The shock index (IS) is the quotient between the heart rate (HR) and the systolic blood pressure (SBP) (IS: HR / SBT), and the age-adjusted shock index (ISA) multiplying the IS by age. We evaluated its predictive value for the combined in-hospital event (EC), death and / or cardiogenic shock (CS) and for individual events in the patients included in the Argentine registry of ST-segment elevation infarction (ARGEN-ST-AMI); 248 with CS on admission were excluded. ROC curves were made for both indices using the best cut-off point to dichotomize the population. The analysis included 2928 subjects. Age (median) 60 years (IQR 25-75% 53-68), men 80%, EC: 6.4%; 30.5% had IS = 0.67, and they had a higher incidence of EC: 11% vs. 4% (p < 0.001), cardiogenic shock (8% vs. 2.6%, p <0.0001) and death (7.3% vs. 3%), p <0.0001) than patients with IS < 0.67. A 28% had ISA = 41.5. These presented plus EC: 14% vs. 3%, p < 0.001, SC: 10% vs. 2%, (p < 0.001) and death: 9.5% vs. 2.3%, (p < 0.001) compared with patients with values < 41.5. The area under the ROC curve of the ISA for EC was significantly better than that of the IS (0.72 vs. 0.62, p < 0.001). In the multivariate analysis models performed, the IS had an OR: 2.56 (95% CI 1.56-4.02; p < 0.001) and the ISA: 3.43 (95% CI 2.08-5.65; p < 0.001) for EC. The IS and ISA predict death and / or the development of in-hospital cardiogenic shock in an unselected population of ST elevation infarcts.
El índice de shock (IS) se obtiene mediante un cálculo simple del cociente entre la frecuencia cardíaca (FC) y la tensión arterial sistólica (PAS) (IS: FC/TAS) y el índice de shock ajustado por edad (ISA) multiplicando el IS x edad. Evaluamos su valor predictivo para el evento combinado intrahospitalario (EC) muerte y/o shock cardiogénico (SC) y de los eventos individuales en los pacientes incluidos en el registro argentino de infarto con elevación del segmento ST (ARGEN-IAM-ST). Se excluyeron 248 con SC de ingreso. Se realizaron curvas ROC para ambos índices utilizando el mejor punto de corte para dicotomizar la población. Se incluyeron 2928 pacientes. Edad (mediana) 60 años (RIC 25-75% 53-68), varones 80%, EC: 6.4%. Un 30.5% tuvo IS = 0.67 y éstos presentaron mayor incidencia de EC: 11% vs. 4% (p < 0.001), shock cardiogénico (8% vs. 2.6%, p <0.0001) y muerte (7.3% vs. 3%, p < 0.0001) que los pacientes con IS < 0.67. Un 28% tuvo ISA = 41.5. Estos presentaron más EC: 14% vs. 3%, p < 0.001, SC: 10% vs. 2%, (p < 0.001) y muerte: 9.5% vs. 2.3%, (p < 0.001) comparados con los pacientes con valores ISA < 41.5. El área bajo la curva ROC del ISA para EC fue significativamente mejor que la del IS (0.72 vs. 0.62, p < 0.001).En los modelos de análisis multivariados realizados, el IS tuvo un OR de 2.56 (IC95% 1.56-4.02; p < 0.001) y el ISA de 3.43 (IC95% 2.08-5.65; p <0.001) para EC. El IS y el ISA predicen muerte y/o el desarrollo de shock cardiogénico intrahospitalario en una población no seleccionada de infartos con elevación del ST.
Keywords: cardiogenic shock; mortality; myocardial infarction; prognostic.