Do flow-gradient groups determined by MDCT predict outcomes: validating CT stroke volume

Area of Science:

• Cardiology
• Medical Imaging
• Interventional Cardiology

Background:

• Accurate diagnosis of severe aortic stenosis is challenging, particularly in patients with low-flow states.
• Non-invasive imaging modalities are crucial for timely diagnosis and treatment initiation.

Purpose of the Study:

• To evaluate the accuracy of CT blood pool based (CT-blp) analysis in estimating stroke volume compared to echocardiogram and right heart catheterization.
• To assess the performance of CT-blp in predicting 30-day and 1-year outcomes in patients undergoing transcatheter aortic valve replacement (TAVR).

Main Methods:

• Retrospective, single-center study involving 345 patients with aortic stenosis undergoing TAVR.
• Stroke volume calculated using CT-blp, echocardiogram, and right heart catheterization prior to TAVR.
• Comparison of modality performance in predicting short-term and long-term clinical outcomes.

Main Results:

• CT-blp demonstrated a stronger correlation with cath-derived stroke volume (r=0.60) than echocardiogram (r=0.37).
• No significant difference in mortality was observed between groups stratified by flow and gradient using CT-blp or echo.
• The composite of mortality and hospital readmission was significantly higher in the low-flow, low-gradient group identified by CT-blp (30-day OR 2.6; 1-year OR 1.9).

Conclusions:

• CT-blp provides a reliable estimation of stroke volume, correlating well with invasive measurements in patients evaluated for TAVR.
• CT-blp can effectively stratify patients into flow-gradient groups, aiding in the identification of low-flow, low-gradient aortic stenosis when echocardiography is limited.
• Further research with larger cohorts is warranted to validate these findings and their clinical implications.