Abstract
Background
Non-invasive global myocardial work recently emerged as new parameter to characterize left ventricle function with potential advantages over both ejection fraction and global longitudinal strain.
Purpose
We aimed to perform a meta-analysis of normal ranges of non-invasive left ventricular myocardial work (MW) indices including global constructive work (GCW), global work index (GWI), global wasted work (GWW), and global work efficiency (GWE) and to identify confounding factors that may contribute to variance in reported measures.
Methods
The authors searched four databases, Pubmed, Scopus, Embase, and Cochrane Library through January 2021 using the key terms “myocardial work”,“global constructive work”, “global wasted work”, “global work index”, “global work efficiency”. Studies were included if the articles reported LV myocardial work using 2D transthoracic echocardiography in healthy normal subjects, either in the control group or comprising the entire study cohort. The weighted mean was estimated by using the random effect model with a 95% confidence interval. Heterogeneity across studies was assessed using the I2 test. Publication bias was examined by funnel plot and Egger's regression test.
Results
The search yielded 476 articles. After abstract and full text screening we included 13 datasets with 1665 patients for meta-analysis. The reported normal mean values of GCW and GWI among the studies were 2278 (95% CI, 2167 to 23878; I2=95%), and 2.010 (95% CI, 1922 to 2098, I2=97%), respectively. The mean GWE was 96.0 (95% CI, 95.6% to 96.5; I2=92%), and the mean GWW was 79.7% (95% CI, 68.8% to 90.7%; I2=90%) (Figure). Furthermore, age and gender did not significantly contribute to variations in normal values. No evidence of significant publication bias was observed in the funnel plots and the Egger test.
Conclusion
In this meta-analysis, we provide echocardiographic reference ranges for non-invasive indices of MW. These normal values should serve as a template for clinical and research use for this promising technology.
FUNDunding Acknowledgement
Type of funding sources: None.
Normal ranges of left ventricular strain in children: a meta-analysis
