Impact of Aortic Stenosis Severity on Left Heart Function Analyzed Using CT-Derived Strain Parameters

Area of Science:

• Cardiology
• Radiology
• Medical Imaging

Background:

• Aortic stenosis (AS) is a progressive condition affecting the heart's pumping chambers.
• Assessing cardiac mechanics in AS is crucial for understanding disease progression and patient outcomes.
• Computed tomography (CT) offers advanced imaging capabilities for evaluating cardiac structure and function.

Purpose of the Study:

• To evaluate changes in left ventricular (LV) and left atrial (LA) mechanics in relation to AS severity.
• To compare CT-derived strain values across different AS severity groups (mild, moderate, severe).
• To investigate the correlation between AS severity and myocardial deformation parameters.

Main Methods:

• A retrospective study of 120 patients with mild, moderate, and severe AS who underwent multiphase cardiac CT.
• Quantitative LV and LA strain parameters were derived from electrocardiography-gated cardiac CT images.
• Statistical analysis (Kruskal-Wallis test) was used to compare strain parameters among AS severity groups.

Main Results:

• Left ventricular global longitudinal strain (LV GLS) absolute values decreased significantly with increasing AS severity.
• Left ventricular global circumferential strain (LV GCS), LV global radial strain (LV GRS), and left atrial conduit strain showed significant differences across AS severity groups.
• Lower absolute strain values were observed in patients with severe AS for LV GCS, LV GRS, and LA conduit strain.

Conclusions:

• CT-derived LV and LA strain parameters demonstrate altered myocardial deformation in patients with AS, correlating with disease severity.
• LV GLS decreases progressively with AS severity.
• LV GCS, LV GRS, and LA conduit strain are initially preserved but decrease in severe AS.