Jassal Davinder S, Lee Candace, Silversides Candice, Tam James W
Department of Medicine, Dalhousie University, Halifax, Canada.
Can J Cardiol. 2003 Aug;19(9):1017-22.
Although echocardiography has been incorporated into the diagnostic algorithm of patients with suspected infective endocarditis, systematic usage in clinical practice remains ill defined.
To test whether the rigid application of a predefined standardized clinical assessment using the Duke criteria by the research team would provide improved diagnostic accuracy of endocarditis when compared with usual clinical care provided by the attending team.
Between April 1, 2000 and March 31, 2001, 101 consecutive inpatients with suspected endocarditis were examined prospectively and independently by both teams. The clinical likelihood of endocarditis was graded as low, moderate or high. All patients underwent transthoracic echocardiography and appropriate transesophageal echocardiography if deemed necessary. All diagnostic and therapeutic outcomes were evaluated prospectively.
Of 101 consecutive inpatients (age 50+/-16 years; 62 males) enrolled, 22% subsequently were found to have endocarditis. The pre-echocardiographic likelihood categories as graded by the clinical and research teams were low in nine and 37 patients, respectively, moderate in 83 and 40 patients, respectively, and high in nine and 24 patients, respectively, with only a marginal agreement in classification (kappa=0.33). Of the 37 patients in the low likelihood group and 40 in the intermediate group, no endocarditis was diagnosed. In 22 of 24 patients classified in the high likelihood group, there was echocardiographic evidence of vegetations suggestive of endocarditis. Discriminating factors that increased the likelihood of endocarditis were a prior history of valvular disease, the presence of an indwelling catheter, positive blood cultures, and the presence of a new murmur and a vascular event. General internists, rheumatologists and intensive care physicians were more likely to order echocardiography in patients with low clinical probability of endocarditis, of which pneumonia was the most common alternative diagnosis.
Although prediction of clinical likelihood varies between observers, endocarditis is generally found only in those individuals with a moderate to high pre-echocardiographic clinical likelihood. Strict adherence to indications for transthoracic echocardiography and transesophageal echocardiography may help to facilitate more accurate diagnosis within the moderate likelihood category. Patients with low likelihood do not derive additional diagnostic benefit with echocardiography although other factors such as physician reassurance may continue to drive diagnostic demand.
尽管超声心动图已被纳入疑似感染性心内膜炎患者的诊断流程，但在临床实践中的系统应用仍不明确。
与主治团队提供的常规临床护理相比，测试研究团队严格应用预定义的标准化临床评估（采用杜克标准）是否能提高心内膜炎的诊断准确性。
在2000年4月1日至2001年3月31日期间，两个团队对101例连续的疑似心内膜炎住院患者进行了前瞻性独立检查。心内膜炎的临床可能性分为低、中、高三个等级。所有患者均接受了经胸超声心动图检查，必要时进行了适当的经食管超声心动图检查。对所有诊断和治疗结果进行了前瞻性评估。
在纳入的101例连续住院患者（年龄50±16岁；男性62例）中，22%的患者随后被发现患有心内膜炎。临床团队和研究团队在超声心动图检查前对可能性类别的分级中，分别有9例和37例患者为低可能性，83例和40例患者为中可能性，9例和24例患者为高可能性，分类仅有轻微一致性（kappa=0.33）。在低可能性组的37例患者和中可能性组的40例患者中，均未诊断出心内膜炎。在高可能性组的24例患者中的22例，有超声心动图证据显示有提示心内膜炎的赘生物。增加心内膜炎可能性的鉴别因素包括瓣膜病病史、留置导管、血培养阳性、新出现的杂音和血管事件。普通内科医生、风湿病学家和重症监护医生更有可能对心内膜炎临床可能性低的患者进行超声心动图检查，其中肺炎是最常见的替代诊断。
尽管观察者之间对临床可能性的预测存在差异，但心内膜炎通常仅在超声心动图检查前临床可能性为中度至高度的个体中发现。严格遵守经胸超声心动图和经食管超声心动图的适应证可能有助于在中度可能性类别中实现更准确的诊断。可能性低的患者通过超声心动图检查并未获得额外的诊断益处，尽管其他因素如医生的安心可能继续推动诊断需求。
