Early surgery in patients with mitral regurgitation due to flail leaflets: a long-term outcome 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.

Changes in left ventricular morphology and function after mitral valve surgery

Degenerative mitral valve disease is the leading cause of mitral regurgitation in North America. Surgical intervention has hinged on the symptoms and ventricular changes that develop as compensatory ventricular remodeling occurs. In the present study, we sought to characterize the temporal response of left ventricular (LV) morphology and function to mitral valve surgery for degenerative disease and to identify the preoperative factors that influence reverse remodeling. From 1986 to 2007, 2,778 patients with isolated degenerative mitral valve disease underwent valve repair (n = 2,607 [94%]) or replacement (n = 171 [6%]) and had ≥1 postoperative transthoracic echocardiogram; 5,336 transthoracic echocardiograms were available for analysis. Multivariate longitudinal repeated-measures analysis was performed to identify the factors associated with reverse remodeling. The LV dimensions decreased in the first year after surgery (end-diastolic from 5.7 ± 0.80 to 4.9 ± 1.4 cm; end-systolic from 3.4 ± 0.71 to 3.1 ± 1.4 cm). The LV mass index decreased from 139 ± 44 to 112 ± 73 g/m(2). The reduction in LV hypertrophy was less pronounced in patients with greater preoperative left heart enlargement (p <0.0001) and a greater preoperative LV mass (p <0.0001). The postoperative LV ejection fraction initially decreased from 58 ± 7.0% to 53 ± 20%, increased slightly during the first postoperative year, and was negatively influenced by preoperative heart failure symptoms (p <0.0001) and a lower preoperative LV ejection fraction (p <0.0001). The risk-adjusted response of LV morphology and function to valve repair and replacement was similar (p >0.2). In conclusion, a positive response toward normalization of LV morphology and function after mitral valve surgery is greatest in the first year. The best response occurs when surgery is performed before left heart dilation, LV hypertrophy, or LV dysfunction develop.

Ten Years’ Follow-Up of Single-Surgeon Minimally Invasive Reparative Surgery for Degenerative Mitral Valve Disease

Objective

Granted that minimally invasive mitral valve (MV) surgery short-term results were found to be equivalent to those achieved with traditional sternotomy with respect to perioperative morbidity and echocardiographic outcomes, little is known about the long-term efficacy of this approach. This report analyzes a 10-year single-surgeon experience with minimally invasive MV surgery through a right minithoracotomy with peripheral cannulation and external aortic cross-clamping and MV repair (MVR) by direct vision.

Methods

We studied 179 patients (48% female) who underwent MVR between December 1999 and December 2010. Mean age was 40.2 ± 10.1 years (range, 15–67 years). One hundred seventy patients (95.0%) had degenerative diseases, and nine patients (5.0%) had endocarditic diseases. Repair techniques for degenerative disease with posterior leaflet prolapse (74 patients, 43.5%) consisted of quadrangular resection (QR) and annuloplasty (AP) combined with sliding plasty (49 patients, 58.1%); for anterior leaflet prolapse (28 patients, 16.5%) and bileaflet prolapse (66 patients, 38.8%), edge-to-edge repair (EE) and AP; in 2 patients (1.2%), annular dilatation alone consisting of AP. Repair techniques for endocarditic disease consisted of EE in six patients (66.7%), perforation closure in two patients (22.2%), and QR combined with AP in one patient (11.1%).

Results

All patients survived the operation and were discharged with MV regurgitation (MR) less than 2+/4+. At 10 years’ follow-up, overall survival was 98.7% ± 1.2%, freedom from redo was 98.5% ± 1.1%, freedom from MR recurrence (>2+/4+) in QR and in EE repair were, respectively, 91.7% ± 2.2% and 90.0% ± 2.4% (P = not significant). The linearized rates of overall mortality, MR recurrence (>2+/4+), and redo at follow-up are 0.10% ± 0.10% per year, 0.63% ± 0.26% per year, and 0.21% ± 0.15% per year, respectively.

Conclusions

Minimally invasive MVR can be performed with very good perioperative and long-term results. Freedom from MR greater than 2+/4+ recurrence for patients with QR is equivalent to that with EE repair in our patient cohort.

Echocardiographic assessment of canine degenerative mitral valve disease

Degenerative mitral valve disease (MVD), the most common acquired heart disease in small-sized dogs, is characterized by valvular degeneration resulting in systolic mitral valve regurgitation (MR). Worsening of MR leads to several combined complications including cardiac remodeling, increased left ventricular filling pressure, pulmonary arterial hypertension, and myocardial dysfunction. Conventional two-dimensional, M-mode, and Doppler examination plays a critical role in the initial and longitudinal assessment of dogs affected by MVD, providing information on mitral valve anatomy, MR severity, left ventricular (LV) size and function, as well as cardiac and vascular pressures. Several standard echocardiographic variables have been shown to be related to clinical outcome. Some of these markers (e.g., left atrium to aorta ratio, regurgitation fraction, pulmonary arterial pressure) may also help in identifying asymptomatic MVD dogs at higher risk of early decompensation, which remains a major issue in practice. However, both afterload and preload are altered during the disease course. This represents a limitation of conventional techniques to accurately assess myocardial function, as most corresponding variables are load-dependent. Recent ultrasound techniques including tissue Doppler imaging, strain and strain rate imaging, and speckle tracking echocardiography, provide new parameters to assess regional and global myocardial performance (e.g., myocardial velocities and gradients, deformation and rate of deformation, and mechanical synchrony). As illustration, the authors present new data obtained from a population of 91 dogs (74 MVD dogs, 17 age-matched controls) using strain imaging, and showing a significant longitudinal systolic alteration at the latest MVD heart failure stage.

Assessment of myocardial deformation: Predicting medium-term left ventricular dysfunction after surgery in patients with chronic mitral regurgitation

INTRODUCTION AND OBJECTIVES

The development of left ventricular dysfunction after mitral valve replacement is a common problem in patients with chronic severe mitral regurgitation. Assessment of myocardial deformation enables myocardial contractility to be accurately estimated. Our aim was to compare the value of the preoperative strain and strain rate derived by either speckle-tracking echocardiography or tissue Doppler imaging (TDI) for predicting the medium-term decrease in left ventricular ejection fraction (LVEF) following surgery.

METHODS

This prospective study involved 38 consecutive patients with chronic severe mitral regurgitation who were scheduled for mitral valve replacement. The longitudinal strain and strain rate in the interventricular septum were measured preoperatively using speckle-tracking echocardiography and TDI. The LVEF was determined preoperatively and postoperatively using 3-dimensional echocardiography. Echocardiographic assessments were performed in the 48 hours prior to surgery and 6 months postoperatively.

RESULTS

The patients' mean age was 59.9+/-11.3 years and 10 (29.4%) were male. Both speckle-tracking echocardiography and TDI were found to be predictors of a >10% decrease in LVEF at 6 months. However, the predictive value of speckle-tracking echocardiography was greater than that of TDI. The longitudinal strain at baseline in the interventricular septum as measured by speckle-tracking echocardiography was the most powerful predictor; the area under the curve was 0.85 and the optimal cut-off value was -0.11.

CONCLUSIONS

Speckle-tracking echocardiography can be used to predict a decrease in LVEF over the medium term after mitral valve replacement. Moreover, the predictive accuracy of speckle-tracking echocardiography was greater than that of TDI.

Can we improve outcomes in patients with previous coronary artery bypass surgery admitted for acute coronary syndrome?

INTRODUCTION AND OBJECTIVES

Prognosis and in-hospital management of patients with acute coronary syndrome (ACS) and a history of coronary artery bypass graft (CABG) surgery are still debated. The objective of this study was to characterize ACS patients with a CABG and to compare their in-hospital and postdischarge outcomes with those of patients without a CABG.

METHODS

This ongoing prospective observational study included 1,495 consecutive patients admitted for ACS to a coronary care unit and followed up for a mean of 19 months. There were two groups: group A (n=73), with CABGs; and group B (n=1,223), without CABGs.

RESULTS

Group A patients were more often male (86.3% versus 69.1%; P=.002), and more frequently had a history of diabetes, myocardial infarction and heart failure. Group B patients more frequently had ST-elevation myocardial infarction, and had a higher median ejection fraction (53% [interquartile range, 47%-60%] vs. 50% [42%-55%]; P< .01) and peak troponin-I concentration. There was no difference in the use of invasive techniques. Regarding medication, Group B patients were more likely to receive dual antiplatelet therapy at discharge. No significant difference was observed in in-hospital mortality (9.5% versus 5.9%; P=.2) or mortality at 1 month, 6 months or 1 year (9.8% versus 9.1%; log-rank test, P=.87) and the cumulative major adverse cardiac event rate was equally low in both groups. The presence of a CABG was associated with more readmissions for unstable angina (11.3% vs. 3.1%; P< .01).

CONCLUSIONS

In our ACS patients, the presence of a CABG had no significant influence on short- or medium-term outcomes, such as all-cause mortality and adverse cardiac events.

Direct measurement of vena contracta area by real-time 3-dimensional echocardiography for assessing severity of mitral regurgitation

We tested the hypothesis that the vena contracta (VC) cross-sectional area in patients with mitral regurgitation (MR) can be reproducibly measured by real-time 3-dimensional (3D) echocardiography and correlates well with the volumetric effective regurgitant orifice area (EROA). Earlier MR repair requires accurate noninvasive measures, but practically, the VC area is difficult to image in 2-dimensional views, which are often oblique to it. 3D echocardiography can provide an otherwise unobtainable true cross-sectional view. In 45 patients with mild or greater MR, 44% eccentric, 2-dimensional and 3D VC areas were measured and correlated with the EROA derived from the regurgitant stroke volume. Real-time 3D echocardiography of the VC area correlated and agreed well with the EROA for both central and eccentric jets (r(2) = 0.86, SEE 0.02 cm(2), difference 0.04 +/- 0.06 cm(2), p = NS). For eccentric jets, 2-dimensional echocardiography overestimated the VC width compared with 3D echocardiography (p = 0.024) and correlated more poorly with the EROA (r(2) = 0.61 vs 0.85, p <0.001), causing clinical misclassification in 45% of patients with eccentric MR. The interobserver variability for the 3D VC area was 0.03 cm(2) (7.5% of the mean, r = 0.95); the intraobserver variability was 0.01 cm(2) (2.5% of the mean, r = 0.97). In conclusion, real-time 3D echocardiography accurately and reproducibly quantified the vena contracta cross-sectional area in patients with both central and eccentric MR. Rapid acquisition and intuitive analysis promote practical clinical application of this central, directly visualized, measure and its correlation with outcome.

Doppler-derived preoperative mitral regurgitation volume predicts postoperative left ventricular dysfunction after mitral valve repair

BACKGROUND

Unexpected postoperative left ventricular (LV) dysfunction after valve repair for mitral regurgitation (MR) occurs in some patients with normal preoperative LV function. Identification of factors that predispose to such LV dysfunction would enhance our understanding of the indications and outcomes of surgery.

METHODS

We retrospectively analyzed pre- and postoperative (median fourth day) echocardiograms of 174 patients undergoing valve repair for pure and isolated MR. Preoperative MR volume was quantified by the quantitative Doppler and/or proximal isovelocity surface area method.

RESULTS

There was an incremental predictive value of MR quantification over the current recommendations (global chi(2) from 48.14 to 81.57, P < .001; Hosmer-Lemeshow test, P = .98), for postoperative LV dysfunction, defined as ejection fraction <50%. The independent predictors were MR volume and LV end-systolic dimension (P < .001 and P = .01, respectively). Sixty-nine patients underwent surgery before development of the current surgical criteria, namely, symptoms, atrial fibrillation, preoperative LV dysfunction, or pulmonary hypertension. Of these, MR volume was the only independent significant predictor (P < .001) of unexpected postoperative LV dysfunction that developed in 14 patients (20%). Unexpected LV dysfunction could be predicted with sensitivity of 86% (95% CI 67%-100%) and specificity of 89% (95% CI 81%-97%), using the optimal cutoff of 80 mL for MR volume.

CONCLUSIONS

Doppler-derived preoperative MR volume is a powerful predictor of unexpected postoperative LV dysfunction. Prompt mitral valve repair may be beneficial for patients with high likelihood of successful repair and MR volume >/=80 mL.

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.

Comparison of real time two-dimensional with live/real time three-dimensional transesophageal echocardiography in the evaluation of mitral valve prolapse and chordae rupture

We compared live/real time three-dimensional transesophageal echocardiography (3D TEE) with real time two-dimensional transesophageal echocardiography (2D TEE) in the assessment of individual mitral valve (MV) segment/scallop prolapse and associated chordae rupture in 18 adult patients with a flail MV undergoing surgery for mitral regurgitation. 2D TEE was able to diagnose the prolapsing segment/scallop and associated chordae rupture correctly in only 9 of 18 patients when compared to surgery. In three of these, 2D TEE diagnosed an additional segment/scallop not confirmed at surgery. In the remaining nine patients, surgical findings were missed by 2D TEE. On the other hand with 3D TEE, the prolapsed segment/scallop and associated ruptured chords correlated exactly with the surgical findings in the operating room in 16 of 18 patients. The exceptions were two patients. In one, 3D TEE diagnosed prolapse and ruptured chordae of the A3 segment and P3 scallop, while the surgical finding was chordae rupture of the A3 segment but only prolapse without chordae rupture of the P3 scallop. In the other patient, 3D TEE diagnosed prolapse and chordae rupture of P1 scallop and prolapse without chordae rupture of the A1 and A2 segments, while at surgery chordae rupture involved A1, A2, and P1. This preliminary study demonstrates the superiority of 3D TEE over 2D TEE in the evaluation of individual MV segment/scallop prolapse and associated ruptured chordae.

Etiology and short-term prognosis of severe mitral regurgitation

PURPOSE

To describe the etiology and to document the course of severe mitral regurgitation (MR).

METHODS

Prospective registry of 272 patients diagnosed with chronic severe MR in an echocardiographic study.

RESULTS

Mean age was 70.2 +/- 13.8 years and 143 patients were women (53%). The most frequent causes of regurgitation were rheumatic disease (72 patients; 26%), ischemic etiology (58; 21%), valve prolapse (57; 21%), and dilated cardiomyopathy (49; 18%). A total of 43 patients (16%) died during follow-up (mean 0.9 +/- 0.3 years, total 2,785 patient-months): 30 from cardiac causes, 9 from non-cardiac causes, and 4 from unknown causes. Actuarial transplant-free survival was 87% at 6 months, and 81% at 1 year. Renal disease, previous stroke, ischemic etiology, and poor left ventricular ejection fraction were independent predictors of mortality.

CONCLUSIONS

Rheumatic disease is still the main cause of severe MR in Spain. Patients with severe MR have advanced age and present poor short-term prognosis.

A methodology for assessing human mitral leaflet curvature using real-time 3-dimensional echocardiography

OBJECTIVES

Using 3-dimensional echocardiography in conjunction with novel geometric modeling and rendering techniques, we have developed a high-resolution, quantitative, 3-dimensional methodology for imaging the human mitral valve. Leaflet and annular geometry are important determinants of mitral valve stress. Repair techniques that optimize valvular geometry will reduce stress and potentially increase repair durability. The development of such procedures will require image-processing methodologies that provide a quantitative description of 3-dimensional valvular geometry.

METHODS

Ten healthy adult subjects underwent mitral valve imaging with real-time 3-dimensional echocardiography. By using specially designed image analysis software, multiple valvular geometric parameters, including 2- and 3-dimensional leaflet curvature, leaflet surface area, annular height, intercommissural width, septolateral annular diameter, and annular area were determined for each subject. Image-rendering techniques that allow for the clear and concise presentation of this detailed information are also presented.

RESULTS

Although 3-dimensional annular and leaflet geometry were found to be highly conserved between healthy human subjects in general, substantial intrasubject and intersubject regional geometric heterogeneity was observed in the midposterior leaflet, the region most commonly involved in leaflet flail in subjects with myxomatous disease.

CONCLUSIONS

The image-processing and graphic-rendering techniques that we have developed can be used to provide a complete description of 3-dimensional mitral valve geometry in human subjects. Widespread application of these techniques to healthy subjects and patients with mitral valve disease will provide insight into the geometric basis of both valvular pathology and repair durability.

The influence of annuloplasty ring geometry on mitral leaflet curvature

BACKGROUND

The effect of mitral leaflet curvature on stress reduction is an important mechanism in optimizing valve function. We hypothesize that annuloplasty ring shape could directly influence leaflet curvature and, potentially, repair durability. We describe an echocardiographically based methodology for quantifying mitral valve geometry and its application to the characterization of ovine mitral valve geometry before and after implantation of an annuloplasty ring.

METHODS

Multiple mitral annular and leaflet geometric variables were calculated for 8 naïve adult male sheep using real-time three-dimensional echocardiographic images. These indexes were recalculated after annuloplasty using a 30-mm Carpentier-Edward Physio ring (n = 4; Edwards Lifesciences, Irvine, CA) or a 30-mm saddle ring (n = 4).

RESULTS

After implantation of the Physio ring, the annular height to commissural width ratio (AHCWR) decreased from 19.4% +/- 2.3% to 11.1% +/- 2.5% (p = 0.06). After implantation of the saddle ring, AHCWR increased from 19.6% +/- 1.3% to 24.3% +/- 1.3% (p < 0.05). Statistically significant increases in three-dimensional Gaussian curvature occurred after implantation within six defined leaflet regions (A1 to A3, P1 to P3) of the saddle ring but only within the P1 and P3 leaflet regions with the Physio ring.

CONCLUSIONS

Annuloplasty ring shape affects leaflet curvature. Implantation of a saddle ring reflecting normal human annular geometry augmented ovine annular nonplanarity and increased three-dimensional leaflet curvature across the entire mitral valve surface. The Physio ring decreased annular nonplanarity and increased leaflet curvature only across limited regions of the posterior leaflet. These findings confirm the hypothesis that ring design influences leaflet curvature.

Results of coronary bypass and valve operations for mitral valve regurgitation

Combined coronary bypass grafting and valve procedures for mitral valve regurgitation result in poor outcomes, but the impact of the etiology of valve regurgitation on operative and long-term outcomes is not well defined. A retrospective analysis of 468 patients who had combined coronary bypass grafting and valve operations for mitral regurgitation showed that 78% had valve repairs and 22% had replacements for ischemic (45%) or degenerative (55%) disease. Predictors of operative mortality were ischemic mitral regurgitation, failure to use the internal mammary artery for grafting, severe coronary disease, acute myocardial infarction, low ejection fraction, advanced heart failure, emergency operation, and mitral valve replacement. The 5-year survival rates for propensity-matched patients with ischemic or degenerative disease were similar (66%). Low ejection fraction (< 35%), advanced age (> 67 years), valve replacement surgery, residual mitral regurgitation, and severe coronary artery disease were predictors of poor long-term outcome. Although the operative outcomes of ischemic mitral regurgitation were poor compared to those of degenerative disease, the long-term survival was similar in both groups of propensity-matched patients. Left ventricular remodeling, an optimal valve procedure without residual mitral regurgitation, and left ventricular function are more important determinants of long-term outcome than the etiology of valve regurgitation.

Mitral valve annuloplasty and myocardial revascularization in the treatment of ischemic dilated cardiomyopathy

The aim of this study was to examine perioperative mortality and morbidity and midterm results in patients undergoing coronary bypass graft and mitral valve annuloplasty with advanced dilated cardiomyopathy. Sixty-one patients with ischemic dilated cardiomyopathy underwent coronary artery bypass grafting and mitral valve annuloplasty between January 1998 and December 2003. Patients eligible for revascularization that presented a mild or more severe mitral valve regurgitation at echocardiography (effective regurgitant orifice > 0.2 cm(2)) were considered for annuloplasty with a Cosgrove ring. New York Heart Association class (NYHA) III/IV was present in 40 patients (66%) and Canadian Cardiovascular Society class III-IV in 19 (31%). A previous acute myocardial infarction was reported in 48 patients (79%). The mean number of graft anastomoses was 2.5 +/- 0.7 and the left internal mammary artery was used in 49 patients (80%). In-hospital mortality was 4.9% (3 patients), due to unsuccessful weaning from cardiopulmonary bypass, multiple organ failure, and stroke, respectively. Left ventricle ejection fraction improved from 28.9% +/- 5.2% preoperatively to 35.4% +/- 8.1% at follow-up (P = 0.0001) and a significant reduction in NYHA III/IV was detected: from 40 patients preoperatively (66%) to 14 (31%) at follow-up (P = 0.031). Midterm cardiac-related mortality rate was 3.4%. In our experience combined coronary artery bypass grafting and ring annuloplasty for ischemic dilated cardiomyopathy can be performed with acceptable risks for in-hospital mortality and morbidity. Midterm results show a good survival rate and a durable functional improvement in this subset of patients.

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.

Future Directions in Degenerative Mitral Valve Repair

Mitral valve repair is by far the most common operation for degenerative mitral regurgitation. If the procedure is performed before left ventricular dysfunction occurs and atrial fibrillation develops, the operative risk is very low and life expectancy is super imposable to that of the sex- and age-matched population. Despite these achievements, there are areas that could still be improved. Progress in treating degenerative mitral regurgitation is expected to move along several directions. More precise diagnostic methods will be developed to reliably quantify mitral regurgitation and identify early irreversible ventricular and atrial changes. The refinement of surgical techniques and search for new, innovative solutions should never be abandoned. Finally, transcatheter correction of mitral regurgitation represents a new, emerging field of cardiovascular medicine and is expected to have a significant impact on the surgical practice in the future.

Indications for Surgery in Degenerative Mitral Valve Disease

There has been great progress during the past decade in management of patients with mitral regurgitation. Doppler echocardiography allows accurate quantification of the degree of valve leakage and tracking of the effect of regurgitation on cardiac size and function. Natural history studies have clearly delineated the deleterious effects of severe, persistent mitral valve regurgitation including an increased risk of cardiac death as well as a predisposition to the development of congestive heart failure and atrial fibrillation. In virtually all of our analyses, short-term and long-term outcomes are improved in patients who have early surgical correction of severe mitral valve regurgitation. Moreover, there are clear benefits of mitral valve repair over valve replacement, including greater regression of left heart dimensions, normalization of left ventricular function, and superior long-term survival.