Objective: In patients with aortic stenosis (AS), the left ventricular (LV) geometry changes due to the increased LV afterload. However, subclinical myocardial dysfunction can develop despite a normal LV ejection fraction (EF). This study was an investigation of subclinical LV systolic dysfunction in patients with severe AS with a normal LV EF using a strain imaging method, speckle-tracking echocardiography (STE), and an evaluation of its correlation with novel indices to assess the severity of AS.
Methods: A total of 45 asymptomatic patients with severe AS and 25 age- and sex-matched controls without any cardiac disease and with preserved LV EF (EF ≥60%) were studied. In addition to performing conventional echocardiography and STE-based strain imaging, novel indices (energy loss index [ELI], valvulo-arterial impedance, systemic arterial compliance) were also measured.
Results: The LV EF, and the LV end-diastolic and end-systolic diameters were similar in the 2 groups. The LV longitudinal peak systolic strain (10.66±1.15% to 19.66±2.62%; p=0.0001) and strain rate (0.32±0.07 s-1 to 1.85±0.32 s-1; p=0.0001) were significantly impaired in the study patients compared to the controls, demonstrating subclinical ventricular systolic dysfunction. A significant positive correlation was observed between the ELI and the LV strain/strain rate (r=0.45, p=0.002; r=0.55, p=0.0001, respectively).
Conclusion: Patients with severe AS develop subclinical LV systolic dysfunction, despite a preserved EF. Novel strain imaging-based echocardiographic techniques may provide additional data that can detect early myocardial systolic deterioration in these patients.