Staging Heart Failure Patients With Secondary Mitral Regurgitation Undergoing Transcatheter Edge-to-Edge Repair

BackgroundSecondary mitral regurgitation (SMR) is a progressive disease with characteristic pathophysiological changes that may influence prognosis. Although the staging of SMR patients suffering from heart failure with reduced ejection fraction (HFrEF) according to extramitral cardiac involvement has prognostic value in medically treated patients, such data are so far lacking for edge-to-edge mitral valve repair (M-TEER).ObjectivesThis study sought to classify M-TEER patients into disease stages based on the phenotype of extramitral cardiac involvement and to assess its impact on symptomatic and survival outcomes.MethodsBased on echocardiographic and clinical assessment, patients were assigned to 1 of the following HFrEF-SMR groups: left ventricular involvement (Stage 1), left atrial involvement (Stage 2), right ventricular volume/pressure overload (Stage 3), or biventricular failure (Stage 4). A Cox regression model was implemented to investigate the impact of HFrEF-SMR stages on 2-year all-cause mortality. The symptomatic outcome was assessed with New York Heart Association functional class at follow-up.ResultsAmong a total of 849 eligible patients who underwent M-TEER for relevant SMR from 2008 until 2019, 9.5% (n = 81) presented with left ventricular involvement, 46% (n = 393) with left atrial involvement, 15% (n = 129) with right ventricular pressure/volume overload, and 29% (n = 246) with biventricular failure. An increase in HFrEF-SMR stage was associated with increased 2-year all-cause mortality after M-TEER (HR: 1.39; CI: 1.23-1.58; P < 0.01). Furthermore, higher HFrEF-SMR stages were associated with significantly less symptomatic improvement at follow-up.ConclusionsThe classification of M-TEER patients into HFrEF-SMR stages according to extramitral cardiac involvement provides prognostic value in terms of postinterventional survival and symptomatic improvement.     

Baseline Functional Capacity and Transcatheter Mitral Valve Repair in Heart Failure With Secondary Mitral Regurgitation

ObjectivesThe aim of this study was to determine the prognostic utility of baseline functional status and its impact on the outcomes of transcatheter mitral valve repair (TMVr) in patients with heart failure (HF) with secondary mitral regurgitation (SMR).BackgroundThe COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial demonstrated that TMVr with the MitraClip in patients with HF with moderate to severe or severe SMR improved health-related quality of life. The clinical utility of a baseline assessment of functional status for evaluating prognosis and identifying candidates likely to derive a robust benefit from TMVr has not been previously studied in patients with HF with SMR.MethodsThe COAPT study was a multicenter, randomized, controlled, parallel-group, open-label trial of TMVr with the MitraClip plus guideline-directed medical therapy (GDMT) versus GDMT alone in patients with HF, left ventricular ejection fraction 20% to 50%, and moderate to severe or severe SMR. Baseline functional status was assessed by 6-min walk distance (6MWD).ResultsPatients with 6MWD less than the median (240 m) were older, were more likely to be female, and had more comorbidities. After multivariate modeling, age (p = 0.005), baseline hemoglobin (p = 0.007), and New York Heart Association functional class III/IV symptoms (p < 0.0001) were independent clinical predictors of 6MWD. Patients with 6MWD <240 m versus ≥240 m had a higher unadjusted and adjusted rate of the 2-year composite of all-cause death or HF hospitalization (64.4% vs. 48.6%; adjusted hazard ratio: 1.53; 95% confidence interval: 1.19 to 1.98; p = 0.001). However, there was no interaction between baseline 6MWD and the relative effectiveness of TMVr plus GDMT versus GDMT alone with respect to the composite endpoint (p = 0.633).ConclusionsBaseline assessment of functional capacity by 6MWD was a powerful discriminator of prognosis in patients with HF with SMR. TMVr with the MitraClip provided substantial improvements in clinical outcomes for this population irrespective of baseline functional capacity.     

Functional Mitral Regurgitation Outcome and Grading in Heart Failure With Reduced Ejection Fraction

ObjectivesThis study aims to define excess-mortality linked to functional mitral regurgitation (FMR) quantified in routine-practice.BackgroundAppraisal of FMR in heart failure with reduced ejection fraction (HFrEF) is challenging because risks of excess mortality remain uncertain and guidelines diverge.MethodsCases of HFrEF (ejection-fraction <50%) Stage B-C that were diagnosed between 2003 and 2011 and had routine-practice FMR quantitation (FMR cohort, n = 6,381) were analyzed for excess mortality thresholds/rates within the cohort and in comparison to the general population. These were also compared to those of a degenerative mitral regurgitation (DMR) simultaneous cohort (DMR cohort, n = 2,416).ResultsIn the FMR cohort (age: 70 ± 11 years, ejection fraction: 36 ± 10%, effective regurgitant orifice area [EROA]: 0.09 ± 0.13 cm²), EROA distribution was skewed towards low-values (≥0.40 cm² in only 8% vs 38% for the DMR cohort; P < 0.0001). One-year mortality was high (15.6%), increasing steeply from 13.3% without FMR to 28.5% with EROA ≥0.30 cm² (adjusted odds ratio: 1.57 [95% CI: 1.19-2.97]; P = 0.001). In the long term, 3,538 FMR cohort patients died with excess mortality threshold ∼0.10 cm² (vs ∼0.20 cm² in the DMR cohort), with 0.10 cm² EROA increments independently associated with considerable mortality increment (adjusted HR: 1.11 [95% CI: 1.08-1.15]; P < 0.0001) and with no detectable interaction. Compared to the general population, FMR excess mortality increased exponentially with higher EROA (risk ratio point estimates 2.8, 3.8, and 5.1 at EROA 0.20, 0.30, and 0.40 cm², respectively), and was much steeper than that of the DMR cohort (P < 0.0001). In nested models, individualized EROA was the strongest FMR survival marker, and a new expanded FMR grading scale based on 0.10 cm² EROA increments provided incremental power over current American Heart Association–American College of Cardiology/European Society of Cardiology guidelines (all P < 0.03).ConclusionsIn HFrEF, FMR is skewed towards smaller EROA. Nevertheless, when measured in routine practice, EROA is the strongest independent FMR determinant of survival after diagnosis. Excess mortality increases exponentially above the threshold of 0.10 cm², with a much steeper slope than in DMR, for any EROA increment. An expanded EROA-based stratification, superior to existing grading schemes in determining survival, should allow guideline harmonization.     

Prognostic Impact of Extra–Mitral Valve Cardiac Involvement in Patients With Primary Mitral Regurgitation

BackgroundIn patients with severe primary mitral regurgitation (MR), the indication for surgery is currently based on the presence of symptoms, left ventricular dilatation and dysfunction, atrial fibrillation, and pulmonary hypertension.ObjectivesThe aim of this study was to evaluate the prognostic impact of the presence of extra–mitral valve cardiac involvement (including known risk factors but also severe left atrial [LA] dilatation and right ventricular [RV] dysfunction) in a large multicenter study of patients with primary MR.MethodsPatients with severe primary MR undergoing surgery were included and categorized according to the extent (highest) of cardiac involvement: group 0, no cardiac involvement; group 1, left ventricular involvement; group 2, LA involvement; group 3, pulmonary vasculature or tricuspid valve involvement; or group 4, RV involvement. The outcome was all-cause mortality.ResultsA total of 1,106 patients were included (mean age 63 ± 12 years, 68% male). In total, 377 patients (34%) were classified in group 0, 239 (22%) in group 1, 213 (19%) in group 2, 180 (16%) in group 3, and 97 (9%) in group 4. Kaplan-Meier curve analysis revealed significantly worse survival (log-rank chi-square = 43.4; P < 0.001) with higher group. On multivariable analysis, age, male sex, chronic obstructive pulmonary disease, kidney function, and group of cardiac involvement were independently associated with all-cause mortality. For each increase in group, a 17% higher risk for all-cause mortality was observed (95% CI: 1.051-1.313; P = 0.005) during a median follow-up time of 88 months.ConclusionsIn patients with severe primary MR, a novel classification system based on extra–mitral valve cardiac involvement may help refine risk stratification and timing of surgery, particularly including severe LA dilatation and RV dysfunction in the assessment.     

Impact of Proportionality of Secondary Mitral Regurgitation on Outcome After Transcatheter Mitral Valve Repair

ObjectivesThe purpose of this paper was to evaluate the impact of proportionality of secondary mitral regurgitation (SMR) in a large real-world registry of transcatheter edge-to-edge mitral valve repair (TMVr)BackgroundDifferences in the outcomes of recent randomized trials of TMVr for SMR may be explained by the proportionality of SMR severity to left ventricular (LV) volume.MethodsThe ratio of pre-procedural effective regurgitant orifice area (EROA) to LV end-diastolic volume (LVEDV) was retrospectively assessed in patients undergoing TMVr for severe SMR between 2008 and 2019 from the EuroSMR registry. A recently proposed SMR proportionality scheme was adapted to stratify patients according to EROA/LVEDV ratio in 3 groups: MR-dominant (MD), MR-LV-co-dominant (MLCD), and LV-dominant (LD). All-cause mortality was assessed as a primary outcome, secondary heart failure (HF) outcomes included hospitalization for HF (HHF), New York Heart Association (NYHA) functional class, N-terminal pro–B-type natriuretic peptide (NT-proBNP), 6-min-walk distance, quality of life and MR grade.ResultsA total of 1,016 patients with an EROA/LVEDV ratio were followed for 22 months after TMVr. MR was reduced to grade ≤2+ in 92%, 96%, and 94% of patients (for MD, MLCD, and LD, respectively; p = 0.18). After adjustment for covariates including age, sex, diabetes, kidney function, body surface area, LV ejection fraction, and procedural MR reduction (grade ≤2+), adjusted rates of 2-year mortality in MD patients did not differ from those for MLCD patients (17% vs. 18%, respectively), whereas it was higher in LD patients (23%; p = 0.02 for comparison vs. MD+MLCD). The adjusted first HHF rate differed between groups (44% in MD, 56% in MLCD, 29% in LD; p = 0.01) as did the adjusted time for first death or HHF rate (66% in MD, 82% in MLCD, 68% in LD; p = 0.02). Improvement of NYHA functional class was seen in all groups (p < 0.001). Values for 6-min-walk distances, quality of life and NT-proBNP improved in most patients.ConclusionsMD and MLCD patients had a comparable, adjusted 2-year mortality rate after TMVr which was slightly better than that of LD patients. Patients treated with TMVr had symptomatic improvement regardless of EROA/LVEDV ratio.     

Myocardial Angiotensin Metabolism in End-Stage Heart Failure

BackgroundThe myocardium exhibits an adaptive tissue-specific renin-angiotensin system (RAS), and local dysbalance may circumvent the desired effects of pharmacologic RAS inhibition, a mainstay of heart failure with reduced ejection fraction (HFrEF) therapy.ObjectivesThis study sought to investigate human myocardial tissue RAS regulation of the failing heart in the light of current therapy.MethodsFifty-two end-stage HFrEF patients undergoing heart transplantation (no RAS inhibitor: n = 9; angiotensin-converting enzyme [ACE] inhibitor: n = 28; angiotensin receptor blocker [ARB]: n = 8; angiotensin receptor neprilysin-inhibitor [ARNi]: n = 7) were enrolled. Myocardial angiotensin metabolites and enzymatic activities involved in the metabolism of the key angiotensin peptides angiotensin 1-8 (AngII) and Ang1-7 were determined in left ventricular samples by mass spectrometry. Circulating angiotensin concentrations were assessed for a subgroup of patients.ResultsAngII and Ang2-8 (AngIII) were the dominant peptides in the failing heart, while other metabolites, especially Ang1-7, were below the detection limit. Patients receiving an ARB component (i.e., ARB or ARNi) had significantly higher levels of cardiac AngII and AngIII (AngII: 242 [interquartile range (IQR): 145.7 to 409.9] fmol/g vs 63.0 [IQR: 19.9 to 124.1] fmol/g; p < 0.001; and AngIII: 87.4 [IQR: 46.5 to 165.3] fmol/g vs 23.0 [IQR: <5.0 to 59.3] fmol/g; p = 0.002). Myocardial AngII concentrations were strongly related to circulating AngII levels. Myocardial RAS enzyme regulation was independent from the class of RAS inhibitor used, particularly, a comparable myocardial neprilysin activity was observed for patients with or without ARNi. Tissue chymase, but not ACE, is the main enzyme for cardiac AngII generation, whereas AngII is metabolized to Ang1-7 by prolyl carboxypeptidase but not to ACE2. There was no trace of cardiac ACE2 activity.ConclusionsThe failing heart contains considerable levels of classical RAS metabolites, whereas AngIII might be an unrecognized mediator of detrimental effects on cardiovascular structure. The results underline the importance of pharmacologic interventions reducing circulating AngII actions, yet offer room for cardiac tissue-specific RAS drugs aiming to limit myocardial AngII/AngIII peptide accumulation and actions.     

Attenuated Mitral Leaflet Enlargement Contributes to Functional Mitral Regurgitation After Myocardial Infarction

BackgroundMitral leaflet enlargement has been identified as an adaptive mechanism to prevent mitral regurgitation in dilated left ventricles (LVs) caused by chronic aortic regurgitation (AR). This enlargement is deficient in patients with functional mitral regurgitation, which remains frequent in the population with ischemic cardiomyopathy. Maladaptive fibrotic changes have been identified in post-myocardial infarction (MI) mitral valves. It is unknown if these changes can interfere with valve growth and whether they are present in other valves.ObjectivesThis study sought to test the hypothesis that MI impairs leaflet growth, seen in AR, and induces fibrotic changes in mitral and tricuspid valves.MethodsSheep models of AR, AR + MI, and controls were followed for 90 days. Cardiac magnetic resonance, echocardiography, and computed tomography were performed at baseline and 90 days to assess LV volume, LV function, mitral regurgitation and mitral leaflet size. Histopathology and molecular analyses were performed in excised valves.ResultsBoth experimental groups developed similar LV dilatation and dysfunction. At 90 days, mitral valve leaflet size was smaller in the AR + MI group (12.8 ± 1.3 cm² vs. 15.1 ± 1.6 cm², p = 0.03). Mitral regurgitant fraction was 4% ± 7% in the AR group versus 19% ± 10% in the AR + MI group (p = 0.02). AR + MI leaflets were thicker compared with AR and control valves. Increased expression of extracellular matrix remodeling genes was found in both the mitral and tricuspid leaflets in the AR + MI group.ConclusionsIn these animal models of AR, the presence of MI was associated with impaired adaptive valve growth and more functional mitral regurgitation, despite similar LV size and function. More pronounced extracellular remodeling was observed in mitral and tricuspid leaflets, suggesting systemic valvular remodeling after MI.     

Transcatheter Edge-to-Edge Repair for Atrial Secondary Mitral Regurgitation

BackgroundAtrial secondary mitral regurgitation (ASMR) is a subtype of SMR that has a poor prognosis, and thus far, evidence of the therapeutic options for the management of ASMR is limited.ObjectivesThis study aimed to investigate the effectiveness of transcatheter edge-to-edge repair (TEER) for ASMR.MethodsThe study retrospectively analyzed consecutive patients who underwent MitraClip at the Heart Center Bonn. ASMR was defined as cases that met all of the following criteria: 1) normal mitral leaflets without organic disorder; 2) left ventricular ejection fraction >50%; and 3) absence of LV enlargement and segmental abnormality. The primary outcome measure was MR reduction to ≤1+, and its predictors were explored in a logistic regression analysis.ResultsAmong 415 patients with SMR, 118 patients met the criteria for ASMR (mean age 80 ± 8 years, 39.8% male). The technical success rate was 94.1%, and MR reduction to ≤1+ after TEER was achieved in 94 (79.7%) patients with ASMR. The in-hospital mortality rate was 2.5%. In multivariable logistic analysis, a large left atrial volume index and low leaflet-to-annulus index were associated with a lower incidence of MR reduction to ≤1+ after TEER for ASMR. In addition, the use of a newer generation of the MitraClip systems (NTR/XTR or G4 systems) was associated with a higher incidence of MR reduction to ≤1+.ConclusionsTEER is a safe and feasible therapeutic option for patients with ASMR. Assessments of left atrial volume index and leaflet-to-annulus index may assist with patient selection for TEER in patients with ASMR.     

Mitral Valve Remodeling and Strain in Secondary Mitral Regurgitation: Comparison With Primary Regurgitation and Normal Valves

ObjectivesThe aim of this study was to assess mitral valve (MV) remodeling and strain in patients with secondary mitral regurgitation (SMR) compared with primary MR (PMR) and normal valves.BackgroundA paucity of data exists on MV strain during the cardiac cycle in humans. Real-time 3-dimensional (3D) echocardiography allows for dynamic MV imaging, enabling computerized modeling of MV function in normal and disease states.MethodsThree-dimensional transesophageal echocardiography (TEE) was performed in a total of 106 subjects: 36 with SMR, 38 with PMR, and 32 with normal valves; MR severity was at least moderate in both MR groups. Valve geometric parameters were quantitated and patient-specific 3D MV models generated in systole using a dedicated software. Global and regional peak systolic MV strain was computed using a proprietary software.ResultsMV annular area was larger in both the SMR and PMR groups (12.7 ± 0.7 and 13.3 ± 0.7 cm², respectively) compared with normal subjects (9.9 ± 0.3 cm²; p < 0.05). The leaflets also had significant remodeling, with total MV leaflet area larger in both SMR (16.2 ± 0.9 cm²) and PMR (15.6 ± 0.8 cm²) versus normal subjects (11.6 ± 0.4 cm²). Leaflets in SMR were thicker than those in normal subjects but slightly less than those with PMR posteriorly. Posterior leaflet strain was significantly higher than anterior leaflet strain in all 3 groups. Despite MV remodeling, strain in SMR (8.8 ± 0.3%) was overall similar to normal subjects (8.5 ± 0.2%), and both were lower than in PMR (12 ± 0.4%; p < 0.0001). Valve thickness, severity of MR, and primary etiology of MR were correlates of strain, with leaflet thickness being the multivariable parameter significantly associated with MV strain. In patients with less severe MR, anterior leaflet strain in SMR was lower than normal, whereas strain in PMR remained higher than normal.ConclusionsThe MV in secondary MR remodels significantly and similarly to PMR with a resultant larger annular area, leaflet surface area, and leaflet thickness compared with that of normal subjects. Despite these changes, MV strain remains close to or in some instances lower than normal and is significantly lower than that of PMR. Strain determination has the potential to improve characterization of MV mechano-biologic properties in humans and to evaluate its prognostic impact in patients with MR, with or without valve interventions.     

Impact of Residual Mitral Regurgitation on Survival After Transcatheter Edge-to-Edge Repair for Secondary Mitral Regurgitation

ObjectivesThe aim of this study was to assess the impact of residual mitral regurgitation (resMR) on mortality with respect to left ventricular dilatation (LV-Dil) or right ventricular dysfunction (RV-Dys) in patients with secondary mitral regurgitation (SMR) who underwent mitral valve transcatheter edge-to-edge repair (TEER).BackgroundThe presence of LV-Dil and RV-Dys correlates with advanced stages of heart failure in SMR patients, which may impact the outcome after TEER.MethodsSMR patients in a European multicenter registry were evaluated. Investigated outcomes were 2-year all-cause mortality and improvement in New York Heart Association functional class with respect to MR reduction, LV-Dil (defined as LV end-diastolic volume ≥159 ml), and RV-Dys (defined as tricuspid annular plane systolic excursion-to-systolic pulmonary artery pressure ratio of <0.274 mm/mm Hg).ResultsAmong 809 included patients, resMR ≤1+ was achieved in 546 (67%) patients. Overall estimated 2-year mortality rate was 32%. Post-procedural resMR was significantly associated with mortality (p = 0.031). Although the improvement in New York Heart Association functional class persisted regardless of either LV-Dil or RV-Dys, the beneficial treatment effect of resMR ≤1+ on 2-year mortality was observed only in patients without LV-Dil and RV-Dys (hazard ratio: 1.75; 95% confidence interval: 1.03 to 3.00).ConclusionsAchieving optimal MR reduction by TEER is associated with improved survival in SMR patients, especially if the progress in heart failure is not too advanced. In SMR patients with advanced stages of heart failure, as evidenced by LV-Dil or RV-Dys, the treatment effect of TEER on symptomatic improvement is maintained, but the survival benefit appears to be reduced.     

Prevalence and Prognostic Significance of Microvascular Dysfunction in Heart Failure With Preserved Ejection Fraction

BackgroundThe pathophysiological and clinical significance of microvascular dysfunction (MVD) in patients with heart failure with preserved ejection fraction (HFpEF) remains uncertain.ObjectivesThe aim of this study was to use cardiovascular magnetic resonance to: 1) quantify coronary microvascular function; 2) examine the relationship between perfusion and fibrosis; and 3) evaluate the impact of MVD and fibrosis on long-term clinical outcomes.MethodsIn a prospective, observational study, patients with HFpEF and control subjects underwent multiparametric cardiovascular magnetic resonance (comprising assessment of left ventricular volumetry, perfusion, and fibrosis [focal by late gadolinium enhancement and diffuse by extracellular volume]). The primary endpoint was the composite of death or hospitalization with heart failure.ResultsOne hundred and one patients with HFpEF (mean age 73 ± 9 years, mean ejection fraction 56% ± 5%) and 43 control subjects (mean age 73 ± 5 years, mean ejection fraction 58% ± 5%) were studied. Myocardial perfusion reserve (MPR) was lower in patients with HFpEF versus control subjects (1.74 ± 0.76 vs 2.22 ± 0.76; P = 0.001). MVD (defined as MPR <2.0) was present in 70% of patients with HFpEF (vs 48% of control subjects; P = 0.014). There was no significant linear correlation between MPR and diffuse fibrosis (r = ?0.10; P = 0.473) and no difference in MPR between those with and without focal fibrosis (mean difference ?0.03; 95% CI: ?0.37 to 0.30). In the HFpEF group, during median follow-up of 3.1 years, there were 45 composite events. MPR was independently predictive of clinical outcome following adjustment for clinical, blood, and imaging parameters (1 SD increase: HR: 0.673 [95% CI: 0.463 to 0.978; P = 0.038]; HR: 0.694 [95% CI: 0.491 to 0.982; P = 0.039]; and HR: 0.690 [95% CI: 0.489 to 0.973; P = 0.034], respectively).ConclusionsMVD is highly prevalent among patients with HFpEF and is an independent predictor of prognosis. The lack of correlation between MVD and fibrosis may challenge the assertion of a direct causal link between these entities. (Developing Imaging and Plasma Biomarkers in Describing Heart Failure With Preserved Ejection Fraction [DIAMONDHFpEF]; NCT03050593)     

Prognostic Value of Left Ventricular Global Longitudinal Strain in Patients With Secondary Mitral Regurgitation

BackgroundLeft ventricular (LV) systolic function may be overestimated in patients with secondary mitral regurgitation (MR) when using LV ejection fraction (EF). LV global longitudinal strain (GLS) is a less load-dependent measure of LV function. However, the prognostic value of LV GLS in secondary MR has not been evaluated.ObjectivesThis study sought to demonstrate the prognostic value of LV GLS over LVEF in patients with secondary MR.MethodsA total of 650 patients (mean 66 ± 11 years of age, 68% men) with significant secondary MR were included. The study population was subdivided based on the LV GLS value at which the hazard ratio (HR) for all-cause mortality was >1 using a spline curve analysis (LV GLS <7.0%, impaired LV systolic function vs. LV GLS ≥7.0%, preserved LV systolic function). The primary endpoint was all-cause mortality.ResultsDuring a median follow-up of 56 (interquartile range: 28 to 106 months) months, 334 (51%) patients died. Patients with a more impaired LV GLS showed significantly higher mortality rates at 1-, 2-, and 5-year follow-up (13%, 23%, and 44%, respectively) when compared with patients with more preserved LV systolic function (5%, 14%, and 31%, respectively). On multivariable analysis, LV GLS <7.0% was associated with increased mortality (HR: 1.337; 95% confidence interval: 1.038 to 1.722; p = 0.024), whereas LVEF ≤30% was not (HR: 1.055; 95% confidence interval: 0.794 to 1.403; p = 0.711).ConclusionsIn patients with secondary MR, impaired LV GLS was independently associated with an increased risk for all-cause mortality, whereas LVEF was not. LV GLS may therefore be useful in the risk stratification of patients with secondary MR.     

Prognostic Impact of Ischemic Mitral Regurgitation Severity and Myocardial Infarct Quantification by Cardiovascular Magnetic Resonance

ObjectivesThis study sought to evaluate the role of cardiac magnetic resonance (CMR) for the quantification of ischemic mitral regurgitation (IMR) and myocardial infarct size (MIS) in patients with ischemic cardiomyopathy (ICM). This study also sought to explore the interaction between IMR severity and MIS and its association with outcomes in patients with ICM.BackgroundIMR occurs secondary to a disease of the left ventricle and is associated with poor outcomes. The role of CMR for the evaluation and risk stratification of patients with ICM and IMR remains uncertain.MethodsConsecutive patients with ICM who underwent baseline CMR were included. MIS was quantified on late gadolinium enhancement imaging as the proportion of left ventricular mass. IMR was quantified with CMR by calculating the mitral regurgitant fraction (MRFraction). Cox proportional hazards models were built to assess the association of IMR and MIS quantification with the combined endpoint of all-cause death or heart transplant.ResultsWe evaluated 578 patients (mean age: 62 ± 11 years, 76% males). The mean left ventricular ejection fraction was 25 ± 11%, with an MIS of 24 ± 16% and MRFraction of 18 ± 17%. Over a median follow-up time of 4.9 years, 198 (34%) patients experienced death or cardiac transplant. On multivariable analysis, after comprehensive medical risk score, subsequent revascularization, implantable cardioverter-defibrillator insertion, and surgical mitral valve intervention were controlled for, the interaction of IMR severity and MIS emerged as a powerful predictor of adverse outcomes (p = 0.008). For patients with significant IMR (MRFraction: ≥35%), the hazard ratio comparing moderate MIS (15% to 29%) versus small MIS (<15%) was 1.51 (0.57 to 3.98), and the hazard ratio comparing large MIS (≥30%) versus small MIS was 5.41 (2.34 to 12.7).ConclusionsRisk associated with IMR is more comprehensively described as an interaction between IMR severity and MIS. Further studies in patients IMR using comprehensive CMR evaluation are needed to verify whether this approach can improve patient selection and procedural outcomes to address IMR.     

Importance of Myocardial Fibrosis in Functional Mitral Regurgitation: From Outcomes to Decision-Making

Functional mitral regurgitation (FMR) is a common and complex valve disease, in which severity and risk stratification is still a conundrum. Although risk increases with FMR severity, it is modulated by subjacent left ventricular (LV) disease. The extent of LV remodeling and dysfunction is traditionally evaluated by echocardiography, but a growing body of evidence shows that myocardial fibrosis (MF) assessment by cardiac magnetic resonance (CMR) may complement risk stratification and inform treatment decisions. This review summarizes the current knowledge on the comprehensive evaluation that CMR can provide for patients with FMR, in particular for the assessment of MF and its potential impact in clinical decision-making.     

Mitral Regurgitation After Percutaneous Mitral Valvuloplasty: Insights Into Mechanisms and Impact on Clinical Outcomes

ObjectivesThe aim of this study was to assess the incidence, mechanisms, and outcomes of mitral regurgitation (MR) after percutaneous mitral valvuloplasty (PMV).BackgroundSignificant MR continues to be a major complication of PMV, with a wide range in clinical presentation and prognosis.MethodsConsecutive patients with mitral stenosis undergoing PMV were prospectively enrolled. MR severity was evaluated by using quantitative echocardiographic criteria, and its mechanism was characterized by 3-dimensional transesophageal echocardiography, divided broadly into 4 categories based on the features contributing to the valve damage. B-type natriuretic peptide levels were obtained before and 24 h after the procedure. Endpoints estimated cardiovascular death or mitral valve (MV) replacement due to predominant MR.ResultsA total of 344 patients, ages 45.1 ± 12.1 years, of whom 293 (85%) were women, were enrolled. Significant MR after PMV was found in 64 patients (18.6%). The most frequent mechanism of MR was commissural, which occurred in 22 (34.4%) patients, followed by commissural with posterior leaflet in 16 (25.0%), leaflets at central scallop or subvalvular damage in 15 (23.4%), and central MR in 11 (17.2%). During the mean follow-up period of 3 years (range 1 day to 10.6 years), 60 patients reached the endpoint. The event-free survival rates were similar among patients with mild or commissural MR, whereas patients with damaged central leaflet scallop or subvalvular apparatus had the worst outcome, with an event-free survival rate at 1 year of only 7%. Long-term outcome was predicted by net atrioventricular compliance (C_n) at baseline and post-procedural variables, including valve area, mean gradient, and magnitude of decrease in B-type natriuretic peptide levels, adjusted for the mechanism of MR.ConclusionsSignificant MR following PMV is a frequent event, mainly related to commissural splitting, with favorable clinical outcome. Parameters that express the relief of valve obstruction and the mechanism by which MR develops were predictors of long-term outcomes.     

3-Year Outcomes of Transcatheter Mitral Valve Repair in Patients With Heart Failure

BackgroundIn the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial, transcatheter mitral valve repair (TMVr) resulted in fewer heart failure hospitalizations (HFHs) and lower mortality at 24 months in patients with heart failure (HF) with mitral regurgitation (MR) secondary to left ventricular dysfunction compared with guideline-directed medical therapy (GDMT) alone.ObjectivesThis study determined if these benefits persisted to 36 months and if control subjects who were allowed to cross over at 24 months derived similar benefit.MethodsThis study randomized 614 patients with HF with moderate-to-severe or severe secondary MR, who remained symptomatic despite maximally tolerated GDMT, to TMVr plus GDMT versus GDMT alone. The primary effectiveness endpoint was all HFHs through 24-month follow-up. Patients have now been followed for 36 months.ResultsThe annualized rates of HFHs per patient-year were 35.5% with TMVr and 68.8% with GDMT alone (hazard ratio [HR]: 0.49; 95% confidence interval [CI]: 0.37 to 0.63; p < 0.001; number needed to treat (NNT) = 3.0; 95% CI: 2.4 to 4.0). Mortality occurred in 42.8% of the device group versus 55.5% of control group (HR: 0.67; 95% CI: 0.52 to 0.85; p = 0.001; NNT = 7.9; 95% CI: 4.6 to 26.1). Patients who underwent TMVr also had sustained 3-year improvements in MR severity, quality-of-life measures, and functional capacity. Among 58 patients assigned to GDMT alone who crossed over and were treated with TMVr, the subsequent composite rate of mortality or HFH was reduced compared with those who continued on GDMT alone (adjusted HR: 0.43; 95% CI: 0.24 to 0.78; p = 0.006).ConclusionsAmong patients with HF and moderate-to-severe or severe secondary MR who remained symptomatic despite GDMT, TMVr was safe, provided a durable reduction in MR, reduced the rate of HFH, and improved survival, quality of life, and functional capacity compared with GDMT alone through 36 months. Surviving patients who crossed over to device treatment had a prognosis comparable to those originally assigned to transcatheter therapy. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation [COAPT]; NCT01626079)     

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     

Impact of Right Ventricular Dysfunction on Outcomes After Transcatheter Edge-to-Edge Repair for Secondary Mitral Regurgitation

ObjectivesThis study sought to assess the impact of right ventricular dysfunction (RVD) as defined by impaired right ventricular-to-pulmonary artery (RV-PA) coupling, on survival after edge-to-edge transcatheter mitral valve repair (TMVR) for severe secondary mitral regurgitation (SMR).BackgroundConflicting data exist regarding the benefit of TMVR in severe SMR. A possible explanation could be differences in RVD.MethodsUsing data from the EuroSMR (European Registry on Outcomes in Secondary Mitral Regurgitation) registry, this study compared the characteristics and outcomes of SMR patients undergoing TMVR, according to their RV-PA coupling, assessed by tricuspid annular plane systolic excursion-to-systolic pulmonary artery pressure (TAPSE/sPAP) ratio.ResultsOverall, 817 patients with severe SMR and available RV-PA coupling assessment underwent TMVR in the participating centers. RVD was present in 211 patients (25.8% with a TAPSE/sPAP ratio <0.274 mm/mm Hg). Although all patients demonstrated significant improvement in their New York Heart Association (NYHA) functional class, there was a trend toward a lower rate of NYHA functional class I or II among patients with RVD (56.5% vs. 65.5%, respectively; p = 0.086) after TMVR. Survival rates at 1 and 2 years were lower among patients with RVD (70.2% vs. 84.0%, respectively; p < 0.001; and 53.4% vs. 73.1%, respectively; p < 0.001). On multivariate analysis, a reduced TAPSE/sPAP ratio was a strong predictor of mortality (odds ratio: 1.62; 95% confidence interval: 1.14 to 2.31; p = 0.007).ConclusionsRVD, as shown by impairment of RV-PA coupling, is a major predictor of adverse outcome in patients undergoing TMVR for severe SMR. The often neglected functional and anatomic RV parameters should be systematically assessed when planning TMVR procedures for patients with severe SMR.     

Effect of Mitral Valve Gradient After MitraClip on Outcomes in Secondary Mitral Regurgitation: Results From the COAPT Trial

ObjectivesThe authors sought to evaluate the association between mean mitral valve gradient (MVG) and clinical outcomes among patients who underwent MitraClip treatment for secondary mitral regurgitation (SMR) in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial.BackgroundIn the COAPT trial, patients with heart failure (HF) and severe SMR who remained symptomatic despite guideline-directed medical therapy had marked 2-year reductions in mortality and HF hospitalizations after treatment with MitraClip.MethodsMitraClip-treated patients were divided into quartiles (Q) based on discharge echocardiographic MVG (n = 250). Endpoints including all-cause mortality, HF hospitalization, and health status measures at 2 years were compared between quartiles.ResultsMean MVG after MitraClip was 2.1 ± 0.4 mm Hg, 3.0 ± 0.2 mm Hg, 4.2 ± 0.5 mm Hg, and 7.2 ± 2.0 mm Hg in Q1 (n = 63), Q2 (n = 61), Q3 (n = 62), and Q4 (n = 64), respectively. There was no difference across quartiles in the 2-year composite endpoint of all-cause mortality or HF hospitalization (43.2%, 49.2%, 40.6%, and 40.9%, respectively; p = 0.80), nor in improvements in New York Heart Association functional class, Kansas City Cardiomyopathy Questionnaire score, or 6-min walk time. Results were similar after adjustment for baseline clinical and echocardiographic characteristics, post-procedure MR grade, and number of clips (all-cause mortality or HF hospitalization Q4 [44.6%] vs. Q1 to Q3 [40.3%]; adjusted hazard ratio: 1.23, 95% confidence interval: 0.60 to 2.51; p = 0.57).ConclusionsAmong HF patients with severe SMR, higher MVGs on discharge did not adversely affect clinical outcomes following MitraClip. These findings suggest that in select patients with HF and SMR otherwise meeting the COAPT inclusion criteria, the benefits of MR reduction may outweigh the effects of mild-to-moderate mitral stenosis after MitraClip.     

Impact of COPD on Outcomes After MitraClip for Secondary Mitral Regurgitation: The COAPT Trial

ObjectivesThe aim of this study was to examine the relationship between chronic obstructive pulmonary disease (COPD) and outcomes after transcatheter mitral valve repair (TMVr) for severe secondary mitral regurgitation.BackgroundTMVr with the MitraClip improves clinical and health-status outcomes in patients with heart failure and severe (3+ to 4+) secondary mitral regurgitation. Whether these benefits are modified by COPD is unknown.MethodsCOAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) was an open-label, multicenter, randomized trial of TMVr plus guideline-directed medical therapy (GDMT) versus GDMT alone. Patients on corticosteroids or continuous oxygen were excluded. Multivariable models were used to examine the associations of COPD with mortality, heart failure hospitalization (HFH), and health status and to test whether COPD modified the benefit of TMVr compared with GDMT.ResultsAmong 614 patients, 143 (23.2%) had COPD. Among patients treated with TMVr, unadjusted analyses demonstrated increased 2-year mortality in those with COPD (hazard ratio [HR]: 2.08; 95% confidence interval [CI]: 1.33 to 3.26), but this association was attenuated after risk adjustment (adjusted HR: 1.48; 95% CI: 0.87 to 2.52). Although TMVr led to reduced 2-year mortality among patients without COPD (adjusted HR: 0.47; 95% CI: 0.33 to 0.67), for patients with COPD, 2-year all-cause mortality was similar after TMVr versus GDMT alone (adjusted HR: 0.94; 95% CI: 0.54 to 1.65; p_int = 0.04), findings that reflect offsetting effects on cardiovascular and noncardiovascular mortality. In contrast, TMVr reduced HFH (adjusted HR: 0.48 [95% CI: 0.28 to 0.83] vs. 0.46 [95% CI: 0.34 to 0.63]; p_int = 0.89) and improved both generic and disease-specific health status to a similar extent compared with GDMT alone in patients with and without COPD (p_int >0.30 for all scales).ConclusionsIn the COAPT trial, COPD was associated with attenuation of the survival benefit of TMVr versus GDMT compared with patients without COPD. However, the benefits of TMVr on both HFH and health status were similar regardless of COPD. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] [COAPT]; NCT01626079)