Effects of age, race, and sex on door-to-electrocardiogram time in emergency department non-ST elevation acute coronary syndrome patients

Background: Chest pain is a frequent complaint in the Emergency Department (ED), and an electrocardiogram (ECG) should be performed quickly to detect acute ST-segment elevation myocardial infarction. Previous studies have demonstrated disparities in cardiovascular care due to factors such as age, race, or sex; these studies have used non-homogenous populations across multiple sites of treatment, which may confound their results. Study Objective: Our hypothesis was that, within a single center, demographic characteristics would not influence door-to-ECG time in ED patients with non-ST elevation acute coronary syndrome (NSTACS). Methods: We performed a retrospective cohort study of patients presenting to the ED with NSTACS, requiring ECG changes or elevated cardiac biomarkers for inclusion, between 2001 and 2005. Multiple variable linear regression was used to evaluate the impact of race, sex, and age on door-to-ECG time. Results: There were 247 patients who met inclusion criteria over the study period. The mean age was 62 ± 14 years; 159 (64%) were white, and 151 (61%) were male. The mean time to ECG was 25.6 ± 32.4 min. Neither age, sex, nor race had a significant impact on door-to-ECG time in either univariate or multiple variable modeling. A full model including age, sex, and race as well as all potential two-way interactions had minimal predictive ability (R² = 0.015). Conclusion: Within a single center, demographic characteristics had no impact on door-to-ECG performance time. We follow with a discussion of statistical methods available to adjust for clustering of observations in multicenter trials.