Rural EMS STEMI Patients - Why the delay to PCI?

BACKGROUND: The objective of this study is to identify patient and EMS agency factors associated with timely reperfusion of patients with ST-elevation myocardial infarction (STEMI).

METHODS: We conducted a cohort study of adult patients (≥18 years old) with STEMI activations from 2016-2020. Data was obtained from a regional STEMI registry, which included eight rural county EMS agencies and three North Carolina percutaneous coronary intervention (PCI) centers. On each patient, prehospital and in-hospital time intervals were abstracted. The primary outcome was ability to achieve the 90-minute EMS FMC to PCI time goal (yes vs. no). We used generalized estimating equations accounting for within-agency clustering to evaluate the association between patient and agency factors and meeting first medical contact (FMC) to PCI time goal, while accounting for clustering within agency.

RESULTS: Among 365 rural STEMI patients 30.1% were female (110/365) with a mean age of 62.5 ± 12.7 years. PCI was performed within time goal in 60.5% (221/365) of encounters. The FMC to PCI time goal was met in 45.5% (50/110) of women vs 69.8% (178/255) of men (p < 0.001). The median PCI center activation time was 12 minutes (IQR 7-19) in the group that received PCI within time goal compared to 21 minutes (IQR 10-37) in the cohort that did not. After adjusting for loaded mileage and other clinical variables (e.g., pulse rate, hypertension etc.), male sex was associated with an improved chance of meeting the goal of FMC to PCI (aOR: 2.94; 95% CI 2.11-4.10) compared to female sex.

CONCLUSION: Nearly 40% of rural STEMI patients transported by EMS failed to receive FMC to PCI within 90 minutes. Women were less likely than men to receive reperfusion within time goal, which represents an important health care disparity.