Mitral Valve Prolapse Mitral Regurgitation Research Articles

Influence of Prolapse Volume in Mitral Valve Prolapse

Mitral valve prolapse (MVP) is characterized by excessive leaflet tissue leading to a wide spectrum of mitral regurgitation (MR) ranging from trivial to severe. The prolapse volume (PV) below the prolapsing leaflets in end-systole was suspected to impact both chamber remodeling and MR grading in MVP. Based on 157 consecutive patients (45 women; mean age 62±15) referred for CMR assessment of MR, either from MVP (n=91; 58%) or fibroelastic disease (FED) (n=66; 42%), we sought to study (i) the interaction between PV and cardiac chamber geometry (ii) to study the impact of PV on MR quantification in MVP. Despite similar left ventricular (LV) size, PV was larger in MVP (11±9ml) than in FED (2±2ml). PV progressively increased with the severity of MR in MVP but not in FED. Despite a low regurgitant volume (32±18ml), some MVP patients with less than moderate MR exhibit significant cardiac chambers remodeling compared to 52 age and sex-matched controls. PV correlated significantly (r=0.52) with the LV dilatation in severe MR but also in less than moderate MR. In MVP, PV>14ml was associated with a significant underestimation (Bias=-26±32ml) of regurgitant volume by PISA compared to CMR. In conclusion, in MVP, PV may play a role in left cardiac chambers remodeling, even in patients without severe MR, and in discordant grading of MR between echocardiography and CMR.

Quantification of regurgitation in mitral valve prolapse with four-dimensional flow cardiovascular magnetic resonance

BackgroundFour-dimensional cardiovascular magnetic resonance (CMR) flow assessment (4D flow) allows to derive volumetric quantitative parameters in mitral regurgitation (MR) using retrospective valve tracking. However, prior studies have been conducted in functional MR or in patients with congenital heart disease, thus, data regarding the usefulness of 4D flow CMR in case of a valve pathology like mitral valve prolapse (MVP) are scarce. This study aimed to evaluate the clinical utility of cine-guided valve segmentation of 4D flow CMR in assessment of MR in MVP when compared to standardized routine CMR and transthoracic echocardiography (TTE).MethodsSix healthy subjects and 54 patients (55 ± 16 years; 47 men) with MVP were studied. TTE severity grading used a multiparametric approach resulting in mild/mild-moderate (n = 12), moderate-severe (n = 12), and severe MR (n = 30). Regurgitant volume (RVol) and regurgitant fraction (RF) were also derived using standard volumetric CMR and 4D flow CMR datasets with direct measurement of regurgitant flow (4DFdirect) and indirect calculation using the formula: mitral valve forward flow - left ventricular outflow tract stroke volume (4DFindirect).ResultsThere was moderate to strong correlation between methods (r = 0.59–0.84, p < 0.001), but TTE proximal isovelocity surface area (PISA) method showed higher RVol as compared with CMR techniques (PISA vs. CMR, mean difference of 15.8 ml [95% CI 9.9–21.6]; PISA vs. 4DFindirect, 17.2 ml [8.4–25.9]; PISA vs. 4DFdirect, 27.9 ml [19.1–36.8]; p < 0.001). Only indirect CMR methods (CMR vs. 4DFindirect) showed moderate to substantial agreement (Lin’s coefficient 0.92–0.97) without significant bias (mean bias 1.05 ± 26 ml [− 50 to 52], p = 0.757). Intra- and inter-observer reliability were good to excellent for all methods (ICC 0.87–0.99), but with numerically lower coefficient of variation for indirect CMR methods (2.5 to 12%).ConclusionsIn the assessment of patients with MR and MVP, cine-guided valve segmentation 4D flow CMR is feasible and comparable to standard CMR, but with lower RVol when TTE is used as reference. 4DFindirect quantification has higher intra- and inter-technique agreement than 4DFdirect quantification and might be used as an adjunctive technique for cross-checking MR quantification in MVP.

Abstract 16731: Novel CMR Anatomical Predictors of Mitral Regurgitation Presence and Severity in Mitral Valve Prolapse

Introduction: Mitral valve (MV) prolapse (MVP) is often associated with mitral regurgitation (MR). The determinants of MR in MVP are incompletely understood. Methods: We retrospectively identified 86 consecutive patients with MVP and preserved ejection fraction undergoing CMR with velocity encoding for MR quantification between 2005 and 2017. On 3-chamber cine images we measured, in end-diastole (Figure), end-systole, and their percentage change during the cardiac cycle, the following parameters: basal and mid inferolateral wall thickness, posterior papillary muscle length, annulus diameter, LV diameter and distance from the posterior papillary muscle to anterior and posterior annulus. In addition, we measured anterior and posterior leaflet thickness in diastole and maximal prolapse distance in end-systole. We explored the associations between these parameters and mitral regurgitant fraction (RF) using multivariate linear regression. Results: Median age was 52.6 years and 48% were males. There was posterior MVP in 49 (57%), bileaflet MVP in 35 (41%) patients, and isolated anterior MVP in 2 (2%) patients. MR was present in 73 (85%) and, in these, median RF was 23% (IQR 13-33%). In multivariate analyses, diastolic papillary muscle to posterior annulus distance, maximal prolapse distance, maximal posterior leaflet thickness, and LV basal inferolateral diastolic thickness were independent predictors of mitral RF (p&lt;0.05 for all). Conclusions: Beyond known determinants of MR in MVP such as maximal prolapse and leaflet thickness, we identified novel anatomical predictors of MR severity, namely increased diastolic papillary muscle to posterior annulus distance and LV basal inferolateral thickness. Whether these abnormalities represent secondary changes to MVP (i.e. basal inferolateral “stretch” and compensatory regional LV hypertrophy, respectively) or primary phenotypic features of the MVP syndrome is uncertain.

Grading of mitral regurgitation in mitral valve prolapse using the average pixel intensity method

AimsWe recently reported the feasibility of the average pixel intensity (API) method for grading mitral regurgitation (MR) in a heterogeneous MR population. Since mitral valve prolapse (MVP) is an important cause of primary MR, we more specifically investigated the feasibility of the API method and the MR flow dynamics in patients with MVP. MethodsTransthoracic echocardiography was performed by a single operator in consecutive MVP patients (n=112). MR was assessed using the API method, color Doppler, vena contracta width (VCW), effective regurgitant orifice area (PISA-EROA) and regurgitant volume (PISA-RV). ResultsThe API method was feasible in 89% of all MVP patients (68%, 71% for VCW and PISA method, respectively ;p<.001). Inter- and intra-observer correlations for API in MVP with non-holosystolic MR were 0.989 and 0.995. For the overall MVP-MR population, API had significant correlations with direct and indirect measures of MR severity. Based on ROC curves, an API cutoff value of 125 au was suggested to identify severe MR in MVP and a MR duration/systolic time ratio<100% (i.e. non-holosystolic MVP-MR) identifies patients with non-severe MR (API<125), whereas the majority of holosystolic MVP had severe MR (API>125). Finally, API analysis of the proto-, mid- and telesystolic phases of MR in MVP showed different kinetics in non-holosystolic compared to holosystolic MVP. ConclusionsThe API method is a feasible and reproducible method for grading MVP-MR. As the API method takes into account the temporal MR flow changes during the entire systolic cycle, it may be of added value in clinical practice.

Quantitative Analysis of Mitral Valve Morphology in Mitral Valve Prolapse With Real-Time 3-Dimensional Echocardiography

Background— Few data exist on the relation of the 3-dimensional morphology of mitral valve and degree of mitral regurgitation (MR) in mitral valve prolapse. Methods and Results— Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 112 subjects, including 36 patients with mitral valve prolapse and significant MR (≥3+; MR+ group), 32 patients with mitral valve prolapse but no or mild MR (≤2+; MR− group), 12 patients with significant MR resulting from nonprolapse pathologies (nonprolapse group), and 32 control subjects. The 3-dimensional geometry of mitral valve apparatus was measured with dedicated quantification software. Compared with the normal and MR− groups, the MR+ group had more dilated mitral annulus ( P &lt;0.0001), a reduced annular height to commissural width ratio (AHCWR) ( P &lt;0.0001) indicating flattening of annular saddle shape, redundant leaflet surfaces ( P &lt;0.0001), greater leaflet billow volume ( P &lt;0.0001) and billow height ( P &lt;0.0001), longer lengths from papillary muscles to coaptation ( P &lt;0.0001), and more frequent chordal rupture ( P &lt;0.0001). Prevalence of chordal rupture increased progressively with annulus flattening (7% versus 24% versus 42% for AHCWR &gt;20%, 15%–20%, and &lt;15%, respectively; P =0.004). Leaflet billow volume increased exponentially with decreasing AHCWR in patients without chordal rupture ( r 2 =0.66, P &lt;0.0001). MR severity correlated strongly with leaflet billow volume ( r 2 =0.74, P &lt;0.0001) and inversely with AHCWR ( r 2 =0.44, P &lt;0.0001). In contrast, annulus dilatation but not flattening occurred in nonprolapse MR patients. An AHCWR &lt;15% (odds ratio=7.1; P =0.0004) was strongly associated with significant MR in mitral valve prolapse. Conclusion— Flattening of the annular saddle shape is associated with progressive leaflet billowing and increased frequencies of chordal rupture and may be important in the pathogenesis of MR in mitral valve prolapse.

The Crossed Swords Sign: Insights into the Dilemma of Repair in Bileaflet Mitral Valve Prolapse

The need for bileaflet repair in bileaflet mitral valve prolapse (MVP) remains controversial. Will anterior leaflet prolapse resolve with posterior leaflet repair or should both leaflets be addressed? Single-leaflet MVP produces oppositely directed mitral regurgitant jets. Some patients show two crossed jets oppositely directed from the coaptation zone. We hypothesized that these indicate bileaflet lesions requiring complex repair. Echocardiograms and surgical reports of 52 consecutive patients with MVP undergoing surgery were reviewed. First, all 14 patients with two oppositely directed jets had prolapse of more than one leaflet. Each jet was related to discrete leaflet distortions causing malcoaptation. Six underwent valve replacement. Seven had both leaflets repaired. One had posterior leaflet repair and annuloplasty, with persistent mitral regurgitation requiring valve replacement. Second, 36 of 38 patients with single jets had single-leaflet MVP. One underwent replacement; all others did well with single-leaflet repair. Two patients with bileaflet MVP but only one jet did well with single-leaflet repair or annuloplasty. This crossed swords sign is an important clue to bileaflet mechanism of mitral regurgitation in MVP, associated with complex repair procedures. Thus, it provides a clue in the dilemma of bileaflet versus single-leaflet repair.