The following is a summary of “Management of Patients With Unexplained Syncope: Derivation and Validation of a Simplified 2‐Step Diagnostic Approach,” published in the November 2023 issue of Cardiology by Doundoulankis et al.

The objective of this study was to devise a structured and noninvasive 2-step diagnostic pathway aimed at guiding the assessment of patients experiencing unexplained syncope episodes, eventually leading to an electrophysiology study. Two distinct cohorts were utilized: an initial phase with 665 patients to craft the diagnostic approach based on electronic health records, followed by a validation phase with 160 prospectively screened patients exhibiting unexplained syncope. Combining noninvasive electrocardiographic and imaging markers with invasive electrophysiology study findings, a positive diagnostic approach, guided by predefined criteria, directed the decision to proceed with permanent pacemaker or implantable cardioverter-defibrillator interventions. The primary endpoint focused on assessing syncope-free survival, calculating the number needed to treat patients with a positive diagnostic approach. The figures showed that for individuals with unexplained syncope and borderline sinus bradycardia, the number needed to treat was 5, while for those with unexplained syncope and bundle branch block, it was 3, over an average follow-up of approximately 4 years. 

Subsequent analysis revealed that among those who received a pacemaker/implantable cardioverter-defibrillator (82 individuals), 14 (17.1%) experienced the primary outcome, while 19 of 57 (33%) encountered it in the group with a negative approach, over an average follow-up of roughly 2.5 years (29.29±12.58 months, P=0.03). The study suggests that the 2-step algorithm, including an electrophysiology study, could be a valuable, cost-effective, and streamlined approach to managing patients experiencing unexplained syncope.

Source: ahajournals.org/doi/10.1161/JAHA.123.031659