非瓣膜性心房颤动患者脑卒中危险因素的研究

目的:探讨非瓣膜性心房颤动(NVAF)患者脑卒中的危险因素。方法:选择2002-01至2009-01在我院住院的NVAF患者1064例,按NVAF有无合并脑卒中分为NVAF无脑卒中组(n=924)和NVAF合并脑卒中组(n=140)。结果:1064例患者NVAF脑卒中的检出率为13.2%。NVAF合并脑卒中组的≥75岁年龄者、既往高血压史及肝功能不全的发生率、纤维蛋白原、甘油三酯、总胆固醇比NVAF不合并脑卒中组升高,而左心室射血分数(LVEF)降低,异常均有统计学意义(P<0.05)。多元素非条件Logistic回归分析:≥75岁高龄、高血压、左心室射血分数、纤维蛋白原、甘油三酯、总胆固醇均与脑卒中显著相关(P<0.05)。结论:患者高龄(≥75岁)、高血压、纤维蛋白原、甘油三酯及总胆固醇为NVAF合并脑卒中的独立危险因素,而左心室射血分数为NVAF合并脑卒中的保护因素,左心室射血分数越高患者越不易发生房颤。     

Pharmacologic Strategies for the Prevention of Stroke in Patients With Atrial Fibrillation

Stroke is a dreaded complication of atrial fibrillation. In the past, preventive therapy included aspirin and oral anticoagulation. Selected patients who are not suitable for oral anticoagulation may benefit from the addition of clopidogrel with aspirin. This combination, when compared with aspirin, offers a reduced risk of stroke at a cost of more major bleeding. We use this therapy in patients with atrial fibrillation who have unstable coronary syndromes or in patients who receive coronary artery stents who are not good candidates for “triple therapy” with aspirin, clopidogrel, and warfarin. The duration of therapy is tempered by many variables. In the case of coronary stents, we ask the interventionalist to consider a bare metal stent to shorten the duration of need for clopidogrel plus aspirin. After several months of combination therapy, we stop this therapy and begin warfarin therapy. Dabigatran is commercially available in the United States. In patients who have difficult to control International Normalized Ratio (INR) values or who do not wish to have regular coagulation monitoring, dabigatran offers a huge advantage. The benefit seems less if the INR is consistently within range. We are impressed with the superior reduction in stroke and systemic embolism with 150 mg of dabigatran twice daily compared to warfarin and also its low risk of intracranial hemorrhage. The results of clinical trials involving factor Xa agents are now being presented. How these agents fit into the marketplace remains to be seen but they will offer clinicians additional therapy for stroke prevention in atrial fibrillation.     

Cardiovascular and Stroke Risk in Japanese Hemodialysis Patients With Atrial Fibrillation

Atrial fibrillation is one of the most common arrhythmias in hemodialysis patients. We evaluated its clinical outcomes among hemodialysis patients with atrial fibrillation in Japan. Using data derived from the Japanese Dialysis Outcomes and Practice Patterns Study, we analyzed backgrounds and outcomes among hemodialysis patients with and without atrial fibrillation in Japan. Among 7002 hemodialysis patients, the prevalence of atrial fibrillation was 5.7% and the incidence was 0.2 per 100 patient‐years. Atrial fibrillation was independently associated with all‐cause mortality (hazard ratio, 1.32; 95% confidence interval, 1.02–1.71) and cardiovascular events (hazard ratio, 1.39; 95% confidence interval, 1.15–1.68), but not with stroke events (hazard ratio, 0.77; 95% confidence interval, 0.55–1.06) after adjustment for other variables. We conclude that patients with atrial fibrillation experienced higher mortality and more cardiovascular events than did patients without atrial fibrillation, although the risk of stroke was lower than expected.     

Direct-Acting Oral Anticoagulant Choice for Stroke Prevention in Obese Patients With Atrial Fibrillation

Anticoagulation with direct-acting oral anticoagulants (DOACs) is recommended over warfarin for stroke prevention in patients with atrial fibrillation (AF). The efficacy of DOACs over warfarin in obese patients with AF is less defined and may carry the potential for subtherapeutic anticoagulation and reduced efficacy. The best available evidence to guide DOAC use in obese patients with AF is from analysis of obese subgroups of all the major landmark DOAC trials. From these subgroup analyses of the RE-LY, ARISTOTLE, ENGAGE-AF TIMI 48, and ROCKET-AF trials, DOAC use in obese patients demonstrated efficacy similar or superior to warfarin for stroke reduction. Major bleeding rates were similar or higher with DOACs compared with warfarin in these obese subgroup analyses. Meta-analysis of the above major clinical trials concluded that DOACs were more effective compared with warfarin for stroke prevention in obese patients (up to a body mass index [BMI] of 50 kg/m²) and had lower incidence of major bleeding. The totality of evidence supports that DOACs are as effective, if not superior, to warfarin in obese patients with AF. We propose an algorithm, based on the available evidence and current guidelines, to guide the use of DOACs based on severity of obesity. Any DOAC can be used in obese patients with BMI < 40 kg/m². In patients with a BMI of 40-50 kg/m², warfarin should be used, but apixaban or edoxaban can be considered. In obese patients with a BMI > 50 kg/m², warfarin should be used.     

Prediction of Stroke Risk in Atrial Fibrillation,Prevention of Stroke in Atrial Fibrillation,and the Impact of Long-Term Monitoring for Detecting Atrial Fibrillation

Atrial fibrillation (AF) is a large public health problem that affects about 1% of the population in the United States. It confers an increased risk for stroke and thromboembolism, but the stroke risk is not equal in all patients. Further refinement in stratifying stroke risk in patients with AF will help in properly directing therapy for AF patients while minimizing adverse events. Warfarin is the first-line treatment for stroke reduction in patients with AF, but many new drugs are on the horizon that will significantly change practice. New and improved cardiac monitoring techniques and devices will help with detection of AF in those at risk for stroke and will assist in assessing which patients will most benefit from anticoagulation.     

Left Atrial Appendage Dimensions Predict the Risk of Stroke/TIA in Patients With Atrial Fibrillation

Risk of Stroke/TIA in Patients With Atrial Fibrillation. Introduction: Most strokes in patients with atrial fibrillation (AF) arise from thrombus formation in left atrial appendage (LAA). Our aim was to identify LAA features associated with a higher stroke risk in patients with AF using magnetic resonance imaging and angiography (MRI/MRA). Methods: The study included 144 patients with nonvalvular AF who were not receiving warfarin and who underwent MRI/MRA prior to catheter ablation for AF. LAA volume, LAA depth, short and long axes of LAA neck, and numbers of lobes were measured. Results: Of the 144 patients, 18 had a prior stroke or transient ischemic attack (TIA) (13 and 5, respectively). Compared with patients who had no history of stroke/TIA, these patients were older, had higher prevalence of hypertension and hyperlipidemia and had higher LAA volume (22.9 ± 9.6 cm³ vs. 14.5 ± 7.1 cm³, P < 0.001). Their LAA depth (3.76 ± 0.9 cm vs. 3.21 ± 0.8 cm, P = 0.006) and the long and short axes of the LAA neck (3.12 ± 0.7 cm vs. 2.08 ± 0.7 cm, P < 0.001; 2.06 ± 0.5 cm vs. 1.37 ± 0.4 cm, P < 0.001, respectively) were larger. Using stepwise logistic regression model, the only statistically significant multivariable predictors of events were age (OR = 1.21 per year, 95% CI 1.06‐1.38, P = 0.004), aspirin use (OR = 0.039, 95% CI 0.005‐0.28, P = 0.001), and LAA neck dimensions (short axis × long axis) (OR = 3.59 per cm², 95% CI 1.93‐6.69, P < 0.001). Conclusion: LAA dimensions predict strokes/TIAs in patients with AF. LAA assessment by MRI/MRA can potentially be used as an adjunctive tool for risk stratification for embolic events in AF patients. (J Cardiovasc Electrophysiol, Vol. 22, pp. 10‐15, January 2011)     

Barriers to Warfarin Use for Stroke Prevention in Patients With Atrial Fibrillation in Hong Kong

Background:

Oral anticoagulation medications such as warfarin reduce the risk of stroke in atrial fibrillation (AF) but have been underutilized. This study aimed to investigate physicians' perceptions of stroke prevention management and patients' knowledge of AF and warfarin therapy in Hong Kong (HK).

Hypothesis:

Both physician and patient's knowledge on warfarin use were the barriers for stroke prevention in patients with atrial fibrillation in Hong Kong.

Methods:

This prospective survey‐based study was conducted between February 2011 and April 2011 to assess physicians' perceptions of stroke prevention management, patients' knowledge of AF, and patients' knowledge of warfarin therapy. The results were scored and compared with those in foreign countries.

Results:

Sixty‐two physicians and 114 warfarin users were recruited in the study. The average score of HK physicians in the knowledge of stroke prevention therapy in AF patients was lower than that of Australian (AUS) family physicians (HK 2.48 vs AUS 4.02 out of 7). The mean scores of AF patients in Hong Kong regarding the knowledge of AF were lower than that of United Kingdom (UK) (HK 1.16 vs UK 2.24 out of 4) (P < 0.001) and that of Finland (FIN) (HK 2.77 vs FIN 5.94 out of 8) (P < 0.001), respectively. The mean score of AF patients in Hong Kong regarding the knowledge of warfarin therapy was lower than that of AF patients in the United States (US) (HK 2.39 vs US 3.92).

Conclusions:

The barriers of warfarin use for AF patients in Hong Kong were related to both physicians and patients. Many Hong Kong physicians did not comply with international recommendations of stroke prevention in AF patients, and AF patients had a low knowledge level about the disease and warfarin therapy. Presented at the International Congress of Cardiology, Hong Kong, Peoples Republic of China, February 24‐26, 2012. This study was supported by the School of Pharmacy, the Chinese University of Hong Kong. The authors have no other funding, financial relationships, or conflicts of interest to disclose.