Baseline fragmented QRS increases the risk of major arrhythmic events in Brugada syndrome: Systematic review and meta-analysis

BACKGROUND:Fragmented QRS reflects disturbances in the myocardium predisposing the heart to ventricular tachyarrhythmias. Recent studies suggest that fragmented QRS (fQRS) is associated with major arrhythmic events in Brugada syndrome. However, a systematic review and meta-analysis of the literature has not been done. We assessed the association between fQRS and major arrhythmic events in Brugada syndrome by a systematic review of the literature and a meta-analysis. METHODS:We comprehensively searched the databases of MEDLINE and EMBASE from inception to May 2017. Included studies were published prospective or retrospective cohort studies that compared major arrhythmic events (ventricular fibrillation, sustained ventricular tachycardia, sudden cardiac arrest, or sudden cardiac death) in Brugada syndrome with fQRS versus normal QRS. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate risk ratios and 95% confidence intervals. RESULTS:Nine studies from January 2012 to May 2017 were included in this meta-analysis involving 2,360 subjects with Brugada syndrome (550 fQRS and 1,810 non-fQRS). Fragmented QRS was associated with major arrhythmic events (pooled risk ratio =3.36, 95% confidence interval: 2.09-5.38, p < .001, I2  = 50.9%) as well as fatal arrhythmia (pooled risk ratio =3.09, 95% confidence interval: 1.40-6.86, p = .005, I2  = 69.7%). CONCLUSIONS:Baseline fQRS increased major arrhythmic events up to 3-fold. Our study suggests that fQRS could be an important tool for risk assessment in patients with Brugada syndrome.