Significant Reduction In Mitral Regurgitation Research Articles

First Experience With Percutaneous Mitral Valve Plication as Primary Therapy for Symptomatic Obstructive Hypertrophic Cardiomyopathy

BackgroundFew therapeutic options exist for patients with severe heart failure due to obstructive hypertrophic cardiomyopathy (HCM) who are at unacceptable surgical risk. We hypothesized that percutaneous plication of the mitral valve could reduce left ventricular outflow tract (LVOT) obstruction and associated mitral regurgitation, thereby leading to amelioration of heart failure symptoms. ObjectivesThis study sought to evaluate the potential effectiveness of percutaneous mitral valve plication as a therapy for patients with symptomatic, obstructive HCM. MethodsSix patients (age 83 ± 8 years; 5 women), judged as not optimal candidates for septal myectomy, were referred for management of severe, drug-refractory heart failure symptoms due to obstructive HCM (New York Heart Association functional class III). Each underwent percutaneous mitral valve leaflet plication to reduce systolic anterior motion (SAM) and mitral regurgitation using the transcatheter mitral clip system. ResultsThe procedure was completed in 5 patients with placement of a single clip at the A2-P2 segments of the mitral valve. One other patient experienced cardiac tamponade, leading to termination of the procedure. Among the 5 treated patients, percutaneous plication with the eliminated SAM and consequently decreased the intraoperative LVOT gradient (91 ± 44 mm Hg to 12 ± 6 mm Hg; p = 0.007), left atrial pressure (29 ± 11 mm Hg to 20 ± 8 mm Hg; p = 0.06), and mitral regurgitation grade (3.0 ± 0 vs. 0.8 ± 0.4; p = 0.0002) associated with improved cardiac output (in n = 4; 3.0 ± 0.6 l/min to 4.3 ± 1.2 l/min; p = 0.03). Over follow-up of 15 ± 4 months, symptom improvement to New York Heart Association functional class I or II occurred in all patients. Follow-up echocardiography after 15 ± 4 months demonstrated continued absence of SAM and significant reduction in mitral regurgitation, although high systolic LVOT velocities (i.e., >4 m/s) were evident in 3 of the 5 treated patients. ConclusionsThis is a report of percutaneous mitral valve plication as a primary therapy in the management of severely symptomatic, obstructive HCM patients. This initial experience suggests that percutaneous mitral valve plication may be effective for symptom relief in such patients via reduction of SAM and mitral regurgitation. The significance of persistent elevations of LVOT velocities in some patients requires further study.

Critical evaluation of the MitraClip system in the management of mitral regurgitation.

The MitraClip (MC) system is a device for percutaneous, transseptal edge-to-edge reconstruction of the mitral valve (MV) in patients with severe mitral regurgitation (MR) not eligible for surgery. Recently, a number of studies have underlined the therapeutic benefit of the MC system for patients with extreme and high risk for MV surgery suffering from either degenerative or functional MR. The MC procedure shows negligible intraprocedural mortality, low periprocedural complication rates, and a significant reduction in MR, as well as an improvement in functional capacity and most importantly quality of life. Presently, the MC system has become an additional interventional tool in the concert of surgical methods. It hereby enlarges the spectrum of MV repair for the Heart Team. Lately, many reviews focused on the MC system. The current review describes the developments in the treatment of MR with the MC system.

Abstract 16418: The Impact of MitraClip® Procedure on Left Atrial Strain and Strain Rate

Background: Left atrial (LA) remodeling due to mitral regurgitation (MR) is associated with abnormal LA strain parameters which may correlate with degree of fibrosis. Although reverse atrial remodeling has been shown after MitraClip placement, changes in LA strain and strain rate have not been evaluated in these patients or compared with mitral valve repair (MVr). Methods: We measured peak positive LA strain (ε) and strain rates [peak systolic (SRp), peak early diastolic (SRe) and peak late diastolic (SRa)] in 107 subjects (mean age 61±12 yrs) with degenerative MR enrolled in the randomized EVEREST II trial. Individuals with paced rhythm, atrial fibrillation, functional MR and poor image quality were excluded. LA strain measures were obtained from 4-chamber and 2-chamber views and averaged at baseline and at 1 year follow up. Results: At one year all 44 MVr subjects had ≤2+ MR, whereas 22 of the 63 MitraClip had >2+ MR. Baseline average ε, SRp, SRe and SRa values were similar in MitraClip and MVr groups (Table 1). At one year follow up there was a significant decrease in LA volumes in the surgical group and in those with MR ≤2+ after MitraClip. Overall average ε was significantly reduced after MVr. There was a small decrease or no change in average ε after MitraClip. SRe was significantly decreased 1 year after MVr and also in the MitraClip arm, regardless of whether there was significant MR reduction. There were no changes in SRp and SRa at 1 year in either group. Conclusion: Average peak positive LA strain either decreased modestly or did not change after treatment of MR in chronic degenerative MR subjects. There was a significant decrease in SRe in both treatment arms at 1 year. This occurred despite evidence of reverse LA remodeling. Further investigation and replication in additional cohorts is needed to explore these findings, which may suggest persistence of LA dysfunction after correction of chronic MR, or irreversible fibrosis. Disclosure: EVEREST II was funded by Abbott Vascular.

Exercise gas exchange analysis in obstructive hypertrophic cardiomyopathy before and after myectomy (cardiopulmonary exercise test combined with exercise-echocardiography in HCM)

Exercise gas exchange analysis in obstructive hypertrophic cardiomyopathy before and after myectomy (cardiopulmonary exercise test combined with exercise-echocardiography in HCM)

3D heart model printing for preparation of percutaneous structural interventions: description of the technology and case report

Structural heart disease, including valvular disease as well as congenital defects, causes important alterations in heart anatomy. As a result, individualised planning for both surgical and percutaneous procedures is crucial for procedural optimisation. Three dimensional (3D) rapid prototyping techniques are being utilised to aid operators in planning structural heart procedures. We intend to provide a description of 3D printing as a clinically applicable heart modelling technology for the planning of percutaneous structural heart procedures as well as to report our first clinical use of a 3D printed patient-specific heart model in preparation for a percutaneous mitral annuloplasty using the Mitralign percutaneous annuloplasty system. Retrospectively gated, contrast enhanced, multi-slice computed tomography (MSCT) scans were obtained. MSCT DICOM data was analysed using software that creates 3D surface files of the blood volume of specific regions of interest in the heart. The surface files are rendered using a software package that creates a solid model that can be printed using commercially available stereolithography machines. The technique of direct percutaneous mitral annuloplasty requires advancement of a guiding catheter through the aorta, into the left ventricle, and requires the positioning of the tip of the catheter between the papillary muscles in close proximity to the mitral annulus. The 3D heart model was used to create a procedural plan to optimise potential device implantation. The size of the deflectable guiding catheter was selected on the basis of the patient's heart model. Target locations for annulus crossing wires were evaluated pre-procedurally using the individual patient's 3D heart model. In addition, the ability to position the Bident Catheter at the appropriate locations under the mitral annulus as well as the manoeuvrability between the papillary muscles were analysed on the heart model, enabling safe completion of the procedure, which resulted in a significant reduction in mitral regurgitation. 3D printing is a helpful tool in individualised planning for percutaneous structural interventions. Future studies are warranted to assess its role in preparing for percutaneous and surgical heart procedures.

Development of mitral stenosis after single mitraclip insertion for severe mitral regurgitation

We report the first case of mitral stenosis following Mitra-Clip insertion in a patient with symptomatic NYHA IV heart failure, secondary to severe mitral regurgitation (MR). A 79-year-old female with a history of prior aortic valve replacement underwent percutaneous mitral valve (MV) repair. A single clip was advanced coaxially down onto the MV under TOE guidance, with the anterior and posterior leaflets clipped together between A2 and P2. TOE confirmed a significant reduction in MR (grade 4 to grade 1). Despite initial symptomatic relief, she represented 3 months later with similar symptoms. Repeat TOE confirmed a well positioned Mitra-Clip with mild residual MR. However, the possibility of significant mitral stenosis was raised due to the presence of significant turbulence through the bi-orifice valve, with a peak gradient of 25 mm Hg. In addition there was evidence of severe functional tricuspid valve (TV) regurgitation with elevated pulmonary artery pressures (PAP 90 mm Hg), confirmed on subsequent right heart catheterization. After repeated heart team discussions and a failure of optimal medical therapy, and despite a logistic EuroScore of 35.5, minimally invasive surgical replacement of the MV and simultaneous TV repair was undertaken via a right thoracotomy. Despite procedural success and initial good postoperative response, the patient died subsequently from a combination of hospital-acquired pneumonia and significant gastrointestinal bleeding (post operative day 35). Mitra-Clip is a promising novel approach to MV repair. The establishment of further clinical and echocardiographic based selection criteria will help identify the correct patients for this treatment.

316 Outcomes of Patients With Mitral Regurgitation Treated With The Mitraclip: One vs. Two Clips

BACKGROUND: Transcatheter leaflet repair of moderate to severe mitral regurgitation (MR) with the MitraClip device has been demonstrated to have superior safety outcomes compared to surgical management but is less effective in reducing the severity of regurgitation. Questions have been raised as to whether or not treatment with more than one clip may be associated with a superior final result. We, therefore, assessed the incremental value of a second MitraClip in high-risk surgical patients with severe MR and suboptimal results using one clip. METHODS: Prospective data was collected on patients undergoing therapy with the MitraClip from December 2010 to March 2012 at the Montreal Heart Institute. Echocardiographic data was obtained pre-procedure, immediately post, and 24 hours following the procedure. Severity of MR was assessed echocardiographically qualitatively and quantitatively, in accordance with ASE Guidelines. Procedural success was defined as a residual MR grade of 2 or less following the procedure. RESULTS: A total of 27 patients, age 75 10 years, 70% male, underwent transcatheter leaflet repair with the MitraClip during the study period. The majority of cases were functional MR (73%). Procedural success was obtained in 93% (n 25) of patients. In one patient we were unable to place a clip, and one patient received three clips. The first clip resulted in a significant reduction in MR (P 0.0001) by 3 grades in4(15%),2grades in10(38%),and1gradein11(42%),and no reduction in 1 (4%) patient. Fifteen patients (58%) that achieved only a modest reduction in MR with the first clip went on to have implantationofasecondclip.Inthisgroup,theincremental reduction in MR was highly significant (P 0.0001), with the second clip further reducingMRby3grades in1(7%),2grades in6(40%),andone grade in 8 (53%) patients. There was no significant difference in the mean mitral gradient in patients receiving one or two clips. CONCLUSION: In high-risk surgical candidates with severe MR in whom suboptimal results are obtained with a single MitraClip, a second clip results in a further highly significant reduction in MR without increasing the mitral valve gradient. 317 MECHANICAL STRESS ENHANCES AORTIC VALVE CALCIFICATION: IMPLICATION FOR BICUSPID AORTIC VALVE MINERALIZATION

Significant Reduction In Mitral Regurgitation After Transcatheter Aortic Valve Implantation In a Patient With Severe Degenerative Aortic Valve Disease, Moderate to Severe Mitral Regurgitation and Normal Ejection Fraction

The best treatment modalities in severe aortic valve disease are surgery and, in selected patients, transcatheter aortic valve implantation (TAVI). At the present time, transcatheter aortic valve implantation performed in inoperable patients or in patients with high surgical risk not only treats the aortic valve stenosis but also treats the low ejection fraction and mitral regurgitation that result from it. An 83-year-old female patient presented with shortness of breath and class 3 angina. Transthoracic and transesophageal echocardiography revealed severe AS, moderate-to-severe MR, and normal ejection fraction. The patient was considered at high risk for aortic valve replacement (Logistic Euroscore 20, STS score 15). A dramatic decrease in the degree of mitral regurgitation was detected after the successful TAVI.

Cardiac Resynchronization Therapy as a Therapeutic Option in Patients With Moderate-Severe Functional Mitral Regurgitation and High Operative Risk

Functional mitral regurgitation (MR) is a common finding in heart failure patients with dilated cardiomyopathy and has important prognostic implications. However, the increased operative risk of these patients may result in low referral or high denial rate for mitral valve surgery. Cardiac resynchronization therapy (CRT) has been shown to have a favorable effect on MR. Aims of this study were to (1) evaluate CRT as a therapeutic option in heart failure patients with functional MR and high operative risk and (2) investigate the effect of MR improvement after CRT on prognosis. A total of 98 consecutive patients with moderate-severe functional MR and high operative risk underwent CRT according to current guidelines. Echocardiography was performed at baseline and 6-month follow-up; severity of MR was graded according to a multiparametric approach. Significant improvement of MR was defined as a reduction ≥ 1 grade. All-cause mortality was assessed during follow-up (median 32 [range 6.0 to 116] months). Thirteen patients (13%) died before 6-months follow-up. In the remaining 85 patients, significant reduction in MR was observed in all evaluated parameters. In particular, 42 patients (49%) improved ≥ 1 grade of MR and were considered MR improvers. Survival was superior in MR improvers compared to MR nonimprovers (log rank P<0.001). Mitral regurgitation improvement was an independent prognostic factor for survival (hazard ratio 0.35, confidence interval 0.13 to 0.94; P=0.043). Cardiac resynchronization therapy is a potential therapeutic option in heart failure patients with moderate-severe functional MR and high risk for surgery. Improvement in MR results in superior survival after CRT.

Usefulness and Limitation of Dobutamine Stress Echocardiography to Predict Acute Response to Cardiac Resynchronization Therapy

It has been hypothesized that a long-term response to cardiac resynchronization therapy (CRT) could correlate with myocardial viability in patients with left ventricular (LV) dysfunction. Contractile reserve and viability in the region of the pacing lead have not been investigated in regard to acute response after CRT. Fifty-one consecutive patients with advanced heart failure, LV ejection fraction <or= 35%, QRS duration > 120 ms, and intraventricular asynchronism >or= 50 ms were prospectively included. The week before CRT implantation, the presence of viability was evaluated using dobutamine stress echocardiography. Acute responders were defined as a >or=15% increase in LV stroke volume. The average of viable segments was 5.8 +/- 1.9 in responders and 3.9 +/- 3 in nonresponders (P = 0.03). Viability in the region of the pacing lead had an excellent sensitivity (96%), but a low specificity (56%) to predict acute response to CRT. Mitral regurgitation (MR) was reduced in 21 patients (84%) with acute response. The presence of MR was a poor predictor of response (sensibility 93% and specificity 17%). However, combining the presence of MR and viability in the region of the pacing lead yields a sensibility (89%) and a specificity (70%) to predict acute response to CRT. Myocardial viability is an important factor influencing acute hemodynamic response to CRT. In acute responders, significant MR reduction is frequent. The combined presence of MR and viability in the region of the pacing lead predicts acute response to CRT with the best accuracy.

Long-Term Effect of Cardiac Resynchronization Therapy on Functional Mitral Valve Regurgitation

Cardiac resynchronization therapy (CRT) has been shown to reduce functional mitral regurgitation (MR). The aims of this study were to analyze the underlying mechanisms leading to this reduction and to identify the best candidates with functional MR for this therapy. Changes in mitral geometry, left ventricular (LV) remodeling, and LV synchrony were studied in patients who underwent CRT acutely and at 6- and 12-month follow-up. Of 151 patients (mean age 69 +/- 9 years, 82% men) who underwent CRT, 57 (38%) had nontrivial MR (regurgitant orifice area > or =10 mm(2)). The median reduction of MR with CRT was 18% acutely and 38% at 12-month follow-up. CRT induced an acute improvement in LV systolic function (LV dP/dt from 508 +/- 143 to 700 +/- 249 mm Hg, p <0.05) and a reduction in dyssynchrony (interventricular delay from 51 +/- 31 to 29 +/- 27 ms, p <0.05). At 12-month follow-up, additional reverse global and local LV remodeling (LV end-systolic volume from 183 +/- 77 to 151 +/- 50 ml, tenting area from 3.36 +/- 0.98 to 2.78 +/- 0.75 cm, p <0.05 for both) and a reduction in LV dyssynchrony (septal-lateral delay from 90 +/- 63 to 53 +/- 42 ms, p <0.05) were found. Significant reductions in MR were found in 28 patients (49%) and similarly observed in either ischemic MR or functional MR of other causes. Baseline mitral tenting area was the strongest predictor of significant MR reduction with CRT. In conclusion, CRT induced acute and sustained reductions in functional MR in almost 50% of patients by initially improving LV systolic function and dyssynchrony; long-term reverse LV remodeling contributed to this sustained effect. Patients with larger mitral valve tenting areas are less amenable to benefit from CRT.

Reduction in Mitral Regurgitation in Patients Undergoing Cardiac Resynchronization Treatment: Assessment of Predictors by Two‐Dimensional Radial Strain Echocardiography

We utilized the novel approach of 2D radial strain (2-DRS) to evaluate whether left ventricular (LV) mechanical dyssynchrony in mid-LV segments corresponding to papillary muscles insertion sites can predict early mitral regurgitation (MR) reduction post-cardiac resynchronization therapy (CRT). We evaluated 32 patients undergoing CRT (mean age 64 +/- 17 years, 54% males) with MR grade > or =3 determined by the MR jet area/left atrial area ratio (JA/LAA). Fifteen (47%) patients responded to CRT (JA/LAA) < 25%). Sixty-seven percent of responders had mild or no residual MR and 33% had mild-to-moderate MR, while 70% of nonresponders had grade 3 or 4 MR (P = 0.0001) post CRT. The percent reduction in LV end-systolic volume was significantly higher in responders (P = 0.03), as was improvement in LVEF (P = 0.007). Significant delay of time-to-peak 2-DRS in the midposterior and inferior segments prior to CRT was found in responders compared with nonresponders (580 +/- 58 vs. 486 +/- 94, P = 0.002 and 596 +/- 79 vs. 478 +/- 127 ms, P = 0.005, respectively). Responders also had higher peak positive systolic 2-DRS in the posterior and inferior segments compared to nonresponders (22 +/- 13 vs. 12 +/- 7%, P = 0.01 and 17 +/- 9 vs. 9 +/- 7%, P = 0.02, respectively). Logistic regression analysis showed that the differences in pre-CRT inferoanterior time-to-peak 2-DRS of >110 ms and MRJA/LAA <40% as well as 2-DRS >18% in the posterior wall were significant predictors of post-CRT improvement in MR. The presence of a significant time-to-peak delay on 2-DRS between inferior and anterior LV segments, preserved strain of posterior wall, and MRJA/LAA <40% were found to be associated with significant MR reduction in patients post-CRT.

Abstract 3052: Initial Human Experiences with a Non-Stented Coronary Sinus Device for the Treatment of Functional Mitral Regurgitation in Heart Failure Patients

Recently, several approaches have been developed for percutaneous mitral valve repair. The percutaneous transvenous mitral annuloplasty system (PTMA TM , Viacor Inc., Wilmington, USA) is an indirect annuloplasty device deployed within the coronary sinus (CS). Its mechanism is based on reduction of the anterior-posterior diameter of the mitral annulus to decrease mitral regurgitation (MR) by reestablishing leaflet coaptation in functional MR. We report the ongoing first-in-human experience with this non-stented device. 27 heart failure patients (NYHA II–IV) with functional MR II–III were enrolled at 5 centers. Via subclavian access, a multi-lumen diagnostic catheter was positioned within the anterior interventricular vein of the CS. Nitinol rods of various length and stiffness patterns were subsequently introduced into the lumina in order to exert pressure to the posterior mitral leaflet and to reduce AP diameter. Under fluoroscopic and echo guidance, different rod combinations were evaluated for maximal effectiveness before exchanging the diagnostic system to the permanent device. After assuring significant MR reduction by the permanent implant, the whole device was implanted in a subcutaneous pocket. 8 patients were excluded prior procedure due to unfavorable CS anatomy. The remaining 19 patients proceeded through a complete diagnostic exam. While the device was ineffective in 6 cases, echocardiography revealed a significant reduction of MR in 13 patients. 9 of these patients underwent successful implantation of the permanent device. 4 devices were subsequently removed, one at 7 days due to device fracture and the other 3 when the patients were referred for annuloplasty surgery due to device migration or diminished efficacy. Sustained reduction in MR and AP dimensions was noted in the remaining 4 long-term implants. No procedure related adverse events with permanent sequelae were observed in all patients. Initial human experiences with the PTMA TM device demonstrate safety and feasibility of this method as well as sustained favorable geometric modifications of the mitral annulus with reduction of MR in responding patients.

Predictors of reduction in mitral regurgitation in patients undergoing cardiac resynchronisation treatment

Background:CRT causes reduction in MR due to left ventricular (LV) remodelling, but determinants of clinically meaningful MR reduction acutely after CRT have not been evaluated.Objectives:We evaluated echocardiographic predictors of significant...

EVEREST Registry (Significant Reduction in Mitral Regurgitation 12 Months Following Percutaneous Mitral Valve Repair: Initial experience with the MitraClip Device)

Clinical CardiologyVolume 30, Issue 8 p. 419-419 Clinical TrialsFree Access EVEREST Registry (Significant Reduction in Mitral Regurgitation 12 Months Following Percutaneous Mitral Valve Repair: Initial experience with the MitraClip Device) First published: 06 August 2007 https://doi.org/10.1002/clc.20219Citations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume30, Issue8August 2007Pages 419-419 RelatedInformation

Burden of Atrial Fibrillation After Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) may diminish atrial fibrillation (AF) burden in patients with chronic heart failure (HF). Each of 27 patients without permanent AF in whom CRT implantation was unsuccessful was paired with 2 active CRT patients-1 responder and 1 nonresponder-based on age, gender, cause of HF, and history of paroxysmal AF. Device-documented high atrial rates and mode-switching episodes were tabulated during a median follow-up of 386 days. CRT responders had significantly improved left ventricular (LV) ejection fraction and New York Heart Association functional class compared with nonresponders and controls. Left atrial dimension change was similar among the groups (+0.03 +/- 0.92 cm controls; -0.18 +/- 0.80 cm responders; -0.11 +/- 1.01 cm nonresponders) despite a significant reduction in mitral regurgitation in responders compared with nonresponders. There was no significant difference in AF burden between controls and patients who underewent CRT when indexed over time. Median AF-free follow-up was significantly longer in patients who underwent CRT without a history of AF (log-rank p = 0.04), but no differences were seen in the overall cohorts. In conclusion, despite inducing LV reverse remodeling and clinical improvement, CRT does not appear to decrease AF burden in responders compared with nonresponders or matched controls in whom CRT implantation failed. CRT may, however, delay onset of new AF.

Optimal Mitral Annular and Subvalvular Shape Change Created by the Coapsys Device to Treat Functional Mitral Regurgitation

We have reported that the Myocor Coapsys (Myocor, Inc, Maple Grove, MN) device treated functional mitral regurgitation (MR) by reducing mitral annular dimension and repositioning papillary muscles. This study was conducted to evaluate the optimal Coapsys device sizing level. The Coapsys device was implanted in seven dogs after induction of MR by rapid ventricular pacing. The device consists of anterior and posterior pads connected by a subvalvular cord. The device was tightened in 5% increments of the left ventricular epicardial to epicardial dimension up to 40%. Hemodynamic and echocardiographic measurements were repeated at each tightening level. The Coapsys significantly reduced or eliminated functional MR, and the reduction was maximized at the 30% tightening level or lower in all cases. Although the left ventricular end diastolic volume decreased significantly, forward stroke volume was maintained until the 35% tightening level. The forward ejection fraction significantly increased from 33 +/- 24% at baseline to 62 +/- 42% at 40% tightening level. Mean aortic pressure decreased slightly but significantly. The Coapsys device can be applied over a broad range of tightening levels with significant reduction in MR without negative physiologic impact. This feature makes the device usable [corrected] in a variety of clinical settings.

OPTIMAL MITRAL ANNULAR AND SUB-VALVULAR SHAPE CHANGE CREATED BY THE COAPSYS DEVICE TO TREAT FUNCTIONAL MITRAL REGURGITATION

Purpose: We have reported that the Myocor Coapsys device treated functional mitral regurgitation (MR) by reducing mitral annular dimension and repositioning papillary muscles. This study was conducted to evaluate the optimal Coapsys device size. Methods: The Coapsys device was implanted in 7 dogs after induction of MR by rapid ventricular pacing. The device consists of anterior and posterior pads connected by a sub-valvular chord. The device was tightened in 5% increments of the left ventricular (LV) epicardial dimension up to 40%. Hemodynamic and echocardiographic measurements were obtained at each tightening level. RESULTS: There was a significant MR reduction with tightening the device. Although LV end-diastolic volume (EDV) decreased significantly, forward stroke volume (SV) was maintained through the 35% tightening level. Mean aortic pressure (AoP) decreased slightly but significantly. There was no significant change in left atrial pressure (LAP). Conclusion: The Coapsys device can be applied over a broad range of tightening levels without negative physiologic impact. This facilitates use of the device in a variety of clinical setting.Figure

Percutaneous mitral valve repair for mitral regurgitation.

Mitral regurgitation (MR) associated with, ischemic, and degenerative (prolapse) disease, contributes to left ventricular (LV) dysfunction due to remodeling, and LV dilation, resulting in worsening of MR. Mitral valve (MV) surgical repair has provided improvement in survival, LV function and symptoms, especially when performed early. Surgical repair is complex, due to diverse etiologies and has significant complications. The Society for Thoracic Surgery database shows that operative mortality for a 1st repair is 2% and for re-do repair is 4 times that. Cardiopulmonary bypass and cardiac arrest are required. The attendant morbidity prolongs hospitalization and recovery. Alfieri simplified mitral repair using an edge-to-edge technique which subsequently has been shown to be effective for multiple etiologies of MR. The MV leaflers are typically brought together by a central suture producing a double orifice MV without stenosis. Umana reported that MR decreased from grade 3.6 +/- 0.5 to 0.8 +/- 0.4 (P < 0.0001) and LV ejection fraction increased from 33 +/- 13% to 45 +/- 11% (P = 0.0156). In 121 patients, Maisano reported freedom from re-operation of 95 +/- 4.8% with up to 6 year follow-up. Oz developed a MV "grasper" that is directly placed via a left ventriculotomy and coapts both leaflets which are then fastened by a graduated spiral screw. An in-vitro model using explanted human valves showed significant reduction in MR and in canine studies, animals followed by serial echo had persistent MV coaptation. At 12 weeks the device was endothelialized. These promising results have paved the way for a percutaneous or minimally invasive-off pump mitral repair. Evalve has developed catheter-based technology, which, by apposing the edges of a regurgitant MV, results in edge-to-edge repair. Release of the device is done after echo and fluoroscopic evaluation under normal loading conditions. If the desired effect is not produced the device can be repositioned or retrieved. Animal studies show excellent healing, with incorporation of the device into the leaflets at 6-10 weeks with persistent coaptation. Another percutaneous approach has been to utilize the proximity of the coronary sinus (CS) to the mitral annulus (MA). Placement of a self-compressing device in the CS along the region of the posterior MA has, in canine models, reduced MR and addresses the issues of MA dilation and its contribution to MR. Ongoing studies are underway for both techniques.

Mechanism of reduction of mitral regurgitation with vasodilator therapy

Acute mitral regurgitation was produced in six open chest dogs by excising a portion of the anterior valve leaflet. Electromagnetic flow probes were placed in the left atrium around the mitral anulus and in the ascending aorta to determine phasic left ventricular filling volume, regurgitant volume and stroke volume. The systolic pressure gradient was calculated from simultaneously measured high fidelity left atrial and left ventricular pressures. The effective mitral regurgitant orifice area was calculated from Gorlin's hydraulic equation. Infusion of nitroprusside resulted in a significant reduction in mitral regurgitation. No significant change occurred in the systolic pressure gradient between the left ventricle and the left atrium because both peak left ventricular pressure and left atrial pressure were reduced. The reduction of mitral regurgitation was largely due to reduction in the size of the mitral regurgitant orifice. Reduction of ventricular volume rather than the traditional concept of reduction of impedance to left ventricular ejection may explain the effects of vasodilators in reducing mitral regurgitation.