Blog | Thursday, July 28, 2011

QD: News Every Day--Chest pain unrelated to heart attack severity

Severe chest pain isn't related to the likelihood of acute myocardial infarction at presentation or death, or to acute myocardial infarction or revascularization within 30 days, researchers found.

There are 6 million visits to the emergency department for chest pain, of which 2 million result in admissions each year, but only a minority of these have an ischemic cause.

But 2% to 5% of patients with acute myocardial infarction are inappropriately discharged, and failure to accurately diagnose acute myocardial infarction accounts for 20% of malpractice dollars. Attorneys glom onto high pain scores when questioning an emergency physician's judgment in discharging a patient.

So, researchers did a secondary analysis of a prospective cohort study of patients presenting with potential acute coronary syndrome to the emergency department of the Hospital of the University of Pennsylvania in Philadelphia. Pain on arrival was scored from 0 to 10 based on nurses' triage, with severe pain defined as 9 or 10. The primary outcome was acute myocardial infarction during the visit. Researchers also looked at death, acute myocardial infarction, revascularization including percutaneous coronary intervention, or coronary bypass artery grafting at 30 days. Results appeared at the Annals of Emergency Medicine.

Of 3,306 patients with chest pain documented upon admission, 3.2% were diagnosed with a myocardial infarction. Severe pain was not strongly associated (adjusted relative risk [aRR], 1.43; 95% confidence interval [CI], 0.91 to 2.22).

By 30 days, 34 patients had died, 105 patients underwent revascularization and 111 patients had a heart attack. There was no relationship between severe pain and acute myocardial infarction (relative risk [RR], 1.28; 95% CI 0.93 to 1.76) or 30-day composite outcome (RR, 1.19; 95% CI, 0.91 to 1.56). Inhospital acute myocardial infarction was not related to pain duration greater than 1 hour (aRR 1.36; 95% CI 0.89 to 2.07), or severe pain (aRR 1.43; 95% CI 0.91 to 2.22). Thirty-day outcomes were not related to pain duration greater than 1 hour (aRR 0.8; 95% CI 0.60 to 1.06), or severe pain (aRR 1.39; 95% CI 0.95 to 1.97).

Patients with chest pain should still be evaluated, the lead author commented. While chest pain is the chief complaint of the majority of patients with acute myocardial infarction, patients may not recognize as many as one third of myocardial infarctions.

"[A]lthough pain management is an important issue to address clinically, pain severity itself should not be a factor in evaluating patients' risk for acute coronary syndrome in terms of discharge decisions," the authors concluded. "Of course, it would still be important to relieve the pain for the sake of patient comfort."