Prevalence and Factors Associated With False-Positive ST-Segment Elevation Myocardial Infarction Diagnoses at Primary Percutaneous Coronary Intervention–Capable Centers: A Report From the Activate-SF Registry

Study Questions:

What is the prevalence of false-positive ST-segment elevation myocardial infarction (STEMI) diagnoses among emergency physicians at primary percutaneous coronary intervention (PCI)-capable centers?

Methods:

The investigators analyzed consecutive patients referred for primary PCI for a possible STEMI at two centers from October 2008 to April 2011. “False-positive STEMI activation” was defined as lack of a culprit lesion by angiography or by assessment of clinical, electrocardiographic, and biomarker data in the absence of angiography. Clinical and electrocardiographic factors associated with false-positive activations were evaluated in a backward stepwise selection bootstrapped logistic regression model.

Results:

Of 411 STEMI activations by emergency physicians, 146 (36%) were deemed to be false-positive activations. Structural heart disease and heart failure were the most common diagnoses among false-positive activations. Electrocardiographic left ventricular hypertrophy (adjusted odds ratio [AOR], 3.15; 95% confidence interval [CI], 1.55- 6.40; p = 0.001), a history of coronary disease (AOR, 1.93; 95% CI, 1.04-3.59; p = 0.04), or prior illicit drug abuse (AOR, 2.67; 95% CI, 1.13-6.26; p = 0.02) independently increased the odds of false-positive STEMI activations. Increasing body mass index decreased the odds of a false-positive activation (AOR, 0.91; 95% CI, 0.86-0.97; p = 0.004), as did angina at presentation (AOR, 0.28; 95% CI, 0.14-0.57; p < 0.001).

Conclusions:

The authors concluded that more than one third of patients referred for primary PCI from the emergency department did not have a STEMI.

Perspective:

This study reports a 36% prevalence of false-positive STEMI team activations among patients presenting to the emergency department at two primary PCI-capable centers. The data suggest that contemporary false-positive STEMI team activation rates at primary PCI-capable centers are more than double than reported previously. While a certain percentage of false-positive STEMI activations are necessary to ensure adequate diagnostic sensitivity, the point of equipoise between necessary diagnostic sensitivity and patient safety requires further investigation, particularly in light of increasing resource limitations. Furthermore, frequent, inappropriate cath lab activation may result in interdisciplinary distrust, disinterest, and tension between cardiology and emergency medicine services.

Keywords: Myocardial Infarction, Coronary Disease, Electrocardiography, Angioplasty, Substance-Related Disorders, Percutaneous Coronary Intervention, Heart Diseases, Prevalence, Body Mass Index, Biomarkers, Cardiology, Hypertrophy


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