Yield of Routine Provocative Cardiac Testing Among Patients in an Emergency Department–Based Chest Pain Unit

Abstract

The American Heart Association recommends routine provocative cardiac testing in accelerated diagnostic protocols for coronary ischemia. The diagnostic and therapeutic yield of this approach are unknown. To assess the yield of routine provocative cardiac testing in an emergency department-based chest pain unit. We examined a prospectively collected database of patients evaluated for possible acute coronary syndrome between March 4, 2004, and May 15, 2010, in the emergency department-based chest pain unit of an urban academic tertiary care center. Patients with signs or symptoms of possible acute coronary syndrome and without an ischemic electrocardiography result or a positive biomarker were enrolled in the database. All patients were evaluated by exercise stress testing or myocardial perfusion imaging. Demographic and clinical features, results of routine provocative cardiac testing and angiography, and therapeutic interventions were recorded. Diagnostic yield (true-positive rate) was calculated, and the potential therapeutic yield of invasive therapy was assessed through blinded, structured medical record review using American Heart Association designations (class I, IIa, IIb, or lower) for the potential benefit from percutaneous intervention. In total, 4181 patients were enrolled in the study. Chest pain was initially reported in 93.5%, most (73.2%) were at intermediate risk for coronary artery disease, and 37.6% were male. Routine provocative cardiac testing was positive for coronary ischemia in 470 (11.2%), of whom 123 underwent coronary angiography. Obstructive disease was confirmed in 63 of 123 (51.2% true positive), and 28 (0.7% overall) had findings consistent with the potential benefit from revascularization (American Heart Association class I or IIa). In an emergency department-based chest pain unit, routine provocative cardiac testing generated a small therapeutic yield, new diagnoses of coronary artery disease were uncommon, and false-positive results were common.