ACS risk similar with normal ECG performed during presence or absence of chest pain

Clinical Question

Is the risk of acute coronary syndrome lower in adults with a normal electrocardiogram performed during the presence of chest pain?

Bottom Line

The presence or absence of chest pain during the acquisition of a normal electrocardiogram (ECG) result does not change the subsequent risk of acute coronary syndrome (ACS). (LOE = 1b)

Reference

Turnipseed SD, Trythall WS, Diercks DB, et al. Frequency of acute coronary syndrome in patients with normal electrocardiogram performed during presence or absence of chest pain. Acad Emerg Med 2009;16(6):495-499.  [PMID:19426294]

Study Design

Cohort (prospective)

Funding

Unknown/not stated

Setting

Emergency department

Synopsis

Most clinicians are taught that a normal ECG result in the presence of chest pain (as opposed to no active pain) significantly reduces the likelihood of ongoing cardiac ischemia. These investigators identified 387 adults, aged 25 to 90 years, presenting to the emergency department with a chief complaint of chest pain suspicious for ACS. All patients had an initial ECG interpreted as normal and underwent standard evaluation for ACS (2 or more measurements of serum troponin I over 6 hours). More than 25% of the patients had a history of coronary artery disease. Two individuals masked to patient outcomes independently interpreted the initial ECG performed in the emergency department as normal or abnormal. Differences were resolved after consensus agreement with a third individual. At the time of the initial ECG, 126 (33%) of patients had no chest pain and 261 (67%) had active pain. The groups were similar in age, sex, cardiac risk factors, and known coronary artery disease. Of the total study group, 67 (17%) met standard diagnostic criteria for ACS. The presence or absence of chest pain during the acquisition of a normal ECG was not significantly associated with the prevalence of ACS: 16% (42/261) versus 20% (25/126), respectively.