Risk Score Model for Brugada Syndrome
- Brugada syndrome (BrS) is an inherited cardiac channelopathy associated with ventricular arrhythmias and sudden cardiac death (SCD).
- A number of risk factors and markers have been identified, but risk stratification remains a challenge in part due to the low adverse event rate.
- The authors of this study therefore sought to comprehensively review the major predictors and to establish a risk score for BrS without a history of SCD.
Can a risk score model predict ventricular arrhythmia (VA) and sudden cardiac death (SCD) in patients with Brugada syndrome (BrS)?
The study group was comprised of a multicenter international cohort of patients with BrS and no history of cardiac arrest. Sixteen clinical or electrocardiogram (ECG) markers were assessed for predicting VAs/SCD during follow-up. VA was defined as aborted SCD or documented sustained ventricular tachycardia. SCD was designated if VA was documented at time of death or if no other etiology was known. A risk score was derived from univariate and multivariable modeling.
Of the 1,110 patients from 16 centers, 114 (10.3%) patients had VA/SCD with an annual event rate of 1.5%. Of the 16 clinical or ECG risk factors assessed, probable arrhythmia–related syncope (hazard ratio [HR], 3.71; p < 0.001), spontaneous type 1 ECG (HR, 3.80; p < 0.001), early repolarization in peripheral leads (HR, 3.42; p < 0.001), and a type 1 Brugada ECG pattern in peripheral leads (HR, 2.33; p < 0.001) had the strongest association with VA/SCD. Diagnosis of BrS by family screening for SCD was also significantly associated with VA/SCD. A risk score model incorporating the four main factors had a sensitivity of 71.2% and a specificity of 80.2% in predicting likelihood of VA/SCD in 5 years.
This 16-center study of BrS without a history of cardiac arrest identified four risk factors for VA/SCD that could guide implantable cardioverter-defibrillator recommendations.
This large multicenter study is the first to assess the major 16 risk factors associated with BrS in one study. The presence of the four most significant risk factors (noted in the Results above) is easily attained and should be considered in the evaluation of BrS for primary prevention of SCD. However, we cannot disregard some of the other proposed risk factors due to the retrospective study design and the heterogeneity of data collection between hospitals. As the authors note, only about two thirds of the cohort underwent genetic testing for SCN5A and just over one third underwent electrophysiology study for programmed ventricular stimulation, so neither were included in risk score modeling. Both have been shown in some studies to be associated with adverse cardiac events, and indeed in this current study, the confidence intervals were quite wide. Fractionated QRS complexes have also been associated with major arrhythmic events in BrS.
Keywords: Arrhythmias, Cardiac, Brugada Syndrome, Death, Sudden, Cardiac, Defibrillators, Implantable, Electrocardiography, Electrophysiology, Genetic Testing, Primary Prevention, Risk Factors, Syncope, Tachycardia, Ventricular
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