[Interobserver correlation in the interpretation of 99mTc-sestamibi SPECT in reperfused acute myocardial infarction]. / Correlación interobservadores en interpretación de SPECT de perfusión con 99mTc-sestamibi en infarto agudo de miocardio reperfundido.

INTRODUCTION AND OBJECTIVES: The correct interpretation of myocardial perfusion single photon emission computed tomography (SPECT) requires knowledge of the technique reproducibility. The objective was analyze the interobserver correlation of different experience in the interpretation of myocardial perfusion SPECT in patients following acute myocardial infarction (AMI) in order to improve the quality of our site. METHODS: Sixty cases (56 +/- 11 years, 87 % men) with transmural AMI who had recently undergone successful thrombolysis were included. Resting perfusion with (99m)Tc-sestamibi was performed at one week post-AMI. ANALYSIS: Semiquantitative interpretation using 17 segment-model by 2 independent specialists and 5 observers, was performed blindly. Left ventricular ejection fraction (LVEF) was measured with isotopic ventriculography one month after AMI, with a mean of 38 %. RESULTS: Using independent and then agreed on perfusion analysis, average involved segments/patient was 9.3 +/- 4 and the sum of severity 25 +/- 13. Readings of other observers ranged from 7 +/- 3.7 to 9.4 +/- 3.9 and 16.7 +/- 9.7 to 24.6 +/- 13, respectively, consistent with the reading of the specialists of between 0.779-0.871 (kappa: 0.565-0.741). There was no significant difference when the number of segments were analyzed in 40 % of the cases and for intensity in 60 % of them in more experienced observers. Correlation with consensus reading for the number of segments ranged from 0.84 to 0.94 and for severity from 0.79 to 0.89. Identification of culprit arteries was acceptable, with r values between 0.612 and 0.683 and kappas between 0.629 and 0.656. Correlation of the number of involved segments and severity with LVEF performed one month after AMI was 0.73 and 0.74, respectively. CONCLUSIONS: There was good correlation in the interpretation of myocardial perfusion SPECT, with a significantly better fit in more experienced observers. This academic exercise was also helpful in improving our residents' skills in cardiology.

Correlación interobservadores en interpretación de SPECT de perfusión con 99mTc-sestamibi en infarto agudo de miocardio reperfundido / Interobserver correlation in the interpretation of 99mTc-sestamibi SPECT in reperfused acute myocardial infarction

Introducción y objetivos. La interpretación de la tomografía de emisión de fotón único (SPECT) de perfusión miocárdica requiere conocer la reproducibilidad de la técnica. El objetivo fue analizar la correlación interobservadores de distinta experiencia en interpretación de SPECT en pacientes post-infarto agudo de miocardio (IAM) en un contexto de mejora de la calidad de nuestros centros. Métodos. Se incluyeron 60 casos (56 ± 11 años, 87 % hombres) con infarto transmural reciente sometidos a trombolisis exitosa. Una semana después del IAM se efectuó perfusión de reposo con 99mTc-sestamibi. Análisis. Semicuantitativo mediante lectura ciega por 2 especialistas independientes y 5 observadores utilizando 17 segmentos. La fracción de eyección ventricular izquierda (FEVI) promedio medida con ventriculografía isotópica al mes fue del 38 %. Resultados. En análisis consensuado, el promedio de segmentos comprometidos/paciente fue 9,3 ± 4 y la sumatoria de severidad 25 ± 13; los otros observadores variaron entre: 7 ± 3,7-9,4 ± 3,9 y 16,7 ± 9,7-24,6 ± 13, respectivamente, concordando con los especialistas entre 0,779 y 0,871 (kappa: 0,565-0,741). No hubo diferencia significativa en el 40 % de los análisis para el número de segmentos comprometidos y en el 60 % para intensidad, en observadores con mayor experiencia. La correlación con consenso para el número de segmentos varió entre 0,84 y 0,94, y para severidad entre 0,79 y 0,89. La asignación de arterias fue adecuada (r: 0,612-0,683 y kappas 0,629-0,656). La correlación de segmentos comprometidos y su severidad con la FEVI efectuada al mes del IAM fueron de 0,73 y 0,74, respectivamente. Conclusiones. Existió buena correlación en interpretación de SPECT, con mejor ajuste en observadores experimentados. Este ejercicio sirvió para mejorar habilidades de interpretación en cardiología

Introduction and objectives. The correct interpretation of myocardial perfusion single photon emission computed tomography (SPECT) requires knowledge of the technique reproducibility. The objective was analyze the interobserver correlation of different experience in the interpretation of myocardial perfusion SPECT in patients following acute myocardial infarction (AMI) in order to improve the quality of our site. Methods. Sixty cases (56 ± 11 years, 87 % men) with transmural AMI who had recently undergone successful thrombolysis were included. Resting perfusion with 99mTc-sestamibi was performed at one week post-AMI. Analysis. Semiquantitative interpretation using 17 segment-model by 2 independent specialists and 5 observers, was performed blindly. Left ventricular ejection fraction (LVEF) was measured with isotopic ventriculography one month after AMI, with a mean of 38 %. Results. Using independent and then agreed on perfusion analysis, average involved segments/patient was 9.3 ± 4 and the sum of severity 25 ± 13. Readings of other observers ranged from 7 ± 3.7 to 9.4 ± 3.9 and 16.7 ± 9.7 to 24.6 ± 13, respectively, consistent with the reading of the specialists of between 0.779-0.871 (kappa: 0.565-0.741). There was no significant difference when the number of segments were analyzed in 40 % of the cases and for intensity in 60 % of them in more experienced observers. Correlation with consensus reading for the number of segments ranged from 0.84 to 0.94 and for severity from 0.79 to 0.89. Identification of culprit arteries was acceptable, with r values between 0.612 and 0.683 and kappas between 0.629 and 0.656. Correlation of the number of involved segments and severity with LVEF performed one month after AMI was 0.73 and 0.74, respectively. Conclusions. There was good correlation in the interpretation of myocardial perfusion SPECT, with a significantly better fit in more experienced observers. This academic exercise was also helpful in improving our residents' skills in cardiology