Introduction
Mitral valve (MV) pathologies are very common and represent
approximately one-third (35%) of all valvulopathies in the Euro Heart
Survey (1). Echocardiography is the gold standard imaging method for MV
assessment, and all patients in need for a precise mitral valve
analysis, undergo a transesophageal examination (TOE) for detailed
assessment of the leaflets and the mitral annulus. Precise
quantification of mitral regurgitation (MR), localization of the
prolapsing scallops and accurate MV area assessment are of paramount
importance for the management of this subgroup of patients (2). However,
considering the semi-invasive nature of the method; repeated, routine
TOE examinations cannot be the common practical approach during the
follow up visits of these patients. In daily practice,
echocardiographers use TTE, with standard two-dimensional (2D) protocols
that rarely include information about mitral annular dimensions.
Three-dimensional (3D) TTE protocols are also seldomly used and depend
on the performer’s training and level of expertise. Technical
advancements in echocardiography, offered the option for MV and annulus
reconstruction and assessment through new, dedicated, post-processing
softwares that provide measurements of all mitral annular and leaflet
dimensions. Until recently, TOE was the only method for correct
measurements. However, TTE probes have evolved and they can achieve
higher spatial and temporal resolution and allow echocardiographers to
assess the mitral annulus accurately without the need of the TOE probe.
This remains as the main advantage of TTE, as we do not have to sedate
the patient and perform this semi-invasive transesophageal method.
3D TOE and CT are essential for planning transcatheter (TCT)
interventions of the MV (3,4) and 3D TOE is the standard method used to
evaluate the MV anatomy. The mitral annulus size is one of the key
parameters necessary to predict outcomes in transcatheter edge-to-edge
repair (TEER), and to decide about the sizing of the valve during
transcatheter mitral valve replacement (TMVR) (3,4). Cardiac CT with ECG
gating is the gold standard method for anatomy assessment and annulus
measurements prior to TCT. However, when contrast CT is contraindicated,
2D/3D TOE may be an alternative, accurate option for MV quantitation.
Insertion of TOE probe is feasible in more than 99% of the patients
that undergo this examination. However, TOE with the common adult probe
may not be possible in patients with esophageal disorders (5-10) and as
pediatric TOE probes do not provide a sufficient image quality, we
should not rely on them for accurate results. In such conditions, 3D TTE
may offer the option for annulus assessment with a non-invasive way.
A direct comparison of 3D TTE and 3D TOE for mitral annulus assessment
has never been previously described. The aim of this study is to
demonstrate the feasibility of MVQ analysis using both methods and to
evaluate the level of agreement for assessing the mitral annular
geometry.