Rheumatic mitral valve repair: a personal perspective and results.

Rheumatic mitral valve disease remains a challenge for cardiac surgeons. Valve repair has several advantages over valve replacement but is technically demanding for good results. To improve rheumatic mitral valve repair, surgeons need to have a deep understand of the mitral valve complex and its dynamics. The goal of repair is to restore normal diastolic and systolic function. The current approach is to perform a holistic repair of the entire mitral complex. Each part of the complex is thoroughly explored to define the problem. Several innovative techniques have been introduced to correct valve dysfunction and provide gratifying results. The details of these techniques will be described, based on an understanding of the relationship of the mitral valve complex and dynamics. With this approach, rheumatic mitral valve repair is becoming more successful, reproducible, and safe. Long-term follow-up is mandatory.

Impact of the Commercial Introduction of Transcatheter Mitral Valve Repair on Mitral Surgical Practice.

Background There has been uncertainty regarding the effect of transcatheter mitral valve repair (TMVr) with MitraClip on cardiac surgical practice. Our aim was to examine the impact of the commercial introduction of TMVr to a comprehensive mitral program. Methods and Results We evaluated 875 patients (aged 69±14 years; 58% men) who underwent transcatheter or mitral surgical procedures over a 6-year period at our institution. Main outcomes were changes in surgical procedural volume after TMVr introduction and short-term mortality for surgical and TMVr procedures. The numbers of patients treated with MitraClip, isolated mitral repair, and any mitral surgery were 249, 292, and 626 patients, respectively. Compared with surgery, patients with MitraClip were older (aged 82±8 versus 64±12 years; P<0.001) and had more severe morbidity. Following the introduction of MitraClip, surgical volumes steadily increased to a rate of 10 (95% CI, 3-7) procedures per year for isolated mitral procedures and 17 (95% CI, 13-20) procedures per year for all mitral surgeries. Both MitraClip and surgical volumes increased at the same rate (P=0.42). In-hospital mortality was 3.2% for MitraClip and 2.1% for all mitral surgeries (P=0.33). At 30 days, survival free of all mortality (P=0.17) and freedom from heart failure rehospitalization (P=0.75) were similar for transcatheter and surgical procedures. Conclusions The commercial introduction of TMVr may be associated with growth in cardiac surgery, without detracting from other therapies, and favorable clinical outcomes for all treated mitral regurgitation patients. These findings demonstrate the potential benefits of complementary therapies in the treatment of patients with mitral regurgitation.

Secondary mitral regurgitation: pathophysiology, proportionality and prognosis.

Secondary mitral regurgitation (SMR) occurs as a result of multifactorial left atrioventricular dysfunction and maleficent remodelling. It is the most common and undertreated form of mitral regurgitation (MR) and is associated with a very poor prognosis. Whether SMR is a bystander reflecting the severity of the cardiomyopathy disease process has long been the subject of debate. Studies suggest that SMR is an independent driver of prognosis in patients with an intermediate heart failure (HF) phenotype and not those with advanced HF. There is also no universal agreement regarding the quantitative thresholds defining severe SMR and indeed there are challenges with echocardiographic quantification. Until recently, no surgical or transcatheter intervention for SMR had demonstrated prognostic benefit, in contrast with HF medical therapy and cardiac resynchronisation therapy. In 2018, the first two randomised controlled trials (RCTs) of edge-to-edge transcatheter mitral valve repair versus guideline-directed medical therapy in HF (Percutaneous Repair with the MitraClip Device for Severe (MITRA-FR), Transcather mitral valve repair in patients with heart failure (COAPT)) reported contrasting yet complimentary results. Unlike in MITRA-FR, COAPT demonstrated significant prognostic benefit, largely attributed to the selection of patients with disproportionately severe MR relative to their HF phenotype. Consequently, quantifying the degree of SMR in relation to left ventricular volume may be a useful discriminator in predicting the success of transcatheter intervention. The challenge going forward is the identification and validation of such parameters while in parallel maintaining a heart-team guided holistic approach.

Bioprosthetic mitral valve paravalvular leak closure using intracardiac echocardiography-guided three dimensional electroanatomic mapping.

The development of paravalvular leak (PVL) following surgical replacement of an aortic or mitral valve is an uncommon complication with significant morbidity and mortality. Surgical or percutaneous repair of PVL can be technically challenging. We describe the application of intracardiac echocardiography guided 3-dimensional electroanatomic mapping to facilitate PVL closure in a symptomatic patient with a previously placed bioprosthetic mitral valve. © 2017 Wiley Periodicals, Inc.

Catheter Ablation of Ventricular Tachycardia in Patients With MitraClip Device: Preliminary Findings.

INTRODUCTION: Patients with mitral regurgitation are increasingly treated by percutaneous implantation of a MitraClip device (Abbott Park, IL, USA). We investigate the feasibility and safety of the transmitral catheter route for catheter ablation of ventricular tachycardia (VT) in these patients. METHODS: The mitral valve with the MitraClip in situ was crossed under transesophageal 3-dimensional echocardiographic and fluoroscopic guidance using a steerable sheath for ablation of the left ventricle. RESULTS: Five patients (all males, median age 74.0 ± 16.0 years) who had previously a MitraClip implanted were referred for catheter ablation of VT. The left ventricular ejection fraction was 29.0% ± 24.0%. One patient had both an atrial septal defect and a left atrial appendage occluder device in addition to a MitraClip. The duration between MitraClip implantation and ablation was 1019.0 ± 783.0 days. After transseptal puncture, ablation catheter was successfully steered through the mitral valve with the use of fluoroscopy. A complete high-density map of the substrate in sinus rhythm could be obtained in all patients using multipolar mapping catheters. In 1 patient, mapping was carried out using a mini-basket catheter. Procedural endpoints, noninducibility of all VTs, and abolition of all late potentials were achieved in all patients. Procedure time was 255.0 ± 52.5 minute, fluoroscopy time was 23.0 ± 7.3, and the radiation dose was 61.0 ± 37.5 Gycm2 . No mitral insufficiency or worsening of regurgitation was documented after the procedure. CONCLUSIONS: This is the first report demonstrating the feasibility and safety of VT ablation in patients with a MitraClip device using the anterograde transmitral catheter route.

The Use of MitraClip for Symptomatic Patients with Hypertrophic Obstructive Cardiomyopathy.

OBJECTIVES: Current nonpharmacological therapies for symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM), including septal myectomy and alcohol septal ablation (ASA), carry significant risks for serious cardiac conduction abnormalities. We present a review of the currently available published data regarding the novel use of the relatively low-risk MitraClip® system in the treatment of symptomatic patients. METHODS: Data were collected from 4 separate studies on the use of the MitraClip on 15 symptomatic HOCM patients with systolic anterior motion (SAM) of the mitral valve apparatus. Information regarding the degree of mitral regurgitation (MR), left-ventricular outflow tract (LVOT) gradient, and NYHA class was consolidated. RESULTS: After MitraClip treatment, all patients had a resolution of SAM, a reduction in MR, and a reduction in the LVOT gradient from a mean of 75.8 ± 39.7 to 11.0 ± 5.6 mm Hg. Nearly all patients demonstrated improvements in symptoms by either new NYHA class designations or improved exercise tolerance. The procedure was not associated with conduction abnormalities or arrhythmias. CONCLUSION: MitraClip therapy may be a safe and effective treatment for symptomatic HOCM patients; it can help to avoid the potential risks associated with alternative therapies in high-risk surgical patients.

Transcatheter mitral valve repair with the MitraClip(®) can be performed without general anesthesia and without conscious sedation.

BACKGROUND: General anesthesia is known to be associated with an increased risk for complications, especially in elderly and multi-morbid patients, the primary target population of the MitraClip(®) technique. The aim is to assess whether general anesthesia and even conscious sedation can be avoided during the MitraClip(®) procedure. METHODS: A total of 91 consecutive patients who underwent MitraClip(®) implantation [median 77 years, (IQR 72-83), 40 % female] were retrospectively analyzed. The first 26 patients were treated in general anesthesia. Afterwards, local anesthesia was chosen as primary anesthetic approach. Altogether, 28 (31 %) patients received general anesthesia, local anesthesia was performed in 35 (38 %) patients with sedation and in 28 (31 %) patients without sedation. RESULTS: The respective patient groups were similar regarding their baseline characteristics. Procedural success (successful implantation of at least one clip and post-procedure MR grade ≤2) was achieved in 89 % with no difference between the groups (93 % in general anesthesia, 89 % in local anesthesia with sedation, 86 % in local anesthesia without sedation, p = ns). No difference regarding hospital complications was noted. Local anesthesia with and without sedation was associated with less necessity for ICU/IMC stay (100 % in general anesthesia, 14 % in local anesthesia with sedation, 14 % in local anesthesia without sedation; p < 0.0001). One-year estimated survival was not significantly different among the groups (63, 82 and 75 %; p = ns). CONCLUSIONS: Transcatheter mitral valve repair with the MitraClip(®) can be performed without general anesthesia and even without conscious sedation with similar procedural success and complication rates.

Treatment of secondary mitral valve regurgitation: why we need combined and evolving percutaneous strategies to tackle this moving target.

Secondary mitral regurgitation (MR) has a complex pathophysiology that includes global or segmental left ventricular (LV) motion abnormalities (of non-ischaemic or ischaemic origin) leading to impaired leaflet coaptation of a normally structured mitral valve (MV). In this context, the LV functional and geometrical changes result in MV leaflet tethering, MV annulus flattening and the decrement of systolic MV closing forces. In light of its complexity, management of secondary MR remains a challenge. In fact, a long-lasting successful treatment using a single medical device and/or intervention that addresses solely the MV target cannot, at least at the present time, be proposed.

Percutaneous edge-to-edge repair in high-risk and elderly patients with degenerative mitral regurgitation: midterm outcomes in a single-center experience.

OBJECTIVE: The study objective was to report the midterm outcomes of MitraClip implantation in inoperable or high-risk surgical candidates with degenerative mitral regurgitation. METHODS: From October 2008, data of all high-risk or elderly patients with severe degenerative mitral regurgitation who underwent MitraClip implantation were prospectively collected. RESULTS: Forty-eight high-risk consecutive patients with severe degenerative mitral regurgitation underwent MitraClip implantation (mean age, 78.5 ± 10.8 years; 56.6% of the patients were aged ≥ 80 years). Mean Society of Thoracic Surgeons score was 12% ± 10%, and 71% were in New York Heart Association class III or IV. Mean left ventricular ejection fraction was 57% ± 11%. The device was successfully implanted in 47 of 48 patients (98%). In-hospital mortality was 2%. The median intensive care unit stay was 22 hours; patients were discharged from the hospital in an average of 4.5 ± 2.4 days. Predischarge echocardiography showed a mitral regurgitation reduction to grade 2+ or less in 43 of 47 patients (91.5%). Actuarial survival was 89% ± 5.2% and 70.2% ± 9% at 1 and 2 years, respectively (82% ± 9% in patients aged <80 years and 95% ± 4.4% in patients aged ≥ 80 years at 1 year; P = .9). Freedom from mitral regurgitation 3+ or greater was 80% ± 7% at 1 year and 76.6% ± 7% at 2 years. At 1 year, 93% of survivors were in New York Heart Association class I or II (100% of patients aged <80 years and 88% of patients aged ≥ 80 years; P = .4). Significant quality of life improvements were documented. A significant improvement in 6-minute walk test performance was observed. CONCLUSIONS: MitraClip therapy is a valuable alternative to surgery in high-risk and elderly patients with degenerative mitral regurgitation. Clinical benefits also are obtained in octogenarians.

Permanent His-bundle pacing maintains long-term ventricular synchrony and left ventricular performance, unlike conventional right ventricular apical pacing.

AIMS: Right ventricular apical pacing (RVAP) may be deleterious, determining abnormal left ventricular (LV) electrical activation and progressive LV dysfunction. Permanent His-bundle pacing (HBP) has been proposed to prevent this detrimental effect. The aim of our study was to compare the long-term effects of HBP on LV synchrony and systolic performance with those of RVAP in the same group of patients. METHODS: Our analysis included 26 patients who received both an HBP lead and an RVAP lead, as backup, in our electrophysiology laboratory between 2004 and 2007. After implantation, all devices were programmed to obtain HBP. An intra-patient comparison of the effects of HBP and RVAP on LV dyssynchrony and function was performed at the last available follow-up examination. RESULTS: After a mean of 34.6 ± 11 months, the pacing modality was temporarily switched to RVAP. During RVAP, LV ejection fraction significantly decreased (50.1 ± 8.8% vs. 57.3 ± 8.5%, P < 0.001), mitral regurgitation significantly increased (22.5 ± 10.9% vs.16.3 ± 12.4%; P = 0.018), and inter-ventricular delay significantly worsened (33.4 ± 19.5 ms vs. 7.1 ± 4.7 ms, P = 0.003) in comparison with HBP. However, the myocardial performance index was not statistically different between the two pacing modalities (P = 0.779). No asynchrony was revealed by tissue Doppler imaging during HBP, while during RVAP the asynchrony index was significantly higher in both the four-chamber (125.8 ± 63.9 ms; P = 0.035 vs. HBP) and two-chamber (126 ± 86.5 ms; P = 0.037 vs. HBP) apical views. CONCLUSION: His-bundle pacing has long-term positive effects on inter- and intra-ventricular synchrony and ventricular contractile performance in comparison with RVAP. It prevents asynchronous pacing-induced LV ejection fraction depression and mitral regurgitation.

Alterations in electrophysiology and tissue structure of the left atrial posterior wall in a canine model of atrial fibrillation caused by chronic atrial dilatation.

BACKGROUND: Chronic left atrial dilatation (CDLA) is associated with an increased incidence of atrial fibrillation (AF). The electrophysiological functions of the left atrial posterior wall (LAPW) are not well understood. METHODS AND RESULTS: Eight control dogs and 8 with CDLA (developed 6 months after partial mitral valve avulsion) were studied. An electrophysiological study was performed using the noncontact mapping system. The conduction velocity was significantly decreased in the LAPW in the CDLA group. During atrial extrastimulation, a sharp curvature in the activation wavefront became apparent in the LAPW of 6 CDLA dogs, with unidirectional block in 1 dog. The effective refractory periods increased homogeneously throughout the atrium in the CDLA group. AF was much more easily inducible in the CDLA dogs than in the controls. After the onset of AF, the LAPW exhibited the earliest disorganized activity as compared with other sites in the left atrial. In the CDLA dogs, the most extensive interstitial fibrosis was observed in the LAPW. CONCLUSIONS: Alterations in the electrophysiologic properties and tissue structure of the LAPW were observed in the CDLA dogs. This study supports the idea that the LAPW may play a role in the mechanism of AF induced by CDLA.

Effects of atrial fibrillation substrate and spatiotemporal organization on atrial defibrillation thresholds.

BACKGROUND: We previously showed that canine models of atrial fibrillation (AF) have different substrates (either structural or electrical) that lead to differences in AF characteristics. OBJECTIVE: The purpose of this study was to determine whether the differences in AF characteristics also would lead to differences in atrial defibrillation thresholds (ADFTs). METHODS: Dogs were divided into five groups: control; MR-mitral regurgitation for 5 weeks; CHF-congestive heart failure for 4 weeks; RAP-rapid atrial pacing for 6 weeks; and METH-acetyl-beta-methylcholine acutely administered. A cross-sectional area of the left atrium was calculated, and AF was induced with rapid atrial pacing. Biphasic shocks with a pulse width of 3/3 ms were delivered through specially constructed shocking catheters with a surface area of 3.7 cm(2) that were placed in the right and left atria. An up-down-up protocol was used to determine the 50% ADFT threshold (ADFT(50)). A wide-bipole AF signal was digitally filtered, and a fast Fourier transform was calculated over a 2-second window every 1 second. The dominant frequency was determined, and the organization index was calculated as the ratio of the area under the dominant peak and its harmonics to the total area of the spectrum. RESULTS: For left atrial size, the CHF and MR groups had a significantly larger atria than did control. ADFT(50) for control, MR, CHF, RAP, and METH groups were 160 +/- 30 V, 120 +/- 50 V, 132 +/- 20 V, 668 +/- 205 V, and 593 +/- 128 V, respectively (analysis of variance, P <.0001). Dominant frequencies were significantly higher and organization indexes significantly lower in the RAP and METH models compared with the other models. CONCLUSION: RAP and METH canine models had a significantly higher ADFT(50) compared with the other AF models. The increase in ADFT(50) in these models corresponded with higher global dominant frequencies and lower measured organization indexes.

Comparison of the correlation of rebreathing method and echocardiography in heart failure patients with moderate to severe mitral regurgitation.

OBJECTIVE: To follow-up and estimate cardiac function in 11 heart failure patients with moderate to severe mitral regurgitation who underwent cardiac resynchronization therapy (CRT) and to compare echocardiography to the rebreathing method (indirect Fick method) which were used for estimation. DESIGN: Prospective, observational, clinical study. SETTING: University teaching hospital. METHODS: Eleven cases (8 males and 3 females) were selected and followed-up during presurgery, postsurgery, and 1, 3, and 6 months after pacemaker implantation. Stroke volume was measured by echocardiography (Simpson's method and velocity-time integral method) and rebreathing each time. RESULTS: Correlations were found between stroke volume with the rebreathing method (RSV) and stroke volume with the velocity-time integral (VSV), R = 0.89, although ANOVA, the q test, and paired t test showed no statistical differences between them. Stroke volume with Simpson's rule (SSV) was poorly correlated with stroke volume using the Indirect Fick method (RSV) and with stroke volume using the velocity-time integral method (VSV) (R = 0.58 and 0.54, respectively). CONCLUSION: The rebreathing method (indirect FICK method) and velocity-time integral method are noninvasive methods with which to measure cardiac function and exhibited good correlation during the follow-up study.

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

OBJECTIVE: We sought to preoperatively identify the suitability of patients with degenerative mitral valve (MV) regurgitation for MV repair (MVR) and MV replacement. BACKGROUND: MVR is the preferred method of treatment over MV replacement, if surgically feasible. MVR preserves left ventricular function and decreases risk of hemolysis, thromboembolism, and-in the absence of anticoagulation-hemorrhage. However, the ability to identify patients suitable for MVR preoperatively is somewhat limited. METHODS: In all, 76 patients underwent MV operation for severe symptomatic mitral regurgitation. The decision to operate was at the discretion of the referring physician in consultation with respective cardiothoracic surgeons at two separate, nonrelated institutions. All patients underwent preoperative and/or intraoperative transesophageal echocardiographic studies. RESULTS: In all, 35 patients (46%) underwent MVR and 41 (54%) underwent MV replacement. There was no difference in the percentage of MVRs between the two institutions: 17 cases (41%) at Hahnemann University Hospital, Philadelphia, Pa, versus 18 cases (53%) at Northwestern University Memorial Hospital, Chicago, Ill (P = not significant). Age was found to be a significant univariate predictor with older age favoring MV replacement. On average, patients who underwent MVR were 11 years younger then those who underwent MV replacement. Heart failure was also found to be a significant univariate predictor: as New York Heart Association functional class worsened, MV replacement was more likely. Echocardiographic variables favoring MVR included chordal length (>29 mm, P <.001), length of posterior mitral leaflet (>17 mm, P <.008), and length of anterior leaflet (>25 mm, P <.01). The only echocardiographic parameter favoring replacement was the presence of anterior mitral annular calcification. Using multivariate analysis, older age (>63 years) was again a significant predictor favoring MV replacement (P <.002; odds ratio [OR] 20). Longer chordal length (>29 mm) was the strongest predictor favoring MVR (P <.001; OR 11.2). Longer length of the posterior leaflet (>17 mm; OR 5.07) and mitral annulus size > 35 mm (OR 7.75) were also significant multivariate predictors favoring MVR. The presence of anterior mitral annular calcification favored MV replacement using multivariate analysis (OR 25). CONCLUSIONS: Patients suitable for MVR can be identified preoperatively using a combination of clinical and echocardiographic parameters.

[Study on protective effect of shenfu injection on cardiac function of patients undergoing valve replacement].

OBJECTIVE: To investigate the protective effect of Shenfu injection (SFI) on cardiac function of patients undergoing valve replacement operation under cardio-pulmonary bypass. METHODS: One hundred and twenty patients undergoing valve replacement operation under cardio-pulmonary bypass were randomly divided into the SFI group and the control group, 60 in each group. Intravenous infusion of 1 ml/kg SFI was given to the SFI group, 30 min before anesthesia, and to the control group, equal volume of normal saline was given instead. The following indices were observed: (1) the hemodynamic changes occurred in the operational period; (2) the dosage of vaso-active drugs used during and after operation; (3) the post-operational recovery time of patients. RESULTS: The mean arterial pressure and heart rate in the SFI group during operation were higher, while the central venous pressure was lower than those in the control group (P < 0.05). The dosage of vaso-active drugs, such as dopamine, dobutamine, sodium nitroprusside and lidocaine, used during and after operation was lower, and the extubation time and the intensive care unit (ICU) staying time were shorter in the SFI group when compared with those in the control group (P < 0.05). CONCLUSION: SFI has certain protective effects on the cardiac function of patients undergoing valve replacement operation under cardio-pulmonary bypass.

Alterations in atrial electrophysiology and tissue structure in a canine model of chronic atrial dilatation due to mitral regurgitation.

BACKGROUND: Clinically, chronic atrial dilatation is associated with an increased incidence of atrial fibrillation (AF), but the underlying mechanism is not clear. We have investigated atrial electrophysiology and tissue structure in a canine model of chronic atrial dilatation due to mitral regurgitation (MR). METHODS AND RESULTS: Thirteen control and 19 MR dogs (1 month after partial mitral valve avulsion) were studied. Dogs in the MR group were monitored using echocardiography and Holter recording. In open-chest follow-up experiments, electrode arrays were placed on the atria to investigate conduction patterns, effective refractory periods, and inducibility of AF. Alterations in tissue structure and ultrastructure were assessed in atrial tissue samples. At follow-up, left atrial length in MR dogs was 4.09+/-0.45 cm, compared with 3.25+/-0.28 at baseline (P<0.01), corresponding to a volume of 205+/-61% of baseline. At follow-up, no differences in atrial conduction pattern and conduction velocities were noted between control and MR dogs. Effective refractory periods were increased homogeneously throughout the left and right atrium. Sustained AF (>1 hour) was inducible in 10 of 19 MR dogs and none of 13 control dogs (P<0.01). In the dilated MR left atrium, areas of increased interstitial fibrosis and chronic inflammation were accompanied by increased glycogen ultrastructurally. CONCLUSIONS: Chronic atrial dilatation in the absence of overt heart failure leads to an increased vulnerability to AF that is not based on a decrease in wavelength.

[Effects of kavergal on indices of lipid peroxidation and the condition of the antioxidant system in patients with rheumatic heart disease presenting with circulatory insufficiency]. / Vliianie kavergala na pokazateli perikisnogo okisleniia lipidov i sostoianie antioksidantnoi sistemy u bol'nykh s revmaticheskim porokom serdtsa s nedostatochnost'iu krovoobrashcheniia.

132 patients with rheumatic heart disease presenting with circulatory insufficiency displayed increased LPO both in the blood plasma and red cells, decline in the antioxidant enzymes activity varying with the circulatory insufficiency functional class degree of severity. Basic therapy with making use of antiinflammatory drugs, cardiac glycosides, diuretics together with drugs endowed with an antiarrhythmic activity and nitroglycerin (where indicated) was found to have practically no effect on LPO level or activity of the antioxidant system. The use of the drug kavergal, 1 g three times daily (total daily dosage being 3 g) in the complex therapy, has been shown to significantly decrease hyperlipoperoxidation both in the blood plasma and red cells increasing the activity of enzymes of the antioxidant defence.