Objectives Experimental and clinical studies have suggested the presence of fragmented QRS (fQRS) are associated with various cardiovascular diseases. fQRS may predict major adverse cardiovascular events (MACE). A meta-analysis was conducted to investigate the relationship between fQRS and MACEs.
Methods A systematic literature search of COCHRANE, MEDLINE, EMBASE, PUBMED, ELSEVIER, SPRINGERLINK and OVID from their respective inceptions to December 2012 was conducted using specific search terms such as “fragmented QRS” and “fQRS”. Data was extracted from applicable articles and odds risk (OR) or mean differences, including 95% confidence intervals (CI) were calculated using RevMan 5.1 software.
Results A total of 14 cohort studies (N = 3609 patients) were identified. Compared with the non-fQRS group, MACEs was significantly higher in the fQRS group (OR 2.53, 95% CI [1.71, 3.73], P < 0.00001), and the results were not changed when the subgroup analysis which divided the aetiology of patients into ischemic, non-ischaemic group were used (OR 2.68, 95% CI [1.69, 4.23], P < 0.0001;OR 2.18, 95% CI [1.05, 4.57], P = 0.04). All-cause mortality was significantly higher in the fQRS group than those in non-fQRS group (OR 1.77, 95% CI [1.11, 2.84], P = 0.02), but the results were different when the subgroup analysis divided the aetiology of patients into ischemic, non-ischemic and mixed groups, the fQRS was only associated with and all-cause mortality in ischemic patients (OR 2.36, 95% CI [1.66, 3.35], P < 0.00001), and there was no significant difference in all-cause mortality between groups in non-ischaemic and mixed patients (OR 2.61, 95% CI [0.7, 9.83], P = 0.15; OR 2.36, 95% CI [1.66, 3.35], P < 0.00001). Patients who had MACE had more leads of fQRS compared with those who without MACE (mean difference 2.1, 95% CI [1.45, 2.75], P < 0.00001). And fQRS was not associated with intraventricular dyssynchrony (OR 3.65, 95% CI [0.24, 56.12], P = 0.35).
Conclusions Based on the current evidence, fQRS seems to be an effective marker in the prediction of MACEs in ischaemic and non-ischemic patients and the all-cause mortality in ischaemic patients.