Ann Intern Med. 1992 Jan 1;116(1):6-12. doi: 10.7326/0003-4819-116-1-6.
To identify echocardiographic predictors of arterial thromboembolism in patients with nonrheumatic atrial fibrillation and to determine whether these add to clinical variables for risk stratification.
Cohort study of patients assigned to placebo in a randomized clinical trial.
Five hundred sixty-eight inpatients and outpatients with nonrheumatic atrial fibrillation assigned to placebo therapy at 15 U.S. medical centers from 1987 to 1989 in the Stroke Prevention in Atrial Fibrillation study. Patients were followed for a mean of 1.3 years.
M-mode and two-dimensional (2-D) echocardiograms performed at study entry and interpreted by local cardiologists. The predictive value of 14 echocardiographic variables for later ischemic stroke or systemic embolism was assessed by multivariate analysis.
Left ventricular dysfunction from 2-D echocardiograms (P = 0.003) and the size of the left atrium from M-mode echocardiograms (P = 0.02) were the strongest independent predictors of later thromboembolism. Multivariate analysis of these two independent echocardiographic predictors with the three independent clinical predictors of thromboembolism (history of hypertension, recent congestive heart failure, previous thromboembolism) identified 26% of the cohort with a low risk for thromboembolism (1.0% per year; 95% Cl, 0.2% to 4.0%). Compared with risk stratification using clinical variables alone, echocardiographic results altered thromboembolic risk stratification in 18% of the entire cohort and in 38% of those without clinical risk factors.
Both left ventricular and left atrial variables are significant predictors of thromboembolism in patients with nonvalvular atrial fibrillation. Our results challenge traditional views of the pathogenesis of ischemic stroke in patients with atrial fibrillation and suggest that standard echocardiography contributes to risk stratification, differentiating the one third of patients without clinical risk factors who are at increased risk for stroke from the remainder who may not need antithrombotic prophylaxis.
确定非风湿性心房颤动患者动脉血栓栓塞的超声心动图预测指标，并判断这些指标是否有助于临床变量进行风险分层。
对一项随机临床试验中分配到安慰剂组的患者进行队列研究。
1987年至1989年在美国15个医学中心参与心房颤动预防卒中研究的568例接受安慰剂治疗的非风湿性心房颤动住院和门诊患者。对患者平均随访1.3年。
研究开始时进行M型和二维（2-D）超声心动图检查，并由当地心脏病专家解读。通过多变量分析评估14项超声心动图变量对后续缺血性卒中或系统性栓塞的预测价值。
二维超声心动图显示的左心室功能障碍（P = 0.003）和M型超声心动图显示的左心房大小（P = 0.02）是后续血栓栓塞最强的独立预测指标。对这两个独立的超声心动图预测指标与血栓栓塞的三个独立临床预测指标（高血压病史、近期充血性心力衰竭、既往血栓栓塞）进行多变量分析，确定26%的队列血栓栓塞风险较低（每年1.0%；95%CI，0.2%至4.0%）。与仅使用临床变量进行风险分层相比，超声心动图结果改变了整个队列中18%患者以及无临床风险因素患者中38%的血栓栓塞风险分层。
左心室和左心房变量都是非瓣膜性心房颤动患者血栓栓塞的重要预测指标。我们的结果挑战了心房颤动患者缺血性卒中发病机制的传统观点，并表明标准超声心动图有助于风险分层，将三分之一无临床风险因素但卒中风险增加的患者与其余可能不需要抗血栓预防的患者区分开来。
