Objective
Accurate assessment of mitral valve leaflet morphology is essential for patient selection and procedural planning in transcatheter mitral valve interventions. While transoesophageal echocardiography (TEE) and cardiac computed tomography (CT) are both routinely employed prior to transcatheter mitral valve replacement, TEE remains the primary imaging modality for screening patients considered for transcatheter mitral edge-to-edge reconstruction (TEER). Assessment of leaflet length is decisive for procedural success. Potential systematic discrepancies between the two imaging modalities remain insufficiently characterized.
Methods
Patients referred for comprehensive imaging prior to transcatheter mitral valve replacement using the TendyneTM Valve were screened for inclusion in this analysis. All patients underwent both TEE and full cycle cardiac CT as part of the TendyneTM screening protocol. The anterior (AML) and posterior (PML) mitral leaflets were each measured in standard anatomical segments (A1-A3, P1-P3). Corresponding segmental measurements obtained from CT and TEE were compared using paired t-tests. For each segment, the mean difference (bias), standard deviation and 95% confidence intervals (CI) were calculated to assess inter-modality agreement.
Results
30 patients (16 female; mean age 75 years) were analyzed. Mean PML lengths in segments P1, P2 and P3 were 11 mm, 13 mm and 11 mm in TEE vs. 12 mm, 13 mm and 12 mm in CT. Mean AML lengths in segments A1, A2 and A3 were 24 mm, 27 mm and 23 mm in TEE vs 25 mm, 28 mm and 24 mm in CT (p < 0.05). Across all segments, leaflet lengths measured by TEE were consistently shorter than those derived from computed tomography. The overall bias was 0.9 mm in AML and 0.6 mm in PML (TEE < CT) (p<0.05), with statistically significant differences observed in 4 segments (A1, A2, P1, P3, p < 0.05 for each).
Conclusions
While segmental mitral leaflet measurements obtained by TEE and CT demonstrate strong correlation, TEE systematically underestimates leaflet lengths relative to CT. These findings warrant consideration in borderline cases where leaflet length may be critical for planning the TEER procedure and clarifying patient eligibility. CT can potentially offer additional information to guide decision making.
