RESUMO
Objetivo: Investigar si la hora del día influye en la efectividad de la terapia trombolítica prehospitalaria en pacientes con infarto agudo de miocardio con elevación del segmento ST (IAMCEST). Método: Estudio observacional de cohortes retrospectivo con pacientes diagnosticados de IAMCEST a quienes se les realizó trombolisis precoz prehospitalaria. Se analizaron, como variables predictoras independientes de la efectividad de la terapia trombolítica, la hora del día de administración de la terapia trombolítica (variable principal), divididos en periodos horarios de 6 h y de 12 h, la edad, el sexo, la hora inicio del dolor torácico, tiempo de evolución del infarto, los factores de riesgo cardiovascular y el área de localización del infarto. Los datos se obtuvieron de la historia clínica y del seguimiento de preavisos hospitalarios a las 24 h. Resultados: Se incluyó a 206 pacientes. Dos variables se muestran como predictores independientes de la efectividad de la trombolisis prehospitalaria: la hora del día de administración de la terapia trombolítica, en el rango de cronorriesgo cardiovascular de 6a 12 h, con respecto al resto de franjas horarias (0-6 h, 12-18 h, 18-24 h) [p = 0,005odds ratio (OR) = 2,46; intervalo de confianza (IC) del 95%, 1,30-4,64] y presentar cardiopatía isquémica previa) (p = 0,003, OR = 5,30; IC del 95%, 1,74-16,15).Conclusiones: Encontramos variaciones circadianas clínicamente significativas en la efectividad del tratamiento trombolítico prehospitalario administrado a los pacientes con IAMCEST, independientemente del agente trombolítico empleado, de manera que existe una tromborresistencia matinal (6-12 am) al tratamiento y una mayor efectividad de reperfusión coronaria cuando se administra en el resto de franjas horarias diurnas ,especialmente en la de tarde (12-18 h) (AU)
Objective: To study whether time of day influences the effectiveness of prehospital thrombolysis in patients who have had acute myocardial infarction with ST-segment elevation (STEMI).Methods: Observational study of retrospective cohorts. We included patients diagnosed with STEMI who received early application of prehospital thrombolytic therapy. The main variable studied as an independent predictor of effectiveness was the time of day the thrombolytic agent was administered; this variable was studied in 6-hour periods and 12-hourperiods. Additional independent variables were patient age and sex, onset of chest pain, duration of pain from onset until administration of the thrombolytic agent, cardiovascular risk factors, and location of infarction. Data were extracted from patient records and ambulance pre-alert calls in the next 24 hours. Results: Two hundred six patients were studied. The 2 independent variables that predicted the effectiveness of prehospital thrombolysis were administration of the thrombolytic agent at a time of day within the period of greatest cardiovascular risk (6 AM to 12 noon) in comparison with the other time frames (12 midnight to 6 AM, 12 noon to 6 PM and 6 PM to midnight) (odds ratio [OR], 2.46; 95% CI, 1.30-4.64; P=.005) and history of ischemic heart disease (OR,5.30; 95% CI, 1.74-16.15; P=.003).Conclusions: We found that circadian rhythm had a clinically significant effect on the effectiveness of prehospital thrombolysis in STEMI patients. The effect was present regardless of which thrombolytic agent was used. The greatest resistance to therapy was observed in the morning hours between 6 AM and 12 noon. The response was greater in the remaining time frames and greatest in the hours between noon and 6 PM (AU)
