Mitral Valve Prolapse With Mid-Late Systolic Mitral Regurgitation

Prognostic Implications of Magnetic Resonance-Derived Quantification in Asymptomatic Patients With Organic Mitral Regurgitation: Comparison With Doppler Echocardiography-Derived Integrative Approach

BACKGROUND

Magnetic resonance imaging (MRI) is an accurate method for the quantitative assessment of organic mitral regurgitation (OMR). The aim of the present study was to compare the discriminative power of MRI quantification and the recommended Doppler echocardiography (ECHO)-derived integrative approach to identify asymptomatic patients with OMR and adverse outcome.

METHODS

The study population consisted of 258 asymptomatic patients (63±14 years, 60% men) with preserved left ventricular ejection fraction (>60%) and chronic moderate and severe OMR (flail 25%, prolapse 75%) defined by using the ECHO-derived integrative approach. All patients underwent MRI to quantify regurgitant volume (RV) of OMR by subtracting the aortic forward flow volume from the total left ventricular stroke volume. Severe OMR was defined as RV≥60 mL.

RESULTS

Mean ECHO-derived RV was on average 17.1 mL larger than the MRI-derived RV (P<0.05). Concordant grading of OMR severity with both techniques was observed in 197 (76%) individuals with 62 (31%) patients having severe OMR (MRI SEV-ECHO SEV) and 135 (69%) patients having moderate OMR (MRI MOD-ECHO MOD). The remaining 61 (24%) individuals had discordant findings (MRI SEV-ECHO MOD or MRI MOD-ECHO SEV) between the 2 techniques. The majority of these differences in OMR classification were observed in patients with late systolic or multiple jets (both κ<0.2). Patients with eccentric jets showed moderate agreement (κ=0.53; 95% confidence interval, 0.41-0.64). In contrast, a very good agreement (κ=0.90; 95% confidence interval, 0.82-0.98) was observed in a combination of holosystolic, central, and single jet. During a median follow-up of 5.0 years (interquartile range, 3.5-6.0 years), 38 (15%) patients died and 106 (41%) either died or developed indication for mitral valve surgery. In separate Cox regression analyses, the MRI-derived left ventricular end-systolic volume index, RV, and OMR category (severe versus moderate), and the ECHO-derived OMR category were independent predictors of all-cause mortality (all P<0.05). The MRI-derived RV showed the largest area under the curve to predict mortality (0.72) or its combination with the development of indication for mitral valve surgery (0.83).

CONCLUSIONS

The findings of the present study suggest that the MRI-derived assessment of OMR can better identify patients with severe OMR and adverse outcome than ECHO-derived integrative approach warranting close follow-up and perhaps, early mitral valve surgery.

Assessment of the severity of native mitral valve regurgitation

Mitral regurgitation (MR) is a major cause of cardiovascular morbidity and mortality. MR is classified as primary (organic) if it is due to an intrinsic valve abnormality, or secondary (functional) if the etiology is because of remodeling of left ventricular geometry and/or valve annulus. Transthoracic echocardiography (TTE) is the initial modality for MR evaluation. Parameters used for the assessment of MR include valve structure, cardiac remodeling, and color and spectral Doppler. Quantitative measurements include effective regurgitant orifice area, regurgitant volume, and regurgitant fraction. Knowledge of advantages and limitations of echo-Doppler parameters is essential for accurate results. An integrative approach is recommended in overall grading of MR as mild, moderate, or severe since singular parameters may be affected by several factors. When the mechanism and/or grade of MR is unclear from the TTE or is discrepant with the clinical scenario, further evaluation with transesophageal echocardiography or cardiac magnetic resonance imaging is recommended, the latter emerging as a powerful MR quantitation tool.

2017 ACC Expert Consensus Decision Pathway on the Management of Mitral Regurgitation: A Report of the American College of Cardiology Task Force on Expert Consensus Decision Pathways

Mitral regurgitation (MR) is a complex valve lesion that can pose significant management challenges for the cardiovascular clinician. This Expert Consensus Document emphasizes that recognition of MR should prompt an assessment of its etiology, mechanism, and severity, as well as indications for treatment. A structured approach to evaluation based on clinical findings, precise echocardiographic imaging, and when necessary, adjunctive testing, can help clarify decision making. Treatment goals include timely intervention by an experienced heart team to prevent left ventricular dysfunction, heart failure, reduced quality of life, and premature death.

Impact of bileaflet mitral valve prolapse on quantification of mitral regurgitation with cardiac magnetic resonance: a single-center study

BACKGROUND

To quantify mitral regurgitation (MR) with CMR, the regurgitant volume can be calculated as the difference between the left ventricular (LV) stroke volume (SV) measured with the Simpson's method and the reference SV, i.e. the right ventricular SV (RVSV) in patients without tricuspid regurgitation. However, for patients with prominent mitral valve prolapse (MVP), the Simpson's method may underestimate the LV end-systolic volume (LVESV) as it only considers the volume located between the apex and the mitral annulus, and neglects the ventricular volume that is displaced into the left atrium but contained within the prolapsed mitral leaflets at end systole. This may lead to an underestimation of LVESV, and resulting an over-estimation of LVSV, and an over-estimation of mitral regurgitation. The aim of the present study was to assess the impact of prominent MVP on MR quantification by CMR.

METHODS

In patients with MVP (and no more than trace tricuspid regurgitation) MR was quantified by calculating the regurgitant volume as the difference between LVSV and RVSV. LVSVuncorr was calculated conventionally as LV end-diastolic (LVEDV) minus LVESV. A corrected LVESVcorr was calculated as the LVESV plus the prolapsed volume, i.e. the volume between the mitral annulus and the prolapsing mitral leaflets. The 2 methods were compared with respect to the MR grading. MR grades were defined as absent or trace, mild (5-29% regurgitant fraction (RF)), moderate (30-49% RF), or severe (≥50% RF).

RESULTS

In 35 patients (44.0 ± 23.0y, 14 males, 20 patients with MR) the prolapsed volume was 16.5 ± 8.7 ml. The 2 methods were concordant in only 12 (34%) patients, as the uncorrected method indicated a 1-grade higher MR severity in 23 (66%) patients. For the uncorrected/corrected method, the distribution of the MR grades as absent-trace (0 vs 11, respectively), mild (20 vs 18, respectively), moderate (11 vs 5, respectively), and severe (4 vs 1, respectively) was significantly different (p < 0.001). In the subgroup without MR, LVSVcorr was not significantly different from RVSV (difference: 2.5 ± 4.7 ml, p = 0.11 vs 0) while a systematic overestimation was observed with LVSVuncorr (difference: 16.9 ± 9.1 ml, p = 0.0007 vs 0). Also, RVSV was highly correlated with aortic forward flow (n = 24, R 2 = 0.97, p < 0.001).

CONCLUSION

For patients with severe bileaflet prolapse, the correction of the LVSV for the prolapse volume is suggested as it modified the assessment of MR severity by one grade in a large portion of patients.

Usefulness of the Mitral Regurgitation Severity Index to Assess the Severity of Chronic Mitral Regurgitation

Existing metrics for grading mitral regurgitation (MR) are limited and fraught with high interobserver variability. We developed and evaluated a Doppler-based, semiquantitative novel index (Mitral Regurgitation Severity Index [MRSI]) of MR severity. In a total of 125 patients (70 in the derivation cohort and 55 in the validation cohort), MRSI was calculated as a ratio of time velocity integral of mitral inflow (continuous-wave Doppler-TVI MV) to the time velocity integral of the left ventricle outflow (pulse-wave Doppler-TVI LVOT). Inter-rater agreement for MRSI and predictive ability of the MRSI were then assessed. In the derivation cohort, MRSI differed significantly between patients with severe MR (2.6 ± 0.51) and mild-moderate (nonsevere) MR (1.4 ± 0.18) and a cutoff of ≥1.8 was associated with optimal diagnostic accuracy. In the validation cohort, MRSI exhibited excellent agreement between a level II and a level III reader with a mean difference of -0.14 (95% confidence limit of agreement: -0.80 to 0.53), correlation coefficient of 0.88 (p <0.001), and 16% CV; and using the cut point of 1.8, it exhibited good inter-rater reproducibility with a kappa coefficient of 0.72 (p <0.001). In conclusion, MRSI appears to be a simple, quantitative, practical, color-independent metric to differentiate severe MR from nonsevere MR.

Evolution of Mitral Valve Prolapse: Insights From the Framingham Heart Study

BACKGROUND

Longitudinal studies of mitral valve prolapse (MVP) progression among unselected individuals in the community, including those with nondiagnostic MVP morphologies (NDMs), are lacking.

METHODS AND RESULTS

We measured longitudinal changes in annular diameter, leaflet displacement, thickness, anterior/posterior leaflet projections onto the annulus, coaptation height, and mitral regurgitation jet height in 261 Framingham Offspring participants at examination 5 who had available follow-up imaging 3 to 16 years later. Study participants included MVP (n=63); NDMs, minimal systolic displacement (n=50) and the abnormal anterior coaptation phenotype (n=10, with coaptation height >40% of the annulus similar to posterior MVP); plus 138 healthy referents without MVP or NDMs. At follow-up, individuals with MVP (52% women, 57±11 years) had greater increases of leaflet displacement, thickness, and jet height than referents (all P<0.05). Eleven participants with MVP (17%) had moderate or more severe mitral regurgitation (jet height ≥5 mm) and 5 others (8%) underwent mitral valve repair. Of the individuals with NDM, 8 (80%) participants with abnormal anterior coaptation progressed to posterior MVP; 17 (34%) subjects with minimal systolic displacement were reclassified as either posterior MVP (12) or abnormal anterior coaptation (5). In comparison with the 33 participants with minimal systolic displacement who did not progress, the 17 who progressed had greater leaflet displacement, thickness, coaptation height, and mitral regurgitation jet height (all P<0.05).

CONCLUSIONS

NDM may evolve into MVP, highlighting the clinical significance of mild MVP expression. MVP progresses to significant mitral regurgitation over a period of 3 to 16 years in one-fourth of individuals in the community. Changes in mitral leaflet morphology are associated with both NDM and MVP progression.

The clinical impact of valvular heart disease in a population-based cohort of subjects aged 80 and older

BACKGROUND

In our ageing society, valvular heart diseases (VHD) have become an increasing public health problem. However, the lack of studies describing the impact of these diseases on the outcome of very old subjects makes it difficult to appreciate their real clinical burden.

METHODS

Prospective, observational, population-based cohort study in Belgium. Five hundred fifty six subjects aged 80 years and older were followed up for 5.1 ± 0.25 years for mortality and 3.0 ± 0.25 years for hospitalization. Echocardiograms were performed at baseline. The Cumulative Illness Rating Scale (CIRS) was calculated for each subject.

RESULTS

The prevalence of moderate-to-severe VHD was 17% (n = 97). Mitral stenosis was more prevalent in women and an age-dependent increase of the prevalence of severe aortic stenosis was seen. The overall disease burden was higher in participants with VHD (median CIRS 3 [IQR 3-5] vs 4 [IQR 3-6] (P = 0.008)). Moderate-to-severe VHD, and more specifically mitral stenosis and aortic stenosis, was found to be an independent predictor of both all-cause (HR 1.42 (95% CI 1.04-1.95)) and cardiovascular mortality (HR 2.13 (95% CI 1.38-3.29)). Moderate-to-severe VHD was also found to be an independent predictor of the need for a first unplanned hospitalization (HR 1.43 (95% CI 1.06-1.94)).

CONCLUSIONS

A high prevalence of moderate-to-severe VHD was found in the very old. Moderate-to-severe VHD was identified as an independent risk factor for all-cause and cardiovascular mortality and as well for unplanned hospitalizations, independent of other structural cardiac abnormalities, ventricular function and major co-morbidities.

Two- and Three-dimensional Transthoracic Echocardiographic Assessment of Tricuspid Valve Prolapse with Mid-to-Late Systolic Tricuspid Regurgitation

We present the two-dimensional echocardiographic findings of tricuspid valve prolapse with mid-to-late systolic tricuspid regurgitation and describe the incremental value provided by live/real time three-dimensional transthoracic echocardiography. We also discuss a potential pitfall when assessing the severity of regurgitation in this setting.

Impact of duration of mitral regurgitation on outcomes in asymptomatic patients with myxomatous mitral valve undergoing exercise stress echocardiography

Background

Significant mitral regurgitation (MR) typically occurs as holosystolic (HS) or mid‐late systolic (MLS), with differences in volumetric impact on the left ventricle (LV). We sought to assess outcomes of degenerative MR patients undergoing exercise echocardiography, separated based on MR duration (MLS versus HS).

Methods and Results

We included 609 consecutive patients with ≥III+myxomatous MR undergoing exercise echocardiography: HS (n=487) and MLS (n=122). MLS MR was defined as delayed appearance of MR signal during mid‐late systole on continuous‐wave Doppler while HS MR occurred throughout systole. Composite events of death and congestive heart failure were recorded. Compared to MLS MR, HS MR patients were older (60±14 versus 53±14 years), more were males (72% versus 53%), and had greater prevalence of atrial fibrillation (16% versus 7%; all P<0.01). HS MR patients had higher right ventricular systolic pressure (RVSP) at rest (33±11 versus 27±9 mm Hg), more flail leaflets (36% versus 6%), and a lower number of metabolic equivalents (METs) achieved (9.5±3 versus 10.5±3), compared to the MLS MR group (all P<0.05). There were 54 events during 7.1±3 years of follow‐up. On step‐wise multivariable analysis, HS versus MLS MR (HR 4.99 [1.21 to 20.14]), higher LV ejection fraction (hazard ratio [HR], 0.94 [0.89 to 0.98]), atrial fibrillation (HR, 2.59 [1.33 to 5.11]), higher RVSP (HR, 1.05 [1.03 to 1.09]), and higher percentage of age‐ and gender‐predicted METs (HR, 0.98 [0.97 to 0.99]) were independently associated with adverse outcomes (all P<0.05).

Conclusion

In patients with ≥III+myxomatous MR undergoing exercise echocardiography, holosystolic MR is associated with adverse outcomes, independent of other predictors.

Spectral Doppler interrogation of mitral regurgitation -spot diagnosis

Mitral regurgitation (MR) is one of the most common valvular lesions that are readily identified by transthoracic echocardiography. Color Doppler imaging is the modality of choice for the recognition of MR, and it plays an important role in the assessment of regurgitation severity. Continuous wave (CW) Doppler is commonly used to interrogate the MR signal, and this modality can provide highly useful data regarding several physiological and pathological parameters. In this manuscript, we present a series of cases that illustrate the various hemodynamic parameters that can be derived from analysis of the CW Doppler signal of MR.

Echocardiographic assessment of mitral valve regurgitation, pattern and prevalence, expanding clinical awareness through an institutional survey with the perspective of a quality improvement project

BACKGROUND

Mitral regurgitation (MR) is frequently reported in everyday echocardiograms; accurate assessment is essential for appropriate management and decision making.

OBJECTIVE

We performed a self-audit in order to define the prevalence and pattern of MR and to evaluate methods of assessment with the perspective of developing a quality improvement project.

METHODS AND SETTING

This retrospective analytical study was conducted in a university hospital.

INCLUSION CRITERIA

age more than 18 years and medical records available within the facility, including a "complete" medical history. Using the picture archiving and communication system, we reviewed 961 echocardiograms performed over a 6-month period. The methods of assessment of native mitral valve regurgitation were reported, and also relevant medical data were collected using an electronic archiving system.

RESULTS AND DISCUSSION

Among the 961 patients reviewed, 322 (33.50%) had MR, with variable grades. MR pattern (organic versus functional) was not specified in 49.68% of cases. "Eyeball" assessment and "color jet area" were the most frequently used methods for MR assessment (90.06% and 27.95%, respectively), while "vena contracta" and "flow convergence" methods were rarely implemented (1.55% and 2.17%, respectively). Discussion is made according to current guidelines, while showing the strengths and weaknesses of each method.

CONCLUSION

The prevalence of MR was 33.50%, and in nearly half of cases, the MR pattern was not specified. Qualitative and semi-quantitative methods of assessment were mostly used; quantitative assessment should be implemented more frequently, in accordance with current guidelines. Increasing clinical awareness by creating and implementing a quality improvement project is essential in this context.

The role of echocardiography in the management of patients with myxomatous disease

Degenerative mitral regurgitation (MR), the leading cause of organic MR in western countries, is primarily characterized by mitral valve prolapse but encompasses a wide spectrum of anatomic lesions from fibroelastic deficiency (localized prolapse segment often associated with ruptured chordae) to diffuse myxomatous degeneration (Barlow's disease, diffuse excessive tissue with multiple valvular segments involved). Echocardiography is the method of choice to evaluate patients with degenerative MR and plays a crucial role in clinical management. It allows accurate assessment of MR severity, left ventricular and atrial consequences, etiology, mechanisms and anatomic lesions and consequently defines the probability of mitral valve repair.

A novel technique to quantify the instantaneous mitral regurgitant rate

BACKGROUND

The systolic variation of mitral regurgitation (MR) is a pitfall in its quantification. Current recommendations advocate using quantitative echocardiographic techniques that account for this systolic variation. While prior studies have qualitatively described patterns of systolic variation no study has quantified this variation.

METHODS

This study includes 41 patients who underwent cardiovascular magnetic resonance (CMR) evaluation for the assessment of MR. Systole was divided into 3 equal parts: early, mid, and late. The MR jets were categorized as holosystolic, early, or late based on the portions of systole the jet was visible. The aortic flow and left ventricular stroke volume (LVSV) acquired by CMR were plotted against time. The instantaneous regurgitant rate was calculated for each third of systole as the difference between the LVSV and the aortic flow.

RESULTS

The regurgitant rate varied widely with a 1.9-fold, 3.4-fold, and 1.6-fold difference between the lowest and highest rate in patients with early, late, and holosystolic jets respectively. There was overlap of peak regurgitant rates among patients with mild, moderate and severe MR. The greatest variation of regurgitant rate was seen among patients with mild MR.

CONCLUSION

CMR can quantify the systolic temporal variation of MR. There is significant variation of the mitral regurgitant rate even among patients with holosystolic MR jets. These findings highlight the need to use quantitative measures of MR severity that take into consideration the temporal variation of MR.