B-PO04-024 PREDICTION OF A POSITIVE SODIUM CHANNEL BLOCKER PROVOCATION TEST IN PATIENTS SUSPECTED OF BRUGADA SYNDROME

Abstract

In patients suspected of Brugada syndrome (BrS) without spontaneous type-1 ECG, a sodium channel provocation test is performed. This test requires a hospital admission and is not without risks. Being able to determine the a priori probability of a positive provocation test could avoid the performance of unnecessary tests. To predict the chance of a positive provocation test. In a large cohort of 1430 patients who underwent provocation testing, a prediction model was constructed using logistic regression. To correct for over-optimism, internal validation-based bootstrapping was performed (n=1000). Candidate predictors included 1) demographics and medical history, 2) test-indication and 3) baseline ECG parameters. ECGs were analyzed and included measurement of the β-angle in leads V1, V2 and their corresponding positions in the 2nd and 3rd intercostal space. Of 1430 patients, 345 (24%) developed a positive provocation test (type-1 ECG). From the candidate predictors, gender, test-indication (e.g. family screening) and ECG parameters (P-wave duration, JT-duration, max right precordial J-amplitude, S-duration and the β-angle) were finally selected for the model (Figure). After bootstrapping, we found an optimism corrected C-statistic of 0.78 (95% CI: 0.75-0.81) indicating a good prediction model. In patients suspected of BrS, our model can reliably predict the chance of a positive sodium channel provocation test. This model could prevent unnecessary tests in both patients with low and high a priori probabilities of BrS.