Comparison of Early Surgery Versus Conventional Treatment in Asymptomatic Severe Mitral Regurgitation

Current status of stress echocardiography: is it a required procedure for every sonographer?

BACKGROUND

Stress echocardiography is a versatile modality in the clinical cardiology. In its earlier days, its sole indication was restricted to diagnosing coronary artery disease. However, in response to the rapid development of ultrasound technology and analysis software, the indications have now evolved with expansion to several fields of cardiovascular disease.

METHODS

I reviewed previous stress echocardiography publications, and discussed the current status of stress echocardiography in routine clinical setting.

RESULTS

Although its portability and online assessment make possible for immediate diagnosis even at the bedside, establishment of an appropriate procedure and an accurate assessment require some experience. Other imaging competitors, such as multidetector computed tomography and cardiac magnetic resonance are gradually replacing the role of stress echocardiography in some fields. However, stress echocardiography has a potential for other new fields, including valvular heart disease and congestive heart failure.

CONCLUSION

Although primary indication of stress echocardiography for coronary artery disease seems to be not relevant especially in Japan, novel indication of stress echocardiography in other field of cardiovascular disease is rapidly expanding in conjunction with the advent of new technology. Stress echocardiography is not a tool for limited researchers, but rather a fundamental routine method of choice for every sonographer.

Mitral regurgitation - Unmet need for improved management strategies

Background

The management of mitral regurgitation (MR) is challenging — patients may be asymptomatic, oligosymptomatic, older with comorbidities, or clinically symptomatic and not appropriate for surgery. The current review assesses morbidity, mortality, and risk factors associated with functional and organic MR, with a focus on severe MR.

Methods

A structured literature review was conducted in MEDLINE, Embase, the Cochrane Library, and via hand-searching of conference proceedings. Prospective randomised controlled trials and observational studies including adult patients with MR reporting on treatment response rates, survival, time-to-treatment failure, quality of life, and adverse events were eligible for inclusion.

Results

In total, 32 publications met the inclusion criteria (9 in functional, 18 in organic, and 5 in functional/organic). Despite study heterogeneity, an increased risk of mortality and morbidity was observed which increased with MR severity. Risk factors associated with mortality and morbidity included advancing age, presence of atrial fibrillation, increasing effective regurgitant orifice, ejection fraction, left ventricle end systolic diameter, diabetes, and increasing New York Heart Association class.

Conclusions

The current review represents one of the most comprehensive conducted in the medical/conservative management of MR. An increased risk of mortality and morbidity, which appeared to rise with greater severity, was associated with MR (versus no MR). An unmet need exists in the management of patients with severe symptomatic MR and a high surgical risk as they have a poor prognosis and limited treatment options. Further research into alternative medical strategies and patient management is needed to improve prognoses and reduce mortality and morbidity.

Robotic-assisted mitral valve repair: surgical technique

Robotic-assisted mitral valve repair represents the least invasive surgical approach currently available for anatomical mitral valve repair in patients with myxomatous mitral valve disease. Standard mitral valve repair techniques utilized during conventional sternotomy/right thoracotomy are exactly replicated with the robotic instrumentation through 1-2 cm port-like incisions with superior 3D visualization. This is performed on cardiopulmonary bypass by peripheral cannulation of the femoral vessels/right internal jugular vein. The ascending aorta is occluded with a transthoracic aortic cross-clamp. Antegrade cardioplegia is delivered centrally into the aortic root through a cardioplegia vent catheter. By replicating conventional mitral valve repair done via an open sternotomy approach, the quality of mitral valve repair is ensured while providing the patients with advantages of less invasive surgery including shorter hospital stay, rapid recovery and return to normal activities, less blood transfusion, superior cosmesis and complete elimination of sternotomy-related morbidities such as deep sternal wound infection and sternal dehiscence. We reviewed the first consecutive 200 patients undergoing robotic mitral valve repair at Mayo Clinic Rochester between 24 January 2008 and 28 January 2011. Successful mitral valve repair was completed in all patients. There were no early (30-day) deaths. One patient suffered a stroke (0.5%). One patient required reoperation for bleeding (0.5%). Two patients (1%) required reoperation for recurrent mitral regurgitation. Twelve patients (6%) required transfusion of allogeneic blood products. We have noted a significant reduction in operative times and resource utilization over time.

Impact of exercise pulmonary hypertension on postoperative outcome in primary mitral regurgitation

AIMS

The management of asymptomatic patients with mitral regurgitation (MR) remains controversial. Exercise-induced pulmonary hypertension (ExPHT) was recently reported as a strong predictor of rapid onset of symptoms. We hypothesised that ExPHT is a predictor of postoperative cardiovascular events in patients with primary MR.

METHODS AND RESULTS

One hundred and two patients with primary MR, no or mild symptoms (New York heart association (NYHA) ≤2), and no LV dysfunction/dilatation, were prospectively recruited in 3 centres and underwent exercise-stress echocardiography. The presence of ExPHT was defined as an exercise systolic pulmonary arterial pressure >60 mm Hg. All patients were closely followed up and operated on when indication for surgery was reached. Postoperative events were defined as the occurrence of atrial fibrillation (AF), stroke, cardiac-related hospitalisation or death. Among the 102 patients included, 59 developed ExPHT (58%). These patients were significantly older than those without ExPHT (p=0.01). During a mean postoperative follow-up of 50±23 months, 28 patients (26%) experienced a predefined cardiovascular event. Patients with ExPHT had significantly higher rate of postoperative events (39% vs 12%, p=0.005); the rate of events was still higher in these patients (32% vs 9%, p=0.013), even when excluding early postoperative AF (ie, within 48 h). Event-free survival was significantly lower in the ExPHT group (all events: 5-year: 60±8% vs 88±5%, p=0.007, events without early AF: 5-year: 67±7% vs 90±4%, p=0.02). Using Cox multivariable analysis, ExPHT remained independently associated with higher risk of postoperative events in all models (all p≤0.04).

CONCLUSIONS

ExPHT is associated with increased risk of adverse cardiac events following mitral valve surgery in patients with primary MR.

Importance of exercise capacity in predicting outcomes and determining optimal timing of surgery in significant primary mitral regurgitation

BACKGROUND

In primary mitral regurgitation (MR), exercise echocardiography aids in symptom evaluation and timing of mitral valve (MV) surgery. In patients with grade ≥3 primary MR undergoing exercise echocardiography followed by MV surgery, we sought to assess predictors of outcomes and whether delaying MV surgery adversely affects outcomes.

METHODS AND RESULTS

We studied 576 consecutive such patients (aged 57±13 years, 70% men, excluding prior valve surgery and functional MR). Clinical, echocardiographic (MR, LVEF, indexed LV dimensions, RV systolic pressure) and exercise data (metabolic equivalents) were recorded. Composite events of death, MI, stroke, and congestive heart failure were recorded. Mean LVEF was 58±5%, indexed LV end-systolic dimension was 1.7±0.5 mm/m(2), rest RV systolic pressure was 32±13 mm Hg, peak-stress RV systolic pressure was 47±17 mm Hg, and percentage of age- and gender-predicted metabolic equivalents was 113±27. Median time between exercise and MV surgery was 3 months (MV surgery delayed ≥1 year in 28%). At 6.6±4 years, there were 53 events (no deaths at 30 days). On stepwise multivariable survival analysis, increasing age (hazard ratio of 1.07 [95% confidence interval, 1.03 to 1.12], P<0.01), lower percentage of age- and gender-predicted metabolic equivalents (hazard ratio of 0.82 [95% confidence interval, 0.71 to 0.94], P=0.007), and lower LVEF (0.94 [0.89 to 0.99], P=0.04) independently predicted outcomes. In patients achieving >100% predicted metabolic equivalents (n=399), delaying surgery by ≥1 year (median of 28 months) did not adversely affect outcomes (P=0.8).

CONCLUSION

In patients with primary MR that underwent exercise echocardiography followed by MV surgery, lower achieved metabolic equivalents were associated with worse long-term outcomes. In those with preserved exercise capacity, delaying MV surgery by ≥1 year did not adversely affect outcomes.

Mitral valve repair in asymptomatic patients with severe mitral regurgitation: pushing past the tipping point

Degenerative mitral valve regurgitation (MR) is the one of the most frequent valvular heart conditions in the Western world and is increasingly recognized as an important preventable cause of chronic heart failure. This condition also represents the most common indication for mitral surgery and is of particular interest because the mitral valve can be repaired in most patients with very low surgical risk. Historical single-center studies have supported the performance of "early mitral valve repair" in asymptomatic patients with severe degenerative MR to normalize survival and improve late outcomes. Emerging recent evidence further indicates for the first time that the prompt surgical correction of severe MR due to flail mitral leaflets within 3 months following diagnosis in asymptomatic patients without classical Class I indications (symptoms or left ventricular dysfunction) conveys a 40% decrease in the risk of late death and a 60% diminution in heart failure incidence. A 10-point rationale based on the weight of rapidly accumulating clinical data, supports the performance of early mitral valve repair even in the absence of symptoms, left ventricular dysfunction, or guideline-based triggers; when effective operations can be provided using conventional or minimally invasive techniques at very low surgical risk.

Timing of surgery in valvular heart disease: prophylactic surgery vs watchful waiting in the asymptomatic patient

In the absence of randomized controlled trial data, the management of patients with severe valvular heart disease without symptoms, ventricular dysfunction, or other identified triggers for surgery is controversial. In this review, we frame the debate between prophylactic surgery vs close follow-up until triggers occur (watchful waiting) for severe aortic stenosis and degenerative mitral regurgitation (MR), the 2 conditions for which the pros and cons of these approaches are best articulated. Classic high-gradient severe aortic stenosis is generally accurately diagnosed. In asymptomatic patients, stress testing can be used to confirm asymptomatic status and identify high-risk features including reduced exercise tolerance, exercise-induced symptoms, and absolute or relative hypotension. Resting echocardiographic predictors of disease progression and/or adverse events include very high gradients, rapid progression, and extensive calcification. Surgical risk calculators can help estimate perioperative morbidity/mortality with the ultimate choice of a medical vs a prophylactic surgical approach to be made after discussion with the patient. With degenerative MR, severity can be inaccurately estimated. Stress testing might clarify whether the patient is truly asymptomatic and identify features associated with worse prognosis and symptom onset. Selecting patients with high probability of repair can be challenging. Perioperative risk and postoperative risks including those of unanticipated valve replacement and recurrent MR after repair are also considerations. In aggregate, management of patients with valvular disease who are asymptomatic and who have no clear trigger for surgery is complex, requires individualization, and should be carried out by or in collaboration with a heart valve centre of excellence.

Review of mitral valve insufficiency: repair or replacement

Mitral valve (MV) dysfunction is the second-most common clinically significant form of valvular defect in adults. MV regurgitation occurs with the increasing frequency of degenerative changes of the aging process. Moreover, other causes of clinically significant MV regurgitation include cardiac ischemia, infective endocarditis and rhematic disease more frequently in less developed countries. Recent evidence suggests that the best outcomes after repair of severe degenerative mitral regurgitation (MR) are achieved in asymptomatic or minimally symptomatic patients, who are selected for surgery soon after diagnosis on the basis of echocardiography. This review will focus on the surgical management of mitral insufficiency according to its aetiology today and will give insight to some of the perspectives that lay in the future.

The impact of preoperative and postoperative pulmonary hypertension on long-term surgical outcome after mitral valve repair for degenerative mitral regurgitation

PURPOSE

The aim of this study is to elucidate the impact of preoperative and postoperative pulmonary hypertension (PH) on long-term clinical outcomes after mitral valve repair for degenerative mitral regurgitation.

METHODS

A total of 654 patients who underwent mitral valve repair for degenerative mitral regurgitation between 1991 and 2010 were retrospectively reviewed. Patients were divided into PH(+) group (137 patients) and PH(-) group (517 patients). Follow-up was complete in 99.0%. The median follow-up duration was 7.5 years.

RESULTS

Patients in PH(+) group were older, more symptomatic and had higher tricuspid regurgitation grade. Thirty-day mortality was not different between 2 groups (p = 0.975). Long-term survival rate was lower in PH(+) group; 10-year survival rate after the operation was 85.2% ± 4.0% in PH(+) group and 89.7% ± 1.8% in PH(-) group (Log-rank, p = 0.019). The incidence of late cardiac events were not different between groups, however, the recurrence of PH was more frequent in PH(+) group. The recurrence of PH had an adverse impact on survival rate, late cardiac events and symptoms. Univariate analysis showed age and preoperative tricuspid regurgitation grade were the predictors of PH recurrence.

CONCLUSION

Early surgical indication should be advocated for degenerative mitral regurgitation before the progression of pulmonary hypertension and tricuspid regurgitation.

Timing of valve repair for severe degenerative mitral regurgitation and long-term left ventricular function

OBJECTIVES

Current guidelines recommended surgery for patients with severe degenerative mitral regurgitation (MR) when specific left ventricular (LV) dimensions or ejection fraction (EF) are reached, based on previous postoperative survival studies. The aim of this study was to evaluate the incidence and predictors of long-term postoperative LV dysfunction, and investigate the preoperative parameters necessary to maintain or recover long-term LV function in the era of mitral valve (MV) repair.

METHODS

We retrospectively reviewed 473 consecutive patients undergoing MV repair for severe degenerative MR for whom both preoperative and 3-year postoperative echocardiographic data were available in our institution. Preoperative and 3-year postoperative echocardiographic data and clinical outcomes were evaluated.

RESULTS

Receiver operating characteristic analysis identified preoperative LVEF 63% or less (area under curve [AUC], 0.725; P<.001) and LV end-systolic dimension (ESD) 39 mm or greater (AUC, 0.724; P<.001) as cut-off values for predicting LVEF less than 50% 3 years after surgery. On multivariate analysis, both preoperative LVEF and LVESD were not significant predictors of 3-year postoperative LV dysfunction among patients with preoperative LVEF greater than 63% and LVESD less 39 mm, whereas preoperative LVESD (odds ratio [OR], 2.22; P=.004), higher age (OR, 1.03; P=.04), and atrial fibrillation (OR, 2.68; P=.01) were independent predictors among patients with preoperative LVEF 63% or less or LVESD 39 mm or greater.

CONCLUSIONS

Early MV repair with LVEF greater than 63% and LVESD less than 39 mm preserved long-term postoperative LV function well, and smaller preoperative LVESD was associated with long-term LV function recovery, even in patients with preoperative LV dysfunction.

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.

Mitral Regurgitation - A Multidisciplinary Challenge

Mitral regurgitation is an increasing valvular disease that represents a difficult management challenge. Surgical treatment for degenerative mitral regurgitation is the standard of care treatment. Percutaneous therapies have emerged rapidly over the past years as an option for treatment of mitral regurgitation for selected, predominantly high-risk patients. Catheter-based devices mimic these surgical approaches with less procedural risk. Mitraclip® implantation mimics the surgical edge-to-edge leaflet repair technique, reducing the regurgitant area. We review the increasing evidence with the Mitraclip device reported to date.

How do we use imaging to aid considerations for intervention in patients with severe mitral regurgitation?

Increasing life expectancy and comorbid conditions, like obesity, especially in industrialized countries, have led to Valvular Heart Disease (VHD) becoming a major epidemic. Mitral valve disease currently accounts for nearly 10% of Valvular Heart Disease in industrialized countries worldwide. It is a known fact that, left untreated, degenerative mitral valve disease not only shortens an individual's life, but is also associated with increased morbidity. Despite current guidelines, there is often marked delay in appropriately sending patients for consideration of surgical intervention-interventions that when performed well can dramatically restore patients to a more normal lifespan. The critical question is really not what the severity of the mitral regurgitation is, but what the effect of the mitral regurgitation is on the heart. Modern day echocardiography utilizing Transthoracic Echo, Stress Echo, and Transesophageal Echo, can provide the clinician and the surgeon with six key factors that when taken together provide clear direction as to the proper timing for consideration for mitral valve repair. Thinking of these in an integrative fashion, the clinician and the surgeon can more appropriately time proper surgical intervention in primary degenerative mitral regurgitation.

Valvular heart disease: classic teaching and emerging paradigms

Valvular heart disease is both prevalent and increases with age. The final pathway of valvular disease is heart failure and sometimes sudden death, so clinicians must identify and treat it before these endpoints occur. Noninvasive diagnostic modalities such as echocardiography, exercise tolerance testing, and cardiac magnetic resonance provide additional quantitative, qualitative, and prognostic data. Studies have elucidated predictors of disease progression and potential medical therapies, but the niche of valvular disease has benefited relatively less from randomized controlled clinical trials than other cardiovascular disease fields. New invasive techniques like transcatheter valve replacement offer hope for high-risk operative candidates. We review classic teaching with current guidelines and emphasize recent advances in disease management.

Late Outcomes of Mitral Valve Repair for Mitral Regurgitation Due to Degenerative Disease

Background—

The pathological spectrum of degenerative diseases of the mitral valve (MV) that causes mitral regurgitation (MR) is broad, and there is limited information on late outcomes of MV repair in various subgroups of patients and pathologies. This study examines this issue.

Methods and Results—

All 840 patients who had MV repair for MR due to degenerative diseases from 1985 to 2004 were prospectively followed with clinical and echocardiographic evaluations at biennial intervals up to 26 years, median of 10.4 years. Clinical, hemodynamic, and pathological variables were evaluated for their association with outcomes. Age, left ventricular ejection fraction, and functional class were predictors of late cardiac- and valve-related deaths by multivariable analysis. MV repair failed to restore life span to normal in patients with functional class IV. Thirty-eight patients had repeat MV surgery, and the probability of reoperation at 20 years was 5.9%. During the follow-up, recurrent severe MR developed in 37 patients, and moderate MR developed in 61. Age, isolated prolapse of the anterior leaflet, the degree of myxomatous changes in the MV, lack of mitral annuloplasty, and duration of cardiopulmonary bypass were associated with increased risk of recurrent MR. At 20 years, the freedom from recurrent severe MR was 90.7%, and the freedom from moderate or severe MR was 69.2%.

Conclusions—

MV repair for degenerative MR restored life span to normal except in patients with symptoms at rest and impaired left ventricular function. Advanced age and complex mitral valve pathologies increased the risk of late recurrent MR.

Single-centre experience with mitral valve repair in asymptomatic patients with severe mitral valve regurgitation

OBJECTIVES

Guidelines recommend surgical mitral valve repair in selected patients with asymptomatic severe mitral valve regurgitation (MR), but the role of repair remains a matter of debate. Survival analyses of operated asymptomatic patients have been reported, but long-term haemodynamics and quality of life are not well defined. The aim of this study was to report the long-term follow-up focusing on these aspects.

METHODS

Our database identified patients who underwent primary isolated mitral valve repair for severe MR and were asymptomatic by New York Heart Association Class I and in sinus rhythm. To obtain sufficient length of follow-up, only patients operated on before 2006 returned for an echocardiogram and quality-of-life assessment (SF-36).

RESULTS

Between May 1991 and December 2005, 46 asymptomatic patients with severe MR and a normal left ventricular function (ejection fraction >60%) were operated on. Mean age was 50.2 ± 13.2 years and 89% of patients were male. There were no operative deaths. Mean follow-up was 8.4 ± 3.9 years with 386 patient-years, survival was 93.3% at 12 years and comparable with the general age-matched Dutch population. Follow-up echocardiography showed that 92% had no to mild MR, and 3 patients had moderate MR. Left ventricular function was good/impaired/moderate in 66/29/5% of patients. Quality-of-life SF-36 assessment showed that mean physical and mental health components were 83 ± 17 and 79 ± 17, which was comparable with that of the general age- and gender-matched Dutch population.

CONCLUSIONS

Our experience shows that mitral valve repair for severe MR in asymptomatic patients is safe, and has satisfactory long-term survival with a low recurrence rate of MR, good left ventricular function, and excellent quality of life that is comparable with the general Dutch population.

Posterior ventricular anchoring neochordal repair of degenerative mitral regurgitation efficiently remodels and repositions posterior leaflet prolapse

OBJECTIVES

Mitral valve repair techniques for degenerative disease typically entail leaflet resection or neochordal construction, which may require extensive resection, leaflet detachment/reattachment, reliance on diseased native chords or precise neochordal measuring. Occasionally, impaired leaflet mobility, reduced coaptation surface and systolic anterior motion (SAM) may result. We describe a novel technique for addressing posterior leaflet prolapse/flail, which both simplifies repair and addresses these issues.

METHODS

Fifty-four patients (age 62 ± 11 years) with degenerative MR underwent this new repair, 36 of whom minimally-invasively. A CV5 Gore-Tex suture was placed into the posterior left ventricular myocardium underneath the prolapsing segment as an anchor. This suture was then used to imbricate a portion of the prolapsed segment into the ventricle, creating a smooth, broad, non-prolapsed coapting surface on a leaflet with preserved mobility, additional neochordal support and posteriorly positioned enough to preclude SAM.

RESULTS

Repair was successful in all patients. The mean MR grade was reduced from +3.8 to +0.1 with 50 of 54 patients having zero MR and 4 of the 54 having trace or mild MR. All patients had proper antero-posterior location of the coaptation line of a mean length of 10.2 mm, and preserved posterior leaflet mobility. No patients had SAM or mitral stenosis. All patients were discharged and are currently doing well.

CONCLUSION

This new technique facilitated efficient single-suture repair of the prolapsed posterior leaflet mitral regurgitation without the need for resection or sliding annuloplasty. It precluded the need for precise neochordal measurement and preserved the leaflet coaptation surface.

Almanac 2012: adult cardiac surgery: the national society journals present selected research that has driven recent advances in clinical cardiology

This review covers the important publications in adult cardiac surgery in the last few years, including the current evidence base for surgical revascularisation and the use of off-pump surgery, bilateral internal mammary arteries and endoscopic vein harvesting. The changes in conventional aortic valve surgery are described alongside the outcomes of clinical trials and registries for transcatheter aortic valve implantation, and the introduction of less invasive and novel approaches of conventional aortic valve replacement surgery. Surgery for mitral valve disease is also considered, with particular reference to surgery for asymptomatic degenerative mitral regurgitation.

Surgical timing of degenerative mitral regurgitation: what to consider

Severe primary mitral regurgitation (MR) is a progressive condition which engenders significant mortality and morbidity if left untreated. The optimal timing of surgery in patients with MR of degenerative origin continues to be debated, especially for those who are asymptomatic. Apart from symptoms, current authoritative guidelines recommend intervention when there is incipient left ventricular dysfunction, pulmonary hypertension or new onset atrial fibrillation. This review focuses on the asymptomatic subject with severe MR, and examines contemporary clinical decision-making and management strategies, including the 2012 European guidelines on valvular heart disease. We discuss the rationale for risk stratifying the asymptomatic individual, and highlight current and novel diagnostic tools that may have a useful role, with an emphasis on echocardiographic imaging.

Heart valve disease

Heart valve disease is often characterized by a prolonged asymptomatic period that lasts for years and presents primary care physicians with an opportunity to detect disease before irreversible heart failure or other cardiac complications develop. Acute valvular disease can masquerade as respiratory illness or present with nonspecific systemic symptoms, and an astute examination by a primary care physician can direct appropriate care. Therefore, an understanding of the common pathologies and presentations of valvular heart disease is critical. This review focuses on the 2 most common valve lesions, aortic stenosis and mitral regurgitation, and provides an overview of other valve disease topics.

Comparison of need for operative therapy in patients with mitral valve prolapse involving both leaflets versus posterior leaflet only

Mitral valve prolapse may involve 1 leaflet or 2 leaflets, yet management guidelines do not differentiate posterior leaflet (PML) from bileaflet (BML) prolapse. We hypothesized that patients with BML have a prolonged natural history with more severe atrial and ventricular enlargement but less severe mitral regurgitation (MR) compared to patients with PML. Patients with mitral valve prolapse undergoing mitral repair were identified and preoperative characteristics were recorded. Patients with predominant PML prolapse (n = 304) versus BML prolapse (n = 131) were identified based on preoperative echocardiographic and intraoperative findings. Timing of operation was based on standard guidelines. Despite being equally symptomatic, patients with BML differed significantly from those with PML in being younger (54 vs 60 years, p <0.0001), more likely to be women (51% vs 24%, p <0.0001), and having a larger valve (37 vs 32 mm, p <0.0001). Despite similar cardiac function and dimensions, patients with BML had less severe MR (24% vs 13% with <4+ MR, p = 0.01) and less severe pulmonary hypertension (14% vs 31%, p <0.0001) at time of operation. In conclusion, patients with BML often meet indications for mitral valve repair with similar cardiac enlargement but less MR than patients with PML prolapse. Patients with BML prolapse may benefit from timing mitral repair based more on symptomatic 3+ MR or cardiac enlargement and less on presence of severe MR.

Early mitral valve repair versus watchful waiting in patients with severe asymptomatic organic mitral regurgitation; rationale and design of the Dutch AMR trial, a multicenter, randomised trial

BACKGROUND

Asymptomatic severe mitral valve (MV) regurgitation with preserved left ventricular function is a challenging clinical entity as data on the recommended treatment strategy for these patients are scarce and conflicting. For asymptomatic patients, no randomised trial has been performed for objectivising the best treatment strategy.

METHODS

The Dutch AMR (Asymptomatic Mitral Regurgitation) trial is a multicenter, prospective, randomised trial comparing early MV repair versus watchful waiting in asymptomatic patients with severe organic MV regurgitation. A total of 250 asymptomatic patients (18-70 years) with preserved left ventricular function will be included. Intervention will be either watchful waiting or MV surgery. Follow-up will be 5 years. Primary outcome measures are all-cause mortality and a composite endpoint of cardiovascular mortality, congestive heart failure, and hospitalisation for non-fatal cardiovascular and cerebrovascular events. Secondary outcome measures are total costs, cost-effectiveness, quality of life, echocardiographic and cardiac magnetic resonance parameters, exercise tests, asymptomatic atrial fibrillation and brain natriuretic peptide levels. Additionally, the complication rate in the surgery group and rate of surgery in the watchful waiting group will be determined.

IMPLICATIONS

The Dutch AMR trial will be the first multicenter randomised trial on this topic. We anticipate that the results of this study are highly needed to elucidate the best treatment strategy and that this may prove to be an international landmark study.

Mitral valve surgery: wait and see vs. early operation

Mitral valve repair represents the optimal surgical treatment for severe degenerative mitral regurgitation. According to the current guidelines, mitral repair is indicated in the presence of symptoms and/or signs of left ventricular (LV) dysfunction. In asymptomatic patients with preserved LV function, surgery should be considered in the presence of atrial fibrillation (AF) and/or pulmonary hypertension. In asymptomatic patients with preserved LV function, normal pulmonary artery pressure, and no episodes of AF, surgical timing is still an object of debate. The controversial issue is whether, in those circumstances, a 'wait and see (watchful waiting)' approach should be followed or an 'early repair' policy should be preferred. Indeed, a randomized trial comparing the two strategies has never been performed. In the absence of evidence-based arguments definitely supporting any particular course of action, advantages, drawbacks, and requirements for both strategies will be discussed in this review on the basis of the most significant observational studies which have focused on this issue.