The Etiology of Cardiac Catheterization Cancellation for ST-Segment Elevation Myocardial Infarction at Three Froedtert Hospitals

When patients arrive to the emergency department (ED) with an acute ST-segment myocardial infraction (STEMI), the cardiac catheterization laboratory (CCL) is activated for immediate treatment. Cancellation of a CCL can occur due to multiple etiologies and involves expenditure of resources. The objective of our study was to determine the etiology behind CCL cancellations for STEMIs at three Froedtert EDs.

All activations at Froedtert, Froedtert Menomonee Falls, and Froedtert West Bend Hospitals were reviewed between 6/1/2024–5/31/2025 using score cards and EPIC chart review. Cancellations of the CCL were classified as avoidable if due to EKG misinterpretation or other process errors. EKG misinterpretations were further analyzed for themes of misinterpretation. Cancellations of CCL were classified as unavoidable if due to patient death, patient refusal, confounding co-morbidities, or relative contraindication.

The dataset was composed of 257 total activations. Patients were excluded if the reason for activation was NSTEMI. The total number of patients was 251. The discrepancy between activations and number of patients is due to some patients having multiple activations. The average age of study participants was 65.5 (SD = 13.8) with 36.7% female and 63.3% male. Of the 257 activations, 173 (67.3%) went to the CCL; of the cancellations, 44 (17.1%) were unavoidable cancellations and 40 (15.6%) were avoidable. The distribution of CCL activations was analyzed with 32.7% of activations resulting in a cancellation. 82.1% of avoidable cancellations were due to the EKG not meeting STEMI criteria followed by 10.3% due to processing issues/error. ST elevation of normal variant was the most common reason that the EKG did not meet STEMI criteria for 28.9% of the cancellations, followed by dynamic changes at 20.0%.

This data analysis of CCL cancellations at Froedtert sites demonstrates insight behind cancellations. While the overall cancellation rate for inappropriate activation within the year was on par with the national average, improvements can be made to reduce cancellations. EKG misinterpretation was the most common reason for inappropriate activation resulting in a cancellation of the CCL. Of the cancellations due to EKGs, ST elevation of normal variant was the most common reason for cancellation. Information from this study can provide educational opportunities.