Is a good perioperative echocardiographic result predictive of durability in ischemic mitral valve repair?

A Computational Pipeline for Patient-Specific Prediction of the Postoperative Mitral Valve Functional State

While mitral valve (MV) repair remains the preferred clinical option for mitral regurgitation (MR) treatment, long-term outcomes remain suboptimal and difficult to predict. Furthermore, pre-operative optimization is complicated by the heterogeneity of MR presentations and the multiplicity of potential repair configurations. In the present work, we established a patient-specific MV computational pipeline based strictly on standard-of-care pre-operative imaging data to quantitatively predict the post-repair MV functional state. First, we established human mitral valve chordae tendinae (MVCT) geometric characteristics obtained from five CT-imaged excised human hearts. From these data, we developed a finite-element model of the full patient-specific MV apparatus that included MVCT papillary muscle origins obtained from both the in vitro study and the pre-operative three-dimensional echocardiography images. To functionally tune the patient-specific MV mechanical behavior, we simulated pre-operative MV closure and iteratively updated the leaflet and MVCT prestrains to minimize the mismatch between the simulated and target end-systolic geometries. Using the resultant fully calibrated MV model, we simulated undersized ring annuloplasty (URA) by defining the annular geometry directly from the ring geometry. In three human cases, the postoperative geometries were predicted to 1 mm of the target, and the MV leaflet strain fields demonstrated close agreement with noninvasive strain estimation technique targets. Interestingly, our model predicted increased posterior leaflet tethering after URA in two recurrent patients, which is the likely driver of long-term MV repair failure. In summary, the present pipeline was able to predict postoperative outcomes from pre-operative clinical data alone. This approach can thus lay the foundation for optimal tailored surgical planning for more durable repair, as well as development of mitral valve digital twins.

Quantitative in vivo assessment of human mitral valve coaptation area after undersized ring annuloplasty repair for ischemic mitral regurgitation

Objectives

Long-term outcomes of mitral valve repair procedures to correct ischemic mitral regurgitation remain unpredictable, due to an incomplete understanding of the disease process and the inability to reliably quantify the coaptation zone using echocardiography. Our objective was to quantify patient-specific mitral valve coaptation behavior from clinical echocardiographic images obtained before and after repair to assess coaptation restoration and its relationship with long-term repair durability.

Methods

To circumvent the limitations of clinical imaging, we applied a simulation-based shape-matching technique that allowed high-fidelity reconstructions of the complete mitral valve in the systolic configuration. We then applied this method to an extant database of human regurgitant mitral valves before and after undersized ring annuloplasty to quantify the effect of the repair on mitral valve coaptation geometry.

Results

Our method was able to successfully resolve the coaptation zone into distinct contacting and redundant regions. Results indicated that in patients whose regurgitation recurred 6 months postrepair, both the contacting and redundant regions were larger immediately postrepair compared with patients with no recurrence (P < .05), even when normalized to account for generally larger recurrent valves.

Conclusions

Although increasing leaflet coaptation area is an intuitively obvious way to improve long-term repair durability, this study has implied that this may not be a reliable target for mitral valve repair. This study underscores the importance of a rigorous understanding of the consequences of repair techniques on mitral valve behavior, as well as a patient-specific approach to ischemic mitral regurgitation treatment within the context of mitral valve and left ventricle function.

Diagnosis and Management of Ischemic Mitral Regurgitation: Evidence-Based Clinical Decision Making at the Point of Care

Anatomical, functional, and pathophysiologic mechanisms of ischemic mitral regurgitation (IMR) are markedly different from the primary mitral regurgitation. The older and ubiquitous cutoff of EROA (effective regurgitant orifice area) and Rvol (regurgitant volume) for IMR has been reinstated in the new guideline after a brief hiatus. There had always been a lack of good-quality evidence for its introduction for guiding IMR severity in the previous guideline, and we still do not have quality evidences that could justify its reintroduction. Unlike primary MR, IMR is usually associated with reduced ejection fraction. Therefore, it appears unrealistic to keep the similar cutoff for primary MR and IMR. The cutoff of severity can be modified according to projected values of Rvol normalized to ejection fraction and EROA normalized to Rvol. In addition, the treatment outcome in these patients is determined by factors (left ventricular dyssynchrony, annular dilatation, tenting area, tenting height, tenting volume, and myocardial viability) other than the simple grading. In this review article, a series of graph have been constructed from the numerical data derived from the literatures on IMR to depict the relationship between EROA, Rvol, left ventricular end diastolic volume, and ejection fraction in order to obtain a reasonable projection formula for EROA and Rvol. Furthermore, a management algorithm has been proposed for patients with IMR undergoing coronary artery bypass grafting based on echocardiographic predictors that influence the postoperative outcome.

Risk of Ischemic Mitral Regurgitation Recurrence After Combined Valvular and Subvalvular Repair

BACKGROUND

Mitral valve repair (MVr) combined with papillary muscle approximation (PMA) may improve repair durability in severe ischemic mitral regurgitation (MR), when compared with MVr alone. We sought to identify preoperative transthoracic echocardiographic markers associated with MR recurrence after MVr with PMA.

METHODS

A post-hoc analysis was performed on patients with severe ischemic MR who underwent coronary artery bypass graft surgery with MVr with PMA in the papillary muscle approximation randomized trial. The PMA was performed utilizing a 4-mm polytetrafluoroethylene graft placed around the papillary muscles. Linear regression analyses and receiver-operating characteristic curves were used to identify echocardiographic variables and diagnostic models associated with recurrent MR.

RESULTS

There were 48 patients with a mean age of 63 ± 7 years, a left ventricular ejection fraction of 35% ± 5%, and a left ventricular end-diastolic diameter of 63 ± 3 mm. Of these, 37 patients had baseline and 5-year follow-up echocardiograms, with moderate-to-severe MR recurring in 27%. Linear regression analyses revealed associations between preoperative pulmonary artery systolic pressure (standardized beta coefficient, β = 0.49/mm Hg, p = 0.002), MV tenting area (β = 0.47/cm², p = 0.004), a symmetric MV tethering pattern (β = 0.44, p = 0.007), and left ventricular end-diastolic diameter (β = 0.37/mm, p = 0.02) with follow-up MR grade. The presence of both MV tenting area 3.1 cm² or greater (area under the curve 0.822) and left ventricular end-diastolic diameter of 64 mm or greater (area under the curve 0.801) was the most robust discriminative model for moderate-to-severe MR recurrence (specificity 92%, sensitivity 69%, area under the curve 0.804, p = 0.003).

CONCLUSIONS

In patients undergoing coronary artery bypass graft surgery with MVr plus PMA, the extent of baseline MV apparatus and left ventricle geometric remodeling identifies patients at increased risk for MR recurrence.

Ischemic mitral regurgitation

Ischemic mitral regurgitation (IMR) is a frequent complication of left ventricular (LV) global or regional pathological remodeling due to chronic coronary artery disease. It is not a valve disease but represents the valvular consequences of increased tethering forces and reduced closing forces. IMR is defined as mitral regurgitation caused by chronic changes of LV structure and function due to ischemic heart disease and it worsens the prognosis. In this review, we discuss on etiology, pathophysiology, and mechanisms of IMR, its classification, evaluation, and therapeutic corrective methods of IMR.

Compassionate use of the PASCAL transcatheter mitral valve repair system for patients with severe mitral regurgitation: a multicentre, prospective, observational, first-in-man study

BACKGROUND

Severe mitral regurgitation is associated with impaired prognosis if left untreated. Using the devices currently available, transcatheter mitral valve repair (TMVr) remains challenging in complex anatomical situations. We report the procedural and 30-day results of the first-in-man study of the Edwards PASCAL TMVr system.

METHODS

In this multicentre, prospective, observational, first-in-man study, we collected data from seven tertiary care hospitals in five countries that had a compassionate use programme in which patients underwent transcatheter mitral valve repair using the Edwards PASCAL TMVr system. Eligible patients were those with symptomatic, severe functional, degenerative, or mixed mitral regurgitation deemed at high risk or inoperable. Safety and efficacy of the procedure were prospectively assessed at device implantation, discharge, and 30 days after device implantation. The key study endpoints were technical success assessed at the end of the procedure and device success 30 days after implantation using the Mitral Valve Academic Research Consortium definitions.

FINDINGS

Between Sept 1, 2016, and March 31, 2017, 23 patients (median age 75 years [IQR 61-82]) had treatment for moderate-to-severe (grade 3+) or severe (grade 4+) mitral regurgitation using the Edwards PASCAL TMVr system. At baseline, the median EuroScore II score was 7·1% (IQR 3·6-12·8) and the median Society of Thoracic Surgeons predicted risk of mortality for mitral valve repair was 4·8% (2·1-9·0) and 6·8% (2·9-10·1) for mitral valve replacement. 22 (96%) of 23 patients were New York Heart Association (NYHA) class III or IV at baseline. The implantation of at least one device was successful in all patients, resulting in procedural residual mitral regurgitation of grade 2+ or less in 22 (96%) patients. Six (26%) of 23 patients had two implants. Periprocedural complications occurred in two (9%) of 23 patients (one minor bleeding event and one transient ischaemic attack). Despite the anatomical complexity of mitral regurgitation in the patients in this compassionate use cohort, technical success was achieved in 22 (96%) of 23 patients, and device success at 30 days was achieved in 18 (78%) patients. Three patients (13%) died during the 30 day follow-up. 19 (95%) of 20 patients alive 30 days after implantation were NYHA class I or II.

INTERPRETATION

This study establishes feasibility of the Edwards PASCAL TMVr system with a high rate of technical success and reduction of mitral regurgitation severity. Further research is needed on procedural and long-term clinical outcomes.

FUNDING

None.

Transapical Coaptation Plate for Functional Mitral Regurgitation: An In Vitro Study

A novel transapical coaptation plate (TCP) device was developed and anchored by sutures in the mitral valve to treat functional mitral regurgitation. The objective of this study was to test efficacy of the TCP in an in vitro model. Eight fresh porcine mitral valves were mounted in a left heart simulator to simulate functional mitral regurgitation by means of annular dilatation and asymmetrical or symmetrical papillary muscle (PM) displacement. Six polyurethane TCPs in thickness of 6.4(#1), 4.8(#2), 3.2(#3) mm and hardness of durometer 30 A (H) and 30 OO(S),were fabricated and labeled as H1, H2, H3 and S1, S2, S3, respectively. These TCPs were anchored by the sutures in the mitral annulus and left ventricle apex, and tested. Steady backward flow leakage in a hydrostatic condition and regurgitant volume in a pulsatile flow were measured before and after implantation of the TCPs. Mean regurgitant volume fractions in the asymmetric PM displacement were reduced significantly from 59.1 to 37.2% for H1, 43.2% for H2, 35.9% for S1 and 34.2% for S2 (p < 0.021), after implantation of the TCPs. No significant reduction in mitral regurgitation was seen for H3 and S3 (p > 0.067). Mitral regurgitation was mild in the symmetric PM displacement, and was not significantly reduced after implantation of the TCPs. In conclusion, the TCP anchored by the sutures in the mitral annulus and left ventricle apex functions successfully as a plug in the mitral valve leaflet gap. The TCP with thickness equal to or greater than 4.8 mm is effective to reduce functional mitral regurgitation. The TCP hardness has no effect on difference in reduction of functional mitral regurgitation.

The value of preoperative 3-dimensional over 2-dimensional valve analysis in predicting recurrent ischemic mitral regurgitation after mitral annuloplasty

OBJECTIVES

Repair for ischemic mitral regurgitation with undersized annuloplasty is characterized by high recurrence rates. We sought to determine the value of pre-repair 3-dimensional echocardiography over 2-dimensional echocardiography in predicting recurrence at 6 months.

METHODS

Intraoperative transesophageal 2-dimensional echocardiography and 3-dimensional echocardiography were performed in 50 patients undergoing undersized annuloplasty for ischemic mitral regurgitation. Two-dimensional echocardiography annular diameter and tethering parameters were measured in the apical 2- and 4-chamber views. A customized protocol was used to assess 3-dimensional annular geometry and regional leaflet tethering. Recurrence (grade ≥2) was assessed with 2-dimensional transthoracic echocardiography at 6 months.

RESULTS

Preoperative 2- and 3-dimensional annular geometry were similar in all patients with ischemic mitral regurgitation. Preoperative 2- and 3-dimensional leaflet tethering were significantly higher in patients with recurrence (n = 13) when compared with patients without recurrence (n = 37). Multivariate logistic regression revealed preoperative 2-dimensional echocardiography posterior tethering angle as an independent predictor of recurrence with an optimal cutoff value of 32.0° (area under the curve, 0.81; 95% confidence interval, 0.68-0.95; P = .002) and preoperative 3-dimensional echocardiography P3 tethering angle as an independent predictor of recurrence with an optimal cutoff value of 29.9° (area under the curve, 0.92; 95% confidence interval, 0.84-1.00; P < .001). The predictive value of the 3-dimensional geometric multivariate model can be augmented by adding basal aneurysm/dyskinesis (area under the curve, 0.94; 95% confidence interval, 0.87-1.00; P < .001).

CONCLUSIONS

Preoperative 3-dimensional echocardiography P3 tethering angle is a stronger predictor of ischemic mitral regurgitation recurrence after annuloplasty than preoperative 2-dimensional echocardiography posterior tethering angle, which is highly influenced by viewing plane. In patients with a preoperative P3 tethering angle of 29.9° or larger (especially when combined with basal aneurysm/dyskinesis), chordal-sparing valve replacement should be strongly considered.

Echocardiographic Assessment of Ischaemic Mitral Regurgitation, Mechanism, Severity, Impact on Treatment Strategy and Long Term Outcome

Introduction:

The commonest mitral regurgitation etiologies are degenerative (60%), rheumatic post-inflammatory, 12%) and functional (25%). Due to the large number of patients with acute MI, the incidence of ischaemic MR is also high. Ischaemic mitral regurgitation is a complex multifactorial disease that involves left ventricular geometry, the mitral annulus, and the valvular/subvalvular apparatus. Ischaemic mitral regurgitation is an important consequence of LV remodeling after myocardial infarction.

Research Objectives:

The objective of this study is to determine the role of echocardiography in detecting and assessment of mitral regurgitation mechanism, severity, impact on treatment strategy and long term outcome in patients with myocardial infarction during the follow up period of 5 years. Also one of objectives to determine if the absence or presence of ischaemic MR is associated with increased morbidity and mortality in patients with myocardial infarction.

Patients and methods:

The study covered 138 adult patients. All patients were subjected to echocardiography evaluation after acute myocardial infarction during the period of follow up for 5 years. The patients were examined on an ultrasound machine Philips iE 33 xMatrix, Philips HD 11 XE, and GE Vivid 7 equipped with all cardiologic probes for adults and multi-plan TEE probes. We evaluated mechanisms and severity of mitral regurgitation which includes the regurgitant volume (RV), effective regurgitant orifice area (EROA), the regurgitant fraction (RF), Jet/LA area, also we measured the of vena contracta width (VC width cm) for assessment of IMR severity, papillary muscles anatomy and displacement, LV systolic function ± dilation, LV regional wall motion abnormality WMA, LV WMI, Left ventricle LV remodeling, impact on treatment strategy and long term mortality.

Results:

We analyzed and follow up 138 patients with previous (>16 days) Q-wave myocardial infarction by ECG who underwent TTE and TEE echocardiography for detection and assessment of ischaemic mitral regurgitation (IMR) with baseline age (62 ± 9), ejection fraction (EF 41±12%), the regurgitant volume (RV) were 42±21 mL/beat, and effective regurgitant orifice area (EROA) 20±16 mm², the regurgitant fraction (RF) were 48±10%, Jet/LA area 47±12%. Also we measured the of vena contracta width (VC width cm) 0,4±0,6 for assessment of IMR severity. During 5 years follow up, total mortality for patients with moderate/severe IMR–grade II-IV (54.2±1.8%) were higher than for those with mild IMR–grade I (30.4±2.9%) (P<0.05), the total mortality for patients with EROA ≥20 mm²(54±1.9%) were higher than for those with EROA <20 mm²(27.2±2.7%) (P<0.05), and the total mortality for patients with RVol ≥30 mL (56.8±1.7%) were higher than for those with RVol<30ml (29.4±2.9%) (P<0.05). After assessment of IMR and during follow up period 64 patients (46%) underwent CABG alone or combined CABG with mitral valve repair or replacement. In this study, the procedure of concomitant down-sized ring annuloplasty at the time if CABG surgery has a failure rate around 24% in terms of high late recurrence rate of IMR during the follow period especially after 18–42 months.

Conclusion:

The presence of ischaemic MR is associated with increased morbidity and mortality. Chronic IMR, an independent predictor of mortality with a reported survival of 40–60% at 5 years. Ischaemic mitral regurgitation has important prognosis implications in patients with coronary heart disease. Recognizing the mechanism of valve incompetence is an essential point for the surgical planning and for a good result of the mitral repair. It is important that echocardiographers understand the complex nature of the condition. Despite remarkable progress in reparative surgery, further investigation is still necessary to find the best approach to treat ischaemic mitral regurgitation.

Predictive factors of long-term results following valve repair in ischemic mitral valve prolapse

BACKGROUND

In patients with ischemic mitral regurgitation, leaflet prolapse requires an accurate evaluation since surgical approach depends on valvular and subvalvular characteristics. This study aims to describe a cohort of patients over a long-term follow up, analyzing survival, reoperation and predictive factors of surgical outcomes.

METHODS AND RESULTS

From March 1994 to June 2011, 75 patients with ischemic mitral regurgitation and leaflet prolapse underwent surgical myocardial revascularization and mitral valve repair (90.7%) or replacement (9.3%). Our cohort was followed up until April 2015, with a mean follow up of 7 ± 3 years. Cardiac-related deaths occurred in 26 patients, with a mean survival of 114.2 months, including eight patients with in-hospital mortality. Reoperation was performed in 14 patients, due to valve repair failure. Twenty-six patients experienced moderate-to-severe mitral regurgitation. A preoperative LVEDD > 62 mm, LVESD > 52 mm, previous anteroseptal myocardial infarction, diffuse coronary artery disease, papillary anatomy type 1, partial rupture of the papillary muscle, A1-A2 scallop prolapse and postoperative mitral valve configuration (tenting area, tenting height, alfa-1 angle and alfa-2 angle) were identified as independent predictors of poor outcome. An index quantifying the stress on the annulus imparted by annuloplasty was elaborated and predicted endpoints.

CONCLUSION

Leaflet prolapse is an important entity in patients with ischemic mitral regurgitation, and its pathogenic mechanism mostly relies on papillary muscle lesion or elongation. Perioperative parameters describing geometric features of left ventricle, valvular and subvalvular components should be considered to provide a tailored approach for mitral valve repair, or to opt for immediate replacement in case of unfavorable geometry.

Double row of overlapping sutures for downsizing annuloplasty decreases the risk of residual regurgitation in ischaemic mitral valve repair

OBJECTIVES

The aim of this study was to evaluate a novel insertion technique of the prosthetic ring that would further magnify the degree of annulus narrowing, thereby reducing the potential for a residual leak in ischaemic mitral valve repair.

METHODS

Thirty-six patients with ischaemic mitral regurgitation (MR) were randomly assigned into two groups. In 18 patients, the prosthetic ring was inserted in the conventional manner with a single row of sutures (control group). In the remaining 18 patients, the ring was attached using a double row of sutures tied both on the inner and on the outer part of the sewing cuff. Both groups had similar preoperative clinical and echocardiographic characteristics with severe leaflet tethering: mean tenting area >2.5 cm(2), mean anterior leaflet angle >25° and posterior leaflet angle >45°. The mean prosthetic ring sizes inserted in both groups were identical (mean: 27.3 mm).

RESULTS

At 12 months, there was no clinical event except for 1 rehospitalization in the control group. The mean mitral regurgitation grade was higher in the control group than in the group with the double row of sutures at 1.6 ± 0.9 vs 0.7 ± 0.3 (P = 0.0003). Annulus diameter reduction was less pronounced in the control group when compared with the group with the double row of sutures, both in the parasternal long-axis: 29.3 ± 3 vs 26.3 ± 3 mm (P = 0.0003) and in apical four-chamber views: 31 ± 3 vs 28 ± 2 mm (P = 0.003). Leaflet tethering indices were greater in the control group than in the group with the double row of sutures: tenting area: 1.42 ± 0.3 vs 1.1 ± 0.5 cm(2) (P = 0.002), anterior leaflet angle: 33 ± 3° vs 28 ± 5° (P = 0.0009) and posterior leaflet angle: 110 ± 13° vs 80 ± 11° (P = 0.0001). Left ventricular function parameters were not statistically different among the two groups.

CONCLUSION

A double row of overlapping sutures for attaching the prosthetic ring in downsizing annuloplasty is more efficient in narrowing the mitral annulus than the conventional technique in ischaemic mitral repair. Even in high-risk patients whose leaflets were severely tethered on echocardiography, it almost eliminated the risk of MR recurrence in this study.

A novel coaptation plate device for functional mitral regurgitation: an in vitro study

A novel mitral valve repair device, coaptation plate (CP), was proposed to treat functional mitral regurgitation. The objective of this study was to test efficacy of the CP in an in vitro model of functional mitral regurgitation. Ten fresh porcine mitral valves were mounted in a left heart simulator, Mitral regurgitation was emulated by means of annular dilatation, and the asymmetrical or symmetrical papillary muscles (PM) displacement. A rigid and an elastic CPs were fabricated and mounted in the orifice of regurgitant mitral valves. Steady flow leakage in a hydrostatic condition and regurgitant volume in a pulsatile flow were measured before and after implantation of the CPs. The rigid and elastic CPs reduced mitral valve regurgitant volume fraction from 60.5 ± 11.4 to 35 ± 11.6 and 36.5 ± 9.9%, respectively, in the asymmetric PM displacement. Mitral regurgitation was much lower in the symmetric PM displacement than in the asymmetric PM displacement, and was not significantly reduced after implantation of either CP. In conclusion, both the rigid and elastic CPs are effective and have no difference in reduction of functional mitral regurgitation. The CP does not aggravate mitral valve coaptation and may be used as a preventive way.

Novel Echocardiographic Indices as Predictors of Immediate Recurrence after Undersized Ring Annuloplasty for Ischemic Mitral Regurgitation

BACKGROUND AND AIM

Ischemic mitral regurgitation (IMR) is among the most serious complications of myocardial infarction which doubles the late mortality; mainly treated by undersizing ring annuloplasty. To find some preoperative echocardiographic indices that predict immediate failure of mitral valve annuloplasty (MVA), we designed the present study with more focusing on some novel parameters.

METHOD

Transthoracic echocardiography (TTE) indices of consecutive patients referred with 3+ or 4+ IMR were registered 24 hours before surgery. Thirty days later, a second TTE was performed. According to the results, the patients were categorized as the "successful" group (with 1+ or less mitral regurgitation) and the "unsuccessful" group (with 2+ or higher MR). Preoperative TTE indices were compared among the two groups using suitable statistical tests.

RESULTS

Of the total of 126 cases, 68 had successful and 58 had unsuccessful MVA. Statistically significant differences were found between the two groups for left ventricular ejection fraction (LVEF) (P = 0.007), left ventricular end systolic volume (LVESV) (P = 0.044), and basal-interpapillary muscle distance (IPMD) diastolic-to-systolic ratio (DSR) (P = 0.008). Receiver Operating Characteristic analysis demonstrated 37.5%, 3.85 cm(3) , and 1.25, as the best cutoff points for LVEF (P = 0.03, sensitivity: 81%, specificity: 69%), LVESV (P = 0.023, sensitivity: 83%, specificity: 57%), and basal-IPMD DSR (P = 0.001, sensitivity: 100%, specificity: 95%), respectively.

CONCLUSION

Among all TTE indices, LVEF, LVESV, and basal-IPMD DSR were helpful to differentiate between the successful and unsuccessful MVA results. We believe the basal-IPMD DSR as a novel index could be targeted in the future studies.

Benefits of submitral procedures for ischemic mitral regurgitation

The surgical strategy for ischemic mitral regurgitation (MR) remains controversial. Ischemic MR is a secondary valve disease caused by left ventricular (LV) remodeling and subsequent papillary muscle displacement, usually without structural valve lesions. Reduction annuloplasty is the standard surgical procedure for this condition, though it cannot clearly provide a survival benefit for those with LV dysfunction and is associated with a high prevalence of late recurrence of MR. The valvular procedure alone could be insufficient to treat ischemic MR in terms of long-term survival and the prevention of recurrence because ischemic MR is primarily a ventricular disorder. Thus, recent studies have focused on alternative procedures that target the primary cause of ischemic MR, the papillary muscles and left ventricle. We believe that the appropriate selection of surgical procedures among valvular, subvalvular, and even ventricular ones, considering the severity of LV remodeling for each patient would be more beneficial. Here we review recent studies featuring various surgical approaches to ischemic MR, especially with submitral procedures.

Can isolated annular dilatation cause significant ischemic mitral regurgitation? Another look at the causative mechanisms

This study was to investigate the mechanisms of ischemic mitral regurgitation (IMR) by using a finite element (FE) approach. IMR is a common complication of coronary artery disease; and it usually occurs due to myocardial infarction. The pathophysiological mechanisms of IMR have not been fully understood, much debate remains about the exact contribution of each mechanism to IMR. Two patient-specific FE models of normal mitral valves (MV) were reconstructed from multi-slice computed tomography scans. Different grades of IMR during its pathogenesis were created by perturbation of the normal MV geometry. Effects of annular dilatation and papillary muscle (PM) displacement (both isolated and combined) on the severity of IMR were examined. We observed greater increase in IMR (in terms of regurgitant area and coaptation length) in response to isolated annular dilatation than that caused by isolated PM displacement, while a larger PM displacement resulted in higher PM forces. Annular dilation, combined with PM displacement, was able to significantly increase the severity of IMR and PM forces. Our simulations demonstrated that isolated annular dilatation might be a more important determinant of IMR than isolated PM displacement, which could help explain the clinical observation that annular size reduction by restrictive annuloplasty is generally effective in treating IMR.

Quantitative assessment of mitral valve coaptation using three-dimensional transesophageal echocardiography

BACKGROUND

Functional mitral regurgitation (FMR) occurs as a consequence of left ventricular remodeling and is an independent predictor of adverse outcome. FMR is assessed qualitatively with two-dimensional echocardiography, but accurate quantitation of the actual degree of mitral valve (MV) coaptation is not possible with this method. We evaluated a novel three-dimensional (3D) approach to quantify the MV coaptation zone in patients with FMR. We hypothesized that measuring the 3D MV coaptation zone is feasible and would correlate with FMR severity when indexed to MV area.

METHODS

Data were gathered on 25 patients with FMR undergoing cardiac operations, and included a comprehensive two-dimensional and 3D examination with intraoperative transesophageal echocardiography. Using available 3D MV quantification software, offline analysis of end-systolic MV coaptation zone and MV area was performed. A novel MV coaptation index was calculated by the following formula: [3D end-systolic MV coaptation zone/3D MV area]. FMR severity was described as trace, mild, moderate, and severe using the integrative approach recommended by official guidelines.

RESULTS

Analysis of variance demonstrated that the coaptation index was associated with the severity of FMR (F = 20.5, r(2) = 0.75, p < 0.0001). There was also a correlation between 2D vena contracta and the coaptation index (r = -0.74, p < 0.0003).

CONCLUSIONS

We describe a novel 3D approach to direct assessment of the MV coaptation zone. When indexed to the MV area, the 3D MV coaptation zone is closely associated with FMR severity. Assessment of the mitral coaptation may be a potentially powerful tool in the perioperative evaluation of the competency of the MV.

Fully automatic segmentation of the mitral leaflets in 3D transesophageal echocardiographic images using multi-atlas joint label fusion and deformable medial modeling

Comprehensive visual and quantitative analysis of in vivo human mitral valve morphology is central to the diagnosis and surgical treatment of mitral valve disease. Real-time 3D transesophageal echocardiography (3D TEE) is a practical, highly informative imaging modality for examining the mitral valve in a clinical setting. To facilitate visual and quantitative 3D TEE image analysis, we describe a fully automated method for segmenting the mitral leaflets in 3D TEE image data. The algorithm integrates complementary probabilistic segmentation and shape modeling techniques (multi-atlas joint label fusion and deformable modeling with continuous medial representation) to automatically generate 3D geometric models of the mitral leaflets from 3D TEE image data. These models are unique in that they establish a shape-based coordinate system on the valves of different subjects and represent the leaflets volumetrically, as structures with locally varying thickness. In this work, expert image analysis is the gold standard for evaluating automatic segmentation. Without any user interaction, we demonstrate that the automatic segmentation method accurately captures patient-specific leaflet geometry at both systole and diastole in 3D TEE data acquired from a mixed population of subjects with normal valve morphology and mitral valve disease.

Ischemic mitral regurgitation: not only a bystander

Ischemic mitral regurgitation (MR) is a common complication of left ventricular (LV) dysfunction related to chronic coronary artery disease. This complex multifactorial disease involves global and regional LV remodeling, as well as dysfunction and distortion of the components of the mitral valve including the chordae, the annulus, and the leaflets. Its occurrence is associated with a poor prognosis. The suboptimal results obtained with the most commonly used surgical strategy, involving mitral valve annuloplasty with coronary bypass grafting, emphasize the need to develop alternative surgical techniques targeting the causal mechanisms of the disease. A comprehensive preoperative assessment of mitral valve configuration and LV geometry and function and an accurate quantification of MR severity at rest and during exercise may contribute to improve risk stratification and to tailor the surgical strategy according to the individual characteristics of the patient.

Antegrade percutaneous valve implantation for mitral ring dysfunction, a challenging case

The operative risk for reoperation of degenerated bioprosthetic valves or failing mitral-valve annuloplasty is higher compared with the risks for first isolated native valve repair or replacement (Astor et al., Eur Heart J 2008;29:2382-2387). In the presence of comorbidities, these risks increase exponentially. The recent introduction of transcatheter valve implantation opened new perspectives for the treatment of patients at very high surgical risk. We report a percutaneous mitral valve (MV) implantation using a transatrial approach within a MV ring using the Edwars Sapien XT valve.

Mitral replacement or repair for functional mitral regurgitation in dilated and ischemic cardiomyopathy: is it really the same?

BACKGROUND

This was a study to compare the results of mitral valve (MV) repair and MV replacement for the treatment of functional mitral regurgitation (MR) in advanced dilated and ischemic cardiomyopathy (DCM).

METHODS

One-hundred and thirty-two patients with severe functional MR and systolic dysfunction (mean ejection fraction 0.32 ± 0.078) underwent mitral surgery in the same time frame. The decision to replace rather than repair the MV was taken when 1 or more echocardiographic predictors of repair failure were identified at the preoperative echocardiogram. Eighty-five patients (64.4%) received MV repair and 47 patients (35.6%) received MV replacement. Preoperative characteristics were comparable between the 2 groups. Only ejection fraction was significantly lower in the MV repair group (0.308 ± 0.077 vs 0.336 ± 0.076, p = 0.04).

RESULTS

Hospital mortality was 2.3% for MV repair and 12.5% for MV replacement (p = 0.03). Actuarial survival at 2.5 years was 92 ± 3.2% for MV repair and 73 ± 7.9% for MV replacement (p = 0.02). At a mean follow-up of 2.3 years (median, 1.6 years), in the MV repair group LVEF significantly increased (from 0.308 ± 0.077 to 0.382 ± 0.095, p < 0.0001) and LV dimensions significantly decreased (p = 0.0001). On the other hand, in the MV replacement group LVEF did not significantly change (from 0.336 ± 0.076 to 0.31 ± 0.11, p = 0.56) and the reduction of LV dimensions was not significant. Mitral valve replacement was identified as the only predictor of hospital (odds ratio, 6; 95% confidence interval, 1.1 to 31; p = 0.03) and overall mortality (hazard ratio, 3.1; 95% confidence interval, 1.1 to 8.9; p = 0.02).

CONCLUSIONS

In patients with advanced dilated and ischemic cardiomyopathy and severe functional MR, MV replacement is associated with higher in-hospital and late mortality compared with MV repair. Therefore, mitral repair should be preferred whenever possible in this clinical setting.

Can three-dimensional echocardiography accurately predict complexity of mitral valve repair?

OBJECTIVE

Feasibility of mitral repair is a key factor in the decision to operate for mitral regurgitation. Repair feasibility is highly dependent on surgical experience and repair complexity. We sought an objective means of predicting complexity of repair using three-dimensional (3D) transoesophageal echocardiography.

METHODS

In a cohort of 786 patients who underwent mitral valve surgery between 2007 and 2010, 3D transoesophageal echocardiography was performed in 66 patients with mitral regurgitation prior to the institution of cardiopulmonary bypass. The surgeon reviewed the 2D echocardiographic images for all patients pre-operatively, but did not view the 3D echocardiographic quantitative data or volumetric analysis until after surgery. Repairs involving no or a single-segment leaflet resection, sliding-plasty, cleft closure, chordal or commissural repair techniques were classed as standard repairs. Complex repairs were defined as those involving bileaflet repair techniques, requiring multiple resections or patch augmentation. Disease aetiology included Barlow's disease (n = 18), fibroelastic deficiency (n = 22), ischaemic (n = 5), endocarditis (n = 5), rheumatic (n = 2) and dilated cardiomyopathy (n = 2).

RESULTS

No patient required mitral replacement or had more than mild mitral regurgitation on pre-discharge echocardiography. Anterior and posterior leaflet areas, annular circumference, anterior and posterior leaflet angles, prolapse and tenting heights and volumes were most strongly predictive of repair complexity. As 21 of the 22 patients with bileaflet pathology and multisegment prolapse were complex repairs, we sought to develop a model predicting repair complexity in the remaining patients. The most predictive model with a c-statistic of 0.91 included three predictors: multisegment pathology, prolapsing height and posterior leaflet angle. After bootstrap validation, the revised c-statistic was 0.88.

CONCLUSIONS

3D transoesophageal echocardiography provides an objective means of predicting mitral repair complexity in mitral regurgitation due to a range of aetiology.

Predictors of failure following restrictive annuloplasty for chronic ischemic mitral regurgitation

AIM OF THE STUDY

We sought to determine the results of restrictive annuloplasty for chronic ischemic mitral regurgitation.

METHODS

Hospital outcome and serial clinical and echocardiographic (preoperative, discharge, 3 months, 12 months, 24 months) follow-up assessments were analyzed in 87 consecutive patients with chronic ischemic mitral regurgitation having coronary artery bypass grafting. Persistent/recurrent mitral regurgitation was defined by grade ≥2 at discharge/during follow-up.

RESULTS

Hospital mortality was 5.7% and persistence of regurgitation was present in 8.4%. Mean follow-up was 24.4 ± 1.7 months and recurrent mitral regurgitation was observed in 32.4% patients. In multivariate analysis only anterior leaflet angle remained an independent predictive factor for regurgitation recurrence with cutoff 27° (sensitivity of 67% and specificity of 76%, p = 0.04).

CONCLUSION

There is high occurrence of early and delayed restrictive annuloplasty failure, particularly in patients with increased anterior leaflet tethering.

Outcomes of coronary artery bypass grafting and reduction annuloplasty for functional ischemic mitral regurgitation: a prospective multicenter study (Randomized Evaluation of a Surgical Treatment for Off-Pump Repair of the Mitral Valve)

OBJECTIVE

Functional ischemic mitral regurgitation is a complication of ventricular remodeling; standard therapy is reduction annuloplasty and coronary artery bypass grafting. Unfortunately, outcomes are retrospective and contradictory. We report a multicenter study that documents the outcomes of reduction annuloplasty for functional ischemic mitral regurgitation.

METHODS

Twenty-one centers randomized 75 patients to the coronary artery bypass grafting + reduction annuloplasty subgroup that was the control arm of the Randomized Evaluation of a Surgical Treatment for Off-pump Repair of the Mitral Valve trial. Entry criteria included patients requiring revascularization, patients with severe or symptomatic moderate functional ischemic mitral regurgitation, an ejection fraction 25% or greater, a left ventricular end-diastolic dimension 7.0 cm or less, and more than 30 days since acute myocardial infarction. All echocardiograms were independently scored by a core laboratory. Reduction annuloplasty was achieved by device annuloplasty. Two patients underwent immediate intraoperative conversion to a valve replacement because reduction annuloplasty was unable to correct mitral regurgitation; as-treated results are presented.

RESULTS

Thirty-day mortality was 4.1% (3/73). Patients received an average of 2.8 bypass grafts. Mean follow-up was 24.6 months. Mitral regurgitation was reduced from 2.6 ± 0.8 preoperatively to 0.3 ± 0.6 at 2 years. Freedom from death or valve reoperation was 78% ± 5% at 2 years. There was significant improvement in ejection fraction and New York Heart Association class with reduction of left ventricular end-diastolic dimension. Cox regression analyses suggested that increasing age (P = .001; hazard ratio, 1.16 per year; 95% confidence interval, 1.06-1.26) and renal disease (P = .018; hazard ratio, 3.48; 95% confidence interval, 1.25-9.72) were associated with decreased survival.

CONCLUSIONS

Coronary artery bypass grafting + reduction annuloplasty for functional ischemic mitral regurgitation predictably reduces mitral regurgitation and relieves symptoms. This treatment of moderate to severe mitral regurgitation is associated with improved indices of ventricular function, improved New York Heart Association class, and excellent freedom from recurrent mitral insufficiency. Although long-term prognosis remains guarded, this multicenter study delineates the intermediate-term benefits of such an approach.

Echocardiographically based treatment of chronic ischemic mitral regurgitation

OBJECTIVES

We evaluated results of an echocardiographically based strategy combining mitral annuloplasty with other procedures to treat chronic ischemic mitral regurgitation.

METHODS

From March 2006 to February 2009, 147 patients underwent mitral valve surgery for chronic ischemic mitral regurgitation. Mean effective regurgitant orifice was 36 ± 11 mm(2), and ejection fraction was 35% ± 9%. On the basis of echocardiographic findings, in 10 cases a prosthesis was inserted and mitral annuloplasty was performed in 137 cases, isolated in 83, associated with chordal cutting in 12 cases (in 5 anterior leaflet was augmented with pericardial patch), and with exclusion of anteroseptal (n = 35) or inferior (n = 7) scars in 42.

RESULTS

Thirty-day mortality was 4.8%; 3-year survival was 86% ± 3%. None of the 126 survivors were in New York Heart Association functional class III or IV. Among 117 survivors of mitral valve repair, after 18 ± 6 months mean effective regurgitant orifice reduced from 34.1 ± 10.2 mm(2) to 2.3 ± 0.4 mm(2) (P < .001). Nine patients showed residual effective regurgitant orifice 10 to 19 mm(2). Reverse remodeling was present in 69 patients (59.0%), no remodeling in 40 (34.1%), and continuous remodeling in 8 (6.9%). Ejection fraction changed from 37% ± 10% to 43% ± 10% (P < .001), improving in 47, remaining unchanged in 63, and worsening in 7.

CONCLUSIONS

Echocardiographically based strategy contributed to reduced postoperative mitral regurgitation persistence (effective regurgitant orifice ≥ 10 mm(2) in 7.7% of cases, with no patients showing effective regurgitant orifice ≥ 20 mm(2)). All patients remained in New York Heart Association functional class I or II, but more than mitral annuloplasty was performed in close to 40%.

Predictors of mitral regurgitation recurrence in patients with heart failure undergoing mitral valve annuloplasty

Restrictive mitral annuloplasty is a surgical treatment option for patients with heart failure (HF) and functional mitral regurgitation (MR). However, recurrent MR has been reported at mid-term follow-up. The aim of the present study was to identify the echocardiographic predictors of recurrent MR in patients with HF undergoing mitral annuloplasty. During a mean follow-up of 2.6 +/- 1.6 years, 109 patients with HF (49% ischemic and 51% idiopathic dilated cardiomyopathy) who had undergone mitral valve repair were followed up (of 122 total patients). The severity of MR was quantified, and the following parameters were measured before intervention and at the mid-term follow-up examination: left ventricular (LV) and left atrial volumes and dimensions, LV sphericity index, mitral annular area, and mitral valve geometry parameters. At mid-term follow-up, 21 patients presented with significant MR (grade 2 to 4), and 88 patients had only MR grade 0 to 1. Both groups of patients had had a similar preoperative MR grade, mitral annular area, and LV volume and dimension. In contrast, patients with recurrent MR had had increased preoperative posterior and anterior leaflet angles, tenting height, tenting area, and LV sphericity index compared to the patients without recurrent MR. Of the different parameters of mitral and LV geometry, the distal mitral anterior leaflet angle (hazard ratio 1.48, 95% confidence interval 1.32 to 1.66, p <0.001) and posterior leaflet angle (hazard ratio 1.13, 95% confidence interval 1.07 to 1.19, p <0.001) were independent determinants of MR at mid-term follow-up. In conclusion, in patients with HF of ischemic or idiopathic etiology and functional MR, distal mitral leaflet tethering and posterior mitral leaflet tethering were associated with recurrent MR after restrictive mitral annuloplasty.

Persistent and recurrent ischemic mitral regurgitation

BACKGROUND

Ischemic mitral regurgitation (IMR) is a consequence of coronary artery disease and the main underlying mechanism is augmented leaflet tethering due to outward displacement of the papillary muscles. Although mitral annuloplasty combined with coronary revascularization is usually effective in the treatment of IMR, occasionally the regurgitation can persist or recur and this can affect patient prognosis.

METHODS

We searched Medline and Google scholar database for articles published since 1996 to June 2009. Search terms included ischemic mitral regurgitation, recurrent mitral regurgitation, persistent mitral regurgitation and annuloplasty failure.

CONCLUSION

This article reviews current knowledge about IMR, the reasons and mechanisms of persistent and recurrent mitral regurgitation. We review clinic and echocardiographic predictive factors associated with persistence a recurrence of mitral regurgitation after annuloplasty.

Mitral repair versus replacement for ischemic mitral regurgitation: comparison of short-term and long-term survival

BACKGROUND

When compared to mitral valve replacement (MVR), mitral valve repair (MVRp) is associated with better survival in patients with organic mitral regurgitation (MR). However, there is an important controversy about the type of surgical treatment that should be used in patients with ischemic MR. The objective of this study was to compare the postoperative outcome of MVRp versus MVR in patients with ischemic MR.

METHODS AND RESULTS

Preoperative and operative data of 370 patients with ischemic MR who underwent mitral valve surgery were prospectively collected and retrospectively analyzed. MVRp was performed in 50% of patients (n=186) and MVR in 50% (n=184). Although operative mortality was significantly lower after MVRp compared to MVR (9.7% versus 17.4%; P=0.03), overall 6-year survival was not statistically different between procedures (73+/-4% versus 67+/-4%; P=0.17). After adjusting for other risk factors and propensity score, the type of procedure (MVRp versus MVR) did not come out as an independent predictor of either operative (OR, 1.5; 95% CI, 0.7-2.9; P=0.34) or overall mortality (HR, 1.2; 95% CI, 0.7-1.9; P=0.52).

CONCLUSIONS

As opposed to what has been reported in patients with organic MR, the results of this study suggest that MVRp is not superior to MVR with regard to operative and overall mortality in patients with ischemic MR. These findings provide support for the realization of a randomized trial comparing these 2 treatment modalities.

Surgical therapy for mitral regurgitation: the key to preventing heart failure?

Five million Americans suffer from heart failure (HF). Despite innovative new pharmacologic and device therapies, the 5-year mortality rate for patients remains near 50%. Conservatively, 300,000 patients with HF also have severe functional mitral regurgitation. Over the past decade, the surgical approach to these patients has become more aggressive because the extent of the problem has become widely recognized, and surgeon familiarity with annuloplasty techniques has increased. Although clinical experience and enthusiasm have resulted in an expansion of literature, the role that mitral valve repair surgery plays in the treatment of HF is not fully established. In this article, we review the existing data on the efficacy of mitral valve surgery in HF patients. Specifically, we will review the available data regarding the effect of mitral valve surgery on longevity, ventricular remodeling, and symptoms. No randomized prospective data are available, but careful analysis of existing retrospective studies allows important conclusions to be made.

Intraoperative TEE Assessment During Mitral Valve Repair for Degenerative and Ischemic Mitral Valve Regurgitation

Intraoperative assessment of the mitral valve (MV) in patients undergoing repair for MV regurgitation is a valuable support for the cardiac surgical team; results can be favored by adequate assessment tailored to the main condition affecting the MV. This article will review current available data for assessment of the MV in degenerative and ischemic mitral regurgitation.

Initial results of the chordal-cutting operation for ischemic mitral regurgitation

OBJECTIVE

Division of secondary chords (chordal cutting) has been proposed as a method for decreasing mitral valve leaflet tethering and mitral regurgitation in patients with ischemic mitral regurgitation. However, very little clinical data exist to date for this procedure.

METHODS

We compared echocardiographic and clinical data in patients who underwent chordal-cutting mitral valve repair (n = 43) and those undergoing conventional mitral valve repair (control, n = 49) for ischemic mitral regurgitation.

RESULTS

Patients who underwent chordal cutting had a higher prevalence of recent myocardial infarction, left main disease, diabetes, and peripheral vascular disease (all P < .05). Left ventricular ejection fraction was lower in the chordal-cutting group (33 +/- 2% vs 44 +/- 2%) (mean +/- SE) and preoperative tent height was greater (11.7 +/- 0.5 vs 9.7 +/- 0.6 mm; both P < .01). In-hospital mortality was 10% in control patients and 9% in the chordal-cutting group (P = .9). Other complication rates were similar for the two groups. The reduction in tent height before-to-after repair was similar in the two groups of patients, but those undergoing chordal cutting had a greater reductions in tent area (53 +/- 3% vs 41 +/- 3%; P = .01). The chordal-cutting group also had greater mobility of the anterior leaflet, as measured by a reduction in the distance between the free edge of the anterior mitral valve leaflet and the posterior left ventricular wall (24 +/- 3% vs 11 +/- 4%; P = .01). Control patients had more recurrent mitral regurgitation during 2 years of follow-up by univariate (37% vs 15%; P = .03) and multivariate analysis (P = .03). Chordal cutting did not adversely affect postoperative left ventricular ejection fraction (10% +/- 5% relative increase in left ventricular ejection fraction vs 11% +/- 6% in the control group; P = .9).

CONCLUSION

Chordal cutting improves mitral valve leaflet mobility and reduces mitral regurgitation recurrence in patients with ischemic mitral regurgitation, without any obvious deleterious effects on left ventricular function.

Effect of Aortic Valve Replacement for Aortic Stenosis on Severity of Mitral Regurgitation

BACKGROUND

Surgically addressing moderate mitral regurgitation (MR) at the time of aortic valve replacement (AVR) for aortic stenosis remains uncertain. The purpose of this study was to examine the change in moderate (2+) or moderate-severe (3+) MR after isolated AVR for aortic stenosis to determine preoperative factors predictive of improvement in MR.

METHODS

Using an institutional databank of prospectively collected data, all patients undergoing isolated AVR for aortic stenosis with moderate (2+) to moderate-severe (3+) MR between 1994 and 1996 at the Montreal Heart Institute were evaluated.

RESULTS

Eighty patients with preoperative and postoperative transthoracic echocardiographic follow-up were identified. Preoperative MR was moderate (2+) in 78 patients (97.5%) and moderate-severe (3+) in 2 patients (2.5%). Mitral regurgitation was classified as rheumatic (32%), ischemic (32%), functional (21%), and myxomatous (15%). At 1-year follow-up transthoracic echocardiography, MR improved by 1 or 2 grades in 29 patients (35%), was unchanged in 44 (55%), and worsened in 7 (10%). On multivariate analysis, isolated ischemic and functional MR were the only preoperative factors predictive of MR improvement after AVR (p = 0.01): 54% of ischemic and 44% of functional MR patients showed improvement in MR after AVR compared with 23% of rheumatic and 17% of myxomatous MR patients.

CONCLUSIONS

Etiology of MR was a significant prognostic factor for improvement in MR grade. Since there was little improvement in the rheumatoid and myxomatous group, replacement or repair should strongly be considered. For functional and ischemic mitral regurgitation, a surgical correction should be performed on an individual basis.

Preoperative Posterior Leaflet Angle Accurately Predicts Outcome After Restrictive Mitral Valve Annuloplasty for Ischemic Mitral Regurgitation

Background— Ischemic mitral regurgitation (MR) often persists after restrictive mitral valve annuloplasty, in which case it is associated with worse clinical outcomes. The goal of the present study was to determine whether persistence of MR and/or clinical outcome could be predicted from preoperative analysis of mitral valve configuration.

Methods and Results— In 51 consecutive patients undergoing restrictive annuloplasty for ischemic MR, posterior leaflet (PL) angle, anterior leaflet angle, coaptation distance, and tenting area were quantified by echocardiography before surgery (6±3 days), and MR severity was assessed before and early after surgery (9±4 days). Postoperatively, persistence of mild to moderate MR (vena contracta >3 mm) was observed in 11 (22%) of the patients. The best predictor of postoperative persistence of MR was a PL angle ≥45 degrees (sensitivity 100%, specificity 97%, positive predictive value 92%, negative predictive value 100%). Patients with persistent MR had markedly lower 3-year event-free survival (26±20%) compared with those with nonpersistent MR (75±12%, P =0.01). Preoperative presence of a PL angle ≥45 degrees also was associated with a markedly lower 3-year event-free survival (22±17% versus 76±12%; P <0.001).

Conclusions— In patients undergoing restrictive annuloplasty for ischemic MR, persistence of MR and 3-year event-free survival can accurately be predicted by preoperative analysis of mitral valve configuration. Patients with a PL angle ≥45 degrees (ie, with high PL restriction) should thus be considered poor candidates for this procedure, and concomitant or alternative procedures should be contemplated.

Percutaneous mitral valve annuloplasty for ischemic mitral regurgitation: First in man experience with a temporary implant

OBJECTIVE

This study evaluated human feasibility and acute efficacy of a novel percutaneous transvenous mitral annuloplasty (PTMA) device (Viacor) placed temporarily in the coronary sinus (CS): the implant allows in-situ incremental adjustment to optimally reduce the anterior-posterior mitral annulus (MA) dimension, and improve leaflet co-aptation and reducing mitral regurgitation (MR).

BACKGROUND

Surgical annuloplasty remains the standard treatment of severe ischemic MR but its application is limited by high morbidity and mortality. The effectiveness of PTMA device (Viacor) to reduce MR in the short-term has been demonstrated in animals studies but not in humans.

METHODS

Symptomatic patients with ischemic MR graded 2+ to 4+ requiring surgical mitral annuloplasty were screened. Patients with any mitral leaflet or mitral apparatus abnormality were excluded. Preoperatively, under general anesthesia and transesophageal echocardiography guidance, a temporary PTMA device was placed via the right internal jugular or subclavian vein.

RESULTS

Four patients were studied. After device placement and adjustment, regurgitant volume was substantially reduced (45.5 +/- 24.4 to 13.3 +/- 7.3 ml) via MA anterior-posterior diameter reduction (40.75 +/- 4.3 to 35.2 +/- 1.6 mm) in 3 patients. In one patient, the PTMA device could not be deployed due to extreme angulated anatomy.

CONCLUSIONS

PTMA in human is feasible and reduces ischemic MR (to grade 1+) by reducing MA anterior-posterior diameter. Temporary placement of the PTMA device may assist in the development of permanent implants and ensure optimal efficacy.

Mitral Valve Surgery for Heart Failure: A Failed Innovation?

Five million Americans suffer from heart failure. Despite innovative new pharmacologic and device therapy, the 5-year mortality rate for these patients remains near 50%. Conservatively, 300,000 patients with heart failure also have severe functional mitral regurgitation. Over the past decade the surgical approach to these patients has become more aggressive as the extent of the problem has become widely recognized and surgeon familiarity with annuloplasty techniques has increased. There are, however, few data to support that such interventions improve longevity, reduce heart size, or limit symptoms. In fact the best available data support the conclusion that surgery for functional mitral regurgitation has no effect on survival. We present a review of the existing data on the efficacy of mitral valve surgery in heart failure patients. These data are sobering but confirm the need for evidence-based decision-making in cardiac surgery no matter how intuitively beneficial a procedure may initially seem.