False-positive cardiac catheterization laboratory activation among patients with suspected ST-segment elevation myocardial infarction

Context Allowing the emergency department physician to activate the cardiac catheterization laboratory is a key strategy to reduce door- to- balloon times in patients with ST- segment elevation myocardial infarction ( STEMI). There are limited data on the frequency of "false- positive" catheterization laboratory activation in patients undergoing percutaneous coronary intervention for suspected STEMI. Objective To determine the prevalence, etiology, and outcomes of false- positive cardiac catheterization laboratory activation in patients with a suspected STEMI. Design, Setting, and Patients Prospective registry from a regional system that includes transfer of patients with STEMI from 30 community and rural hospitals with pretransfer catheterization laboratory activation for percutaneous coronary intervention at a tertiary cardiovascular center in Minnesota. A total of 1345 patients were enrolled from March 2003 to November 2006. Main Outcome Measure Prevalence of false- positive catheterization laboratory activation in patients with suspected STEMI by 3 criteria: no culprit coronary artery, no significant coronary artery disease, and negative cardiac biomarker results. Results Of the 1335 patients with suspected STEMI who underwent angiography, 187 ( 14%; 95% confidence interval [ CI], 12.2%- 16.0%) had no culprit coronary artery and 127 ( 9.5%; 95% CI, 8.0%- 11.2%) did not have significant coronary artery disease. Cardiac biomarker levels were negative in 11.2% ( 95% CI, 9.6%-13.0%) of patients. The combination of no culprit artery with negative cardiac biomarker results was present in 9.2% ( 95% CI, 7.7%- 10.9%) of patients. Thirty- day mortality was 2.7% ( 95% CI, 0.4%- 5.0%) without vs 4.6% ( 95% CI, 3.4%- 5.8%) with a culprit coronary artery ( P =. 33). Conclusions The frequency of false- positive cardiac catheterization laboratory activation for suspected STEMI is relatively common in community practice, depending on the definition of false- positive. Recent emphasis on rapid door- to- balloon times must also consider the consequences of false- positive catheterization laboratory activation.