Detailed transthoracic and transesophageal echocardiographic analysis of mitral leaflets in patients undergoing mitral valve repair

A recent histological study of resected scallop-P2 in mitral valve (MV) prolapse, showed that chordae tendinae may be missing or hidden in superimposed fibrous tissue of the leaflets, contributing to their thickening. This may have relevant clinical implication because detailed analysis of MV leaflets has a central role in the evaluation of patients undergoing repair. The aim of this study was to analyze MV leaflets focusing on thickness of prolapsing segments and the presence of chordal rupture (CR). We enrolled 246 patients (age 63 ± 13 years, 72 men) with isolated P2 prolapse and also 50 age-matched patients with normal MV anatomy as control group. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were retrospectively analyzed to quantify the length and the proximal and distal thickness of both anterior (A2) and posterior (P2) MV scallops. Measurements were performed at end diastole in the standard TTE and TEE views. TTE and TEE measurements were feasible in all cases. Echocardiographically 176 patients had CR (group A), 45 had no rupture (group B), and 25 had an uncertain diagnosis (group C). All pathological groups showed thickening and elongation of involved leaflets versus normal, whereas no differences in leaflets characteristics were found among MV groups. Most patients undergoing MV repair had CR with thickening of the prolapsed segment. These findings are in agreement with recent histological studies showing superimposed fibrous tissue on MV leaflets partially including ruptured chordae. This may also explain that in cases without ruptured chordae, thickness of the leaflets is markedly increased (hidden chordae?). In conclusion, detailed analysis of MV apparatus may further improve knowledge of these patients and may influence surgical timing.