Rates of cardiac catheterization cancelation for ST-segment elevation myocardial infarction after activation by emergency medical services or emergency physicians: results from the North Carolina Catheterization Laboratory Activation Registry.

BACKGROUND

For patients with an acute ST-segment elevation myocardial infarction, cardiac catheterization laboratory (CCL) activation by emergency medical technicians or emergency physicians has been shown to substantially reduce treatment times. One drawback to this approach involves overtriage, whereby CCL staffs are activated for patients who ultimately do not require emergent coronary angiography or for patients who undergo angiography but are not found to have coronary artery occlusion.

METHODS AND RESULTS

We examined CCL activation at 14 primary angioplasty hospitals to determine the course of management, including the rate of inappropriate activation. Among 3973 activations (29% by emergency medical technicians, 71% by emergency physicians) between December 2008 and December 2009, appropriate CCL activations occurred for 3377 patients (85%), with 2598 patients (76.9% of appropriate activations) receiving primary percutaneous coronary intervention. Reasons for inappropriate activations (596 patients; 15%) included ECG reinterpretations (427 patients; 72%) or the fact that the patient was not a CCL candidate (169 patients; 28%). The rate of cancellation because of reinterpretation of emergency medical technicians' ECG (6% of all activations) was more common than for cancellation because of reinterpretation of emergency physicians' ECG (4.6%).

CONCLUSIONS

This represents the first report of the rates of CCL cancellation for ST-segment elevation myocardial infarction system activation by emergency medical technicians and emergency physicians in a large group of hospitals organized within a statewide program. The high rate of coronary intervention and relatively low rate of inappropriate activation suggest that systematic CCL activation by emergency personnel on a broad scale is feasible and accurate, and these rates set a benchmark for ST-segment elevation myocardial infarction systems.