Tobin K, Stomel R, Harber D, Karavite D, Sievers J, Eagle K
Division of Cardiology, William Beaumont Hospital, Royal Oak, Mich 48086, USA.
Arch Intern Med. 1999 Feb 22;159(4):353-7. doi: 10.1001/archinte.159.4.353.
A previous study showed that patients with previous myocardial infarction (MI) who meet 4 simple clinical and/or electrocardiographic criteria have a left ventricular ejection fraction (LVEF) of 40% or greater, with a positive predictive value of 98%. The objective of this study was to validate this clinical rule in the community hospital setting.
Retrospective chart review in a 330-bed community hospital. Two hundred thirteen consecutive patients with MI were identified between June 1, 1993, and March 31, 1995. Left ventricular ejection fraction was predicted in a blinded fashion by means of the clinical rule before the actual LVEF test was reviewed.
We identified 213 patients admitted with the primary discharge diagnosis of acute MI. All patients met standard clinical and enzymatic definitions for acute MI and had at least 1 measure of LVEF, such as echocardiography, ventricular angiography, or gated blood pool scan. The clinical rule predicted that 83 patients (39.0%) would have an LVEF of 40% or greater. Of these 83 patients, 71 had an ejection fraction of 40% or greater, for a positive predictive value of 86%. Of the 12 patients who were incorrectly predicted to have a preserved LVEF, 6 (50%) had an index non-Q-wave anterior MI (P<.001). Reanalyzing the patient population with a fifth variable (anterior non-Q-wave MI) added to the original 4 variables increased the positive predictive value to 91%.
This simple clinical prediction rule has a positive predictive value of 86% when applied in the community hospital setting. Patients with anterior non-Q-wave MI may be 1 group in whom the rule is inaccurate, and expanding the clinical rule to 5 variables may increase the positive predictive value. When a technology-based assessment of left ventricular function is considered in patients after an MI, this prediction rule may allow for a more cost-effective patient selection, and as many as 40% of patients who have had acute MIs may require no testing at all.
先前的一项研究表明，符合4条简单临床和/或心电图标准的既往心肌梗死（MI）患者左心室射血分数（LVEF）≥40%，阳性预测值为98%。本研究的目的是在社区医院环境中验证这一临床规则。
在一家拥有330张床位的社区医院进行回顾性病历审查。1993年6月1日至1995年3月31日期间连续纳入213例MI患者。在审查实际LVEF检测结果之前，采用该临床规则以盲法预测左心室射血分数。
我们确定了213例以急性MI为主要出院诊断入院的患者。所有患者均符合急性MI的标准临床和酶学定义，且至少有1次LVEF检测，如超声心动图、心室造影或门控心血池扫描。临床规则预测83例患者（39.0%）的LVEF≥40%。在这83例患者中，71例射血分数≥40%，阳性预测值为86%。在被错误预测为LVEF保留的12例患者中，6例（50%）为首次非Q波前壁MI（P<0.001）。在原始4个变量中增加第5个变量（前壁非Q波MI）重新分析患者群体，可将阳性预测值提高至91%。
在社区医院环境中应用时，这一简单的临床预测规则阳性预测值为86%。前壁非Q波MI患者可能是该规则不准确的一组人群，将临床规则扩展至5个变量可能会提高阳性预测值。当考虑对MI后患者进行基于技术的左心室功能评估时，该预测规则可能有助于更具成本效益地选择患者，多达40%的急性MI患者可能根本无需检测。
