Changes in the numeric descriptive scale for pain after sublingual nitroglycerin do not predict cardiac etiology of chest pain

Study objective: We determine whether the change in numeric descriptive scale for pain after sublingual nitroglycerin use can predict cardiac etiology of chest pain. Methods: A prospective study of a convenience sample of patients who had chest pain, presented to the emergency department from May 24, 2001, to April 30, 2002, and received sublingual nitroglycerin during their evaluation was performed. The 11-point numeric descriptive scale for chest pain was recorded before and after the initial dose of sublingual nitroglycerin. Cardiac-related pain was defined as chest pain in a patient with a discharge diagnosis of myocardial infarction or the diagnosis of coronary artery disease based on a positive diagnostic study (cardiac catheterization or noninvasive stress imaging). Change in the numeric descriptive scale was divided into 4 categories: (1) significant/complete reduction; (2) moderate reduction; (3) minimal reduction; and (4) no change. Results: The study cohort was composed of 664 patients: 345 women (52%) and 319 men (48%), mean age 52 years (±12.4 years). Cardiac-related chest pain was identified in 122 patients (18%). In the overall patient population, 125 (19%) patients had no change in pain, 206 (31%) patients had minimal reduction, 145 (22%) patients had moderate reduction, and 188 (28%) patients had significant or complete reduction in pain. There was no significant difference in any subgroup of numeric descriptive scale response to sublingual nitroglycerin administration in patients with and without a diagnosis of cardiac chest pain. Conclusion: In this convenience sample, the response of chest pain to sublingual nitroglycerin was not a reliable indicator of a cardiac etiology.