial fibrillation: adherence with guidelines in an elderly cohort

PURPOSE: To determine adherence with practice guidelines in a population-based cohort of elderly persons aged 70 years or older with atrial fibrillation. SUBJECTS AND METHODS: This was a cross-sectional analysis of a subgroup of participants in the Cardiovascular Health Study, a prospective observational study involving four communities in the United States. Subjects were participants with atrial fibrillation on electrocardiogram at one or more yearly examinations from 1993 to 1995. The outcome measure was self-reported use of warfarin in 1995. RESULTS: In 1995, 172 (4.1%) participants had atrial fibrillation together with information regarding warfarin use and no preexisting indication for its use. Warfarin was used by 63 (37%) of these participants. Of the 109 participants not reporting warfarin use, 92 (84%) had at least one of the clinical risk factors (aside from age) associated with stroke in patients with atrial fibrillation. Among participants not taking warfarin, 47% were taking aspirin. Several characteristics were independently associated with warfarin use, including age [odds ratio (OR) = 0.6 per 5-year increment, 95% CI 0.5-0.9], a modified mini-mental examination score <85 points [OR = 0.3, 95% confidence interval (CI) 0.1-0.9], and among patients without prior stroke, female sex (OR = 0.5, 95% CI 0.2-1.0). CONCLUSIONS: Despite widely publicized practice guidelines to treat patients who have atrial fibrillation with warfarin, most participants who had atrial fibrillation were at high risk for stroke but were not treated with warfarin. More studies are needed to determine why elderly patients with atrial fibrillation are not being treated with warfarin.     

Left atrial appendage exclusion and the risk of thromboembolic events following mitral valve surgery

Objectives: We aimed to evaluate left atrial appendage (LAA) exclusion in patients undergoing mitral valve surgery with respect to thromboembolic events.
Background: LAA is the predominant source of emboli in patients with atrial fibrillation. Prophylactic LAA exclusion at the time of heart surgery has been recommended to reduce the risk of future thromboembolism.
Methods: An observational cohort of 136 patients undergoing LAA exclusion during mitral valve surgery was identified between May 1993 and November 1998 at our institution.
Results: During a mean follow-up of 3.6 ± 1.3 years, there were 14 (12.3%) thromboembolic events. Compared with patients who received warfarin upon hospital discharge, there were more thromboembolic events in patients not prescribed warfarin upon hospital discharge (n = 7/67, 10% vs n = 6/40, 15%, respectively). The warfarin status was not known for one patient. The majority of thromboembolic events (n = 10/14, 71%) occurred in those who underwent mitral valve repair.
Conclusion: In this observational study, patients who undergo LAA exclusion during mitral valve surgery to reduce the risk of thromboembolism have a significant incidence of thromboembolic events, especially when warfarin therapy is not prescribed upon hospital discharge.     

Postoperative atrial fibrillation and mortality after coronary artery bypass surgery

OBJECTIVES: We sought to determine if the occurrence of postoperative atrial fibrillation (AF) affects early or late mortality following coronary artery bypass surgery (CABG). BACKGROUND: Atrial fibrillation is the most common arrhythmia seen following CABG. METHODS: The Texas Heart Institute Cardiovascular Research Database was used to identify all patients that developed AF after isolated initial CABG from January 1993 to December 1999 (n = 994). This population was compared with patients who underwent CABG during the same period but did not develop AF (n = 5,481). In-hospital end points were adjusted using logistic regression models to account for baseline differences. Long-term survival was evaluated using a retrospective cohort design, where Cox proportional hazards methods were used to adjust for baseline differences, and with case-matched populations (n = 390, 195 per arm). RESULTS: Atrial fibrillation was diagnosed in 16% of the population. Postoperative AF was associated with greater in-hospital mortality (odds ratio [OR] 1.7, p = 0.0001), more strokes (OR 2.02, p = 0.001), prolonged hospital stays (14 vs. 10 days, p < 0.0001), and a reduced incidence of myocardial infarction (OR 0.62, p = 0.01). At four to five years, survival was worse in patients who developed postoperative AF (74% vs. 87%, p < 0.0001 in the retrospective cohort; 80% vs. 93%, p = 0.003 in the case-matched population). On multivariate analysis, postoperative AF was an independent predictor of long-term mortality (adjusted OR 1.5, p < 0.001 in the retrospective cohort; OR 3.4, p = 0.0018 in the case-matched population). CONCLUSIONS: The occurrence of AF following CABG identifies a subset of patients who have a reduced survival probability following CABG. The impact of various strategies, such as antiarrhythmics and warfarin, aimed at reducing AF and its complications deserves further study.     

The Impact of Age on the Epidemiology of Atrial Fibrillation Hospitalizations

Background

Given that 4 million individuals in the United States have atrial fibrillation, understanding the epidemiology of this disease is crucial. We sought to identify and characterize the impact of age on national atrial fibrillation hospitalization patterns.

Methods

The study sample was drawn from the 2009-2010 Nationwide Inpatient Sample. Patients hospitalized with a principal International Classification of Diseases, 9th Revision discharge diagnosis of atrial fibrillation were included. Patients were categorized as “older” (≥65 years) or “younger” (<65 years) for the purposes of analysis. The outcomes measured included hospitalization rate, length of stay, in-hospital mortality, and discharge status.

Results

We identified 192,846 atrial fibrillation hospitalizations. There was significant geographic variation in hospitalizations for both younger and older age groups. States with high hospitalizations differed from those states known to have high stroke mortality. Younger patients (33% of the sample) were more likely to be obese (21% vs 8%, P < .001) and to use alcohol (8% vs 2%, P < .001). Older patients were more likely to have kidney disease (14% vs 7%, P < .001). Both age groups had high rates of hypertension and diabetes. Older patients had higher in-hospital mortality and were more likely to be discharged to a nursing or intermediate care facility.

Conclusions

Younger patients account for a substantial minority of atrial fibrillation hospitalizations in contemporary practice. Younger patients are healthier, with a different distribution of risk factors, than older patients who have higher associated morbidity and mortality.     

Warfarin and aspirin use and the predictors of major bleeding complications in atrial fibrillation (the Framingham Heart Study)

The Framingham Heart Study records of participants with atrial fibrillation (AF) during 1980 and 1994 were retrospectively reviewed to determine the prevalence of warfarin and aspirin use in AF. Anticoagulant use increased significantly in the 393 men and women (mean ages 72.5 and 79.0 years, respectively) who developed AF over the observation period: aspirin use increased from 14% to 39% in men and from 19% to 33% in women, and warfarin use increased from 10% to 39% in men and from 17% to 38% in women. There were no significant gender differences in anticoagulant use (p = 0.61), but participants using warfarin were younger. A total of 65 participants (17%) had major bleeding complications 相似文献   

Functional status in rate- versus rhythm-control strategies for atrial fibrillation: results of the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) Functional Status Substudy.

OBJECTIVES: The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) functional status substudy aimed to test the hypothesis that functional status is similar in rate-control and rhythm-control strategies. BACKGROUND: Randomized studies, including the AFFIRM study, have failed to demonstrate survival benefits between rate-control and rhythm-control strategies for atrial fibrillation (AF). However, AF may cause functional capacity or cognitive impairment that might justify maintenance of sinus rhythm. METHODS: Investigators of the AFFIRM study enrolled 4,060 patients with AF who required long-term therapy and who were 65 years of age or older or who had another risk factor for stroke or death. New York Heart Association functional class (NYHA-FC) and Canadian Cardiovascular Society Angina Classification were assessed at initial and each follow-up visit. From 22 randomly chosen functional status substudy sites, 245 participants underwent 6-min walk tests and Mini-Mental State Examination (MMSE) at initial, two-month, and yearly visits. Patients were assigned randomly to rate-controlling drugs, allowing AF to persist, or rhythm-controlling antiarrhythmic drugs, to maintain sinus rhythm. RESULTS: The NYHA-FC worsened with time in both rate-control and rhythm-control groups, with no differences between groups. Presence of AF was associated with worse NYHA-FC (p < 0.0001). No differences were observed in Canadian Cardiovascular Society Angina Classification or MMSE scores. Six-minute walk distance improved over time in both study arms. On average, walk distance was 94 feet greater in the rhythm-control group (adjusted p = 0.049). CONCLUSIONS: Modest improvement in 6-min walk distance was noted in the rhythm-control arm. Presence of AF was associated with worse NYHA-FC. No difference in cognitive function was detected.     

老年心房颤动高危患者抗凝治疗的药物选择及安全性

目的探讨老年心房颤动患者抗凝治疗的药物剂量选择及安全性。方法选择确诊的老年心房颤动患者210例,按照年龄将60～79岁130例作为老年段及≥80岁80例作为高龄段。2个年龄段患者按服药治疗不同分为老年华法林组30例、高龄华法林组30例,老年联合用药组50例(氯吡格雷75 mg+阿司匹林100 mg),老年阿司匹林组50例和高龄阿司匹林组50例(阿司匹林100 mg)。观察服用华法林剂量及国际标准化比值(INR);各组患者栓塞及出血发生率。结果高龄华法林组剂量(2.88±0.46)mg,INR 2.29±0.55,老年华法林组剂量(2.93±0.75)mg,INR 2.30±0.52,差异无统计学意义(P>0.05)。老年华法林组和高龄华法林组及老年联合用药组栓塞发生率明显低于老年阿司匹林组和高龄阿司匹林组(P<0.05)。与老年华法林组和高龄华法林组及老年阿司匹林组和高龄阿司匹林组比较,老年联合用药组出血发生率明显高(P<0.05)。结论老年心房颤动患者服用华法林或氯吡格雷+阿司匹林能更有效预防脑卒中事件的发生,老年、尤其是高龄高危患者服用华法林治疗,INR控制在1.5～2.5是安全、有效。对于不适合应用华法林的患者,可应用氯吡格雷+阿司匹林预防血栓形成。     

Prevention of ischemic stroke in middle aged patients with atrial fibrillation. Effect of sinus rhythm maintenance, aspirin, warfarin, and simvastatin

Patients (n=263, age 49-64 years) with persistent nonvalvular atrial fibrillation were subjected to controlled treatment aimed at restoration and maintenance of sinus rhythm (n=134) or slowing of rate of ventricular contractions. Efficacy of complementary use of combination of simvastatin with aspirin, warfarin and aspirin for prevention of ischemic stroke was assessed in both of these strategies. First strategy, supplemented with combination of simvastatin and aspirin prevented ischemic stroke and lethal outcome most successfully, while the use of warfarin was unexpectedly associated with comparative elevation of risk of ischemic stroke. It is impossible to exclude that long term administration of warfarin in strategy of sinus rhythm maintenance attenuated advantages of normal rhythm in relation of lowering of stroke risk in AFFIRM study and other similar works. Contrary to known cardio-embolic mechanism of cerebral embolism in permanent atrial fibrillation main aim of the treatment in successful sinus rhythm maintenance may become prevention of arterio-arterial emboli.     

Are Transthoracic Echocardiographic Parameters Associated With Atrial Fibrillation Recurrence or Stroke?: Results From the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) Study

OBJECTIVES: The purpose of this study was to evaluate the associations of transthoracic echocardiographic parameters with recurrent atrial fibrillation (AF) and/or stroke. BACKGROUND: The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study, an evaluation of elderly patients with AF at risk for stroke, provided an opportunity to evaluate the implications of echocardiographic parameters in patients with AF. METHODS: Transthoracic echocardiographic measures of mitral regurgitation (MR), left atrial (LA) diameter, and left ventricular (LV) function were evaluated in the AFFIRM rate- and rhythm-control patients who had sinus rhythm resume and had these data available. Risk for recurrent AF or stroke was evaluated with respect to transthoracic echocardiographic measures. RESULTS: Of 2,474 patients studied, 457 had > or =2(+)/4(+) MR, and 726 had a LA diameter >4.5 cm. The LV ejection fraction was abnormal in 543 patients. The cumulative probabilities of at least one AF recurrence/stroke were 46%/1% after 1 year and 84%/5% by the end of the trial (> 5 years), respectively. Multivariate analysis showed that randomization to the rhythm-control arm (hazard ratio [HR] = 0.64; p < 0.0001) and a qualifying episode of AF being the first known episode (HR = 0.70; p < 0.0001) were associated with decreased risk. Duration of qualifying AF episode >48 h (HR = 1.55; p < 0.0001) and LA diameter (p = 0.008) were associated with an increased risk of recurrent AF. Recurrent AF was more likely with larger LA diameters (HR = 1.21, 1.16, and 1.32 for mild, moderate, and severe enlargement, respectively). No transthoracic echocardiographic measures were associated with risk of stroke. CONCLUSIONS: In the AFFIRM study, large transthoracic echocardiographic LA diameters were associated with recurrent AF, but no measured echocardiographic parameter was associated with stroke.     

Episodes of atrial fibrillation and atrial vulnerability after successful radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome.

Episodes of atrial fibrillation occur in patients with WPW syndrome but frequently disappear after successful radiofrequency ablation. AIMS: To analyze the incidence of atrial fibrillation before and after successful ablation and the presence of increased atrial vulnerability. METHODS AND RESULTS: Fifty-four of 183 WPW patients had at least one documented episode of atrial fibrillation before ablation. During a follow-up of 24 +/- 12 months 13/54 patients (24%) experienced atrial fibrillation. At baseline, the patients with atrial fibrillation were more often men (74%) vs 53%, P=0.007), were older (45 +/- 15 vs 34 +/- 16 years, P=0.0001), more often had pre-excitation during sinus rhythm (87% vs, 73%, P=0.04) and had increased atrial vulnerability (41%, vs 18%, P<0.001). Only patients with atrial fibrillation before, developed atrial fibrillation after ablation. The 13 (of 54) patients who relapsed were also older (53 +/- 13 vs 42 +/- 15 years, P= 0.03), had increased atrial vulnerability at baseline (77% vs 29%, P=0.002), and were more symptomatic, (13 +/- 21 vs 1 +/- 3 arrhythmia attacks/month, P=0001). No patient without atrial fibrillation before ablation developed atrial fibrillation after treatment. CONCLUSIONS: The accessory pathway was important for the development of atrial fibrillation. Frequent tachycardias seem to promote an electrical remodelling and an increased atrial vulnerability to atrial fibrillation, whereas after successful ablation the majority of patients remain free of atrial fibrillation.     

华法林与阿司匹林预防非瓣膜性心房颤动患者血栓栓塞的随机对照研究

目的通过前瞻性、随机、多中心研究比较阿司匹林与调整剂量华法林预防非瓣膜性心房颤动(房颤)患者发生血栓栓塞的有效性和安全性。方法在18个中心,根据入选标准将非瓣膜性房颤患者随机分配至阿司匹林组(150~160mg/d)和调整剂量华法林组(初始剂量2mg/d),目标国际标准化比值(INR)为2·0~3·0(年龄≥75岁者的INR为1·6~2·5)。常规门诊随访,调整华法林剂量并记录两组患者的终点事件和不良反应发生情况。主要终点事件为缺血性脑卒中和死亡,次要终点事件包括短暂性脑缺血发作、腔隙性脑梗死、外周动脉栓塞、急性心肌梗死和严重出血。结果共704例患者进入分析,阿司匹林组369例,华法林组335例。男性420例(59·7%),平均年龄(63·3±9·9)岁,两组患者基线特征(包括合并疾病和伴随用药)差异无统计学意义。随访时间中位数19个月(2~24个月)。与阿司匹林比较,调整剂量华法林明显降低主要终点事件发生率[2·7%比6·0%,P=0·03,OR0·44,95%可信区间(CI)为0·198~0·960],相对危险下降54%;缺血性脑卒中的相对危险下降62%(1·8%比4·6%,P=0·04,OR0·38,95%CI为0·147~0·977);总血栓栓塞事件相对危险下降52%(10·6%比5·4%,P=0·01,OR0·48,95%CI为0·269~0·858)。次要终点事件两组间差异无统计学意义。华法林组轻微出血和严重出血发生率均高于阿司匹林组(P<0·05)。华法林组总死亡率低于阿司匹林组[4例(1·2%)比8例(2·2%)],但差异无统计学意义(P>0·05);包括主要和次要终点的联合终点事件华法林组低于阿司匹林组(8·4%比13·0%,P=0·047)。结论与阿司匹林相比,华法林可明显降低国人非瓣膜性房颤患者脑卒中的发生率,华法林组出血的发生率高于阿司匹林组,但多数出血并发症发生在INR>3·0。严密监测(INR2·0~3·0)下的调整剂量华法林安全有效。