Abstract 4863: Emergency Cardiac Catheterization for “False-Positive” ST-Segment Elevation Myocardial Infarction
Introduction: In a push to treat STEMI patients with primary PCI within 90 minutes of door-to-balloon time, medical institutions have developed emergency cardiac catheterization laboratory activation protocols that bypass other routine clinical assessments. This has raised concerns about more frequent catheterizations in patients who may not need them. Our study objective was to determine the incidence, predictors and prognosis of false-positive STEMI.
Methods: We studied a prospective cohort of patients diagnosed with STEMI who received emergency cardiac catheterization with intention of primary PCI between January 2005 and December 2007 at a tertiary care center serving more than 20 community hospitals. False-positive STEMI was defined as absence of a clear culprit lesion on coronary angiography. Multivariate logistic regression was used to identify independent predictors of false-positive STEMI.
Results: Of 489 patients who received emergency cardiac catheterization indicated for STEMI, 54 (11.0%, 95% CI 8.3%–13.8%) had no culprit lesion on coronary angiography. Independent predictors of false-positive STEMI identified on multivariate analysis are shown in the table⇓. Among patients with false-positive STEMI, 22.2% had a serious cardiac diagnosis by catheterization. One-year incidence of acute myocardial infarction or PCI was 7.5% in patients with a culprit lesion vs. 1.9% in patients with no culprit lesion (p=0.08). One-year mortality was 6.5% among patients with a culprit lesion vs. 3.7% without (p=0.22).
Conclusion: False-positive STEMI is common among patients undergoing emergency cardiac catheterization. A better understanding of the identifiers for false-positive STEMI may help physicians quickly reassess the utility of emergency cardiac catheterization when the diagnosis of STEMI is in doubt.