Color flow imaging compared with quantitative Doppler assessment of severity of mitral regurgitation: influence of eccentricity of jet and mechanism of regurgitation

Contrast Echocardiography: Unveiling Eccentric Mitral Regurgitation

•Leaflet prolapse, flail, and perforation often result in eccentric MR. •Eccentric jets appear smaller than central jets of similar severity on color Doppler. •The use of UEAs is helpful in better visualizing eccentric MR jets on TTE.

Variation in resource utilization and mortality among patients with varying MR type and severity

BACKGROUND

Limited data exists regarding the relationships between resource use and outcomes in patients with mitral regurgitation (MR). We examined resource utilization and outcomes across MR type and severity.

METHODS

Using the Duke Echocardiography Laboratory Database, we identified patients with an index echo demonstrating moderate or severe MR (2000-2016) and examined 5-year cumulative rates of resources (ie, TTE, TEE, cardiac catheterization, cardiology/CTS referral, MV surgery/TEER, hospitalizations) by severity and type. We performed a multivariable landmark analysis of resource use during a 6 to 12 month period and 5-year mortality; and a multivariable analysis of the association between MR type and 5-year hospitalization costs.

RESULTS

Among 4,511 patients with moderate or severe MR, 84.7% had moderate MR and 42.2% had secondary ischemic MR. The median age was 70 years-moderate, 66 years-severe. The mean 5-year cumulative resource utilization rate was 11.1 encounters/patients. Among patients with moderate or severe MR, there was significant variation in utilization of each resource by MR type (all P < .05). For severe MR, the performance of cardiac catheterization or MV surgery during the landmark period was associated with significantly lower mortality; for moderate MR, CTS referral during the landmark was associated with significantly lower mortality (P < .05). Patients with secondary ischemic and non-ischemic MR had significantly higher 5-year hospitalization costs compared with primary myxomatous MR (P < .05).

CONCLUSIONS

Resource utilization and outcomes vary by MR type and severity. Utilization of resources, such as TTE, during guideline-recommended surveillance periods was not associated with a reduction in mortality while other care (catheterization or surgery) was associated with improved survival.

Quantification of primary mitral regurgitation by echocardiography: A practical appraisal

The accurate quantification of primary mitral regurgitation (MR) and its consequences on cardiac remodeling is of paramount importance to determine the best timing for surgery in these patients. The recommended echocardiographic grading of primary MR severity relies on an integrated multiparametric approach. It is expected that the large number of echocardiographic parameters collected would offer the possibility to check the measured values regarding their congruence in order to conclude reliably on MR severity. However, the use of multiple parameters to grade MR can result in potential discrepancies between one or more of them. Importantly, many factors beyond MR severity impact the values obtained for these parameters including technical settings, anatomic and hemodynamic considerations, patient's characteristics and echocardiographer' skills. Hence, clinicians involved in valvular diseases should be well aware of the respective strengths and pitfalls of each of MR grading methods by echocardiography. Recent literature highlighted the need for a reappraisal of the severity of primary MR from a hemodynamic perspective. The estimation of MR regurgitation fraction by indirect quantitative methods, whenever possible, should be central when grading the severity of these patients. The assessment of the MR effective regurgitant orifice area by the proximal flow convergence method should be used in a semi-quantitative manner. Furthermore, it is crucial to acknowledge specific clinical situations in MR at risk of misevaluation when grading severity such as late-systolic MR, bi-leaflet prolapse with multiple jets or extensive leak, wall-constrained eccentric jet or in older patients with complex MR mechanism. Finally, it is debatable whether the 4-grades classification of MR severity would be still relevant nowadays, since the indication for mitral valve (MV) surgery is discussed in clinical practice for patients with 3+ and 4+ primary MR based on symptoms, specific markers of adverse outcome and MV repair probability. Primary MR grading should be seen as a continuum integrating both quantification of MR and its consequences, even for patients with presumed "moderate" MR.

Are There Any Differences in the Prognostic Value of Left Ventricular Ejection Fraction in Coronary Artery Disease Patients With or Without Moderate and Severe Mitral Regurgitation?

Background

Left ventricular ejection fraction (LVEF) is a vital variable to describe left ventricle systolic function and contractility of left ventricle. However, the association between LVEF and the prognostic effect in patients with moderate or severe mitral regurgitation (MR) is still controversial.

Methods

This study comprised 30,775 coronary artery disease (CAD) patients who underwent coronary arteriography (CAG) in the Cardiorenal ImprovemeNt (CIN) registry from January 2007 to December 2018. Patients were divided into none or mild MR group and moderate or severe MR group, and 3 levels of LVEF ≥50, 40–50%, and <40% were further distinguished according to hospital baseline. Univariate and multivariate Cox proportional analyses were used to investigate the association between LVEF levels and long-term all-cause mortality in patients with different MR severities.

Results

Of 30,775 CAD patients (62.9 ± 10.6 years, females 23.8%), 26,474 (86.0%) patients had none or mild MR. Compared with none or mild MR patients, patients with moderate or severe MR were older and had worse cardio-renal function. In multivariable Cox proportional analysis, LVEF <40% was independently associated with higher mortality compared with LVEF ≥ 50% in all kinds of MR severity {none or mild MR [adjusted hazard ratio (HR): 1.79; 95% CI: 1.56–2.05, p < 0.001], moderate or severe MR [adjusted HR: 1.57; 95% CI: 1.29–1.91, p < 0.001]}.

Conclusions

LVEF is a reliable prognostic index in CAD patients, even in those with moderate or severe MR. LVEF monitoring would still be clinically useful in CAD patients with moderate or severe MR. Clinical trials are needed to prospectively evaluate the optimal threshold for LVEF in patients with moderate or severe MR.

Consequences of functional mitral regurgitation and atrial fibrillation in patients with left ventricular assist devices

BACKGROUND

Functional mitral regurgitation (MR) (FMR) and atrial fibrillation (AF) are common in patients undergoing left ventricular assist device (LVAD) implantation. However, the impact of FMR and AF on clinical outcomes is uncertain. This study aimed to investigate the characteristics and prognostic significance of FMR and AF in patients with LVADs.

METHODS

We retrospectively reviewed all patients who underwent LVAD implantation at our center between January 2010 and December 2017. We defined significant FMR as the ratio of MR color jet area to left atrial area of >20% and persistent or permanent AF (PeAF) as persistent or permanent AF at LVAD implantation.

RESULTS

A total of 380 patients were included in this analysis. Patients were divided into 6 groups: patients with no PeAF and no significant FMR (Group 1), patients with no PeAF but with significant FMR (Group 2), patients with PeAF but no significant FMR (Group 3), patients with PeAF and significant FMR (Group 4), patients with concomitant mitral valve surgery (MVS) at LVAD implantation and without PeAF (Group 5), and patients with concomitant MVS and with PeAF (Group 6). A total of 56 patients (15%) died within 2 years. Kaplan-Meier curve analysis demonstrated a 2-year survival of 81% in Group 1, 89% in Group 2, 87% in Group 3, 47% in Group 4, 87% in Group 5, and 79 % in Group 6 (log-rank test, p < 0.001). The multivariable Cox proportional-hazards model showed that classification in Group 4 was an independent predictor of mortality (hazard ratio, 4.31; 95% CI: 2.19-8.46; p < 0.001).

CONCLUSIONS

The coexistence of significant FMR and PeAF may represent a poor prognostic marker in patients undergoing LVAD implantation.

Color Doppler Splay: A Clue to the Presence of Significant Mitral Regurgitation

BACKGROUND

The authors describe a previously unreported Doppler signal associated with mitral regurgitation (MR) as imaged using transthoracic echocardiography. Horizontal "splay" of the color Doppler signal along the atrial surface of the valve may indicate significant regurgitation when the MR jet otherwise appears benign.

METHODS

Splay was defined as a nonphysiologic arc of color centered at the point at which the MR jet emerges into the left atrium. The authors present a series of 10 cases of clinically significant MR (moderately severe or severe as defined by transesophageal echocardiography) that were misclassified on transthoracic echocardiography as less than moderate. The splay signal was present on at least one standard transthoracic view in each case. To better characterize the splay signal, two groups were created from existing clinically driven transthoracic echocardiograms: 100 consecutive patients with severe MR and 100 with mild MR.

RESULTS

Splay was present in the majority of severe MR cases (81%) regardless of vendor machine, ejection fraction, or MR etiology. Splay was particularly prevalent among patients with wall-hugging jets (28 of 30 [93%]). In patients with mild MR, splay was present less often (16%), on fewer frames per clip, and had smaller dimensions compared with severe MR. Color scale did not differ between subjects with and those without splay, but color gain was higher when splay was present (P = .04). Machine settings were further explored in a single subject with prominent splay: increasing transducer frequency reduced splay, while increasing color gain increased it.

CONCLUSIONS

The authors describe a new transthoracic echocardiographic sign of MR. Horizontal splay may be a clue to the presence of severe MR when the main body of the jet is out of the imaging plane. Splay is likely generated as a side-lobe artifact due to a high-flux regurgitant jet.

Prognostic impact of moderate mitral regurgitation on hospitalized heart failure patients with preserved ejection fraction: A report from the JASPER registry

A growing body of evidence suggests that mitral regurgitation (MR) is associated with higher mortality in heart failure patients with reduced ejection fraction. However, prognostic impact of MR on heart failure patients with preserved ejection fraction (HFpEF) has not been fully examined. The Japanese Heart Failure Syndrome with Preserved Ejection Fraction (JASPER) registry is a nationwide, observational, prospective registration of consecutive Japanese hospitalized HFpEF patients with LVEF ≥ 50%. Severe valvular heart disease was excluded from this cohort. We divided the consecutive 341 patients into two groups based on the severity of MR at discharge: no or mild MR group (n = 317) and moderate MR group (n = 24). Compared with no or mild MR group, moderate MR group showed larger left ventricular end-diastolic diameter (52 [48-59] vs. 46 [42-50] mm, P < 0.001), left ventricular systolic diameter (35 [30-37] vs. 29 [26-34] mm, P = 0.006), left atrial diameter (49 [46-56] vs. 45 [40-50] mm, P < 0.001), and higher tricuspid regurgitation peak gradient (33 [25-40] vs. 27 [21-33] mmHg, P = 0.012). In contrast, levels of plasma B-type natriuretic peptide and left ventricular ejection fraction were comparable between the two groups. In the follow-up period (median 738 days), there were 57 all-cause deaths. In the Kaplan-Meier analysis, all-cause mortality was higher in moderate MR group than in no or mild MR group (log-rank P = 0.023). In the Cox proportional hazard analysis, moderate MR at discharge was a predictor of all-cause mortality (hazard ratio 2.256, 95% confidence interval 1.035-4.917, P = 0.041). Moderate MR at discharge is associated with adverse prognosis in hospitalized patients with HFpEF.

The Accuracy of a Large V Wave in the Pulmonary Capillary Wedge Pressure Waveform for Diagnosing Current Mitral Regurgitation

Background: Large V waves in the pulmonary capillary wedge pressure (PCWP) waveform traditionally indicate severe mitral regurgitation (MR). However, our understanding of MR etiology and hemodynamics has changed in recent decades. Objectives: We aimed to reevaluate the association between large V waves and current MR to determine whether traditional large V wave criteria remain optimal. Method: We reviewed 1,964 right heart catheterizations (RHCs) performed at our institution from 2010 to 2017, and retrospectively selected 126 patients with sinus rhythm who underwent echocardiography within 2 days (0.3 ± 0.5 days) of the RHC. The diagnostic accuracy of 3 traditional criteria for large V waves was assessed, and the optimal cut-off points were determined as those with the maximal Youden indices. Results: Severe MR was observed on echocardiography in 26 (21%) patients, including 15 (58%) with Carpentier classification type II MR and 11 (42%) with type IIIB MR. Large V waves, defined as a difference between the peak V wave and mean PCWP ≥10 mm Hg, had a high specificity of 94% (95% confidence interval: 87–98%), but a low sensitivity of 27% (12–48%) for diagnosing severe MR. The optimal cut-off point for the V wave was 3 mm Hg above the mean PCWP, with a sensitivity of 73% (52–88%) and a specificity of 64% (54–73%). Conclusions: For diagnosing current MR, the cut-off point for a large V wave should be reduced from that previously employed for rheumatic valvular heart disease. This information may be useful in guiding contemporary transcatheter therapies for MR under RHC monitoring.

Long-term outcomes of mitral regurgitation by type and severity

BACKGROUND

We aimed to determine the association of MR severity and type with all-cause death in a large, real-world, clinical setting.

METHODS

We reviewed full echocardiography studies at Duke Echocardiography Laboratory (01/01/1995-12/31/2010), classifying MR based on valve morphology, presence of coronary artery disease, and left ventricular size and function. Survival was compared among patients stratified by MR type and baseline severity.

RESULTS

Of 93,007 qualifying patients, 32,137 (34.6%) had ≥mild MR. A total of 8094 (8.7%) had moderate/severe MR, which was primary myxomatous (14.1%), primary non-myxomatous (6.2%), secondary non-ischemic (17.0%), and secondary ischemic (49.4%). At 10 years, patients with primary myxomatous MR or MR due to indeterminate cause had survival rates of >60%; primary non-myxomatous, secondary ischemic, and non-ischemic MR had survival rates <50%. While mild (HR 1.06, 95% CI 1.03-1.09), moderate (HR 1.31, 95% CI 1.27-1.37), and severe (HR 1.55, 95% CI 1.46-1.65) MR were independently associated with all-cause death, the relationship of increasing MR severity with mortality varied across MR types (P ≤ .001 for interaction); the highest risk associated with worsening severity was seen in primary myxomatous MR followed by secondary ischemic MR and primary non-myxomatous MR.

CONCLUSIONS

Although MR severity is independently associated with increased all-cause death risk for most forms of MR, the absolute mortality rates associated with worse MR severity are much higher for primary myxomatous, non-myxomatous, and secondary ischemic MR. The findings from this study support carefully defining MR by type and severity.

Identification and Quantification of Degenerative and Functional Mitral Regurgitation for Patient Selection for Transcatheter Mitral Valve Repair

Chronic mitral regurgitation (MR), whether due to valve degeneration or secondary to myocardial disease, affects an increasing proportion of the aging population. Percutaneous mitral valve interventions, including edge-to-edge repair, are emerging as feasible and effective therapy for patients with severe MR at high or prohibitive surgical risk. Imaging with echocardiography is crucial for patient selection by evaluating mitral anatomy, the mechanism of dysfunction, and MR severity. In this article, the authors review the imaging characteristics for identifying and quantifying degenerative and functional MR for transcatheter mitral valve repair.

Intravascular hemolysis in patients with mitral regurgitation: Evaluation by erythrocyte creatine

BACKGROUND

Intravascular hemolysis has been reported in patients with cardiac valve prostheses, but intravascular hemolysis in patients with mitral regurgitation with native valve has not been evaluated in detail. We designed a study to elucidate the impact of regurgitation flow on intravascular hemolysis in patients with primary mitral regurgitation by measuring erythrocyte creatine.

METHODS

Erythrocyte creatine was enzymatically assayed in 29 patients with moderate to severe primary mitral regurgitation and 12 age-matched healthy volunteers. The size and characteristics of mitral regurgitation were determined by color Doppler echocardiography.

RESULTS

Erythrocyte creatine was significantly higher in patients with eccentric jet (n=17, 2.64±0.77μmol/g Hb) than that of central jet (n=12, 1.68±0.13μmol/g Hb) and control subjects (1.39±0.25μmol/g Hb). Patients with eccentric jet had a significantly lower erythrocyte count and hemoglobin (385±58 x10⁴/μL and 116±19g/l) compared to those with central jet (450±47×10⁴/μL and 137±14g/l) and control subjects (433±31×10⁴/μL and 134±19g/l). There were no significant differences in age, estimated glomerular filtration rate, pulmonary artery systolic pressure, left atrial size and left ventricular end-diastolic dimension between patients with eccentric jet and central jet.

CONCLUSIONS

Intravascular hemolysis associated with subclincal anemia in patients with eccentric jet was due to the destruction of erythrocyte by collision of the eccentric jet to the atrial wall.

Ischemic or Nonischemic Functional Mitral Regurgitation and Outcomes in Patients With Acute Decompensated Heart Failure With Preserved or Reduced Ejection Fraction

The aim of this study was to evaluate the association of functional mitral regurgitation (FMR), preserved or reduced ejection fraction (EF), and ischemic or nonischemic origin with outcomes in patients discharged alive after hospitalization for acute decompensated heart failure (HF). Of the 4,842 patients enrolled in the Acute Decompensated Heart Failure Syndromes (ATTEND) registry, 3,357 patients were evaluated to assess the association of FMR, preserved or reduced EF, and ischemic or nonischemic origin with the primary end point (all-cause death and readmission for HF after discharge). At the time of discharge, FMR was assessed semiquantitatively (classified as none, mild, or moderate to severe) by color Doppler analysis of the regurgitant jet area. According to multivariable analysis, in the ischemic group, either mild or moderate to severe FMR in patients with a preserved EF had a significantly higher risk of the primary end point than patients without FMR (hazard ratio [HR] 1.60; 95% confidence interval [CI] 1.12 to 2.29; p = 0.010 and HR 1.98; 95% CI 1.30 to 3.01; p = 0.001, respectively). In patients with reduced EF with an ischemic origin, only moderate to severe FMR was associated with a significantly higher risk of the primary end point (HR 1.67; 95% CI 1.11 to 2.50; p = 0.014). In the nonischemic group, there was no significant association between FMR and the primary end point in patients with either a preserved or reduced EF. In conclusion, among patients with acute decompensated HF with a preserved or reduced EF, the association of FMR with adverse outcomes may differ between patients who had an ischemic or nonischemic origin of HF.

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.

Utility of cardiac magnetic resonance for evaluation of mitral regurgitation prior to mitral valve surgery

Mitral regurgitation (MR) is a common cause of morbidity worldwide and an accepted indication for interventional therapies which aim to reduce or resolve adverse clinical outcomes associated with MR. Cardiac magnetic resonance (CMR) provides highly accurate means of assessing MR, including a variety of approaches that can measure MR based on quantitative flow. Additionally, CMR is widely accepted as a reference standard for cardiac chamber quantification, enabling reliable detection of subtle changes in cardiac chamber size and function so as to guide decision-making regarding timing of mitral valve directed therapies. Beyond geometric imaging, CMR enables tissue characterization of ischemia and infarction in the left ventricular (LV) myocardium as well as within the mitral valve apparatus, thus enabling identification of structural substrates for MR. This review provides an overview of established and emerging CMR approaches to measure valvular regurgitation, including relative utility of different approaches for patients with primary or secondary MR. Clinical outcomes studies are discussed with focus on data demonstrating advantages of CMR for guiding diagnosis, risk stratification, and management of patients with known or suspected MR. Comparative data is reviewed with focus on diagnostic performance of CMR in comparison to conventional assessment via echocardiography (echo). Emerging literature is reviewed concerning potential new approaches that utilize CMR tissue characterization to guide clinical decision-making in order to improve therapeutic outcomes and clinical prognosis for patients with MR.

Primary mitral valve regurgitation: Update and review

Mitral regurgitation is the second most common valvular disorder requiring surgical intervention worldwide. This review summarizes the current understanding of primary, degenerative mitral regurgitation with respect to etiology, comprehensive assessment, natural history and management. The new concept of staging of the valvular disorders, newer predictors of adverse and controversy of “watchful waiting” versus “early surgical intervention” for severe, asymptomatic, primary mitral regurgitation are addressed.

Functional mitral regurgitation at discharge and outcomes in patients hospitalized for acute decompensated heart failure with a preserved or reduced ejection fraction

AIMS

The relationship between functional mitral regurgitation (FMR), left ventricular ejection fraction (EF), and outcomes is unclear in acute decompensated heart failure (HF) patients. The aim of this study was to evaluate the relationship between FMR and post-discharge outcomes in HF patients with a preserved or reduced EF.

METHODS AND RESULTS

Of the 4842 patients enrolled in the Acute Decompensated Heart Failure Syndromes (ATTEND) registry, 3357 patients were evaluated to assess the association among FMR (none, mild, or moderate/severe) at discharge, a preserved or reduced EF, and the primary endpoint (all-cause mortality and readmission for HF). The median follow-up period after discharge was 530 (387-800) days. According to multivariate analysis, patients with either mild FMR or moderate/severe FMR from the preserved EF group had a significantly higher risk of reaching the endpoint than patients without FMR [hazard ratio (HR) 1.40; 95% confidence interval (CI) 1.14-1.72; P = 0.001 and HR 1.40; 95% CI 1.09-1.81; P = 0.009, respectively]. In the reduced EF group, patients with moderate or severe FMR had a significantly higher risk relative to patients without FMR (HR 1.41; 95% CI 1.07-1.86; P = 0.015), but there was no significant association of mild FMR with the risk of reaching the endpoint (HR 1.09; 95% CI 0.84-1.42; P = 0.510).

CONCLUSION

Our findings demonstrate that even mild FMR is associated with an increased risk of adverse outcomes in HF patients with a preserved EF, while moderate or severe FMR (but not mild FMR) is associated with adverse outcomes in HF patients with a reduced EF.

Systolic arterial blood pressure estimated by mitral regurgitation velocity, high definition oscillometry, and Doppler ultrasonography in dogs with naturally occurring degenerative mitral valve disease

INTRODUCTION

To determine if systolic blood pressure estimated by mitral regurgitation (MR) velocity can be used interchangeably with that estimated by high definition oscillometry (HDO) and Doppler ultrasonography (DU) in dogs with naturally occurring mitral valve disease (MVD).

ANIMALS

Forty-nine client-owned dogs with naturally occurring MVD.

MATERIALS AND METHODS

This is a retrospective study. Medical records were reviewed and dogs with MR caused by degenerative MVD were included if systolic blood pressure was estimated from MR velocity determined by continuous wave Doppler (CW), DU and HDO at the same visit. A Pearson product moment correlation coefficient was determined for each combination of measures and tested for significance with a paired t-test. Limits of agreement between 2 measures were determined by the 95% confidence interval of the average difference of the means and illustrated by Bland-Altman plots.

RESULTS

Systolic pressure estimated from CW was significantly but only moderately correlated to DU (r = 0.42, p=0.0015) and HDO (r = 0.40, p=0.0021). Pressure estimated from DU was significantly but only moderately correlated to HDO (r = 0.57, p≤0.0001). Limits of agreement were wide for all measures including DU and CW (-61.9to 44.6 mmHg), HDO and CW (-65.2to 26.9 mmHg), and HDO and DU (-63.1 to 42.06 mmHg).

DISCUSSION

Systolic blood pressure estimated by CW cannot be used interchangeably with HDO or DU in dogs with naturally occurring MVD.

Left ventricular early inflow-outflow index: a novel echocardiographic indicator of mitral regurgitation severity

BACKGROUND

No gold standard currently exists for quantification of mitral regurgitation (MR) severity. Classification by echocardiography is based on integrative criteria using color and spectral Doppler and anatomic measurements. We hypothesized that a simple Doppler left ventricular early inflow-outflow index (LVEIO), based on flow velocity into the left ventricle (LV) in diastole and ejected from the LV in systole, would add incrementally to current diagnostic criteria. LVEIO was calculated by dividing the mitral E-wave velocity by the LV outflow velocity time integral.

METHODS AND RESULTS

Transthoracic echocardiography reports from Montefiore Medical Center and its referring clinics from July 1, 2011, to December 31, 2011 (n=11 235) were reviewed. The MR severity reported by a cardiologist certified by the National Board of Echocardiography was used as a reference standard. Studies reporting moderate or severe MR (n=550) were reanalyzed to measure effective regurgitant orifice area by the proximal isovelocity surface area method, vena contracta width, MR jet area, and left-sided chamber volumes. LVEIO was 9.3±3.9, 7.0±3.2, and 4.2±1.7 among those with severe, moderate, and insignificant MR, respectively (ANOVA P<0.001). By receiver operating characteristic analysis, area under the curve for LVEIO was 0.92 for severe MR. Those with LVEIO ≥8 were likely to have severe MR (likelihood ratio 26.5), whereas those with LVEIO ≤4 were unlikely to have severe MR (likelihood ratio 0.11). LVEIO performed better in those with normal LV ejection fraction (≥50%) compared with those with reduced LV ejection fraction (<50%) (area under the curve 0.92 versus 0.80, P<0.001). By multivariate logistic regression analysis, LVEIO was independently associated with severe MR when compared with vena contracta width, MR jet area, and effective regurgitant orifice area measured by the proximal isovelocity surface area method.

CONCLUSION

LVEIO is a simple-to-use echocardiographic parameter that accurately identifies severe MR, particularly in patients with normal LV ejection fraction.

Echocardiographic predictors of survival in dogs with myxomatous mitral valve disease

OBJECTIVES

To evaluate vena contracta and other echocardiographic measures of myxomatous mitral valve disease (MMVD) severity in a multivariable analysis of survival in dogs.

ANIMALS

70 dogs diagnosed with MMVD from stored echocardiographic images that met study inclusion criteria.

METHODS

Left heart dimensions were measured as well as mitral regurgitant jet area/left atrial area (JAR), early mitral filling velocity (Evel), extent of mitral valve prolapse in right and left views (ProlR, ProlL), Prol indexed to aortic diameter (ProlR:Ao, ProlL:Ao), presence of a flail leaflet (FlailR, FlailL), and mitral regurgitation vena contracta diameter (VCR, VCL) indexed to aortic diameter (VCR:Ao, VCL:Ao). Follow-up from referring veterinarians was obtained by questionnaire or telephone to determine survival times. Inter- and intra-observer agreement was evaluated with Bland-Altman plots and weighted Kappa analysis. Survival was analyzed using Kaplan-Meier curves, logrank tests and Cox's proportional hazards.

RESULTS

Logrank analysis showed VCL:Ao, VCR:Ao, FlailL, ProlR:Ao, ProlL:Ao, left ventricular internal dimension in diastole indexed to aortic diameter (LVIDD:Ao) >2.87, left atrium to aorta ratio (LA/Ao) >1.6, and Evel >1.4 m/s were predictors of cardiac mortality. In a multivariable analysis, the independent predictors of cardiac mortality were Evel >1.4 m/s [hazard ratio (HR) 5.0, 95% confidence interval (CI) 2.5-10.3], FlailL (HR 3.1, 95% CI 1.3-7.9), and ProlR:Ao (HR 2.8, 95% CI 1.3-6.3).

CONCLUSIONS

Echocardiographic measures of mitral regurgitation severity and mitral valve pathology provide valuable prognostic information independent of chamber enlargement in dogs with MMVD.

Functional mitral regurgitation and left ventricular systolic dysfunction in the recent era of cardiovascular clinical practice, an observational cohort study

Functional mitral regurgitation (MR) is frequently associated with left ventricular systolic dysfunction (LVSD). Ventricular volume overload that occurs in patients with MR may lead to a progression of myocardial dysfunction. However, the prevalence and clinical outcomes of functional MR in Japanese patients with LVSD remain unclear. The aim of the present study is to clarify the prevalence and prognosis of functional MR in Japanese LVSD patients in the contemporary era. We followed patients with LVSD (LV ejection fraction (LVEF) ⩽ 40%) who were listed within a single, hospital-based cohort in the Shinken Database from 2004 to 2011, which was composed of all new patients (n = 17,517) who visited the Cardiovascular Institute. A total of 506 patients were included: 86 FMR (moderate-to-severe functional MR) patients and 420 non-FMR (none or mild functional MR) patients. FMR patients were older, had lower rates of hypertension and ischemic heart disease but had higher rates of chronic kidney disease, dilated cardiomyopathy and New York Heart Association III/IV classification. FMR patients had higher brain natriuretic peptide levels and lower LVEF. The Kaplan-Meier curves revealed that the incidence of all-cause death, cardiovascular death and heart failure (HF) admission was significantly higher in FMR patients. The presence of FMR was independently associated with a significantly higher risk of composite end point, including all-cause death and/or HF admission (hazard ratio 1.551, 95% confidence interval 1.045-2.303, P = 0.029). FMR was common in Japanese patients with LVSD and was associated with adverse long-term outcomes. Future study is warranted to establish the optimal therapeutic strategy for FMR and LVSD.

Prevalence and the long-term prognosis of functional mitral regurgitation in Japanese patients with symptomatic heart failure

Functional mitral regurgitation (FMR) is a common and critical condition in patients with heart failure (HF); however, the prevalence and clinical outcome of FMR in Japanese real-world clinical practice remain unclear. Within a single hospital-based cohort in the Shinken Database 2004-2011, which comprised all new patients (n = 17,517) who visited the Cardiovascular Institute, we followed symptomatic HF patients. A total of 1,701 patients were included: 104 FMR patients (who had moderate to severe FMR) and 1,597 non-FMR patients (who had none or mild FMR). FMR patients had lower rates of hypertension and dyslipidemia, but higher rates of dilated cardiomyopathy, atrial fibrillation, and New York Heart Association functional class III/IV. FMR patients had higher levels of brain natriuretic peptide and lower left ventricular function. Use of cardiovascular drugs was more common among FMR patients. Kaplan-Meier curves revealed that the incidences of all-cause death, cardiovascular death, and admission for HF were significantly higher in FMR patients. The adjusted Cox regression analysis showed that significant FMR was associated with higher incidences of all-cause death [hazard ratio (HR) 2.179, 95 % confidence interval (CI) 1.266-3.751; P = 0.005], cardiovascular death (HR 2.371, 95 % CI 1.157-4.858; P = 0.018), and admission for HF (HR 1.819, 95 % CI 1.133-2.920; P = 0.013). FMR was common in Japanese symptomatic HF patients and was associated with adverse long-term outcomes. Establishing optimal therapeutic strategies for FMR is warranted.

Pre-operative echocardiographic features associated with persistent mitral regurgitation after left ventricular assist device implantation

BACKGROUND

Previous studies have shown remarkable decrease in size of the left ventricle after left ventricular assist device (LVAD) implantation due to mechanical unloading. However, a certain number of patients continue to have significant mitral regurgitation (MR) under LVAD support. We investigated pre-operative echocardiographic features associated with persistent MR after LVAD implantation.

METHODS

We retrospectively reviewed 82 consecutive patients undergoing continuous-flow LVAD implantation between 2007 and 2010. We obtained echocardiograms performed within 2 weeks before and 1 week after surgery. We investigated the pre-operative echocardiographic findings associated with significant MR post-LVAD and compared 1-year mortality after LVAD surgery between patients with and without significant MR post-LVAD.

RESULTS

MR was significant in 43 patients (52.4%) before LVAD surgery. Among those, 5 underwent concomitant mitral valve repair (MVr) at the time of LVAD implantation. Of the remaining 38 patients, 25 (65.8%) showed improvement of MR, whereas 13 patients (34.2%) continued to have significant MR post-LVAD. Multivariate analysis revealed that posterior displacement of the coaptation point of mitral leaflets was significantly associated with significant MR post-LVAD (hazard ratio, 1.335; 95% confidence interval, 1.035-1.721; p = 0.026) even after adjusting for the amount of pre-operative MR flow. Post-LVAD 1-year survival of patients with and without significant MR post-LVAD was not significantly different (92.3% vs 89.1%, p = 0.826).

CONCLUSIONS

Pre-LVAD posterior displacement of mitral leaflets may be indicative of post-operative significant MR, which would help identify echocardiographic features of functional MR refractory to simple volume reduction of the ventricle.

Treatment strategies for acute coronary syndrome with severe mitral regurgitation and their effects on short- and long-term prognosis

Mitral regurgitation (MR) of even mild severity affects the prognosis of patients with acute coronary syndrome (ACS). The present study retrospectively analyzed 1,142 patients with ACS and MR of varying severity. Of the 95 patients with severe MR, 57 (60%) underwent primary percutaneous coronary intervention only and 38 (40%) underwent coronary artery bypass grafting (CABG) and mitral valve replacement (MVR). The severity of MR was significantly associated with the risk of heart failure but not with in-hospital or long-term mortality. In patients with severe MR, in-hospital mortality was no greater in those treated with CABG and MVR than in those treated with percutaneous coronary intervention alone. However, the incidence of long-term hard events (heart failure and all-cause mortality) was lower in those who had received the combined treatment. Multivariate analysis showed that, compared to percutaneous coronary intervention alone, CABG combined with MVR at the acute phase of ACS resulted in a significantly improved prognosis (odds ratio 0.172, 95% confidence interval 0.046 to 0.649, p = 0.009), even after adjusting for age, left ventricular filling pressure, and ejection fraction. In conclusion, the severity of MR in patients with ACS is associated with long-term heart failure events. Even at the acute phase of ACS, CABG combined with MVR results in an acceptable in-hospital mortality rate. The combined strategy also reduced the long-term hard events.

Impact of mitral regurgitation on exercise capacity and clinical outcomes in patients with ischemic left ventricular dysfunction

There is uncertainty and debate regarding whether ischemic mitral regurgitation (MR) is a secondary epiphenomenon resulting from left ventricular (LV) dysfunction or confers an independent effect on exercise capacity and outcomes. We tested whether ischemic MR negatively affects exercise capacity and cardiovascular morbidity and mortality in patients with coronary artery disease (CAD) and those with inferior wall motion abnormality independent of LV dysfunction. Clinical follow-up over 5 years was obtained in 77 patients (64 ± 10 years old, LV ejection fraction 54 ± 11%) with at least mild ischemic MR from CAD and evidence of inferior wall motion abnormality who had exercise stress testing with perfusion imaging within 24 hours of echocardiography. Patients with active heart failure, ischemia, intrinsic valve disease, pulmonary and vascular diseases were excluded. Exercise capacity (METs, peak double product) was tested for relation to MR (vena contracta [VC] and jet area), LV size and function, and pulmonary pressures. Cox proportional hazards analysis assessed whether MR predicted cardiovascular events including hospitalization for heart failure, acute coronary syndrome, and myocardial infarction and cardiovascular and total mortalities. Univariate correlation identified MR with VC (r = -0.674, p <0.0001) and MR jet area (r = -0.575, p <0.0001) as determinants of decreased functional capacity evaluated by METs, with VC the stronger predictor. MR VC >2 mm (moderate ischemic MR) and age were independent predictors of cardiovascular events and death (hazard ratio 6.72 for MR, p = 0.04). In conclusion, in patients with CAD and LV inferior wall motion abnormality, MR negatively affects exercise capacity and is associated with increased cardiovascular morbidity and mortality. This effect appears independent of degree of LV dysfunction.

Diagnostic utility and clinical usefulness of the pocket echocardiographic device

BACKGROUND

The pocket echocardiograph (PE) with color Doppler imaging belongs to a new class of diagnostic tools, the feasibility and accuracy of which is not well established. The aim of this study was to assess the feasibility and diagnostic value of transthoracic echocardiography (TTE) performed with the use of PE by a cardiology resident (2nd year of training) and by an experienced cardiologist.

METHODS

The study population comprised 220 consecutive patients (142 men, mean age 63 ± 8 years), 110 of whom were admitted to our intensive cardiac care unit (ICU) and 110 patients referred for TTE from the outpatient clinic. All patients had PE TTE performed by a resident (60 ICU patients, 60 outpatients) or a cardiologist (50 ICU patients, 50 outpatients). Within 24 h of PE TTE, all subjects had a standard TTE (sTTE) performed by an experienced echocardiographer.

RESULTS

96% of patients had echocardiographic measurements completed by both PE TTE and sTTE. The dimensions measured with PE TTE by the resident and the cardiologist showed good to excellent correlation with sTTE (r = 0.64-0.96, P < 0.001). The agreement in detection of various pathologies between PE TTE performed by the resident and sTTE examinations was moderate to very good, whereas it was good to excellent if PE TTE was performed by the experienced cardiologist.

CONCLUSION

The diagnostic accuracy of the PE in basic assessment of cardiac morphology and function as compared to standard echocardiography is moderate to very good for a cardiology resident and good to excellent for an experienced cardiologist. (Echocardiography 2012;29:1-6).

Mechanism and severity of mitral regurgitation by transesophageal echocardiography in patients referred for percutaneous valve repair

Percutaneous mitral valve repair with the MitraClip has been shown to decrease mitral regurgitation (MR) severity, left ventricular volumes, and functional class in patients with severe (3+ or 4+) MR. Determination of which patients are optimal candidates for MitraClip therapy versus surgery has not been rigorously evaluated. Transesophageal echocardiography was prospectively performed in 113 consecutive patients referred for potential MitraClip therapy under the REALISM continued access registry. MR severity was assessed quantitatively in all patients. Mitral valve anatomy and feasibility of MitraClip placement were assessed by transesophageal echocardiography and clinical parameters. MR was degenerative (mitral valve prolapse) in 60 patients (53%), functional (anatomically normal) in 44 (39%), and thickened with restricted motion (Carpentier IIIB classification) in 9 (8%). MR was mild in 19 patients (17%), moderate in 27 (24%), and severe (3 to 4+) in 67 (59%) by Transesophageal echocardiography. MitraClip placement was performed in only 17 of 113 patients (15%); all were successful. Surgical mitral valve repair was performed in 25 patients (22%), mitral valve replacement in 12 (11%). Most patients (59 of 113, 52%) were treated medically, usually because MR was not severe enough to warrant intervention. In conclusion, most patients referred for MitraClip therapy do not have severe enough MR to warrant intervention. Of those with clinical need for intervention, surgery is more often recommended for anatomic or clinical reasons. Three-dimensional transesophageal echocardiography with quantitative assessment of MR severity is helpful in evaluating these patients.

Haemodynamic evaluation of aortic regurgitation after transcatheter aortic valve implantation using cardiovascular magnetic resonance

AIMS

Echocardiography may underestimate the degree of paravalvular aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve bioprosthesis due to inherent limitations of ultrasound imaging in the evaluation of implanted cardiac prostheses. We aimed to evaluate the accuracy and feasibility of cardiovascular magnetic resonance (CMR) in quantifying regurgitant volume (RV) and regurgitant fraction (RF) in patients treated with this bioprosthesis for severe calcific aortic stenosis, and to compare the results with echocardiography and aortography.

METHODS AND RESULTS

This study included 16 patients with a mean age of 78.7 years (eight women, eight men) who underwent successful TAVI using Medtronic CoreValve bioprosthesis. AR was evaluated by CMR, echocardiography, and aortography. Angiography was performed immediately after valve implantation. CMR and echocardiography were performed four weeks after valve implantation. There was a highly significant correlation between the CMR-derived and the angiographically-estimated degree of AR (r=0.86, p<0.001). On the other hand, there was only a limited correlation between CMR and echocardiography (r=0.374, p=0.15) as well as angiography and echocardiography (r=0.319, p=0.23) regarding the degree of AR. The weighted kappa for agreement between echocardiography and angiography was 0.14, for agreement between echocardiography and CMR 0.20, and for agreement between angiography and CMR 0.72. Echocardiography underestimated AR by one degree compared to CMR in five patients and 2 degrees in two patients; in six of these, the degree of AR obtained by CMR was similar to angiography.

CONCLUSIONS

In patients undergoing TAVI, comparisons between purely quantitative measurements of AR by CMR and qualitative assessment by angiography showed better correlations than those with echocardiography. This suggests that echocardiography may underestimate the degree of AR and CMR in these circumstances has a great potential in reliably measuring the severity of AR in a quantitative manner.

Left ventricular function and C-reactive protein levels in acute myocardial infarction

To examine left ventricular (LV) function in patients after acute myocardial infarction (AMI) and assess its relation to C-reactive protein (CRP) as a measure of the early inflammatory response. We measured the CRP levels early after AMI and correlated them with the early structural and functional cardiac alterations. From November 2002 to December 2007, we prospectively enrolled community subjects who had experienced an AMI, as defined by standardized criteria, measured the CRP level, and obtained an echocardiogram. The study consisted of 514 patients (mean age 67 +/- 15 years, 59% men). CRP was measured early after symptom onset (median 6.1 hours; twenty-fifth to seventy-fifth percentile 2.2 to 11.1). The median CRP level was 4.8 mg/L (twenty-fifth to seventy-fifth percentile 1.8 to 24). The echocardiograms were obtained at a median of 1 day after AMI. The wall motion score index, LV ejection fraction, and LV diameter were similar across the CRP tertiles (all p >0.05). Greater CRP levels were associated with the presence of moderate or severe diastolic dysfunction (p = 0.002) and moderate or severe mitral regurgitation (p <0.001). The association with moderate or severe mitral regurgitation was independent of the clinical characteristics and ST-segment elevation status. In conclusion, at the initial phase of AMI, CRP elevation was associated with the presence and severity of mitral regurgitation and diastolic dysfunction. This suggests that inflammation is related to the ventricular remodeling processes, independently of LV systolic function.

Prognostic implications of functional mitral regurgitation according to the severity of the underlying chronic heart failure: a long-term outcome study

AIMS

To examine the independent prognostic role of functional mitral regurgitation (FMR) and its impact across the severity of chronic heart failure (CHF) in a large population of outpatients with systolic CHF followed at two multidisciplinary clinics.

METHODS AND RESULTS

Echocardiography was performed upon enrolment in 469 CHF patients. Follow-up for death and heart transplant was updated on January 2007. Five-year transplant-free survival was 82.7% in patients with no or Grade I FMR, 64.4% in Grade II, 58.5% in Grade III, and 46.5% in Grade IV (P < 0.0001). There was a strong graded association between FMR and the long-term risk of death and heart transplant, which remained significant after multivariable adjustment (P = 0.0003). The association between FMR and events was strong and independent in patients with less severe symptoms and in those at lower overall risk based on a propensity score analysis, while it was not significant in patients with more advanced CHF or in the high-risk subgroup (P < 0.0001 for interactions).

CONCLUSION

This study clarifies previous apparently discrepant results by demonstrating that FMR is an independent determinant of death and heart transplantation only in less severe CHF and in patients with a lower risk profile. This finding indicates that FMR plays a major role in the early phase of CHF, suggesting that this should be the focus of strategies attempting to reduce it.

Direction of persistent ischemic mitral jet after restrictive valve annuloplasty: implications for interpretation of perioperative echocardiography

BACKGROUND

Ischemic mitral regurgitation (MR) often persists after restrictive mitral valve annuloplasty (MVA) and is associated with a poor prognosis. It was hypothesized that the anterior displacement of the posterior aspect of the annulus caused by annuloplasty could induce a change in the direction of MR jet.

METHODS

The echocardiograms of 21 patients who underwent restrictive MVA for ischemic MR and who had detectable postoperative MR were analyzed before and early after surgery to evaluate the direction of MR jet.

RESULTS

The MR jet direction was posterior in 15 patients (72%) and central or anterior in six patients (28%) before the operation, compared with four patients (20%) and 17 patients (80%), respectively, after MVA (P<0.001). Overall, the jet direction was modified in 16 of 21 patients (76%) following MVA. Among the subset of 11 patients with clinically significant persistent MR (vena contracta width greater than 3 mm), the MR jet direction changed in nine patients (82%) compared with their preoperative evaluation. Importantly, the initial clinical interpretation, based on a subjective evaluation, had classified MR severity as nonsignificant in six of 11 patients (55%), likely due to the eccentricity of the jet and its change in direction.

CONCLUSION

The direction of the persistent MR jet early after annuloplasty is often different from that of preoperative MR jet and may lead to significant misinterpretation of the postoperative echocardiogram.

Mitral regurgitation

Mitral regurgitation affects more than 2 million people in the USA. The main causes are classified as degenerative (with valve prolapse) and ischaemic (ie, due to consequences of coronary disease) in developed countries, or rheumatic (in developing countries). This disorder generally progresses insidiously, because the heart compensates for increasing regurgitant volume by left-atrial enlargement, causes left-ventricular overload and dysfunction, and yields poor outcome when it becomes severe. Doppler-echocardiographic methods can be used to quantify the severity of mitral regurgitation. Yearly mortality rates with medical treatment in patients aged 50 years or older are about 3% for moderate organic regurgitation and about 6% for severe organic regurgitation. Surgery is the only treatment proven to improve symptoms and prevent heart failure. Valve repair improves outcome compared with valve replacement and reduces mortality of patient with severe organic mitral regurgitation by about 70%. The best short-term and long-term results are obtained in asymptomatic patients operated on in advanced repair centres with low operative mortality (<1%) and high repair rates (>/=80-90%). These results emphasise the importance of early detection and assessment of mitral regurgitation.

Real-time 3-dimensional echocardiography in the operating room

Real-time 3-dimensional transesophageal echocardiography (RT-3D-TEE) represents a novel clinical and intuitively educational perioperative cardiovascular imaging modality. The development of RT-3D-TEE allows for live 3D imaging as it circumvents most of the disadvantages of reconstructive 3D methods. RT-3D-TEE will likely revolutionize perioperative assessment of complex 3D structures, such as the mitral valve (MV), as it provides important mechanistic insights into functional and ischemic mitral regurgitation. The MV is particularly suited to live RT-3D-TEE assessment because of the complex interrelationships among the valve, chordae, papillary muscles, and myocardial walls. The 3D en face view of the MV is in accordance with the surgical view and allows to illustrate the unique saddle shape of the MV annulus and to define and localize mitral leaflet lesions in MV prolapse, endocarditis, or congenital MV abnormalities, all potentially important in guiding surgical repair. RT-3D-TEE will soon be integrated into routine perioperative practice. Its unique ability of real-time acquisition, online rendering and cropping capabilities, accurate identification of the precise pathology and location of cardiac disease, together with its ability to promptly quantify 3D data sets using built-in software, will likely help in transitioning this modality into standard of care.

Echocardiographic quantitation of mitral regurgitation

Mitral valve regurgitation is a common valvular problem, particularly in developing nations. It causes significant morbidity and mortality, especially if the severity of valve regurgitation is underestimated. Echocardiography plays a significant role in the diagnoses, serial follow-up and management of patients with valvular heart disease. However, precise quantitation of the severity of mitral regurgitation is a crucial element in the therapeutic decisions for managing mitral regurgitation. An accurate assessment of the severity of mitral regurgitation allows for optimal timing of surgical intervention, culminating in improved patient outcomes. This review provides a systematic approach to the quantitation of mitral regurgitation using the echocardiography and Doppler methodologies that are available in the modern noninvasive imaging and hemodynamic laboratory. Additional, novel and evolving noninvasive imaging modalities are reviewed briefly.

Left ventricular remodeling is associated with the severity of mitral regurgitation after inaugural anterior myocardial infarction--optimal timing for echocardiographic imaging

BACKGROUND

Although mitral regurgitation (MR) has been associated with an increased risk of death and heart failure after myocardial infarction (MI), the relationship between post-MI MR and left ventricular (LV) remodeling has not been entirely clarified. In addition, the optimal timing for assessing MR after MI remains unknown.

METHODS

Post-MI MR was assessed by Doppler echocardiography at hospital discharge (baseline) and after 3 months in 261 patients with an inaugural anterior MI. We studied LV remodeling during a 1-year period and clinical follow-up after 3 years, according to MR severity at baseline and at 3 months.

RESULTS

Left ventricular remodeling was demonstrated as an increase in LV end-diastolic volume from 56 +/- 15 mL/m(2) at baseline to 63 +/- 19 mL/m(2) at 1 year (P < .0001). MR severity at baseline was not significantly associated with LV remodeling. By contrast, MR severity at 3 months was a strong indicator of LV remodeling. There was a graded increase in the proportion of patients with a >20% increase in LV end-diastolic volume between baseline and 1 year according to MR severity at 3 months (no MR: 21%, mild MR: 32%, moderate/severe MR: 60%) (P = .008). Both MR at baseline and at 3 months were associated with death or rehospitalization for heart failure by univariate analysis (P = .014 and P < .0001, respectively). By multivariable analysis, MR at baseline was not an independent predictor of adverse outcome (P = .66). By contrast, MR at 3 months was independently associated with adverse outcome with a hazard ratio of 2.23 (1.02-4.91 [P = .04]).

CONCLUSIONS

After an inaugural anterior MI, MR is associated with LV remodeling and adverse clinical outcome. For prognostic purpose, the optimal timing for assessing MR is the chronic post-MI stage rather than the early post-MI period.