Impacto de los datos clínicos y concordancia interhospitalaria en la interpretación de la tomogammagrafía miocárdica de perfusión

Abstract

The aim of this study is to analyze the impact of clinical data and the interhospital agreement in the interpretation of myocardial perfusion single photon emission tomography (SPECT) images and polar mapping. 150 patients from 5 hospitals were studied. Each center contributed with tomographic images and polar maps of 99mTc-tetrofosmin exercise SPECT and clinical reports of 30 patients. Thus, 300 images (150 of tomographic images and 150 of polar maps) were interpreted by each center without knowledge of clinical data of the patient ("blinded" report). 90 (60%) out of 150 patients had a coronary stenosis > or = 50%. Sensitivity and specificity of "non blinded" report were 91% and 86%, respectively. Sensitivity determined by majority decision (three or more centers) was 82% for tomographic images and 83% for polar maps (p = 0.002 and p = 0.03, respectively, regarding the "non-blinded" report). Specificity was 88% for tomographic images and 79% for polar map (p = 0.05 with respect to tomographic images). Interhospital agreement was good not only for tomographic images (kappa: 0.625) but for polar maps (kappa: 0.7) as well. Sensitivity of clinical or "non blinded" report of myocardial perfusion SPECT is significantly higher than the "blinded" report. Specificity of the "blinded" report of polar mapping is lower than that of tomographic images. A good interhospital agreement in interpretation of both types of images was observed.