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Association between electrocardiographic QRS transition zone and mortality from all causes and cardiovascular
Ziliang Chen1, Ming Yuan1, Aapo L Aro2
1Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, PR China.
Aims:
To investigate whether clockwise rotation (CWR) and counterclockwise rotation (CCWR) of electrocardiographic QRS transition zone is associated with mortality from all causes and cardiovascular diseases (CVD).
Methods:
Studies were identified from searching of PubMed, EMBASE and the reference lists of relevant papers. Summary multivariate-adjusted hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) and 95% prediction intervals (PIs) were computed through meta-analysis.
Results:
A total of five observational cohort studies fulfilled the inclusion criteria, which included 47,252 participants from the general population (8.8% CWR; 44.1% CCWR). Pooling data revealed that CWR was significantly associated with the increased risk of all-cause mortality (HR, 1.18; 95% CI: 1.12-1.24; 95% PI: 1.03-1.37) and CVD mortality (HR, 1.18; 95% CI: 1.08-1.29; 95% PI: 0.98-1.42) compared to NR pattern, with low heterogeneity among studies (P = 0.29, I2 = 20%; P = 0.37; I2 = 7%; respectively). However, CCWR was inversely associated with the risk of all-cause mortality (HR, 0.92; 95% CI: 0.89-0.95; 95% PI: 0.80-1.05) with low heterogeneity (P = 0.14; I2 = 43%), while no significant association existed between CCWR and CVD mortality (HR, 0.89; 95% CI: 0.77-1.02; 95% PI: 0.53-1.48) with high heterogeneity (P < 0.01; I2 = 78%).
Conclusion:
Our meta-analysis demonstrated CWR was positively associated with higher risk of mortality from all-cause and CVD, while CCWR was negatively associated with the risk of all-cause mortality and no significant association with CVD mortality. These findings suggested that QRS transition zone carries important prognostic value, more attention should be paid in clinical practice.
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