Is Duration of Symptoms Predictive of Acute Myocardial Infarction?

Patient interviews regarding the duration of symptoms are commonly conducted when evaluating a patient with possible acute myocardial infarction (AMI) and are believed to distinguish between AMI and non-AMI symptoms. In a single center, 569 patients evaluated in the emergency department (ED) for possible AMI from May 2013 to April 2015 were prospectively studied. Patients in the ED were asked by trained research personnel about the duration of their predominant symptom. The final diagnosis of AMI was determined by an independent cardiologist and emergency medicine physician in accordance with the third universal definition of AMI. Disagreements were settled by a third physician (cardiologist) who reviewed the case. There were 44 (8%) AMIs and 484 (85%) patients had chest pain as their predominant symptom. In the 26 type 1 AMIs, the median symptom duration was 3.3 hours, while in the 18 type 2 AMIs it was 1.3 hours. AMI was not present if symptom duration was under 20 minutes and was more likely during the 20-59 minute period. In conclusion, clinical symptoms still play a prominent role in the evaluation of a patient with possible AMI in the ED. Duration of symptoms was not very helpful in distinguishing between patients with AMI and those with non-AMI, except in the time interval of 20-59 minutes.