Prognostic Scale to Stratify Risk of Intrahospital Death in Patients with Acute Myocardial Infarction with ST-Segment Elevation.

INTRODUCTION The scales available to predict death and complica-tions after acute coronary syndrome include angiographic studies and serum biomarkers that are not within reach of services with limited resources. Such services need specifi c and sensitive instruments to evaluate risk using accessible resources and information. OBJECTIVE Develop a scale to estimate and stratify the risk of intra-hospital death in patients with acute ST-segment elevation myocardial infarction. METHODS An analytical observational study was conducted in a universe of 769 patients with acute ST-segment elevation myocardial infarction who were admitted consecutively to the Camilo Cienfuegos Provincial Hospital in Sancti Spíritus Province, Cuba, from January 2013 to March 2018. The fi nal study cohort included 667 patients, ex-cluding 102 due to branch blocks, atrial fi brillation, drugs that prolong the QT interval, low life expectancy or history of myocardial infarction. The demographic variables of age, sex, skin color, classic cardiovas-cular risk factors, blood pressure, heart rate, blood glucose level, in addition to duration and dispersion of the QT interval with and without correction, left ventricular ejection fraction, and glomerular fi ltration rate were included in the analysis. Patients were categorized according to the Killip-Kimball Classifi cation for degree of heart failure. A risk scale was constructed, the predictive ability of which was evaluated using the detectability index associated with an receiver-operator curve.RESULTS Seventy-seven patients died (11.5%). Mean blood glucose levels were higher among the deceased, while their systolic and dia-stolic blood pressure, left ventricular ejection fraction, and glomerular fi ltration rate were lower than those participants discharged alive. Rel-evant variables included in the scale were systolic blood pressure, Killip-Kimball class, cardiorespiratory arrest, glomerular fi ltration rate, corrected QT interval dispersion, left ventricular ejection fraction, and blood glucose levels. The variable with the best predictive ability was cardiorespiratory arrest, followed by a blood glucose level higher than 11.1 mmol/L. The scale demonstrated a great predictive ability with a detectability index of 0.92. CONCLUSIONS The numeric scale we designed estimates and strati-fi es risk of death during hospitalization for patients with ST-segment elevation myocardial infarction and has good metric properties for predictive ability and calibration. KEYWORDS ST-segment elevation myocardial infarction, mortality, risk assessment, Cuba.

Dispersión del intervalo QT corregido como predictor de arritmias ventriculares en el infarto agudo del miocardio / Dispersion of the corrected QT interval as a predictor of ventricular arrhythmias in acute myocardial infarction

RESUMEN Fundamento: La dispersión del intervalo QT es un marcador electrocardiográfico que puede resultar útil en la estratificación de riesgo arrítmicos en pacientes con infarto agudo del miocardio. Objetivo: Describir la influencia de la dispersión del intervalo QT corregido en asociación a otros factores de riesgo como predictores de arritmias ventriculares en el infarto agudo del miocardio con elevación del segmento ST. Metodología: Se estudiaron de menera prospectiva 209 pacientes que ingresaron de forma consecutiva con diagnóstico de infarto agudo de miocardio con elevación del segmento ST de enero de 2013 a junio de 2014 en el Hospital Provincial General Camilo Cienfuegos de Sancti Spíritus. Se recogieron datos clínicos, de laboratorio electrocardiográficos y ecocardiográficos; se determinó la implicación pronóstica de la dispersión del intervalo QT corregido en la aparición de arritmias ventriculares a través de la regresión logística binaria y las curvas de operador-receptor. Resultados: Las arritmias ventriculares se presentaron en 39 (18.7 %) pacientes. La dispersión del QT corregido mostró una adecuada capacidad de discriminación en la predicción de cualquier episodio arrítmico ventricular grave (c=0.768, p=0.0001). En el análisis multivariado la dispersión del QT resultó un predictor independiente de arritmias ventriculares (OR= 7.075; IC 95%= 1.6- 32.9; p=0.009). Conclusiones: La probabilidad de presentar arritmias ventriculares durante el infarto agudo del miocardio es mayor cuando se incrementan la dispersión del intervalo QT, por lo que se sugiere debe ser una variable a evaluar en la estratificación pronostica del infarto agudo del miocardio.(AU)

ABSTRACT Background: Dispersion of the QT interval is an electrocardiographic marker that can be useful in the stratification of arrhythmic risk in patients with acute myocardial infarction. Objective: To describe the influence of corrected QT interval dispersion in association with other risk factors as predictors of ventricular arrhythmias in acute myocardial infarction with ST-segment elevation. Methodology: 209 patients who entered consecutively with diagnosis of acute myocardial infarction with elevation of the ST segment from January 2013 to June 2014 at Camilo Cienfuegos General Provincial Hospital of Sancti Spíritus were studied prospectively. Clinical, electrocardiographic and echocardiographic laboratory data were collected; the prognostic implication of the corrected QT interval dispersion in the appearance of ventricular arrhythmias through binary logistic regression and operator-receiver curves was determined. Results: Ventricular arrhythmias occurred in 39 (18.7%) patients. The dispersion of the corrected QT showed an adequate discrimination capacity in the prediction of any serious ventricular arrhythmic episode (c = 0.768, p = 0.0001). In the multivariate analysis, QT dispersion was an independent predictor of ventricular arrhythmias (OR = 7.075, 95% CI = 1.6-32.9, p = 0.009). Conclusions: The probability of presenting ventricular arrhythmias during acute myocardial infarction is greater when the dispersion of the QT interval is increased, so it is suggested that it should be a variable to be evaluated in the prognostic stratification of acute myocardial infarction.(AU)

Dispersión del intervalo QT corregido como predictor de arritmias ventriculares en el infarto agudo del miocardio / Dispersion of the corrected QT interval as a predictor of ventricular arrhythmias in acute myocardial infarction

RESUMEN Fundamento: La dispersión del intervalo QT es un marcador electrocardiográfico que puede resultar útil en la estratificación de riesgo arrítmicos en pacientes con infarto agudo del miocardio. Objetivo: Describir la influencia de la dispersión del intervalo QT corregido en asociación a otros factores de riesgo como predictores de arritmias ventriculares en el infarto agudo del miocardio con elevación del segmento ST. Metodología: Se estudiaron de menera prospectiva 209 pacientes que ingresaron de forma consecutiva con diagnóstico de infarto agudo de miocardio con elevación del segmento ST de enero de 2013 a junio de 2014 en el Hospital Provincial General Camilo Cienfuegos de Sancti Spíritus. Se recogieron datos clínicos, de laboratorio electrocardiográficos y ecocardiográficos; se determinó la implicación pronóstica de la dispersión del intervalo QT corregido en la aparición de arritmias ventriculares a través de la regresión logística binaria y las curvas de operador-receptor. Resultados: Las arritmias ventriculares se presentaron en 39 (18.7 %) pacientes. La dispersión del QT corregido mostró una adecuada capacidad de discriminación en la predicción de cualquier episodio arrítmico ventricular grave (c=0.768, p=0.0001). En el análisis multivariado la dispersión del QT resultó un predictor independiente de arritmias ventriculares (OR= 7.075; IC 95%= 1.6- 32.9; p=0.009). Conclusiones: La probabilidad de presentar arritmias ventriculares durante el infarto agudo del miocardio es mayor cuando se incrementan la dispersión del intervalo QT, por lo que se sugiere debe ser una variable a evaluar en la estratificación pronostica del infarto agudo del miocardio.

ABSTRACT Background: Dispersion of the QT interval is an electrocardiographic marker that can be useful in the stratification of arrhythmic risk in patients with acute myocardial infarction. Objective: To describe the influence of corrected QT interval dispersion in association with other risk factors as predictors of ventricular arrhythmias in acute myocardial infarction with ST-segment elevation. Methodology: 209 patients who entered consecutively with diagnosis of acute myocardial infarction with elevation of the ST segment from January 2013 to June 2014 at Camilo Cienfuegos General Provincial Hospital of Sancti Spíritus were studied prospectively. Clinical, electrocardiographic and echocardiographic laboratory data were collected; the prognostic implication of the corrected QT interval dispersion in the appearance of ventricular arrhythmias through binary logistic regression and operator-receiver curves was determined. Results: Ventricular arrhythmias occurred in 39 (18.7%) patients. The dispersion of the corrected QT showed an adequate discrimination capacity in the prediction of any serious ventricular arrhythmic episode (c = 0.768, p = 0.0001). In the multivariate analysis, QT dispersion was an independent predictor of ventricular arrhythmias (OR = 7.075, 95% CI = 1.6-32.9, p = 0.009). Conclusions: The probability of presenting ventricular arrhythmias during acute myocardial infarction is greater when the dispersion of the QT interval is increased, so it is suggested that it should be a variable to be evaluated in the prognostic stratification of acute myocardial infarction.