Zero calcium scores is not reliable to rule out coronary artery disease in the emergency room

Abstract

Introduction: Several diagnostic tools have been proposed to investigate patients with acute chest pain in the emergency room. Recently, coronary computed angiotomography (CTA) has been studied for this purpose. Since CTA has some limitations including the use of ionizing radiation, iodine contrast and the need of drugs such as beta blockers and nitrates to achieve good image quality some authors have suggested that a negative calcium score would yield those patients with very low risk in which CTA could be safely avoided. Objectives: Evaluate the diagnostic accuracy of a negative calcium score when compared with CTA in the acute setting and subsequent downstream evaluation Methods: 65 patients (32 female) with acute chest pain, normal eletrocardiogram and cardiac biomarkers who underwent calcium score and CTA which had a negative calcium score were included. The exams were performed in a 64 detectors CT device with standard settings, and the CTA was performed using prospective acquisition, after beta blocker and nitrate unless contraindicated. The calcium score exams were compared to the CTA results. The CTA was considered positive if any lesion 50% was identified. Results: 65 patients were evaluated from February to August 2011. The mean age was 53.8 14.7 years and mean heart rate was 62 bpm. 2 of these zero calcium scores had non obstructive disease (50%), 3 of these zero calcium scores had obstructive disease and 1 patient had an invaluable CTA due to motion artifacts. These last 4 patients were furtherstratified with invasive coronary angiography and all 4 underwent coronary angioplasty. Conclusion: 8.2% of the patients with coronary artery disease would be misdiagnosed if coronary calcium score was used as the sole imaging strategy in this sample. Not only that, 4 patients which had an intervention performed would remain untreated.