Prediction of surgical strategy in mitral valve regurgitation based on echocardiography. Interuniversity Cardiology Institute of The Netherlands

Ischemic mitral regurgitation: pathophysiology, diagnosis and surgical treatment

Ischemic mitral valve regurgitation often complicates acute myocardial infarction and also represents a negative prognostic factor for long-term survival in patients undergoing surgical myocardial revascularization. While severe mitral regurgitation should always be corrected during a coronary artery bypass operation, the decision making is more difficult in patients with a mild-to-moderate degree of regurgitation. Recent studies and experimental protocols have elucidated the pathophysiological mechanisms leading to mitral regurgitation with great interest in annular modifications and subvalvular alterations. These data suggest that new and integrated surgical approaches that address annuloplasty ring sizing, ring type selection and tethering phenomenon (i.e., chordal cutting, 'edge-to-edge' technique and left-ventricular plasty techniques) are required for a safer and durable valve repair. Transthoracic and transesophageal echocardiography are useful in determining the etiology and the degree of mitral regurgitation, to assess mitral deformation and to measure indexes of global and regional left-ventricular remodeling. Stress echocardiography may unmask higher degrees of mitral regurgitation. More data are needed in order to confirm the promising and interesting preliminary experimental findings of magnetic resonance imaging in diagnosis and clinical evaluation of ischemic mitral regurgitation.

Surgical revision after percutaneous mitral repair with the MitraClip device

BACKGROUND

Percutaneous mitral repair with the MitraClip device (Evalve, Menlo Park, CA) has been reported. Preserving conventional surgical options in the event of percutaneous treatment failure is important. We describe surgical treatment at varying intervals after the MitraClip procedure in 32 patients.

METHODS

One hundred seven patients with moderate-to-severe or severe mitral regurgitation who were either symptomatic (91%) or, if asymptomatic (9%), had evidence of left ventricular dysfunction were enrolled as part of the Endovascular Valve Edge-to-Edge REpair STudy (EVEREST) phase I registry study or as "roll-in" subjects in the EVEREST II study. Thirty-two of the 107 patients (30%) underwent surgery after an attempted MitraClip procedure.

RESULTS

Of the 32 patients undergoing post-clip mitral valve surgery, 23 patients (72%) had one or more clips implanted and 9 patients (28%) received no clip implant. The indications for mitral valve surgery in the 23 patients with a clip included partial clip detachment (n = 10), residual or recurrent mitral regurgitation greater than 2+ (n = 9), and other (atrial septal defect [n = 2], device malfunction [n = 1], and incorrectly diagnosed mitral stenosis [n = 1]). Twenty-seven of 31 patients (87%) underwent the surgical procedure planned before surgery (planned procedure unknown in 1 patient). Four of 25 patients (16%) with planned repair underwent mitral valve replacement.

CONCLUSIONS

Standard surgical options were preserved in patients who had surgery after percutaneous repair with the MitraClip device. Successful repair was feasible in the majority of patients after the MitraClip procedure, with repair performed as late as 18 months after clip implantation.

Live/real-time three-dimensional transthoracic assessment of mitral regurgitation and mitral valve prolapse

Evaluation of the mitral valve requires appreciation of its complex geometry. To accurately guide surgical interventions and describe pathology, three-dimensional transthoracic echocardiography (TTE) is an immense improvement over the cumbersome mental reconstruction required by two-dimensional approaches. Here we describe real-time, three-dimensional transthoracic techniques for assessing mitral regurgitation and mitral valve prolapse.

A New Echocardiographic Index for Assessing Left Ventricular Function and Mechanism of Mitral Regurgitation and Its Relation to Other Echocardiographic Indices

OBJECTIVE

Mitral regurgitation (MR) is a progressive disease of the mitral valve, which can be primary or functional. The assessment of left ventricular function in MR is still troublesome. In this study, we evaluated the validity of a new parameter, total dt, in patients with MR.

METHODS

Forty patients with severe MR constituted the study group. According to the transesophageal echocardiographic evaluation, the patients were dichotomized into two groups: (1) Primary MR; n = 21, (2) Functional MR; n = 19. The total dt was defined as the sum of time intervals from 1 msto 3 ms (positive dt) and from 3 ms to 1 ms (negative dt) on the CW Doppler recording of MR jet. It was compared to other indices of left ventricular function and left ventricular geometry, including ejection fraction, fractional shortening, myocardial performance index, coaptation distance, left ventricular volume and diameter, sphericity index, and parameters of diastolic function.

RESULT

The total dt correlated with myocardial performance index, coaptation distance, and sphericity index. It could differentiate between primary and functional MR with an area under curve of 0.878, followed by myocardial performance index with 0.860. The total dt > 104 ms was 79% sensitive and 81% specific for discrimination.

CONCLUSION

The total dt is useful for assessing left ventricular function and also for differentiating primary MR from functional MR.

Assessment of functional anatomy of the mitral valve in patients with mitral regurgitation with cine magnetic resonance imaging: comparison with transesophageal echocardiography and surgical results

The ability of magnetic resonance imaging (MRI) to accurately define the functional anatomy of mitral regurgitation was assessed. Transesophageal echocardiography (TEE) and cine MRI were performed on 43 patients with mitral regurgitation and were compared for the jet number, location, direction and presence of a prolapse (atrial displacement, malapposition or a flail). In 36 patients, diagnostic accuracy in reference to surgery was assessed. Comparing TEE and MRI the jet number and location were judged in concordance in 86% of patients. Jet location did not show a significant difference (Wilcoxon: P = 0.66) and both modalities correlated strongly (Spearman: r = 0.68, P<0.0001). Jet direction was judged with high concordance (kappa=0.63). Additionally, prolapse evaluation showed high concordance (kappa: valve, 0.63; anterior mitral leaflet, 0.70; posterior mitral leaflet, 0.73). Compared with surgery, the sensitivity for the detection of malapposition of any leaflet or one of both leaflets ranged between 75% and 93% for TEE and 71% and 89% for MRI. Specificities ranged between 88 and 96% for TEE and 88 and 100% for MRI. TEE detected torn chordae in all ten patients, six of which were missed by MRI. MRI is comparable with TEE in prolapse and jet evaluation. MRI is inferior to TEE in depicting anatomical details such as torn chordae.

Usefulness of Live/Real Time Three-Dimensional Transthoracic Echocardiography in the Identification of Individual Segment/Scallop Prolapse of the Mitral Valve

In this report, we present 34 patients in whom surgical intervention was undertaken for severe mitral insufficiency due to mitral valve prolapse (MVP). Location and severity of MVP and regurgitation were assessed preoperatively by live/real time three-dimensional transthoracic echocardiography and closely agreed with the surgical findings.

Medical and surgical treatment of chronic mitral regurgitation

Chronic severe mitral regurgitation is a progressive disease that can lead to left ventricular dysfunction. New information on the natural history of the disease, along with advances in surgical techniques, has changed the roles of medical and surgical therapies. There is no well-defined role for medical therapy in chronic mitral regurgitation. The goal of the treating physician is therefore to identify the optimal timing for surgical intervention. The timing of surgical intervention depends primarily on two factors: (i) clinical symptoms and (ii) the left ventricular response to volume overload. However, the aetiology of mitral regurgitation, the likelihood of surgical repair, the occurrence of atrial fibrillation and the presence of pulmonary hypertension, together with the haemodynamic response to exercise, are important factors in the optimal surgical timing. New concepts in the understanding of the natural history of the disease coupled with success of mitral repair have recently resulted in a widespread evolution towards earlier surgery.

Functional Assessment of Mitral Regurgitation by Transthoracic Echocardiography Using Standardized Imaging Planes

OBJECTIVES

We sought to assess the value of transthoracic echocardiography (TTE) using standardized imaging planes for the functional analysis of mitral regurgitation (MR) as well as for postoperative outcome implications.

BACKGROUND

The feasibility of mitral valve repair is based on functional assessment of MR, mainly by transesophageal echocardiography (TEE). Considering the recent advances in TTE imaging, the incremental value of TEE in this setting needs to be re-examined.

METHODS

Consecutive patients (n = 279; 181 men; median age 68 years [quartiles, 61 to 74]) who underwent surgery for MR were enrolled prospectively in two tertiary care centers. The accuracy of TTE (harmonic imaging) versus TEE for functional assessment of MR was evaluated against surgical findings.

RESULTS

Valve repair (n = 237 patients, 85%) or replacement (n = 42) was predicted accurately by TTE in 97% of cases; TEE added significant information for only two patients. In the subgroup of degenerative MR (n = 190), agreement with surgical findings for the localization of prolapsed segments was 91% for TTE (kappa, 0.81) and 93% for TEE (kappa, 0.85) without incremental value of TEE (p = 0.40). Patients with single prolapse of the middle posterior scallop (P2) had a better postoperative outcome as compared with patients who had non-P2 lesions (p = 0.008). Furthermore, mitral replacement predicted by TTE was an independent predictor for postoperative long-term mortality (odds ratio 5.7, 95% confidence interval 1.97 to 16.4, p = 0.001).

CONCLUSIONS

In experienced hands, functional assessment of MR by TTE can predict accurately valve repairability and has a strong influence on postoperative outcome. Thus, in most cases preoperative TEE is not mandatory, provided intraoperative TEE is performed.

Identifying patients with degenerative mitral regurgitation for mitral valve repair and replacement: A transesophageal echocardiographic study

OBJECTIVE

We sought to preoperatively identify the suitability of patients with degenerative mitral valve (MV) regurgitation for MV repair (MVR) and MV replacement.

BACKGROUND

MVR is the preferred method of treatment over MV replacement, if surgically feasible. MVR preserves left ventricular function and decreases risk of hemolysis, thromboembolism, and-in the absence of anticoagulation-hemorrhage. However, the ability to identify patients suitable for MVR preoperatively is somewhat limited.

METHODS

In all, 76 patients underwent MV operation for severe symptomatic mitral regurgitation. The decision to operate was at the discretion of the referring physician in consultation with respective cardiothoracic surgeons at two separate, nonrelated institutions. All patients underwent preoperative and/or intraoperative transesophageal echocardiographic studies.

RESULTS

In all, 35 patients (46%) underwent MVR and 41 (54%) underwent MV replacement. There was no difference in the percentage of MVRs between the two institutions: 17 cases (41%) at Hahnemann University Hospital, Philadelphia, Pa, versus 18 cases (53%) at Northwestern University Memorial Hospital, Chicago, Ill (P = not significant). Age was found to be a significant univariate predictor with older age favoring MV replacement. On average, patients who underwent MVR were 11 years younger then those who underwent MV replacement. Heart failure was also found to be a significant univariate predictor: as New York Heart Association functional class worsened, MV replacement was more likely. Echocardiographic variables favoring MVR included chordal length (>29 mm, P <.001), length of posterior mitral leaflet (>17 mm, P <.008), and length of anterior leaflet (>25 mm, P <.01). The only echocardiographic parameter favoring replacement was the presence of anterior mitral annular calcification. Using multivariate analysis, older age (>63 years) was again a significant predictor favoring MV replacement (P <.002; odds ratio [OR] 20). Longer chordal length (>29 mm) was the strongest predictor favoring MVR (P <.001; OR 11.2). Longer length of the posterior leaflet (>17 mm; OR 5.07) and mitral annulus size > 35 mm (OR 7.75) were also significant multivariate predictors favoring MVR. The presence of anterior mitral annular calcification favored MV replacement using multivariate analysis (OR 25).

CONCLUSIONS

Patients suitable for MVR can be identified preoperatively using a combination of clinical and echocardiographic parameters.

A method for the morphological analysis of the regurgitant mitral valve using three dimensional echocardiography

BACKGROUND

Atrial en-face reconstructions are commonly used to assess mitral valve morphology in three dimensional (3D) echocardiography but may miss important abnormalities.

OBJECTIVE

To present a systematic method for the analysis of the regurgitant mitral valve using a combination of en-face and longitudinal views for better anatomical evaluation.

METHODS

Detailed 3D assessment was done on 58 patients undergoing mitral valve repair. En-face and longitudinal views were compared for detection and location of primary pathology. The quality of acquisitions under general anaesthesia and sedation was also compared.

RESULTS

Recognition of valve structure was significantly better with longitudinal reconstruction for both mitral leaflets but not for the commissures. Accurate identification of pathology was possible in 95% cases, compared with 50% for en-face reconstruction (p < 0.001). There was no significant difference between imaging under sedation and anaesthesia.

CONCLUSION

En-face reconstructions alone are inadequate. Additional longitudinal reconstructions are necessary to ensure full inspection of valve morphology.

Echocardiographic assessment of anatomic lesions predicts surgical strategy in mitral regurgitation

OBJECTIVE

In the present study, we evaluate our ability to predict surgical procedure repair or replacement using preoperative echocardiography.

DESIGN

The reports from transthoracic echocardiographic examinations of 298 patients were analyzed and the gross anatomic lesions and the mechanisms involved were classified into one of three main groups (functional with normal valves, organic degenerated with hypermobile valve or organic degenerated without hypermobility).

RESULTS

It was possible to assess the likelihood of repair in 226 patients (76%). The criteria used were institution based and reflect the surgical procedures during the study period (1995-1999). The proportion of patients undergoing repair was 58%. In patients with a high likelihood, repair was performed in 86%. The corresponding figures in the intermediate- and low-likelihood groups were 63 and 23%, respectively. Hypermobility in the posterior leaflet and functional mitral regurgitation led to repair in the majority of patients, while patients with hypermobility in the anterior or both valves more frequently underwent replacement.

CONCLUSION

We conclude that it is possible to identify patients with a high likelihood of repair using transthoracic echocardiography.

[Usefulness of intraoperative echocardiography for the management of mitral regurgitation]

Intraoperative transesophageal echocardiography is crucial in the management of patients with mitral regurgitation. In fact, a vast majority mitral insufficiencies may actually be repaired. This kind of surgery require an excellent definition of anatomic lesions and mechanisms of mitral regurgitation in order to optimize the result of the repair. In this field, intraoperative echocardiographic findings are complementary with anatomical findings for the surgeon. Before surgery, intraoperative echography help to describe all valvular lesions and mechanisms of the regurgitation. Three-dimensional echocardiography may be obtained using intraoperative echography and may be useful in mitral valve prolapse to better define the location and size of prolapse and to communicate informations to the surgeon. After repair, echographyallow the control of the result and also of right and left ventricular function. In case of major abnormality such as residual significant mitral regurgitation or important intra-ventricular obstruction, a second procedure may be required. The collaboration between the echographist and the surgeon is crucial to obtain the best results in mitral valve repair. Indications for intraoperative echocardiography are dependent on the experience of the surgeon and the complexity of mitral lesions to repair.

Surgical timing for mitral valve regurgitation

Advances in diagnostic and surgical techniques in the management of mitral regurgitation have resulted in improved survival rates and clinical outcomes. Echocardiography is a valuable noninvasive diagnostic tool in the determination of the timing of surgical correction of mitral regurgitation. Improved surgical techniques, the growing role of mitral valve repair, low operative mortality rates, and improved long-term survival rates are important considerations for earlier surgical intervention in symptomatic patients and in asymptomatic patients with echocardiographic criteria of left ventricular dilatation. Intraoperative transesophageal echocardiography is very useful in mitral valve repair and valve replacement with preservation of chordal structures.

Functional anatomy of mitral regurgitation: accuracy and outcome implications of transesophageal echocardiography

OBJECTIVES

This study was performed to determine the accuracy and outcome implications of mitral regurgitant lesions assessed by echocardiography.

BACKGROUND

In patients with mitral regurgitation (MR), valve repair is a major incentive to early surgery and is decided on the basis of the anatomic mitral lesions. These lesions can be observed easily with transesophageal echocardiography (TEE), but the accuracy and implications for outcome and clinical decision-making of these observations are unknown.

METHODS

In 248 consecutive patients operated on for MR, the anatomic lesions diagnosed with TEE were compared with those observed by the surgeon and those seen on 216 transthoracic echocardiographic (TTE) studies, and their relationship to postoperative outcome was determined.

RESULTS

Compared with surgical diagnosis, the accuracy of TEE was high: 99% for cause and mechanism, presence of vegetations and prolapsed or flail segment, and 88% for ruptured chordae. Diagnostic accuracy was higher for TEE than TTE for all end points (p < 0.001), but the difference was of low magnitude (<10%) except for mediocre TTE imaging or flail leaflets (both p < 0.001). The type of mitral lesions identified by TEE (floppy valve, restricted motion, functional lesion) were determinants of valve repairability and postoperative outcome (operative mortality and long-term survival; all p < 0.001) independent of age, gender, ejection fraction and presence of coronary artery disease.

CONCLUSIONS

Transesophageal echocardiography provides a highly accurate anatomic assessment of all types of MR lesions and has incremental diagnostic value if TTE is inconclusive. The functional anatomy of MR defined by TEE is strongly and independently predictive of valve repairability and postoperative outcome. Therefore, the mitral lesions assessed by echocardiography represent essential information for clinical decision making, particularly for the indication of early surgery for MR.

Improved evaluation of the location and mechanism of mitral valve regurgitation with a systematic transesophageal echocardiography examination

Mitral regurgitation (MR) is a major determinant of outcome in cardiac surgery. The location and mechanism of mitral lesions determine the approach to various repairs and their feasibility. Because of incomplete evaluations or change in patient condition, detailed intraoperative transesophageal echocardiography (TEE) examination of the mitral valve may be required. We hypothesized that a systematic TEE mitral valve examination would allow precise identification of the anatomic location and mechanism of MR in patients undergoing mitral surgery. We designed a systematic mitral valve examination consisting of six views: five-chamber, four-chamber, two-chamber anterior, two-chamber mid, two-chamber posterior and short-axis. We used this examination prospectively in 13 patients undergoing mitral valve surgery for severe MR and compared the results with the surgical findings. We then retrospectively interpreted 11 similar patients who had undergone intraoperative TEE studies before this examination. TEE correctly diagnosed the mechanism and precise location of pathology in 12 of 13 patients in the prospective group, but in only 6 of 10 patients in the retrospective group. TEE also correctly identified 75 of 78 mitral segments (96%) as being normal or abnormal. In the retrospective group, only 42 of 60 segments (70%) were correctly identified (P < 0.001). We conclude that this systematic TEE mitral valve examination improves identification of mitral segments and precise localization of pathologies and may also improve the diagnosis of the mechanism of MR.

IMPLICATIONS

In this article, we describe how a systematic examination of the mitral valve by using transesophageal echocardiography allows identification of the different segments of the mitral valve, precise localization of pathology, and helps to diagnose the mechanism of mitral regurgitation. This is important in determining an approach to mitral valve repair and its feasibility.

Management of mitral regurgitation. Optimal timing for surgery

Chronic mitral regurgitation is a progressive disorder that can produce myocardial dysfunction in the absence of symptoms. Improvements in surgical techniques have resulted in earlier intervention, at times in asymptomatic patients. This article discusses the factors that influence prognosis, reviews the evidence supporting earlier intervention and provides guidelines for the management of patients with this lesion.