BAsel Syncope EvaLuation (BASEL IX) Study

Background: Management of patients with syncope is a serious problem concerning 1-2% of emergency department (ED) visits. In 6-20% of these, syncope will be due to a cardiac origin. The rapid and accurate identification of these patients is an important unmet clinical need.

Aim: The aim of the study is to evaluate the diagnostic value of patient's history, clinical judgement and novel biomarkers, alone or in combination, in the diagnosis and risk stratification of patients > 40 years of age presenting with syncope to the ED.

Patients and Methods: This prospective, observational, international multicenter study is initially designed to enroll 720 adult patients > 40 years presenting to the ED with syncope within the last twelve hours. Patient history will be standardized using a predefined form. Treating physicians will be asked to quantify their clinical judgment regarding the presence of cardiac syncope. Digital 12-lead ECG will be recorded at presentation and stored electronically. Blood samples for the measurement of novel cardiovascular biomarkers (including copeptin, pro-endothelin-1, pro-adrenomedullin, natriuretic peptides and high-sensitive cardiac troponins) will be obtained at presentation and stored anonymized. Patients will be contacted by phone at 6, 12 and 24 months to determine major adverse events (death, resuscitation, recurrence of syncope, hospitalization for syncope) and results of follow-up examinations. The final diagnosis will be adjudicated by two independent experts after review of all documents pertaining to the individual patient after 6 months. The primary endpoint is to assess the performance of a standardized form of patient's history, clinical judgment and biomarkers, alone and in combination, in the diagnosis of a cardiac syncope, as adjudicated by two independent experts. Secondary endpoints include the accuracy of the above cited items in prognostic stratification and the determination of the cost-effectiveness of the best approach.

Clinical significance: A more accurate and more rapid diagnosis and risk stratification of cardiac syncope can significantly improve patient management and therefore reduce patient morbidity and treatment cost. Overall, we expect this study to provide novel insights, holding important scientific, clinical and economic implications.