Background: Research has shown the safety and effectiveness of drawing a standard troponin level at presentation and again at 2 hours in only low-risk patients. Because high-sensitivity troponins are not currently approved in the United States, we studied the utility of a standard troponin that is presently in use. Our goal was to determine if 2-hour standard troponin would be safe and effective in the evaluation of a high-risk cohort of patients never studied previously.
Methods: We conducted a single-center prospective observational study of adult patients presenting to the emergency department with signs and symptoms suggestive of acute coronary syndrome. Patients were defined as high risk if the attending physician planned to admit or transfer the patient to the observation unit. History, Electrocardiography, Age, Risk factors, Troponin scores were calculated on all patients to provide verification that the individuals were high risk. The primary outcome was a composite of 30-day myocardial infarction, death, cardiac arrest with return of spontaneous circulation, or dysrhythmia. The secondary outcome was 30-day revascularization.
Results: We included a total of 122 patients with an average follow-up of 112 days (minimum 30 days). A total of 86% of cases had History, Electrocardiography, Age, Risk factors, Troponin scores ≥4. The primary outcome was met in 22 (18%) patients, and the secondary outcome occurred in 7 (5.7%) patients. The negative predictive value of negative 2-hour troponins along with no significant delta troponin rise was 98.7%.
Conclusions: Discharging patients thought to be high risk who have negative troponins at 0 and 2 hours and no delta troponin rise appears safe. No deaths occurred in follow-up. Larger studies are warranted.