Factors associated with advanced cardiac care in prehospital chest pain patients

Many patients transported by emergency medical services (EMS) may require advanced cardiac care but do not have ST-segment elevation (STEMI) on the initial prehospital EKG. We sought to identify factors associated with the need for advanced cardiac care in undifferentiated EMS patients reporting chest pain in the absence of STEMI on EKG.

We performed a retrospective analysis of all adult patients, reporting atraumatic chest pain from a single EMS agency, presenting to a single, urban hospital over a 10-year period. Patients with STEMI on prehospital electrocardiogram were excluded. Patient demographics, chest pain characteristics and prehospital factors were abstracted for all patients. We identified those patients that required advanced cardiac care and performed regression analysis to determine associated factors.

A total of 956 charts were analyzed. Of this total, 193 patients (20.2%) met the primary composite outcome. Of the outcome group, 185 patients (95.9%) had coronary artery disease documented on cardiac catheterization, 22 patients (11.4%) underwent CABG, and seven patients (3.6%) died in the hospital. Most significant variables (multivariable IRR) included age (1.02), male gender (1.65), history of MI (1.47), PCI (1.66), hyperlipidemia (1.40), diaphoresis (1.51), home aspirin (1.53), and improvement with EMS treatment (1.60).

We have identified several factors that could be considered when risk stratifying prehospital patients reporting chest pain. While potentially predictive, the factors are broad and support the need for other objective factors that could augment prediction of patients who may benefit from early advanced cardiac care.