Baseline fragmented QRS is associated with increased all-cause mortality in heart failure with reduced ejection fraction: A systematic review and meta-analysis

BACKGROUND: Recent studies suggested that fragmented (fQRS) is associated with poor clinical outcomes in heart failure with reduced ejection fraction (HFrEF) patients. However, no systematic review or meta-analysis has been done. We conducted a systematic review and meta-analysis to assess the association between baseline fQRS and all-cause mortality in HFrEF. METHODS: We comprehensively reviewed the databases of MEDLINE and EMBASE from inception to February 2018. Published studies of HFrEF that reported fQRS and outcome of all-cause mortality and major arrhythmic event (sudden cardiac death, sudden cardiac arrest, ventricular fibrillation, or sustained ventricular tachycardia) were included. Data were integrated using the random-effects, generic inverse-variance method of DerSimonian and Laird. RESULTS: Ten studies from 2010 to 2017 were included. Baseline fQRS was associated with increased all-cause mortality (risk ratio [RR] 1.63, 95% confidence interval [CI] 1.22-2.19, p < 0.0001, I2  = 73%) as well as major arrhythmic events (RR = 1.74, 95% CI 1.09-2.80, I2  = 89%). Baseline fQRS increased all-cause mortality in both Asian and Caucasian cohorts (RR = 2.17 with 95% CI 1.33-3.55 and RR = 1.45 with 95% CI 1.05-1.99, respectively) as well as increased major arrhythmic events in Asian cohort (RR = 1.50, 95% CI 1.05-2.13). Baseline fQRS also increased all-cause mortality in patients who had not received implantable cardioverter-defibrillator, significantly more than in patients who had received implantable cardioverter-defibrillator (RR = 2.46 with 95% CI 1.56-3.89 and 1.36 with 95% CI 1.08-1.71, respectively). CONCLUSION: Baseline fQRS is associated with increased all-cause mortality up to 1.63-fold in HFrEF patients. Fragmented QRS could be a predictor of clinical outcome in patients with HFrEF.