Ischemic mitral regurgitation: long-term outcome and prognostic implications with quantitative Doppler assessment

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Methodologic Considerations on Four Cardiovascular Interventions Trials With Contradictory Results

BACKGROUND

Contradictory findings from randomized trials addressing similar research questions are not uncommon in medicine. Although differing results may reflect true differences in the treatment effects or in the deliverability of the intervention, more commonly it is as a consequence of small but important discrepancies in study design.

METHODS

The writing group selected 4 recent trials with apparently contradictory results (2 on revascularization for left main coronary stenosis and 2 on treatment of secondary mitral regurgitation). Detailed methodologic analysis was performed to elucidate the difference in findings.

RESULTS

Differences in the definition of the primary outcome are the most likely explanation for the contradictory findings of NOBLE versus EXCEL. Differences in study design (leading to substantially different patient populations) and in outcome definition might explain the discrepant findings of MITRA-FR versus COAPT.

CONCLUSIONS

As shown by the comparative analysis of NOBLE and EXCEL and MITRA-FR and COAPT, changes in study design, outcome definitions, and patient population can markedly affect the outcome of randomized clinical trials.

Natural History of Functional Tricuspid Regurgitation Quantified by Cardiovascular Magnetic Resonance

BACKGROUND

Quantitation of tricuspid regurgitant (TR) severity can be challenging with conventional echocardiographic imaging and may be better evaluated using cardiovascular magnetic resonance (CMR).

OBJECTIVES

In patients with functional TR, this study sought to examine the relationship between TR volume (TRVol) and TR fraction (TRF) with all-cause mortality.

METHODS

We examined 547 patients with functional TR using CMR to quantify TRVol and TRF. The primary outcome was all-cause mortality. Thresholds for mild, moderate, and severe TR were derived based on natural history outcome data.

RESULTS

During a median follow-up of 2.6 years (interquartile range: 1.7 to 3.3 years), there were 93 deaths, with an estimated 5-year survival of 79% (95% confidence interval [CI]: 73% to 83%). After adjustment of clinical and imaging variables, including RV function, both TRF (adjusted hazard ratio [AHR] per 10% increment: 1.26; 95% CI: 1.10 to 1.45; p = 0.001) and TRVol (AHR per 10-ml increment: 1.15; 95% CI: 1.04 to 1.26; p = 0.004) were associated with mortality. Patients in the highest-risk strata of TRVol ≥45 ml or TRF ≥50% had the worst prognosis (AHR: 2.26; 95% CI: 1.36 to 3.76; p = 0.002 for TRVol and AHR: 2.60; 95% CI: 1.45 to 4.66; p = 0.001 for TRF).

CONCLUSIONS

This is the first study to use CMR to assess independent prognostic implications of functional TR. Both TRF and TRVol were associated with increased mortality after adjustment for clinical and imaging covariates, including right ventricular ejection fraction. A TRVol of ≥45 ml or TRF of ≥50% identified patients in the highest-risk strata for mortality. These CMR thresholds should be used for patient selection in future trials to determine if tricuspid valve intervention improves outcomes in this high-risk group.

Percutaneous Mitral Valve Repair with the MitraClip System in the Current Clinical Practice

Severe mitral valve regurgitation (MR) carries a significant burden both in prognosis and quality of life of patients, as well as on healthcare systems, with high rates of hospitalization for heart failure. While mitral valve surgery constitutes the first-line treatment option for primary MR in suitable patients, surgical treatment for secondary severe MR remains controversial, with a substantial lack of evidence on a survival benefit. In recent decades, percutaneous mitral valve repair has emerged as an alternative treatment for patients deemed not suitable for surgery. Among several devices under development or evaluation, the MitraClip system is the most widespread and is supported by the strongest evidence. While the role of MitraClip in patients with chronic primary MR who are not deemed suitable for surgery is well established, with consistent data showing improvement in both prognosis and quality of life, MitraClip treatment in secondary MR is a rapidly evolving field. Two recent randomized clinical trials generated apparently controversial results but actually provided an interesting pathophysiologic frame that could help discerning patients who will benefit from the procedure versus patients who will not. In this review, we will discuss current treatment options for mitral regurgitation, focusing on percutaneous mitral valve repair with the MitraClip system.

Transcatheter reshaping of the mitral annulus in patients with functional mitral regurgitation: one-year outcomes of the MAVERIC trial

AIMS

The aim of this study was to assess the one-year safety and efficacy of the transcatheter ARTO system in the treatment of functional mitral regurgitation (FMR).

METHODS AND RESULTS

MAVERIC is a multicentre, prospective, non-randomised pre-commercial study. Eligible patients were on guideline-recommended therapy for NYHA Class II-IV systolic heart failure and had an FMR grade ≥2+. The ARTO system was implanted in forty-five (100%) patients. The primary safety composite endpoint (death, stroke, myocardial infarction, device-related surgery, cardiac tamponade, renal failure) at 30 days and one year was 4.4% (95% CI: 1.5-16.6) and 17.8% (95% CI: 9.3-32.4), respectively. Periprocedural complications occurred in seven patients (15.5% [95% CI: 6.5-29.5]), and five patients (11.1% [95% CI: 4.9-24.0]) died during one-year follow-up. Paired results for 36 patients demonstrated that 24 (66.7%) had grade 3+/4+ mitral regurgitation at baseline; however, only five (13.9%) and three (8.3%) patients remained at grade 3+/4+ 30 days and one year post procedure (p<0.0001). Echocardiographic parameters such as anteroposterior annulus diameter decreased from 41.4 mm (baseline) to 36.0 and 35.3 mm at 30 days and one year, respectively (p<0.0001). Twenty-five patients (69.4%) had baseline NYHA Class III/IV symptoms decreasing significantly to nine (25.0%) at 30 days and eight (22.2%) at one year post procedure (p<0.0001).

CONCLUSIONS

The ARTO transcatheter mitral valve repair system is both safe and effective in decreasing FMR up to one year post procedure.

Left Atrial Volumetric/Mechanical Coupling Index: A Novel Predictor of Outcome in Heart Failure With Reduced Ejection Fraction

BACKGROUND

Left atrial assessment is complex, particularly in heart failure with reduced ejection fraction due to interactions with functional mitral regurgitation (FMR). Pilot data suggest that left atrial volumetric/mechanical coupling index (LACI) may be useful, but large outcome data are lacking.

METHODS

We enrolled a comprehensively characterized cohort of patients in sinus rhythm with heart failure with reduced ejection fraction diagnosis at Mayo Clinic from 2007 to 2011. Routinely measured left atrial volume index and tissue-doppler-imaging a' allowed LACI calculation as (left atrial volume index)/(tissue-doppler-imaging a'). Survival was the outcome measured.

RESULTS

The cohort's 4196 patients (69 [58-77] years, ejection fraction 40 [31-45]%) had mild FMR in 1505 and moderate-severe FMR in 1068. LACI was overall 5.06 (3.50-8.10) and increased with each FMR grade (3.86 [2.94-5.29] without FMR, 5.38 [3.80-8.02] with mild, 5.45 [1.49-8.07] with moderate/severe FMR; P<0.0001). At diagnosis, higher LACI was independently determined by more severe FMR and by higher left ventricular mass index, lower ejection fraction, higher E/e', and lower glomerular filtration rate (all P<0.0001). During follow-up 1588 (38%) patients died. In spline modeling, excess mortality appeared around LACI=6 and steeply increased thereafter (5-year survival 72±1% with LACI<6 and 49±2% with LACI ≥6, P<0.0001). Multivariable comprehensive adjustment showed LACI strong association with excess mortality (adjusted hazard ratio, 1.41 [1.23-1.61], P<0.0001 for LACI ≥6). Independent link to mortality persistent across FMR grades (adjusted hazard ratio, 1.45 [1.13-1.86], P=0.004 without FMR, 1.42 [1.16-1.77], P=0.0008 with mild FMR, and 1.38 [1.01-1.66], P=0.04 with moderate/severe FMR) without interaction (P=0.3). LACI independent impact on outcome was incremental to that of left atrial volume index, tissue-doppler-imaging a', or any other characteristic including the Meta-Analysis Global Group in Chronic-score (least significant P=0.02).

CONCLUSIONS

In this large cohort, left atrial volumetric/mechanical coupling measured by LACI in routine practice integrates the influence of several morphological/hemodynamic determinants but displays progressive deterioration with increasing FMR severity in heart failure with reduced ejection fraction. About outcome, higher LACI is strongly, independently, and incrementally associated with excess mortality, irrespective of FMR grade and in all subsets. Hence, LACI is a novel and critical measure in heart failure with reduced ejection fraction, quantifiable in routine practice, which should be integrated in prognostication and decision-making.

Risk Stratification of Percutaneous Edge-to-Edge Repair by MitraClip in Patients with Mitral Regurgitation

Edge-to-edge repair using the MitraClip system is indicated in patients with severe mitral regurgitation (MR) who are at high risk for open-heart surgery due to comorbidity or reduced cardiac function. However, less is known about pre-procedural risk factors for mortality and morbidity following MitraClip implantation. Consecutive 25 patients with severe MR who underwent MitraClip therapy (mean age, 77 years old, 14 males) were included. Right heart catheterization and echocardiographic data before and after the procedure were collected and their prognostic impacts were investigated. Acute procedural success was 96%. At one week following MitraClip repair, left ventricular ejection fraction (LVEF) remained unchanged and left ventricular end-diastolic volume tended to be smaller. Cardiac index and mean pulmonary artery pressure (mPAP) were markedly improved following the procedure (P < 0.001 for both). In the multivariate analyses using baseline characteristics, both lower LVEF (hazard ratio 0.57, 95% confidence interval 0.30-0.89) and higher mPAP (hazard ratio 1.23, 95% confidence interval 1.06-1.56) were independently associated with post-procedural 1-year death or heart failure readmission (P < 0.05 for both). The lower LVEF and higher mPAP group had lower 1-year survival free from HF readmission compared with those without (16.7% versus 100%; P < 0.001). In conclusion, a combination of baseline mPAP and LVEF might be a useful tool in predicting post-MitraClip procedural clinical outcomes.

Predictors of moderate to severe ischemic mitral regurgitation after myocardial infarction: a cardiac magnetic resonance study

OBJECTIVES

The purpose of this study is to explore the predictors of moderate to severe ischemic mitral regurgitation (IMR) after myocardial infarction with cardiovascular magnetic resonance (CMR).

METHODS

From January 2016 to September 2018, 109 patients (mean age 60 ± 8 years) with IMR were studied retrospectively. All patients underwent CMR-cine with True-FISP sequence and late gadolinium enhancement (LGE) with a phase-sensitive inversion recovery sequence. The presence of papillary muscle infarction (PMI), global left ventricular (LV) infarcted extent, LV functional parameters, and LV myocardial strain were assessed. Univariate and multivariate analyses were performed to identify factors in the development of moderate to severe IMR.

RESULTS

Mild IMR was present in 61 patients (56%), and moderate to severe IMR was present in 48 patients (44%). PMI was identified in 22 patients (20.1%); 14 of them (63.63%) showed a moderate or severe IMR. Global LV infarcted extent was increased in patients with moderate to severe IMR (p < 0.001). LV functional parameters of patients with moderate to severe IMR were statistically different from those of the patients with mild IMR (all p < 0.001), except the LV SV index (p = 0.142) and LV CI (p = 0.447). The global longitudinal strain (GLS), regional radial strain (RS), and circumferential strain (CS) of the moderate-to-severe IMR group were significantly decreased compared with those of the mild IMR group (p < 0.05). In multivariable analyses, age (OR = 1.11; p = 0.001), global LV infarct extent (OR = 1.14; p = 0.000), and GLS (OR = 1.31; p = 0.000) were associated with moderate-to-severe chronic IMR.

CONCLUSIONS

The incidence of PMI was higher in patients with moderate-to-severe IMR. The extent of global LV infarcted extent and GLS were independent predictors of moderate-to-severe IMR.

KEY POINTS

• Cardiovascular magnetic resonance late gadolinium enhancement and feature-tracking imaging provide reliable information on LV function, myocardial viability, and papillary muscle morphology. • Papillary muscle infarction is not an independent predictor of moderate-to-severe IMR. • The extent of global LV infarction and LV global longitudinal strain were independent predictors of moderate-to-severe chronic IMR.

Prognostic relevance and clinical features of papillary muscle infarction with mitral regurgitation in patients with ST segment elevation myocardial infarction

Background

Papillary muscle infarction (PapMI) combined with mitral regurgitation (MR) is a severe complication of ST-segment elevation myocardial infarction (STEMI). The features detected by cardiac magnetic resonance (CMR) imaging in PapMI have not been characterized. The aim of the present study was to assess the incidence, determinants, and the prognostic significance of PapMI with MR at 1-year follow-up in a study of patients with STEMI after primary percutaneous coronary intervention (pPCI).

Methods

We enrolled 209 patients with STEMI reperfused by pPCI (<12 hours after symptom onset) at 2 centers. CMR and echocardiography were performed within 1 week after infarction using a standardized protocol. According to the results of CMR and echocardiography, patients were divided into PapMI with MR, PapMI (PapMI without MR), and non-PapMI groups. The primary clinical endpoint of the study was the occurrence of major adverse cardiovascular events (MACE).

Results

PapMI with MR was found in 27 patients (13%). The existence of PapMI with MR was associated with age (P<0.001), impaired left ventricular ejection fraction (LVEF) (P=0.005), higher SYNTAX score (P=0.002), concentration of troponin I (P<0.001), longer time to reperfusion (P<0.001), more diabetics (P<0.001), and microvascular occlusion (MVO) (P<0.001). Binary logistic regression with stepwise backward selection analysis showed that advanced age, MVO, and impaired LVEF were independent risk factors for PapMI with MR. Patients in the PapMI with MR group had significantly more MACE compared with the PapMI and non-PapMI groups [PapMI with MR, 23 (85.2%) vs. PapMI, 21 (55.3%) vs. non-PapMI, 29 (20.1%)] at 1-year follow-up (P<0.001). However, there were no pronounced differences in mortality rates among the 3 groups (P=0.071).

Conclusions

The presence of PapMI with MR in patients with STEMI is associated with advanced age, MVO, and impaired LVEF, which can increase the rates of MACE.

Transcatheter mitral valve replacement: latest advances and future directions

Mitral regurgitation remains the most common form of valve disease worldwide and given an aging population with a significant proportion of secondary mitral regurgitation, a transcatheter approach to mitral valve replacement has become a major goal of the transcatheter therapeutics field. Mitral regurgitation can be caused by disease of the leaflets (primary) or by diseases of the left atrium or left ventricle (LV) (secondary or functional), and may involve overlap of the two (mixed disease). The location of the mitral valve (and large size), the approach to anchoring a valve replacement, and concerns about left ventricular outflow tract (LVOT) obstruction are all issues that have made the transcatheter delivery of a valve replacement challenging. Despite these challenges, both transapical and transseptal devices are currently being developed, with several in early feasibility trials and several entering pivotal trials. As the field of transcatheter mitral valve replacement (TMVR) improves and develops, a critical part of evaluating patients with mitral valve disease will be utilizing the heart team approach to identify and individualize the most appropriate treatment for each patient.

Multimodality Imaging in Secondary Mitral Regurgitation

Secondary mitral regurgitation (sMR) is characterized by left ventricular (LV) dilatation or dysfunction, resulting in failure of mitral leaflet coaptation. sMR complicates up to 35% of ischaemic cardiomyopathies (1) and 57% of dilated cardiomyopathies (2). Due to the prevalence of coronary artery disease worldwide, ischaemic cardiomyopathy is the most frequently encountered cause of sMR in clinical practice. Although mortality from cardiovascular disease has gradually fallen in Western countries, severe sMR remains an independent predictor of mortality (3) and hospitalization for heart failure (4). The presence of even mild sMR following acute MI reduces long-term survival free of major adverse events (1). Such adverse outcomes worsen as the severity of sMR increases, due to a cycle in which LV remodeling begets sMR and vice versa. Current guidelines do not recommend invasive treatment of the sMR alone as a first-line approach, due to the paucity of evidence supporting improvement in clinical outcomes. Furthermore, a lack of international consensus on the thresholds that define severe sMR has resulted in confusion amongst clinicians determining whether intervention is warranted (5, 6). The recent Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial (7) assessing the effectiveness of transcatheter mitral valve repair is the first study to demonstrate mortality benefit from correction of sMR and has reignited interest in identifying patients who would benefit from mitral valve intervention. Multimodality imaging, including echocardiography and cardiovascular magnetic resonance (CMR), plays a key role in helping to diagnose, quantify, monitor, and risk stratify patients for surgical and transcatheter mitral valve interventions.

Pathophysiology, Diagnosis, and New Therapeutic Approaches for Ischemic Mitral Regurgitation

Ischemic mitral regurgitation (MR) is a valvular complication frequently seen in patients with coronary artery disease and is associated with increased mortality and morbidity. Ischemic mitral regurgitation has a complex, heterogeneous, and still incompletely understood pathophysiology involving both the mitral valve and the left ventricle. The occurrence of valve regurgitation in patients with ischemic cardiomyopathy in return accelerates left ventricular remodelling and dysfunction, ultimately leading to irreversible heart failure. Diagnostic evaluation of ischemic MR is unique and different from the other causes of MR. The severity thresholds associated with outcomes are different from primary MR, and specific imaging characteristics are potentially useful to guide therapy. The use of imaging modalities such as 3-dimensional echocardiography and cardiac magnetic resonance imaging can refine the diagnostic evaluation and help in choosing the correct management. Although multiple treatments are available to improve ischemic MR, each therapeutic option is associated with limitations and incomplete success. Therapy has therefore to be individualised for each patient. Current options include optimal medical therapy, cardiac resynchronisation therapy, percutaneous or surgical revascularisation, surgical mitral repair or replacement, and new percutaneous interventions. This review aims to discuss the latest insights regarding the pathophysiology, diagnosis, and treatment of ischemic MR.

MitraClip for Secondary Mitral Regurgitation: Approach to the 2020 ACC/AHA Valvular Heart Disease Guidelines

We describe the case of an 83-year-old man with a history of ischemic cardiomyopathy and severe secondary mitral regurgitation. This case highlights the role of transcatheter edge-to-edge repair with the MitraClip in the management of symptomatic functional mitral regurgitation in a surgically unfavorable patient. (Level of Difficulty: Advanced.)

Impact of Myocardial Scar on Prognostic Implication of Secondary Mitral Regurgitation in Heart Failure

OBJECTIVES

The objective of the present study was to use cardiovascular magnetic resonance (CMR) to examine the natural history of secondary MR severity and the implication of left ventricular (LV) scar on its prognostic significance.

BACKGROUND

There is a need for further understanding of the prognostic implication of secondary mitral regurgitation (MR) given the heterogeneous findings of the 2 recent randomized trials on percutaneous mitral intervention in patients with secondary MR.

METHODS

Patients with heart failure were enrolled into a prospective observational registry between 2008 and 2019. Outcomes were a composite of all-cause death, heart transplantation, or LV assist device implantation at follow-up. CMR was used to quantify the mitral regurgitation volume and mitral regurgitation fraction (MRF) along with scar burden utilizing late gadolinium enhancement. Patients were categorized into 4 subgroups based on presence and tertiles of scar extent: no scar, limited scar (scar burden 1% to 4%), intermediate scar (scar burden 5% to 20%), and extensive scar (scar burden >20%).

RESULTS

Among patients (n = 441) included in the study (age 59 ± 14 years, 43% with ischemic etiology), 85 (19%) experienced an adverse event. MRF ≥30% was associated with increased risk of events among the study group (hazard ratio: 1.74; 95% confidence interval: 1.10 to 2.76; p = 0.02). When stratified by presence or absence of scar, MRF ≥30% was associated with events only among patients with scar (hazard ratio: 1.67; 95% confidence interval: 1.02 to 2.76; p = 0.04) but not among patients without scar. On further classification of patients with scar, the prognostic significance of secondary MR was observed primarily among patients with intermediate scar burden.

CONCLUSIONS

The natural history of secondary MR is complex, and outcomes are affected by severity of MR and vary depending upon the extent of scar. (DeBakey Cardiovascular Magnetic Resonance Study [DEBAKEY-CMR]; NCT04281823).

Comparison of percutaneous MitraClip versus mitral valve surgery for severe mitral regurgitation: a meta-analysis: Mitraclip and mitral valve surgery meta-analysis

AIMS

Mitral valve surgery (MVS) is the gold-standard treatment for severe symptomatic mitral regurgitation. Percutaneous mitral valve interventions such as the MitraClip procedure offer another dimension to its management particularly in high-risk patients. We meta-analysed the outcomes of MitraClip and MVS.

METHODS AND RESULTS

PubMed, MEDLINE, Embase, Cochrane and Scopus from 1980/01-2019/06 were searched for eligible studies. Data were extracted and pooled using random-effects models. After screening 959 studies and reviewing 21 full-text articles, nine studies totalling 640 MitraClip and 531 MVS (91% valve repair) procedures were included in the meta-analysis. MitraClip patients were older, with a higher prevalence of previous cardiac surgery, coronary disease and a higher EuroSCORE (all p<0.05) than MVS patients. Pooled operative mortality was similar for MitraClip, 3%, versus MVS, 5%, odds ratio (OR): 0.58, 95%, CI: 0.28-1.19, as well as at 1 year mortality, OR: 1.09, CI: 0.71-1.68 and 3-year mortality, OR: 1.08, CI: 0.72-0.163. MitraClip patients had higher rates of early and late significant mitral regurgitation (MR) and more cardiovascular readmissions, while MVS had higher rates of in-hospital bleeding and pacemaker implantation (all p<0.05).

CONCLUSIONS

MitraClip patients had a higher baseline risk than MVS, but there were no significant differences in short- and long-term mortality. MitraClip patients had higher rates of cardiovascular admissions and significant MR post-operatively, while MVS patients had more procedural complications.

Transcatheter Mitral Valve Repair in Patients with Heart Failure: A Meta-Analysis

BACKGROUND

Severe secondary mitral regurgitation (MR) is associated with poor prognosis in heart failure patients with left ventricular systolic dysfunction. Few observational and randomized controlled studies demonstrated the efficacy of transcatheter mitral valve repair in heart failure patients with significant MR. A meta-analysis of published studies was performed to evaluate the role of transcatheter mitral valve repair using the MitraClip device in heart failure patients with significant secondary MR.

METHODS

A literature search was performed using PubMed, Cochran CENTRAL, and Embase databases using the search terms "percutaneous mitral valve repair" or "transcatheter mitral valve repair" and "heart failure." Studies that compared medical therapy plus transcatheter mitral valve repair using MitraClip to medical therapy alone in heart failure patients with significant secondary MR were included for pooled analysis. A random-effects model with the Mantel-Haenszel method was used to analyze the data.

RESULTS

Four studies, 2 randomized controlled and 2 nonrandomized studies met the criteria for analysis. Pooled analysis included a total of 1,421 patients, of which 746 patients underwent transcatheter mitral valve repair and 675 patients received medical therapy alone. When compared to medical therapy, transcatheter mitral valve repair significantly decreased all-cause mortality (OR 0.58, 95% CI 0.37-0.91; p = 0.02). A trend toward significant reduction in rehospitalizations (OR 0.35, 95% CI 0.12-1.00; p = 0.05) was also observed. Periprocedural complications ranged from 7.5 to 12.6%.

CONCLUSION

Evidence from pooled analysis suggests that transcatheter mitral valve repair using MitraClip on top of medical therapy, in appropriately selected symptomatic heart failure patients with significant secondary MR, provides survival benefit and may decrease hospitalizations when compared with guideline-directed medical therapy alone.

Significant functional mitral regurgitation affects left atrial function in heart failure patients: haemodynamic correlations and prognostic implications

AIMS

Functional mitral regurgitation (FMR) is a well-known pathophysiological factor in heart failure (HF) patients, and left atrial function (LAF) is a novel determinant of clinical status and outcome in this setting. However, little is known about the pathophysiological role of FMR on LAF in HFrEF patients. Aim of this study is to explore the possible interplay between the severity of FMR and LAF in heart failure with reduce ejection fraction (HFrEF) patients and their possible consequences.

METHODS AND RESULTS

We studied 97 consecutive patients with FMR classified in two groups: mild-to-moderate MR ore less (FMR group, n = 38) and moderate-to-severe or more (SFMR group, n = 59). Using the phasic method, left atrial contractile, conduit, reservoir, and total emptying function (TLAEF) were calculated to assess LAF. SFMR group showed significantly lower values of LAF compared to FMR group. LA dysfunction (LA-dys) was defined for TLAEF values below the median and groups divided in four subgroups based on its presence. Patient with LA-Dys in SFMR group showed a worse clinical status, higher incidence of right ventricular dysfunction (RV-Dys), and pulmonary hypertension (PH), and a significant worse clinical survival compared to all other groups.

CONCLUSION

In our study, the survival was significantly lower in SFMR/LA-Dys+ group. Furthermore, LA-Dys was strongly related with worse clinical status and higher incidence of PH and RV-Dys. These results suggest that in patients with SFMR and HFrEF, LA-Dys may represent both a marker of more advanced disease and a novel prognostic factor.

Transcatheter Mitral Valve Replacement: Rationale and Current Status

Mitral regurgitation (MR) is the most prevalent form of moderate or severe valve disease in the developed world. MR can result from impairment of any part of the mitral valve apparatus and is classified as primary (disease of the leaflets) or secondary (functional). The presence of at least moderate MR is associated with increased morbidity and mortality. With the goal of avoiding the risks of traditional surgery, transcatheter mitral valve therapies have been developed. The current transcatheter repair techniques are limited by therapeutic target and incomplete MR reduction, and thus transcatheter mitral valve replacement (TMVR) has been pursued. Several devices (both transapical and transseptal) are under development, with both early feasibility and pivotal trials under way. As this field develops, the decision to treat with TMVR will require a heart team approach that takes patient-, disease-, and device-specific factors into account.

Causes and mechanisms of isolated mitral regurgitation in the community: clinical context and outcome

AIMS

To define the hitherto unknown aetiology/mechanism distributions of mitral regurgitation (MR) in the community and the linked clinical characteristics/outcomes.

METHODS AND RESULTS

We identified all isolated, moderate/severe MR diagnosed in our community (Olmsted County, MN, USA) between 2000 and 2010 and classified MR aetiology/mechanisms. Eligible patients (n = 727) were 73 ± 18 years, 51% females, with ejection fraction (EF) 49 ± 17%. MR was functional (FMR) in 65%, organic (OMR) in 32% and 2% mixed. Functional MR was linked to left ventricular remodelling (FMR-v) 38% and isolated atrial dilatation (FMR-a) 27%. At diagnosis FMR-v vs. FMR-a, vs. OMR displayed profound differences (all P < 0.0001) in age (73 ± 14, 80 ± 10, 68 ± 21years), male-sex (59, 33, 51%), atrial-fibrillation (28, 54, 13%), EF (33 ± 14, 57 ± 11, 61 ± 10%), and regurgitant-volume (38 ± 13, 37 ± 11, 51 ± 24 mL/beat). Dominant MR mechanism was Type I (normal valve-movement) 38%, Type II (excessive valve-movement) 25%, Type IIIa (diastolic movement-restriction) 3%, and Type IIIb (systolic movement-restriction) 34%. Outcomes were mediocre with excess-mortality vs. general-population in FMR-v [risk ratio 3.45 (2.98-3.99), P < 0.0001] but also FMR-a [risk ratio 1.88 (1.52-2.25), P < 0.0001] and OMR [risk ratio 1.83 (1.50-2.22), P < 0.0001]. Heart failure was frequent, particularly in FMR-v (5-year 83 ± 3% vs. 59 ± 4% FMR-a, 40 ± 3% OMR, P < 0.0001). Mitral surgery during patients' lifetime was performed in 4% of FMR-v, 3% of FMR-a, and 37% of OMR.

CONCLUSION

Moderate/severe isolated MR in the community displays considerable aetiology/mechanism heterogeneity. Functional MR dominates, mostly FMR-v but FMR-a is frequent and degenerative MR dominates OMR. Outcomes are mediocre with excess-mortality particularly with FMR-v but FMR-a, despite normal EF incurs notable excess-mortality and frequent heart failure. Pervasive undertreatment warrants clinical trials of therapies tailored to specific MR cause/mechanisms.

Impact of recurrent mitral regurgitation after mitral valve repair for functional mitral regurgitation: long-term analysis of competing outcomes

AIMS

Recurrent mitral regurgitation (MR) has been reported after mitral valve repair for functional MR. However, the impact of recurrent MR on long-term survival remains poorly defined. In the present study, mortality-adjusted recurrent MR rates, the clinical impact of recurrent MR and its determinants were studied in patients after mitral valve repair with revascularization for functional MR in the setting of ischaemic heart disease.

METHODS AND RESULTS

Long-term clinical and echocardiographic outcome was evaluated in 261 consecutive patients after restrictive mitral annuloplasty and revascularization for moderate to severe functional MR, between 2000 and 2014. The cumulative incidence of recurrent MR ≥ Grade 2, assessed by competing risk analysis, was 9.6 ± 1.8% at 1-year, 20.3 ± 2.5% at 5-year, and 27.6 ± 2.9% at 10-year follow-up. Cumulative survival was 85.8% [95% confidence interval (CI) 81.0-90.0] at 1-year, 67.3% (95% CI 61.1-72.6%) at 5-year, and 46.1% (95% CI 39.4-52.6%) at 10-year follow-up. Age, preoperative New York Heart Association Class III or IV, a history of renal failure, and recurrence of MR expressed as a time-dependent variable [HR 3.28 (1.87-5.75), P < 0.001], were independently associated with an increased mortality risk. Female gender, a history of ST-elevation myocardial infarction, a preoperative QRS duration ≥120 ms, a higher preoperative MR grade, and a higher indexed left ventricular end-systolic volume were independently associated with an increased likelihood of recurrent MR.

CONCLUSION

Mitral valve repair for functional ischaemic MR resulted in a low incidence of recurrent MR with favourable clinical outcome up to 10 years after surgery. Presence of recurrent MR at any moment after surgery proved to be independently associated with an increased risk for mortality.

MITRA-FR vs. COAPT: lessons from two trials with diametrically opposed results

Percutaneous mitral valve repair using the MitraClip device has been proposed to correct secondary mitral regurgitation (MR). Recently, the results of two randomized controlled trials, that is MITRA-FR (Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation) and COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation), assessing the efficacy and safety of MitraClip in patients with systolic heart failure and severe secondary MR were published. A priori, these two trials targeted the same patient populations with the same disease using the same device but the results of these trials were diametrically opposed, MITRA-FR being neutral and COAPT being highly positive with respect to efficacy of the MitraClip procedure. The objectives of this viewpoint are: (i) to highlight not only the similarities but also the differences between MITRA-FR and COAPT, which may explain the strikingly different results and conclusions between these two trials and (ii) to derive from these results, implications with regards to the application of the MitraClip procedure in clinical practice.

Ventricular arrhythmias in patients with functional mitral regurgitation and implantable cardiac devices: implications of mitral valve repair with Mitraclip®

Background

Limited information has been reported regarding the impact of percutaneous mitral valve repair (PMVR) on ventricular arrhythmic (VA) burden. The aim of this study was to address the incidence of VA and appropriate antitachycardia implantable cardiac defibrillator (ICD) therapies before and after PMVR.

Methods

We retrospectively analyzed all consecutive patients with heart failure with reduce left ventricular ejection fraction (LVEF), functional mitral regurgitation (FMR) grade 3+ or 4+ and an active ICD or cardiac resynchronizer who underwent PMVR in any of the eleven recruiting centers. Only patients with complete available device VA monitoring from one-year before to one year after PMVR were included. Baseline clinical and echocardiographic characteristics were collected before PMVR and at 12-months follow-up.

Results

Ninety-three patients (68.2±10.9 years old, male 88.2%) were enrolled. PMVR was successfully performed in all patients and device success at discharge was 91.4%. At 12-month follow-up, we observed a significant reduction in mitral regurgitation severity, NT-proBNP and prevalence of severe pulmonary hypertension and severe kidney disease. Patients also referred a significant improvement in NYHA functional class and showed a non-significant trend to reserve left ventricular remodeling. After PMVR a significant decrease in the incidence of non-sustained ventricular tachycardia (VT) (5.0±17.8 vs. 2.7±13.5, P=0.002), sustained VT or ventricular fibrillation (0.9±2.5 vs. 0.5±2.9, P=0.012) and ICD antitachycardia therapies (2.5±12.0 vs. 0.9±5.0, P=0.033) were observed.

Conclusions

PMVR was related to a reduction in arrhythmic burden and ICD therapies in our cohort.

Impact of Mitral Regurgitation Severity and Left Ventricular Remodeling on Outcome After MitraClip Implantation: Results From the Mitra-FR Trial

OBJECTIVES

This study aimed to identify a subset of patients based on echocardiographic parameters who might have benefited from transcatheter correction using the MitraClip system in the MITRA-FR (Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation) trial.

BACKGROUND

It has been suggested that differences in the degree of mitral regurgitation (MR) and left ventricular (LV) remodeling may explain the conflicting results between the MITRA-FR and the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trials.

METHODS

In a post hoc analysis, we evaluated the interaction between the intervention and subsets of patients defined based on MR severity (effective regurgitant orifice [ERO], regurgitant volume [RVOL] and regurgitant fraction [RF]), LV remodeling (end-diastolic and end-systolic diameters and volumes) and combination of these parameters with respect to the composite of death from any cause or unplanned hospitalization for heart failure at 24 months.

RESULTS

We observed a neutral impact of the intervention in subsets with the highest MR degree (ERO ≥30 mm², RVOL ≥45 ml or RF ≥50%) as in patients with milder MR degree. The same was seen in subsets with the milder LV remodeling using either diastolic or systolic diameters or volumes. When parameters of MR severity and LV remodeling were combined, there was still no benefit of the intervention including in the subset of patients with an ERO/end-diastolic volume ratio ≥ 0.15 despite similar ERO and LV end-diastolic volume compared with COAPT patients.

CONCLUSIONS

In the MITRA-FR trial, we could not identify a subset of patients defined based on the degree of the regurgitation, LV remodeling or on their combination, including those deemed as having disproportionate MR, that might have benefited from transcatheter correction using the MitraClip system. (Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients With Severe Secondary Mitral Regurgitation [MITRA-FR]; NCT01920698).

Determinants of outcome in patients with heart failure with reduced ejection fraction & secondary mitral regurgitation

BACKGROUND

The outcome of secondary mitral regurgitation (MR) in patients with heart failure is poor. Survival is related to the severity of MR. We sought to investigate the effect of left ventricular contractility, the ratio of left ventricular end-diastolic volume (LVEDV) to effective orifice area (EROA) and the ratio of regurgitant volume (RVol) to stroke volume (SV) on cardiovascular survival.

METHODS

188 patients with a left ventricular ejection fraction (LVEF) < 50% and secondary MR were included. Groups were divided into tertiles. The Kaplan Meier method and log rank test were used to identify differences in survival between groups. Cox regression was used to identify independent predictors of cardiac mortality.

RESULTS

Median follow-up was 30.4 months. Patients with a more abnormal global longitudinal strain (GLS) had lower survival, p = 0.001. There was no difference in survival between patients with an LVEF <30%, 30%-40% and >40%, p = 0.27. Patients with a higher RVol/SV ratio had lower survival than those with a lower ratio, p < 0.0001. Patients with a lower LVEDV/EROA ratio had worse survival than those with a higher ratio, p < 0.0001. Independent predictors of cardiovascular mortality were GLS (<5.6%) hazard ratio (HR) 2.7, the ratio of RVol/SV (>1.38) HR 4.96 and the ratio of LVDEV to EROA (<263) HR 4.49.

CONCLUSION

The main determinants of cardiovascular mortality in patients with secondary MR and heart failure are more abnormal GLS, lower LVEDV/EROA ratio and higher RVol/SV ratio. These may help risk stratify patients to help determine the optimal management strategy.

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

OBJECTIVES

The 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).

BACKGROUND

Quantification 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.

METHODS

A 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.

RESULTS

During 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).

CONCLUSIONS

In 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.

An observational, prospective study on surgical treatment of secondary mitral regurgitation: The SMR study. Rationale, purposes, and protocol

The natural history of secondary mitral regurgitation (MR) is unfavorable. Nevertheless, there are no evidence that its correction can improve the outcome. If from one side the original cause of secondary MR can be such to limit the possibilities of improvement, from the other side it is possible that the surgical technique widely applied to repair, restrictive mitral annuloplasty, is not adequate to correct the regurgitation. The addition of valvular and/or subvalvular techniques has been considered a possible technical solution. However, we do not know the prevalence of each technique, how many times mitral replacement is used to correct secondary MR. This aspect is of particular importance, as we know that a successful mitral repair causes a better left ventricular systolic remodeling than a unsuccessful repair or replacement. This study is a prospective, observational registry, conceived to understand what is done in the real world. Any surgeon will use the technique he thinks the most suitable for the patient. Every year, for 5 years, patients will have a clinical and echocardiographic follow-up, to evaluate the risk factors for a worse result (death, rehospitalization for heart failure, reoperation for MR return, moderate, or more MR return). This knowledge will give us the possibility to understand which is the technique, or the strategy, more efficient to treat this disease and the real efficacy of the surgical treatment.

Natural history of bivalvular functional regurgitation

AIMS

Bivalvular functional regurgitation (BVFR) defined as concomitant mitral and tricuspid insufficiency has not been described or systematically assessed before. Therefore, this study sought to define incidence, impact and natural history of BVFR in heart failure with reduced ejection fraction (HFrEF) to provide the foundation for risk assessment and directions for potential treatment strategies.

METHODS AND RESULTS

We enrolled 1021 consecutive patients with HFrEF under guideline-directed medical therapy and performed comprehensive echocardiographic and neurohumoral profiling. All-cause mortality during a 5 years of follow-up served as the primary endpoint. Thirty percent of patients suffered from moderate or severe BVFR. Long-term mortality increased with the presence and severity of functional regurgitation (FR) with severe BVFR representing the highest risk-subset (P < 0.001). Severe BVFR patients were more symptomatic and displayed an adverse remodelling and neurohumoral activation pattern (all P < 0.05). Severe BVFR was associated with excess mortality independently of clinical [adjusted hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.39-1.84; P < 0.001] and echocardiographic (adjusted HR 1.31, 95% CI 1.11-1.54; P = 0.001) confounders, guideline-directed medical therapy (adjusted HR 1.55, 95% CI 1.35-1.79; P < 0.001) and neurohumoral activation (adjusted HR 1.31, 95% CI 1.07-1.59; P = 0.009). Moderate BVFR (n = 99) comprised equal baseline characteristics and similar risk as isolated severe FR (HR 0.95, 95% CI 0.69-1.30; P = 0.73).

CONCLUSION

This long-term outcome study shows the multi-faceted nature of FR and defines BVFR as an important clinical entity associated with impaired functional class, adverse cardiac remodelling, and excess risk of mortality. Moderate BVFR conveys similar risk as isolated severe FR reflecting the deleterious impact of the global regurgitant load on the failing heart and the need of an integrated understanding for risk-assessment.

Percutaneous Interventions for Secondary Mitral Regurgitation

Mitral regurgitation is frequently associated with ventricular dysfunction and carries a high mortality. Guideline-directed medical therapy, surgical mitral valve repair or replacement, and, in the setting of advanced heart failure, heart transplant and left ventricular assist devices have been the mainstay of treatment. However, rapid advancement in the field has resulted in approval of edge-to-edge mitral valve repair with the MitraClip, and there are several novel catheter-based percutaneous options in clinical trials. Percutaneous options, while promising, must be deployed in patients who are most likely to benefit, and thus, understanding the pathophysiology of specific subgroups of patients with functional mitral regurgitation (eg, disproportionate versus proportionate mitral regurgitation) is key to the success of new devices. We review the pathophysiology, percutaneous therapeutic treatment options, and ongoing clinical trials for functional mitral regurgitation.

Dismal Outcomes and High Societal Burden of Mitral Valve Regurgitation in France in the Recent Era: A Nationwide Perspective

Background Although US recent data suggest that mitral regurgitation (MR) is severely undertreated and carries a poor outcome, population-based views on outcome and management are limited. We aimed to define the current treatment standards, clinical outcomes, and costs related to MR at the nationwide level. Methods and Results In total, 107 412 patients with MR were admitted in France in 2014 to 2015. Within 1 year, 8% were operated and 92% were conservatively managed and constituted our study population (68% primary MR and 32% secondary MR). The mean age was 77±15 years; most patients presented with comorbidities. In-hospital and 1-year mortality rates were 4.1% and 14.3%, respectively. Readmissions were common (63% at least once and 37% readmitted ≥2 times). Rates of 1-year mortality or all-cause readmission and 1-year mortality or heart failure readmission were 67% and 34%, respectively, and increased with age, Charlson index, heart failure at admission, and secondary MR etiology; however, the event rate remained notably high in the primary MR subset (64% and 28%, respectively). The mean costs of hospital admissions and of readmissions were 5345±6432 and 10 080±10 847 euros, respectively. Conclusions At the nationwide level, MR was a common reason for admission and affected an elderly population with frequent comorbidities. Less than 10% of patients underwent a valve intervention. All subsets of patients who were conservatively managed incurred high mortality and readmissions rates, and MR represented a major societal burden with an extrapolated annual cost of 350 to 550 million euros (390-615 million US dollars). New strategies to improve the management and outcomes of patients with both primary and secondary MR are critical and warranted.

Secondary valve regurgitation in patients with heart failure with preserved ejection fraction, heart failure with mid-range ejection fraction, and heart failure with reduced ejection fraction

Secondary mitral regurgitation and secondary tricuspid regurgitation due to heart failure (HF) remain challenging in almost every aspect: increasing prevalence, poor prognosis, notoriously elusive in diagnosis, and complexity of therapeutic management. Recently, defined HF subgroups according to three ejection fraction (EF) ranges (reduced, mid-range, and preserved) have stimulated a structured understanding of the HF syndrome but the role of secondary valve regurgitation (SVR) across the spectrum of EF remains undefined. This review expands this structured understanding by consolidating the underlying phenotype of myocardial impairment with each type of SVR. Specifically, the current understanding, epidemiological considerations, impact, public health burden, mechanisms, and treatment options of SVR are discussed separately for each lesion across the HF spectrum. Furthermore, this review identifies important gaps in knowledge, future directions for research, and provides potential solutions for diagnosis and treatment. Mastering the challenge of SVR requires a multidisciplinary collaborative effort, both, in clinical practice and scientific approach to optimize patient outcomes.

Percutaneous mitral valve repair for secondary mitral valve regurgitation: A systematic review and meta-analysis

BACKGROUND

The first two randomized control trials (RCTs) studying the role of MitraClip in patients with secondary mitral regurgitation (MR) had antagonizing results. We, therefore, performed an updated meta-analysis of RCTs and propensity score-matched observational studies investigating the role of MitraClips in patients with secondary MR. A novel method of Kaplan Meier Curve reconstruction from derived individual patient data will be used to compare the survival probability of control groups in COAPT and MITRA HF trail, and hence, access inter-study heterogeneity.

METHODS

Medline and Cochrane databases was used for systematic search. We used the Mantel-Haenszel method with a random-effect model to calculate risk ratio (RR) with 95% confidence interval (CI) and inverse variance method with a random-effect model to calculate the mean difference (MD) with 95% confidence interval (CI). We used a fixed-effect approach for meta-regression.

RESULTS

MitraClip reduced the risk of all-cause mortality [RR: 0.72, CI: 0.55-0.95, P value = 0.02, I2 = 55%, χ²P-value = 0.08] and readmission [RR: 0.62, CI: 0.42-0.92, P value = 0.02, I² = 90%, χ²P-value<0.01] at two years follow-up. There was no effect of MitraClip on change in cardiovascular mortality and 6 m walking distance at 12 months follow-up. Meta-regression indicated left ventricular end diastolic volume and age among the factors affecting outcomes. Reconstructed Kaplan Meier curves confirmed considerable heterogeneity among patients randomized in MITRA HF and COAPT trial.

CONCLUSION

The present meta-analysis confirms the beneficial role of percutaneous mitral valve repair in patients with secondary MR. However, all the results were associated with considerable heterogeneity.

Percutaneous mitral repair: current and future devices

Mitral regurgitation (MR) is the second most common valvular heart disease and its prevalence is increasing with population ageing. In the recent years we have witnessed the development of several transcatheter devices to correct MR in patients at high-risk for surgery. The majority of evidence regarding safety and efficacy of this new therapy comes from MitraClip studies. However, new alternatives on the field of valve repair have emerged with promising results. The aim of this review is to portrait the landscape of transcatheter mitral repair alternatives, from currently used devices to those that will have a role in the near future.

Proportionate or disproportionate secondary mitral regurgitation: how to untangle the Gordian knot?

Recent randomised percutaneous mitral intervention trials in patients with heart failure with secondary mitral regurgitation (SMR) have yielded contrasting results. A 'relative load' or 'proportionality' conceptual framework for SMR has been proposed to partly explain the disparate results. The rationale behind the framework is that SMR depends on the left ventricular dimension and not vice versa. In this review, we provide an in-depth analysis of the proportionality parameters used in this framework and also discuss the regurgitant fraction. We also consider haemodynamic observations in SMR that may affect the interpretation and comparisons among proportionality parameters. The conclusion is that the proportionality concept remains hypothetical and requires prospective validation before envisaging its use at individual patient level for risk stratification or therapeutic decision-making.

Relation of Mitral Annulus and Left Atrial Dysfunction to the Severity of Functional Mitral Regurgitation in Patients with Dilated Cardiomyopathy

METHODS

56 patients (58 ± 17 years, 42 men) with DCM and FMR and 52 controls, prospectively enrolled, underwent 3DTTE dedicated for mitral valve (MV), LA, and left ventricle (LV) quantitative analysis.

RESULTS

Patients with FMR vs. controls presented increased MA size and sphericity during the entire systole, whereas MA fractional area change (MAFAC) and MA displacement were decreased (15 ± 5 vs. 28 ± 5%; and 5 ± 3 vs. 10 ± 2 mm, p < 0.001). In patients with moderate/severe FMR, MA diameters correlated with PISA radius, EROA, and regurgitant volume (Rvol), as also did the MA area (with PISA radius, EROA, and Rvol: r = 0.48, r = 0.58, and r = 0.47, p < 0.05). MAFAC correlated inversely with EROA and Rvol (r = -0.32 and r = -0.35, p < 0.05), with both active and total LA emptying fractions and with LV ejection fraction as well. In a stepwise multivariate regression model, decreased MAFAC and increased LA volume independently predicted patients with severe FMR.

CONCLUSIONS

Patients with DCM and FMR have MA geometry remodeling and contractile dysfunction, correlated with the severity of FMR. MA contractile dysfunction correlated with both LA and left LV pumps dysfunctions and predicted patients with severe FMR. Our results provide new insights that might help with better selection of patients for MV transcatheter procedures.

A fully automated software platform for structural mitral valve analysis

OBJECTIVE

To evaluate a novel fully automated mitral valve analysis software platform for cardiac computer tomography angiography (CCTA)-based structural heart therapy procedure planning.

METHODS

The study included 52 patients (25 women; mean age, 66.9 ± 12.4 years) who had undergone CCTA prior to transcatheter mitral valve replacement (TMVR) or surgical mitral valve intervention (replacement or repair). Therapeutically relevant mitral valve annulus parameters (projected area, circumference, trigone-to-trigone (T-T) distance, anterior-posterior (AP) diameter, and anterolateral-posteromedial (AL-PM) diameter) were measured. Results of the fully automated mitral valve analysis software platform with and without manual adjustments were compared with the reference standard of a user-driven measurement program (3mensio, Pie Medical Imaging). Measurements were compared between the fully automated software, both with and without manual adjustment, and the user-driven program using intraclass correlation coefficients (ICC). A secondary analysis included the time to obtain all measurements.

RESULTS

Fully automated measurements showed a good to excellent agreement (circumference, ICC = 0.70; projected area, ICC = 0.81; T-T distance, ICC = 0.64; AP, ICC = 0.62; and AL-PM diameter, ICC = 0.78) compared with the user-driven analysis. There was an excellent agreement between fully automated measurement with manual adjustments and user-driven analysis regarding circumference (ICC = 0.91), projected area (ICC = 0.93), T-T distance (ICC = 0.80), AP (ICC = 0.78), and AL-PM diameter (ICC = 0.79). The time required for mitral valve analysis was significantly lower using the fully automated software with manual adjustments compared with the standard assessment (134.4 ± 36.4 s vs. 304.3 ± 77.7 s) (p < 0.01).

CONCLUSION

The fully automated mitral valve analysis software, when combined with manual adjustments, demonstrated a strong correlation compared with the user-driven software while reducing the total time required for measurement.

KEY POINTS

• The novel software platform allows for a fully automated analysis of mitral valve structures. • An excellent agreement was found between the fully automated measurement with manual adjustments and the user-driven analysis. • The software showed quicker measurement time compared with the standard analysis of the mitral valve.

Intraoperative post-annuloplasty three-dimensional valve analysis does not predict recurrent ischemic mitral regurgitation

BACKGROUND

High ischemic mitral regurgitation (IMR) recurrence rates continue to plague IMR repair with undersized ring annuloplasty. We have previously shown that pre-repair three-dimensional echocardiography (3DE) analysis is highly predictive of IMR recurrence. The objective of this study was to determine the quantitative change in 3DE annular and leaflet tethering parameters immediately after repair and to determine if intraoperative post-repair 3DE parameters would be able to predict IMR recurrence 6 months after repair.

METHODS

Intraoperative pre- and post-repair transesophageal real-time 3DE was performed in 35 patients undergoing undersized ring annuloplasty for IMR. An advanced modeling algorhythm was used to assess 3D annular geometry and regional leaflet tethering. IMR recurrence (≥ grade 2) was assessed with transthoracic echocardiography 6 months after repair.

RESULTS

Annuloplasty significantly reduced septolateral diameter, commissural width, annular area, and tethering volume and significantly increased all segmental tethering angles (except A2). Intraoperative post-repair annular geometry and leaflet tethering did not differ significantly between patients with recurrent IMR (n = 9) and patients with non-recurrent IMR (n = 26). No intraoperative post-repair predictors of IMR recurrence could be identified.

CONCLUSIONS

Undersized ring annuloplasty changes mitral geometry acutely, exacerbates leaflet tethering, and generally fixes IMR acutely, but it does not always fix the delicate underlying chronic problem of continued left ventricular dilatation and remodeling. This may explain why pre-repair 3D valve geometry (which reflects chronic left ventricular remodeling) is highly predictive of recurrent IMR, whereas immediate post-repair 3D valve geometry (which does not completely reflect chronic left ventricular remodeling anymore) is not.

Redistribution of cardiac output during exercise by functional mitral regurgitation in heart failure: compensatory O2 peripheral uptake to delivery failure

This is an analysis involving 134 heart failure patients with reduced ejection fraction versus 80 controls investigated during functional evaluation with gas exchange and hemodynamic, addressing the severe mitral regurgitation phenotype and testing the hypothesis that the backward cardiac output redistribution to the lung during exercise impairs delivery and overexpresses peripheral extraction. This information is new and has important implications in the management of heart failure.