[Comparison between electrocardiographic test with dobutamine and exercise stress testing on coronary risk stratification]. / Valor del test de dobutamina comparado con la ergometría en la evaluación de riesgo coronario.

The exercise testing is still the most common test used to stratify the patients's risk of new events following an acute myocardial infarction, but about 20 to 40% of the patients can not perform it appropriately. Since the electrocardiographic test with dobutamine has proved to be easy and safe, our aim was to evaluate its capacity to predict the results of the exercise testing on patients after an acute myocardial infarction. A total of 210 patients (average of age 60.5+/-11.7 years old and 23.3% females) recovering from a first uncomplicated myocardial infarction, were consecutively included. An electrocardiographic test with dobutamine was performed during the fifth day of admission, and an exercise test during the sixth. The development of chest pain and/or a descending ST segment > or = 1 mm during a test qualified it as positive for ischemia. The sensitivity, specificity, positive and negative predictive values of both tests were determinated, as well as the congruence on their results, a p-value < 0.05 was considered as statistically significative. Whereas 91 patients achieved a positive result on the electrocardiographic dobutamine tests, 54 patients were positive during exercise. On the other hand, both tests came up positive in 49 patients, and negative in 114 patients. The hemodynamic variables were similar during both tests, except in those patients with negative results with both methods, who developed a higher maximal arterial pressure and double product during exercise. Accordingly, the electrocardiographic dobutamine test showed a sensivity 90.17%, a specificity 73%, positive and negative predictive values 54% and 95.8%, respectively, to predict the results of the exercise testing, with a Kappa value of 0.52. In conclusion, the electrocardiographic dobutamine test showed not only to predict the results of the exercise testing adequately with a high negative predictive value, but also to be safe, a useful and simple diagnostic tool for the evaluation of patients after an acute myocardial infarction.

Valor del test de dobutamina comparado con la ergometria en la evaluacion de riesgo coronario / Comparison between electrocardiographic test with dobutamine and exercise stress testing on coronary risk stratification

La ergometría es el método de elección para estratificar el riesgo de eventos luego de un infarto agudo de miocardio, pero el 20-40% de la población no puede realizarla. La utilización de dobutamina con control electrocardiográfico es una propuesta segura, fácil de realizar y reproducible. Nuestro objetivo fue evaluar la utilidad de dicho test para predecir los resultados de la ergometría en pacientes (49 mujeres), edad: 60.5+/- 11.7 años con primer infarto agudo de miocardio no complicado. Se realizó al quinto día del test de dobutamina con control electrocardiográfico y al sexto día la ergometría. Se consideró positiva la presencia de angor y/o infradesnivel del segmento ST mayor ou igual 1mV en ambas pruebas. Se determinó sensibilidad, especificidad, valor predictivo positivo y negativo del test de dobutamina, test de concordancia y valor kappa, con p>0.05. El test de dobutamina fue positivo en 91 casos. La ergometría fue positiva en 54 pacientes. No hubo diferencias hwemodinámicas entre ambos métodos. Cuarenta y nueve presentaron ambas pruebas positivas sin diferencias en las variables analizadas; 114 pacientes ambas negativas, en los que durante la ergometría se alcanzó mayor presión arterial y doble producto máximo. En 47 los resultados fueron discorfdantes. El test dobutamina predijo los resultados de la ergometría con sensibilidad: 90.7% (IC95%:78.9-96.5%), especificidad: 73%(IC95%:65.3-79.7%), valor predictivo positivo:54% (IC95%:43.1-62.2%) y negativo: 95.8% (IC95%:89.9-98.4%), concordancia: 77% (IC95%:53-74) y valor kappa:0.52 (IC95%:0.41-0.63). El test de dobutamina predijo los resultados de la ergometría con adecuadas sensibilidad, especificidad y valor predictivo positivo; se destaca el alto valor predictivo negativo del método que resultó un procedimiento seguro, eficaz y sencillo.