Mitral Valve Interventions Research Articles

Abstract 17000: Quantifying Mitral Annular Calcification Using Echocardiography: Comparison to MAC Calcium Score From Gated Computed Tomography

Introduction: Mitral Annular Calcification (MAC) is present in 25-40% of people ≥ 60 years old and has associations with atrial fibrillation, stroke, endocarditis, mitral regurgitation, and mitral stenosis. MAC poses major challenges to surgical or transcatheter mitral valve interventions. Current echocardiographic methods for assessing MAC are limited. Goals: To assess transthoracic echocardiographic (TTE) approaches for quantifying MAC severity compared to a gold standard of MAC calcium score by gated computed tomography (CT). Methods: 75 patients undergoing evaluation for TAVR had TTE and CT in close proximity. MAC area and circumference were measured in parasternal long-axis (PLAX), parasternal short-axis (PSAX), and apical 2, 3, and 4-chamber views on TTE. Mitral valve gradients and left atrial volume were recorded. The curvilinear length of MAC in the PSAX view on TTE and cardiac CT were also measured. Associations between various TTE measures and MAC calcium score were assessed using linear regression. Results: Median age was 75.3, 50.4% female, 85.3% Caucasian. MAC area and circumference in PSAX on TTE showed moderate correlations (R 2 =0.32-0.37) with MAC calcium score. Curvilinear MAC length measures on SAX TTE and CT had improved correlation with MAC score (R 2 =0.41 & 0.78, Figure). Combined circumference of MAC from PLAX+PSAX had the strongest association (R 2 = 0.48). Interobserver variability on CT and TTE had coefficients of variation ranging 17-37%. Left atrial volume and mitral valve gradients had weak associations with MAC severity (R 2 =0.03-0.12). Tertiles of MAC calcium scores were 2650, 5150 and 7750. Conclusions: MAC length in the PSAX view showed the strongest association with MAC severity. Dedicated PSAX views of the mitral annulus may improve the ability to reproducibly grade MAC severity by echo.

Intraprocedural guidance in percutaneous mitral valve repair

Percutaneous mitral valve intervention is emerging as a valid alternative for patients affected by mitral regurgitation. By addressing the pathophysiology, therapeutic options mainly target the leaflets, annulus or left ventricle. The present review will cover the intraprocedural guidance of the most used approaches, such as edge to edge repair, adjustable transapical beating-heart chordal implantation and percutaneous direct or indirect annuloplasty. Intraprocedural monitoring relies on integration of fluoroscopy and echocardiography, and is based on the continuous communication between the interventional imager and the interventional cardiologist.

Symptoms and natural history in patients with isolated severe calcific mitral stenosis

Abstract Background Prevalence of calcific mitral stenosis (MS) increases with age. Mitral valve interventions for calcific MS are often delayed until symptoms are severely limiting because the natural history of calcific MS and its relation to cardiac symptoms or comorbidities have not been well assessed. Objectives We assessed the prevalence of symptoms, comorbidities and determinants of all-cause mortality in patients with severe calcific MS. Methods We retrospectively investigated adults with echocardiographic isolated severe MS, defined as mitral valve area (MVA by the continuity equation) ≤1.5 cm2, from July 2003 to December 2017. Among them, calcific MS was identified as obstruction of left ventricular inflow due to degenerative calcification of the mitral annulus using echocardiography and, whenever available, operative findings including histopathological examination. Inactivity was defined as requirement for assistance with activities of daily living. Follow up was obtained by review of medical records. Results Of 491 patients with isolated severe MS, calcific MS was present in 200 (41%; age 78±11 years, 18% men, 32% with atrial fibrillation). Charlson Comorbidity Index (CCI) was 5.1±1.7 and 14 (7%) were inactive. MVA and transmitral gradient (TMG) were 1.26±0.19 cm2 and 8.1±3.8 mmHg, respectively. Symptoms were present at baseline in 120 (60%) including dyspnea in 97, chest discomfort in 12, syncope in 3, lower extremity edema in 3, thrombosis in 3 and fatigue in 2. Of them, mitral valve interventions including surgical or transcatheter mitral valve replacement and mitral valve bypass were performed in 27 (23%): within 1 year after index TTE in 23 (19%) and at 2, 4, 5 and 6 years in 1 each. Of 80 patients without symptoms at index TTE, 20 (25%) developed symptoms at mean 2.9±3.2 years and interventions were performed in 5 (6%). Of 168 who did not receive interventions, 60 (36%) did not develop symptoms during follow up, 58 (35%) were considered to have moderate MS, 46 (27%) were not offered surgery because of high risk due to advanced age, multiple comorbidities or heavy calcification, and 2 (1%) declined interventions. During follow-up of 2.8±3.0 years, Kaplan-Meier survival at 1 and 3 years without intervention were 72% and 52%, respectively (Fig. A). Inactivity, CCI >5, left ventricular ejection fraction (LVEF) <50%, TMG ≥8 mmHg (the mean TMG) and right ventricular systolic pressure (RVSP) ≥50 mmHg were independently associated with mortality (Fig. B). Symptoms were associated with referral for interventions (OR 3.43, 95% CI 1.22–9.65; p=0.019), but not with mortality. Conclusion Patients with isolated severe calcific MS had a high burden of comorbidities and had high mortality without intervention. Symptoms were common (60%), but were not associated with mortality. TMG ≥8 mmHg, RVSP ≥50 mmHg, LVEF<50%, CCI >5 and inactivity were independently associated with mortality. Funding Acknowledgement Type of funding source: None

A novel mitral stenosis assessment using projected transmitral gradient improves the diagnostic and prognostic yields of doppler-based gradient

Abstract Background Transmitral gradient (TMG) is highly dependent on hemodynamic state, leading to discordance between TMG and mitral valve area (MVA). The effect of heart rate (HR) and stroke volume (SV) on TMG among patients with mitral stenosis (MS) is poorly understood. Purposes We aimed to (1) develop a formula for projected TMG (proTMG) for assessment of MS severity under varying hemodynamics; (2) assess the prognostic value of proTMG in patients with MS. Methods All patients evaluated for suspected MS without ≥moderate other valve disorder at our tertiary center between 2001 and 2017 were analyzed. Projected TMG is the expected gradient under normal flow (SV 80–94 ml and HR 60–79 bpm), and was modeled based on the observed impact of HR and SV on TMG by multiple regression analysis. The data were randomly split (2:1) into training and testing sets. The improvement in agreement between MVA and proTMG was evaluated. Composite cardiac events including all-cause death and mitral valve interventions were compared according to TMG grade using TMG and proTMG. Severe and moderate MS were defined as MVA ≤1.5 cm2 and 1.5–2.0 cm2 respectively, by the continuity equation. MVA ≤1.0 cm2 was considered as very severe MS. Results Of 4973 patients with suspected MS (age 73±12 years, 33% male), severe MS was present in 437 (9%, including 98 with very severe MS) and moderate MS in 934 (19%). In 838 patients with normal HR and SV, very severe, severe and moderate MS corresponded to TMG ≥12 mmHg, ≥6 mmHg and 4–6 mmHg, respectively. In the training set (n=3315), the median [interquartile range] of HR and SV were 70 [61–80] bpm and 97 [83–113] mL in men (n=1120), and 72 [63–82] bpm and 84 [71–97] mL in women (n=2195), respectively. The impact of HR and SV on TMG for men and women were 0.07 and 0.08 mmHg per 1 bpm increase in HR (95% confidence interval [CI] 0.06–0.07 and 0.07–0.08), and 0.03 and 0.05 mmHg per 1 mL increase in SV (95% CI 0.03–0.03 and 0.04–0.05), respectively. Therefore, the final formula to calculate proTMG was: proTMG=TMG-0.07(HR-70)-0.03(SV-97) in men and proTMG=TMG-0.08(HR-72)-0.05(SV-84) in women. In the testing set (n=1658), the proTMG (kappa=0.63, 95% CI 0.60–0.66) had better agreement with MS severity by MVA than TMG (kappa=0.28, 95% CI 0.24–0.32). To explore the prevalence of patients reclassified using proTMG, in 98 with TMG ≥12 mmHg, proTMG remained ≥6 mmHg. Of 657 with TMG 6–12 mmHg, proTMG remained ≥6 mmHg in 356 (54%), and decreased to <6 mmHg in 301 (46%). In patients with TMG 6–12 mmHg, proTMG ≥6 mmHg was associated with higher probability of cardiac events compared with <6 mmHg during follow-up of 2.8±3.1 years (Figure). Conclusion We propose a novel concept of projected TMG defined as the expected transmitral gradient at normal HR and SV levels. This improved the diagnostic yield of Doppler TMG measurements for MS severity assessment and identified a low-risk subset of patients with elevated TMG due to high HR or SV. Funding Acknowledgement Type of funding source: None

Prognostic differences between atrial functional mitral regurgitation and ventricular functional mitral regurgitation

Abstract Introduction Atrial functional mitral regurgitation (A-FMR) has been under-recognized until recently as a cause of FMR, and the prognostic difference between A-FMR and ventricular FMR (V-FMR) has not been fully elucidated. As there has been different mechanisms of FMR suggested in A-FMR and V-FMR, we hypothesized that prognosis and prognostic predictors of A-FMR may differ from those of V-FMR. Purpose To investigate the prognosis and prognostic predictors of A-FMR in comparison with V-FMR. Methods Among 1312 consecutive patients with grade 3+ (moderate to severe) or 4+ (severe) MR, 378 consecutive FMR patients were identified by excluding patients with degenerative MR, previous cardiac surgery, or concomitant aortic valve disease and/or mitral stenosis. FMR with ejection fraction (EF) <40% or FMR due to regional wall motion abnormalities with leaflet tethering were classified as V-FMR (N=288), and FMR due to left atrial (LA) and/or annular dilatation with preserved or mid-range EF (≥40%) were classified as A-FMR (N=90). All-cause death and heart failure hospitalization were analyzed as cardiovascular (CV) events in this study. Surgical or percutaneous mitral valve intervention without CV events was handled as not reaching an endpoint and these cases were censored. Results A-FMR were significantly older (76 [69–82] vs. 70 [58–77] years), higher rates of female (64 vs. 35%) and atrial fibrillation (88 vs. 42%), and lower B-type natriuretic peptide (BNP) values (169 [101–318] vs. 447 [213–952] pg/ml) compared to V-FMR (all P<0.05). On echocardiography, LV end-diastolic and end-systolic dimensions (52 [48–57] vs. 64 [58–72] mm, 34 [31–37] vs. 55 [48–64] mm), respectively) were smaller, and EF (55 [50–60] vs. 28 [19–35] %) and LA volume (99 [73–137] vs. 73 [57–91] ml/m2) were larger in A-FMR (all P<0.05). Effective regurgitant orifice area (32 [26–40] vs. 31 [24–45] mm2) and regurgitant volume (50±15 vs. 52±16 ml) were similar (both n.s.). During a median follow up of 1407 days, 206 (54%) patients developed CV events. Kaplan-Meier analysis revealed that V-FMR had a significantly higher rates of CV events compared to A-FMR (Figure) with adjusted hazard ratio (HR) of 1.762 [1.168–2.660], P=0.007 after adjusted for variables including age, sex, New York Heart Association functional class, previous heart failure hospitalization, estimated glomerular filtration rate (eGFR) and BNP. Further, stepwise multivariate analysis showed that independent prognostic predictors of A-FMR were LA volume and eGFR, while those for V-FMR were LA volume, age, and LV end-systolic dimension. Conclusions A-FMR had relatively better prognosis compared to V-FMR, and there were different prognostic predictors between A-FMR and V-FMR. Our results suggest that different treatment strategies need to be considered between A-FMR and V-FMR. The Kaplan-Meier life table Funding Acknowledgement Type of funding source: None

Impact of left atrial diameter on outcome in patients undergoing edge-to-edge mitral valve repair: results from the German TRAnscatheter Mitral valve Interventions registry (TRAMI)

Abstract Background Left atrium (LA) dimension is a marker of disease severity and outcome in primary and secondary mitral regurgitation. In transcatheter mitral valve repair LA enlargement might additionally impact on device handling and technical success through an altered anatomy and atrial annular dilatation. Methods Data from the multicenter German transcatheter mitral valve intervention registry “TRAMI” were used to analyse the association of baseline LA diameter by tertiles and efficacy, safety and long-term clinical outcome in patients undergoing edge-to-edge repair with the MitraClip. Results In 520 of 843 patients prospectively enrolled in TRAMI baseline LA diameter were reported (median [interquartile range] LA diameter in tertiles: 44 [40–46] mm, 51 [48–53] mm and 60 [55–66] mm). Larger LA diameters were significantly associated with secondary etiology of mitral regurgitation, lower ejection fraction, larger left ventricle, male sex and atrial fibrillation (all p<0.05). Technical success was not different across tertiles (96%, 95.4%, 98.4% respectively, p=0.43) as were major in-hospital cardiovascular and cerebral adverse events (mortality, myocardial infarction or stroke) (1.8%, 1.2% and 4.4%, p=0.11 across tertiles). However, 4-year mortality significantly increased with larger LA diameter (32.9%, 46.4% and 51.7% respectively, p<0.01), as did hospitalization in survivors (60%, 67.6% and 78.9% respectively, p<0.05). The association between LA diameter and all-cause mortality remained significant after multivariable adjustment including baseline left ventricular end-diastolic diameter. Conclusion LA enlargement is a strong and independent predictor of adverse long-term outcome in mitral regurgitation suggesting that timely transcatheter mitral valve repair may have the potential to modify outcome. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): The TRAMI registry has been supported by proprietary means of IHF. Additional funding is provided by “Deutsche Herzstiftung” and a grant from Abbott Vascular.

Long-term outcome of minimally invasive mitral valve annuloplasty in disproportionate mitral regurgitation

Abstract Background Hypothetical concept of disproportionate secondary mitral regurgitation (SMR) has been recently introduced to facilitate patient's selection for mitral valve intervention. However, real world data validating this concept are unavailable. Purpose To investigate long-term effects of minimally invasive mitral valve annuloplasty (MVA) in patients with disproportionate (dSMR) versus proportionate SMR. Methods The study population consisted of 44 consecutive patients (age 67±9,5 years; 64% males) on guidelines-directed therapy with advanced heart failure (HF), reduced LV ejection fraction (EF) (32±9,7%) and SMR undergoing isolated mini-invasive MVA. Patients with organic mitral regurgitation or concomitant myocardial revascularization were excluded. To assess SMR disproportionality, the PISA-derived effective regurgitant orifice area (EROA) and regurgitant volume (RV) were compared to the estimated EROA and RV by using Gorlin formula and pooled real world data. Results According to EROA, a total of 20 (46%) and 24 (54%) patients, respectively, had dSMR and proportionate SMR (pSMR). According to RV, a total of 17 (39%) had dSMR and 27 (61%) had pSMR. Patients with dSMR showed significantly lower prevalence of male gender and higher prevalence of diabetes mellitus than patients with pSMR (p<0,001). Moreover, we observed smaller LV end-diastolic volume, larger EROA and RV (both p<0,01) and higher LV EF (p=0,02) in the dSMR versus the pSMR group. Other baseline characteristics were similar. During median follow up of 4.39 y (IQR 2,2–9,96y), a total of 25 (56%) patients died from any cause while 21 (47%) individuals were readmitted for worsening HF. Patients with dSMR versus pSMR according to both EROA and RV showed significantly lower rate of HF readmissions (both p<0.05) (Figure 1, 2). In Cox regression analysis combining clinical and imaging parameters, dSMR was the only independent predictor of HF readmissions (HR 0.20, 95% CI 0.07–0.60, p=0.004). In contrast, mortality was similar between dSMR and pSMR (NS) with age as the only independent predictor (HR 1,10; 95% CI 1,03–1,18, p=0,003). Conclusions Minimally invasive MVA is associated with significant reduction of HF readmissions in patients with dSMR versus pSMR while the mortality is similar. This suggests the importance of other parameters, i.e. age and degree of LV remodeling, to guide clinical management in SMR. Funding Acknowledgement Type of funding source: None

Prevalence and prognosis of mitral disease due to mitral annular calcification

Abstract Background While mitral annular calcification (MAC) is associated with valvular regurgitation or stenosis, this disease entity remains poorly understood. Purpose We sought to evaluate the prevalence and outcomes of patients with MAC. Methods Between January 2014 and December 2015, we reviewed all patients who underwent transthoracic echocardiography (TTE), and were identified as having MAC with either mitral regurgitation (MR) or stenosis (MS). Medical records were manually examined for demographics, morbidities, type and severity of mitral disease, and clinical outcomes for this cohort. Results Of 41,136 patients who had undergone TTE, MAC was identified in 2,855 (6.9%) patients, including 434 (1.0%) patients who had significant concomitant MR or MS (mean age, 78.9±10.4 years; 63% women). Severe heart failure (NYHA III or IV, 37%), renal failure (mean GFR, 47.3±15.7 ml/min), aortic stenosis (26% with severe stenosis or prior aortic intervention), diabetes (35%), and atrial fibrillation (50%) were common. The mean mitral gradient was 6.2±3.0 mmHg. Fifty-eight patients (13%) underwent surgical or transcatheter mitral valve intervention, with two procedural deaths (3.4%). Overall, the 3-year survival free of all-cause mortality was 53.9%, while freedom from all-cause mortality, hospitalization for heart failure, myocardial infarction and cerebrovascular accident was only 26.5% (Figure 1). Three-year survival free of all-cause mortality for those who had surgery or transcatheter therapy was better in comparison to those treated medically (77.6% vs. 50.3%; p<0.001). Conclusions Patients with MAC with MR or MS are common, have severe co-morbidities, and have poor long-term survival. Further study is needed to improve the clinical outcomes of these patients. KM curves for MAC and MR/MS patients Funding Acknowledgement Type of funding source: None

Cardiopulmonary exercise testing as a guideline indicator for mitral valve intervention

Abstract Background Primary mitral regurgitation (MR) is one of the most common heart valvular pathologies. However, optimum timing of surgery remains controversial. Purpose To describe changes in cardiopulmonary exercise testing (CPET) parameters after surgery for severe primary MR. Methods In a single centre prospective study, patients undergoing surgery under current ESC guidelines for severe primary MR underwent assessment with transthoracic echocardiogram, CPET, cardiac MRI and quality of life questionnaire pre-operatively and at six months after surgery. The primary outcome was a per protocol analysis of impaired post-operative functional capacity (defined as post-operative left ventricular ejection fraction on transthoracic echocardiogram <50% and/or post-operative percentage predicted peak VO2 ≤84%). Results 43 of the 50 patients recruited between February 2017 and October 2018 were included in the per protocol analysis. Thirty five patients (72.9%) had impaired post-operative functional capacity. In the overall cohort (n=43), there was a significant fall post-operatively in percentage predicted peak VO2 (ppVO2) (81.8±15.7% vs. 76.2±16.2%, p<0.01) and anaerobic threshold (AT) (48.0±11.1% vs. 44.3±10.1%, p=0.01). In patients with a class I indication for surgery (n=30), there was no significant change post-operatively in ppVO2 (79.6±15.7% vs. 75.6±16.7%, p=0.09) or AT (49.9±11.4% vs. 46.4±10.2%, p-0.09). However, in patients with a class II indication for surgery (n=13), there was a significant change post-operatively in ppVO2 (86.9±15.1% vs. 77.4±15.9%, p<0.01), but not in AT (43.5±9.6% vs. 39.5±8.3%, p=0.16). In the multivariable analysis, pre-operative left ventricular ejection fraction ≤60% (hazard ratio, 1.69; 95% confidence interval, 1.56 to 480.1, p=0.04) and pre-operative percentage predicted peak VO2 ≤84% (hazard ratio, 1.22; 95% confidence interval, 2.13 to 107.1, p<0.01) were independent predictors for impaired post-operative functional capacity. Conclusions Pre-operative percentage predicted peak VO2 ≤84% is an independent predictor of impaired post-operative functional capacity. Subject to a confirmatory study, this may help to refine current ESC guidelines for intervention for severe primary MR. Change in ppVO2 after surgery Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Rosetrees Trust and Friends of Hammersmith Hospital

Determinants and prognostic significance of focal myocardial fibrosis by cardiac magnetic resonance imaging in patients with mitral valve prolapse

Abstract Background Mitral valve prolapse (MVP) is a frequent disease that can be complicated by mitral regurgitation (MR), heart failure, arterial embolism, rhythm disorders and death. Purpose We sought to evaluate the correlates of late gadolinium enhancement (LGE), and the prognostic significance of ventricular size, function, and LGE by cardiac magnetic resonance (CMR) imaging on cardiovascular morbi-mortality in patients with MVP Methods We included 426 patients (54±15 years, 57% male) with MVP (trace to severe MR) between 2010 and 2019 who underwent a comprehensive echocardiography and CMR imaging. Gadolinium was injected in 411 (96%) patients. The main outcome endpoint was a composite endpoint of cardiovascular death, heart failure, new onset atrial fibrillation or arterial embolism, censored at the time of mitral valve intervention. Results Among the 411 patients, LGE+ was found in 118 (29%; 100 myocardial wall including 78 basal inferolateral midwall, 30 papillary muscles) and was more frequent with worse MR volume and LV remodeling. Correlates of LGE in multivariable analysis were LV mass index (OR 1.02, P=0.008), moderate-severe MR (OR 2.15, P=0.017) and coronary artery disease (OR 5.8, P=0.013). At 4 years, survival without cardiovascular events was decreased in patients with LGE+ (50.0±11.9 vs 73.5±6.3%, p<0.0001). In a stepwise multivariable analysis including classical predictors of outcome, grade of MR, LA volume index and the presence of LGE on CMR imaging (HR: 2.15 [1.15–4.02], P=0.017) were associated with impaired event-free survival. Conclusion CMR imaging provides additional information to echocardiography in the clinical work-up of MVP. Localized LV myocardial fibrosis is a predictor of cardiovascular event in MVP patients. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): DGOS (PHRCI), Fondation Cœur et Recherche

Long Term Survival After Surgery for Ischaemic Mitral Regurgitation: A Single Centre Australian Experience

Ischaemic mitral regurgitation (IMR) is associated with an increase in both mortality and congestive heart failure in patients undergoing coronary artery bypass grafting (CABG). Intervention for moderate to severe IMR involves either valve repair or replacement. The ideal option is yet to be fully defined with relatively poor long-term survival being noted in the literature. A retrospective observational study was conducted to review the outcomes of patients undergoing CABG in combination with either mitral valve repair (MVr) or mitral valve replacement (MVR) for concurrent coronary artery disease with moderate to severe IMR at The Prince Charles Hospital in Brisbane between the years 2002 to2015. One hundred and five (105) patients were included, 81 patients (77%) undergoing CABG and MVr and 24 patients (23%) undergoing CABG and MVR. There was no difference in 30-day mortality between the two groups (1% in MVr and 0% in MVR, p=0.589), however patients in the MVr group were significantly more likely, in univariate and multivariate analysis, to develop at least moderate MR (40% v. 8%, p=0.006). The 5-year survival was 87% and 55% at 10 years. In patients undergoing CABG and mitral valve intervention for IMR, long-term mortality remains high. There was no difference in short- or long-term mortality between repair and replacement although recurrence of at least moderate mitral regurgitation was significantly higher with mitral valve repair.

Hemodynamic and transcriptomic studies suggest early left ventricular dysfunction in a preclinical model of severe mitral regurgitation

ObjectivePrimary mitral regurgitation is a valvular lesion in which the left ventricular ejection fraction remains preserved for long periods, delaying a clinical trigger for mitral valve intervention. In this study, we sought to investigate whether adverse left ventricular remodeling occurs before a significant fall in ejection fraction and characterize these changes. MethodsSixty-five rats were induced with severe mitral regurgitation by puncturing the mitral valve leaflet with a 23-G needle using ultrasound guidance. Rats underwent longitudinal cardiac echocardiography at biweekly intervals and hearts explanted at 2 weeks (n = 15), 10 weeks (n = 15), 20 weeks (n = 15), and 40 weeks (n = 15). Sixty age- and weight-matched healthy rats were used as controls. Unbiased RNA-sequencing was performed at each terminal point. ResultsRegurgitant fraction was 40.99 ± 9.40%, with pulmonary flow reversal in the experimental group, and none in the control group. Significant fall in ejection fraction occurred at 14 weeks after mitral regurgitation induction. However, before 14 weeks, end-diastolic volume increased by 93.69 ± 52.38% (P < .0001 compared with baseline), end-systolic volume increased by 118.33 ± 47.54% (P < .0001 compared with baseline), and several load-independent pump function indices were reduced. Transcriptomic data at 2 and 10 weeks before fall in ejection fraction indicated up-regulation of myocyte remodeling and oxidative stress pathways, whereas those at 20 and 40 weeks indicated extracellular matrix remodeling. ConclusionsIn this rodent model of mitral regurgitation, left ventricular ejection fraction was preserved for a long duration, yet rapid and severe left ventricular dilatation, and biological remodeling occurred before a clinically significant fall in ejection fraction.

TCT CONNECT-353 The Impact of Mitral Valve Intervention on Outcomes of Patients With Mitral Annulus Calcification and Mitral Valve Dysfunction

TCT CONNECT-353 The Impact of Mitral Valve Intervention on Outcomes of Patients With Mitral Annulus Calcification and Mitral Valve Dysfunction

Mitra-clip in Transthyretin Amyloidosis Cardiomyopathy A Case Series

IntroductionNon-invasive valvular interventions have dramatically changed the management of patients with multiple complex comorbidities. Patients with cardiac amyloidosis (CA) are often considered high-risk for surgical intervention. Trans-catheter aortic valve replacement (TAVR) is tolerated in this population, however, little is known about the safety and efficacy of per-cutaneous mitral valve interventions, such as the MitraClip procedure. We present three patients with CA and mitral regurgitation (MR) who have undergone this procedure.CasesA 75-year-old man with wild-type transthyretin cardiac amyloidosis (wtATTR), atrial fibrillation with prior ablations, a Watchman device in the left atrial appendage, resection of a malignant lung nodule presented with recurrent right pleural effusions. On exam, he had a loud MR murmur, which had been present for many years. Transthoracic echocardiogram (TTE) showed moderate MR. A transesophageal echocardiogram (TEE) revealed a partial flail of the posterior leaflet of the mitral valve resulting in moderate to severe eccentric anteriorly directed MR, amenable to the placement of a MitraClip. Two MitraClips were places, which led to marked improvement in his dyspnea and a decrease in the frequency of thoracenteses for recurrent pleural effusions. A 71-year-old man with wtATTR and a permanent pacemaker was seen in follow-up with marked dyspnea on exertion and fatigue, despite being euvolemic on exam; jugular venous pressure was not elevated but there was a Kussmaul's sign. First and second heart sounds normal and no MR murmur was heard, even in the left lateral position. TTE revealed moderate MR. His symptoms appeared disproportionate to the severity of his amyloid heart disease by exam as he had no evidence of right-sided congestion. It was suspected that the degree of MR was underestimated by TTE. TEE reveled mild diffuse thickening of the mitral valve leaflets with severe, functional MR that was directed centrally. The valve anatomy was suitable for MitraClip, and he underwent successful placement of 2 MitraClips. A 88-year-old man with MR and aortic insufficiency (AI) was seen with a new diagnosis of wtATTR. He had dyspnea on minimal exertion, marked fatigue, 3 pillow orthopnea and paroxysmal nocturnal dyspnea, he was euvolemic on examination, with a Kussmaul's sign, pansystolic and diastolic murmurs. TTE showed severe MR and moderate to severe AI, confirmed with TEE, which also showed the mitral valve was suitable for MitraClip. A single MitraClip was put in situ, with trace residual MR. He noted improvement in his energy and level of dyspnea following.DiscussionIt is important to consider other cardiac pathologies that co-exist in wtATTR, which can contribute to patients’ symptoms and are amenable to intervention. These cases demonstrate that MitraClip is feasible in MR in CA with careful patient selection.

Transcatheter Mitral Valve Repair and Replacement: What's on the Horizon?

There are more than 4 million people affected by mitral regurgitation in both the United States and Europe. Prior to the last decade the only options for treatment of MR were medical therapy and open-heart surgery which left many high risk patients with little option once medically optimized. However, we saw a flood in innovative transcatheter mitral valve interventions. As the technologies are refined these new approaches are considerably less invasive and for some high-risk patients may represent a superior option to conventional open-heart surgery. There are 3 main approaches currently being considered for transcatheter mitral valve repair, edge to edge repair, indirect annuloplasty and direct annuloplasty. There have also been large advancements in recent years in transcatheter replacement of the mitral valve. Although many of these devices are under investigation still, we sought to examine the current state of innovative transcatheter mitral valve technologies.

Intraventricular flow features and cardiac mechano-energetics after mitral valve interventions – feasibility of an isolated heart model

Abstract The aim of this work was the development of an isolated heart setup to delineate the interactions between intraventricular flow features, hemodynamic parameters and mechano-energetics after certain mitral valve therapies. Five porcine hearts were explanted and prepared for (i) edge-to-edge mitral valve repair, (ii) implantation of a rotatable biscupid mechanical valve prosthesis. Flow structures were visualized using echocardiography while hemodynamics was recorded in terms of pressures, flow rates and ventricular volume. Hemodynamic and cardiac mechano-energetics implied a marginal effect (&lt;5%) of alternating leaflet orientation on ventricular pre-load and stroke work. After edge-to-edge repair, substantial variations in flow structures were observed. Beside promoting profound insights into fundamental physiologic mechanisms, the setup may be used for validation of computer aided therapy planning tools.

Acute Severe Functional Mitral Regurgitation After Non-Mitral Valve Cardiac Surgery—Left Ventricular Dyssynchrony as a Potential Mechanism

Functional mitral regurgitation (MR) describes valve leakage in the absence of disease or damage to the mitral leaflets or subvalvular apparatus. Significant, new functional MR after cardiopulmonary bypass (CPB) may result from a number of intraoperative processes, including left ventricular (LV) ischemia and enlargement, left atrial enlargement secondary to increased filling pressure, and systolic anterior motion of the mitral valve after mitral repair. Assessment of new MR after CPB is important because it may direct hemodynamic maneuvers or prompt reinitiation of CPB if surgical intervention is deemed necessary. Described extensively in the electrophysiology literature but underreported as a cause of MR after CPB, LV dyssynchrony represents another possible mechanism of functional MR, in which resynchronization of conduction via pacing maneuvers may prove beneficial. Herein, a series of 4 patients in whom new MR was found after non-mitral valve cardiac surgery in the setting of normal LV systolic function is presented, and LV dyssynchrony is proposed as a major contributing factor. The findings suggested that the concomitant observation of new or worsened functional MR, together with normal global and regional LV systolic function, should lead the clinician to consider ventricular dyssynchrony as a possible cause. Attempts to improve or alter ventricular conduction should be considered before contemplating a return to CPB for mitral valve intervention.

Regurgitant Volume/Left Ventricular End-Diastolic Volume Ratio: Prognostic Value in Patients With Secondary Mitral Regurgitation

ObjectivesThe purpose of this study was to investigate the prognostic implications of the ratio of mitral regurgitant volume (RVol) to left ventricular (LV) end-diastolic volume (EDV) in patients with significant secondary mitral regurgitation (MR). BackgroundQuantification of secondary MR remains challenging, and its severity can be over- or underestimated when using the proximal isovelocity surface area method, which does not take LV volume into account. This limitation can be addressed by normalizing mitral RVol to LVEDV. MethodsA total of 379 patients (mean age 67 ± 11 years; 63% male) with significant (moderate and severe) secondary MR were divided into 2 groups according to the RVol/EDV ratio: RVol/EDV ≥20% (greater MR/smaller EDV) and <20% (smaller MR/larger EDV). The primary endpoint was all-cause mortality. ResultsDuring median (interquartile range) follow-up of 50 (26 to 94) months, 199 (52.5%) patients died. When considering patients receiving medical therapy only, patients with RVol/EDV ratio ≥20% tended to have higher mortality rates than those with RVol/EDV ratio <20% (5-year estimated rates 24.1% vs. 18.4%, respectively; p = 0.077). Conversely, when considering the entire follow-up period including mitral valve interventions, patients with a higher RVol/EDV ratio (≥20%) had lower rates of all-cause mortality compared with patients with RVol/EDV ratio <20% (5-year estimated rates 39.0% vs. 44.8%, respectively; p = 0.018). On multivariable analysis, higher RVol/EDV ratio (per 5% increment as a continuous variable) was independently associated with lower all-cause mortality (0.93; p = 0.023). ConclusionsIn patients with significant secondary MR treated medically, survival tended to be lower in those with a higher RVol/EDV ratio. Conversely, a higher RVol/EDV ratio was independently associated with reduced all-cause mortality. when mitral valve interventions were taken into consideration

Fusion imaging for transcatheter mitral and tricuspid interventions.

Image guidance for transcatheter mitral and tricuspid valve intervention commonly utilizes the unique advantages of both fluoroscopy and live echocardiography. In some cases, pre-procedural computed tomography is also needed. Classically, they are displayed separately even if modalities are in simultaneous use. This requires procedural operators to watch separate images displaying complementary information and mentally combine these data sources. New hybrid, or fusion, imaging systems allow for multiple imaging modalities to be overlaid on one another to provide the most relevant information on a single screen. While this technological advancement may have some advantages in certain procedures, more data is needed to understand if these systems will improve procedural or clinical outcomes.

Immediate, early and mid-term outcomes following balloon mitral valvotomy in patients having severe rheumatic mitral stenosis with significant tricuspid regurgitation.

The study examined the influence of significant tricuspid regurgitation (TR) on the immediate, early and mid-term outcomes of patients with severe mitral stenosis (MS) undergoing balloon mitral valvotomy (BMV). Among the 818 consecutive patients who underwent elective BMV in this institute from 1997 to 2003, 114 had significant TR. After propensity score-matched analysis, the data of 93 patients with significant TR were compared with the data of 93 patients who had no significant TR at the baseline. Outcomes were assessed immediately, at 1year (early) and at 5years (mid-term) after BMV. Patients with significant TR presented more frequently with NYHA class III-IV status, atrial fibrillation (AF), severe pulmonary hypertension (PH), advanced mitral valve disease as assessed by echocardiographic score >8, and with history of previous BMV. After propensity score-matched analysis, it was found that the immediate procedural success (54.8% vs. 58.1%, P = 0.650), immediate in-hospital events and prevalence of AF and heart failure at 1year of follow-up were comparable between the two groups. At 5years after BMV, the significant TR group had higher prevalence of heart failure and AF, greater attrition in mitral valve area (MVA) and higher pulmonary artery (PA) pressure. Significant TR identifies a sicker patient population with MS. Even though patients with significant TR have comparable immediate and early outcomes after BMV, they have poor outcomes on mid-term follow-up. Longer follow-up with more patients is needed to assess survival aspect of TR on patients undergoing BMV and also to look at the need for interventions to address the significant TR, apart from the mitral valve interventions.