The effects of delays at each stage of care on mortality in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Background: Timely restoration of blood flow is critical for ST-segment elevation myocardial infarction (STEMI) management. We evaluate the effects of time intervals - total ischemic time, time from symptom onset to first medical contact, delay within the healthcare system, and time from hospital arrival to balloon inflation and from arrival at the catheterization laboratory to balloon inflation - on in-hospital mortality among patients with STEMI undergoing primary percutaneous coronary intervention.

Methods: We analyzed data from 315 patients with STEMI who underwent primary percutaneous coronary intervention in a hospital between 2020 and 2021. A random forest model was used to assess the predictive importance of time delay components for in-hospital mortality.

Results: Of the total sample, 35 patients died. The median (interquartile range) for total ischemic time was 310.0 (215.0-547.5) min. Univariate analysis showed significant differences between the two groups in time to first medical contact [120.0 (60.0-245.0) vs. 210.0 (120.0-272.5); P = 0.007] and total ischemic time [300.0 (210.0-531.2) vs. 370.0 (320.0-720.0); P = 0.001]; however, the multivariable model (accuracy = 0.971, sensitivity = 0.800, specificity = 0.999, and an area under the curve = 0.93) identified total ischemic time as the most important time-based predictor of mortality, followed by system delay, time from hospital arrival to balloon inflation, from symptom onset to first medical contact, and from arrival at the catheterization laboratory to balloon inflation.

Conclusion: Each delay component in STEMI management carries distinct clinical consequences that necessitate targeted intervention.