Acute coronary occlusion among cancelled STEMI alerts: A prospective study in a telemedicine-guided network

Background ST-segment elevation myocardial infarction (STEMI) networks often face false-positive activations, leading to unnecessary catheterization laboratory use. To optimize resource allocation, STEMI alerts are sometimes cancelled after telematics evaluation; however, this strategy may result in missed cases of acute coronary occlusion (ACO) requiring urgent revascularization. Methods This prospective, single-centre study included patients with initially activated but subsequently cancelled STEMI alerts via the ODISEA digital platform between January 2022 and December 2024. Based on coronary angiography, patients were classified as having ACO (TIMI 0–1 flow with thrombotic appearance) or no occlusion. Baseline characteristics, ECG findings, angiographic data, and in-hospital mortality were compared. Results Of 2,259 STEMI activations, 665 alerts (29.4%) were cancelled following telematic assessment. Among these, 28 patients (4.2%) had ACO. Compared to the remaining cohort, they had higher rates of hypertension (78.6% vs. 60.3%; p = 0.03), diabetes (46.4% vs. 28.4%; p = 0.03), and prior coronary artery bypass grafting (10.7% vs. 2.5%; p = 0.01). Predominant ECG findings included <1mm ST-segment elevation (67.8%) and ST-segment depression (25%). The left anterior descending artery was most frequently involved. In-hospital mortality was 10.7% in the ACO group and 7.7% in the non-ACO group (p = 0.50). Conclusion Among cancelled STEMI alerts, missed ACO cases were infrequent, often presenting with subtle or non-classical ECG findings. These patients showed a higher burden of cardiovascular risk and increased in-hospital mortality