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

Abstract

Purpose: Degenerative mitral stenosis (DMS) is an increasingly recognized cause of mitral stenosis. The goal of this study was to compare echocardiographic differences between DMS and rheumatic mitral stenosis (RMS), identify echocardiographic variables reflective of DMS severity, and propose a dimensionless mitral stenosis index (DMSI) for assessment of DMS severity. Methods: This is a single-center, retrospective cohort study. We included patients with at least mild MS and a mean transmitral pressure gradient (TMPG) ≥4 mm Hg. Mitral valve area by the continuity equation (MVA CEQ) was used as an independent reference. The DMSI was calculated as follows: DMSI = VTI LVOT / VTI MV. All-cause mortality data were collected retrospectively. Results: A total of 64 patients with DMS and 24 patients with RMS were identified. MVA CEQ was larger in patients with DMS (1.43 ± 0.4 cm 2) than RMS (0.9 ± 0.3 cm 2) by ~0.5 cm 2 (P = <.001), and mean TMPG was lower in the DMS group (6.0 ± 2 vs 7.9 ± 3 mm Hg, P = .003). A DMSI of ≤0.50 and ≤0.351 was associated with MVA CEQ ≤1.5 and MVA CEQ ≤1.0 cm 2 (P < .001), respectively. With the progression of DMS from severe to very severe, there was a significant drop in DMSI. There was a nonsignificant trend toward worse survival in patients with MVA CEQ ≤1.0 cm 2 and DMSI ≤0.35, suggesting severe stenosis severity. Conclusion: Our results show that TMPG correlates poorly with MVA in patients with DMS. Proposed DMSI may serve as a simple echocardiographic indicator of hemodynamically significant DMS.

Mid-term outcomes of the COMMENCE trial investigating mitral valve replacement using a bioprosthesis with a novel tissue

“…Given that literature suggests the continuity equation may underestimate EOAs due to variability in left ventricular outflow tract diameter measurements, DVI is presented to supplement the EOA data. 15 , 16 From discharge to 5 years follow-up, DVI was stable (2.4 [1.3] and 2.0 [0.8], respectively) and largely within expected range. New York Heart Association class improved universally after MVR, and 94% of patients were maintained in New York Heart Association class I or II through 5 years of follow-up.…”

Profibrotic VEGFR3-Dependent Lymphatic Vessel Growth in Autoimmune Valvular Carditis

“…The dimensionless index has been demonstrated as a reliable metric for identifying hemodynamically significant mitral valve stenosis. 29 Importantly, both valve thickness (Figure 5E) and lymphatic density (Figure 5F) were greater in these aged K/B.g7 mice than in controls. Together, these results suggest that inflammation and resultant fibrosis that occurs in the mitral valves of K/B.g7 mice induce measurable LV diastolic dysfunction and mitral valve stenosis, and these metrics correlate with increased valve thickness and lymphatic density.…”

Degenerative Mitral Stenosis: A Case-Based Review

“…In a study of 64 patients with DMS, a DVI of 0.31 ± 0.04 was correlated with a valve area ≤ 1 cm 2 , and a 0.43 ± 0.07 was correlated with a valve area between 1 and 1.5 cm 2 . 23 Further validation of cutoff is needed before routine use of this metric.…”