Calcific extension towards the mitral valve causes non-rheumatic mitral stenosis in degenerative aortic stenosis: real-time 3D transoesophageal echocardiography study

Abstract

ObjectiveMitral annular/leaflet calcification (MALC) is frequently observed in patients with degenerative aortic stenosis (AS). However, the impact of MALC on mitral valve function has not been established. We aimed to investigate whether MALC reduces mitral annular area and restricts leaflet opening, resulting in non-rheumatic mitral stenosis.MethodsReal-time three-dimensional transoesophageal images of the mitral valve were acquired in 101 patients with degenerative AS and 26 control participants. The outer and inner borders of the mitral annular area (MAA) and the maximal leaflet opening angle were measured at early diastole. The mitral valve area (MVA) was calculated as the left ventricular stroke volume divided by the velocity time integral of the transmitral flow velocity.ResultsAlthough the outer MAA was significantly larger in patients with AS compared to control participants (8.2±1.3 vs 7.3±0.9 cm2, p<0.001), the inner MAA was significantly smaller (4.5±1.1 vs 5.9±0.9 cm2, p<0.001), resulting in an average decrease of 45% in the effective MAA. The maximal anterior and posterior leaflet opening angle was also significantly smaller in patients with AS (64±10 vs 72±8°, p<0.001, 71±12 vs 87±7°, p<0.001). Thus, MVA was significantly smaller in patients with AS (2.5±1.0 vs 3.8±0.8 cm2, p<0.001). Twenty-four (24%) patients with AS showed MVA <1.5 cm2. Multivariate regression analysis including parameters for mitral valve geometry revealed that a decrease in effective MAA and a reduced posterior leaflet opening angle were independent predictors for MVA.ConclusionsCalcific extension to the mitral valve in patients with AS reduced effective MAA and the leaflet opening, resulting in a significant non-rheumatic mitral stenosis in one-fourth of the patients.

Intramyocardial calcification in a 37-year-old patient with severe aortic stenosis

“…Endomyocardial fibrosis is characterized by the presence of fibrous tissue in the endocardium eventually extending into the myocardium, a finding not identified in our patient. Mitral annular and leaflet calcification occurs frequently with degenerative aortic stenosis and is known to reduce leaflet opening and result in significant mitral stenosis in 25% of patients with calcific aortic stenosis [11]. In our patient, however, no involvement of the mitral valve was noted.…”

3D and 4D Ultrasound: Current Progress and Future Perspectives

“…Hung et al showed that if there is papillary muscle displacement outside of the mitral annulus after ring annuloplasty for IMR, MR persists due to persistent abnormal leaflet tethering due to restricted posterior leaflet motion [ 49 ]. Lastly, Iwataki et al studied the effect of extension of calcification to the mitral valve leaflet in patients with aortic stenosis and found that this condition can result in significant non-rheumatic mitral stenosis with decreased leaflet opening and mitral annular area [ 50 ].…”

Dimensionless index of the mitral valve for evaluation of degenerative mitral stenosis

“…6 As the disease process continues, the dystrophic calcification extends into the left ventricular (LV) inflow tract and onto the MV leaflets, thereby obstructing LV inflow (Figure 1). 7 This disease process has increasingly been recognized as degenerative MS (DMS).…”