Chest Pain Relief by Nitroglycerin Does Not Predict Active Coronary Artery Disease

Background: The belief that chest pain relief with nitroglycerin indicates the presence of active coronary artery disease is common. However, this hypothesis has not been tested. Objective: To define the diagnostic and prognostic value of chest pain relief with nitroglycerin. Design: Prospective observational cohort study. Setting: Urban community teaching hospital. Patients: 459 consecutive patients with chest pain admitted through the emergency department who received nitroglycerin from emergency services personnel or an emergency department nurse. Follow-up was obtained by telephone contact at 4 months. Measurements: Chest pain relief was defined as a decrease of at least 50% in patients' self-reported pain within 5 minutes of the initial dose of sublingual or spray nitroglycerin. Active coronary artery disease was defined as any elevated serum enzyme levels, coronary angiography demonstrating a 70% or greater stenosis, or a positive exercise test result. Results: Nitroglycerin relieved chest pain in 39% of patients (181 of 459). In patients with active coronary artery disease as the likely cause of their chest pain, 35% (49 of 141) had chest pain relief with nitroglycerin. In contrast, in patients without active coronary artery disease, 41% (113 of 275) had chest pain relief (P > 0.2). Four-month clinical outcomes were similar in patients with or without chest pain relief with nitroglycerin (P > 0.2). Conclusions: These data suggest that, in a general population admitted for chest pain, relief of pain after nitroglycerin treatment does not predict active coronary artery disease and should not be used to guide diagnosis.