Quantifying myocardial function characteristic with myocardial work measurement in patients with different aortic regurgitation severity.

BACKGROUND: Assessing subclinical myocardial dysfunction in aortic regurgitation (AR) with preserved left ventricular ejection fraction (LVEF) is challenging due to load-dependent conventional parameters. Non-invasive myocardial work (MW) integrates left ventricular pressure and strain to provide afterload-adjusted performance indices. This study aimed to characterize MW across AR severity in patients with preserved LVEF.

METHODS: We prospectively enroled 130 patients categorized as control (n = 30), mild (n = 30), moderate (n = 34), and severe (n = 36) according to guidelines. MW parameters were assessed using Vivid E95 ultrasound and included: global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE).

RESULT: Compared to controls, AR groups demonstrated reduced GWI (p < 0.001), with severe AR group significantly lower than mild/moderate groups. GCW (p < 0.001) decreased in moderate/severe AR (p < 0.001). GWW progressively increased (p < 0.001) and GWE decreased (p < 0.001) from mild to severe AR. ROC analysis revealed excellent discrimination between severe AR and controls: GWI (AUC: 0.892), GCW (AUC: 0.806), GWW (AUC: 0.961), and GWE (AUC: 0.982). Intra- and inter-observer variability was excellent (ICCs > 0.80).

CONCLUSIONS: Non-invasive MW indices, particularly GWW and GWE, progressively deteriorate with AR severity in preserved LVEF patients. These findings provide novel, physiology-based insights into myocardial energetic efficiency in chronic volume overload. MW parameters may offer incremental value in functional evaluation, potentially aiding subclinical dysfunction identification. Future large-scale, longitudinal studies are warranted to validate prognostic utility and role in optimizing intervention timing.