Validation of the San Francisco Syncope Rule in Two Hospital Emergency Departments in an Asian Population

Objectives The objective was to externally validate the ability of the San Francisco Syncope Rule (SFSR) to accurately identify patients who will experience a 7-day serious clinical event in an Asian population. Methods This was a prospective cohort study, with a sample of adult patients with syncope and near-syncope enrolled. Patients 12 years old and below and patients with loss of consciousness after head trauma, a witnessed seizure, with known alcohol or illicit drug ingestion, and altered level of consciousness or persistent new neurologic deficits were excluded. The patients were evaluated for the presence of one or more of the five SFSR variables: shortness of breath, history of heart failure, hematocrit <30%, systolic blood pressure <90 mm Hg, and abnormal electrocardiogram (ECG). The patients were followed up by medical record review or telephone interview. Seven-day outcomes were death, arrhythmia, myocardial infarction, acute pulmonary edema, significant structural heart disease, pulmonary embolism, major cardiac procedure, stroke, subarachnoid hemorrhage, major bleeding, and anemia. Results A total of 1,250 patients from two centers were recruited. Fifty-six patients were excluded from primary analysis because of incomplete data (n = 55) and/or they were noncontactable for follow-up (n = 32). Of the 1,194 patients analyzed, 138 patients (11.6%) experienced adverse outcomes at 7 days. The rule performed with a sensitivity of 94.2% (95% confidence interval [CI] = 89.0% to 97.0%) and a specificity of 50.8% (95% CI = 47.7% to 53.8%). Conclusions In this study, SFSR rule had a sensitivity of 94.2%. This suggests caution on the strict application of the rule to all patients presenting with syncope. It should only be used as an aide in clinical decision-making in this population. Resumen Validacion en una Poblacion Asiatica de la Escala de Sincope de San Francisco en Dos Servicios de Urgencias Hospitalarios Objetives Validar externamente la capacidad de la Escala de Sincope de San Francisco (San Francisco Syncope Rule (SFSR)) para identificar con certeza los pacientes que experimentaran un evento clinico grave a los 7 dias siguientes en una poblacion asiatica. Metodologia Estudio de cohorte prospectivo que incluyo pacientes adultos con sincope o presincope. Se excluyeron los pacientes de 12 anos o menos, pacientes con perdida de consciencia tras un traumatismo craneoenfalico, con crisis presenciada o ingesta conocida de alcohol o toxicos, y pacientes con un nivel de conciencia alterado o un nuevo deficit neurologico persistente. Se evaluo la presencia de uno o mas de las cinco variables de la SFSR: dificultad respiratoria, historia de insuficiencia cardiaca, hematocrito <30%, presion arterial sistolica <90 mmHg y alteraciones electrocardiograficas. Se siguio a los pacientes mediante la revision de las historias clinicas o entrevista telefonica. Los resultados a los siete dias fueron muerte, arritmia, infarto de miocardio, edema agudo de pulmon, cardiopatia estructural significativa, embolia de pulmon, procedimiento cardiaco mayor, ictus, hemorragia subaracnoidea, sangrado mayor y anemia. Resultados Se reclutoa un total de 1.250 pacientes entre los dos centros. Se excluyeron 56 pacientes del analisis primario por datos incompletos (n = 55) y/o por falta de contacto en el seguimiento (n = 32). De los 1.194 pacientes analizados, 138 pacientes (11,6%) experimentaron resultados adversos a los siete dias. La escala tuvo una sensibilidad del 94,2% (IC 95% = 89,0% a 97,0%) y una especificidad del 50,8% (IC 95% = 47,7% a 53,8%). Conclusiones En el presente estudio, la escala tuvo una sensibilidad de 94,2%. Esto sugiere precaucion con la aplicacion estricta de la escala a todos los pacientes que presentan sincope. Deberia usarse como una ayuda en la toma de decision clinica en esta poblacion.