Management of Severe Mitral Regurgitation in Patients With Acute Myocardial Infarction: JACC Focus Seminar 2/5

Severe acute mitral regurgitation after myocardial infarction includes partial and complete papillary muscle rupture or functional mitral regurgitation. Although its incidence is <1%, mitral regurgitation after acute myocardial infarction frequently causes hemodynamic instability, pulmonary edema, and cardiogenic shock. Medical management has the worst prognosis, and mortality has not changed in decades. Surgery represents the gold standard, but it is associated with high rates of morbidity and mortality. Recently, transcatheter interventions have opened a new door for management that may improve survival. Mechanical circulatory support restores vital organ perfusion and offers the opportunity for a steadier surgical repair. This review focuses on the diagnosis and the interventional management, both surgical and transcatheter, with a glance on future perspectives to enhance patient management and eventually decrease mortality.

Regurgitant volume to LA volume ratio in patients with secondary MR: the COAPT trial

AIMS

The conceptual framework of proportionate vs. disproportionate mitral regurgitation (MR) translates poorly to individual patients with heart failure (HF) and secondary MR. A novel index, the ratio of MR severity to left atrial volume (LAV), may identify patients with 'disproportionate' MR and a higher risk of events. The objectives, therefore, were to investigate the prognostic impact of MR severity to LAV ratio on outcomes among HF patients with severe secondary MR randomized to transcatheter edge-to-edge repair (TEER) with the MitraClip™ device plus guideline-directed medical therapy (GDMT) vs. GDMT alone in the COAPT trial.

METHODS AND RESULTS

The ratio of pre-procedural regurgitant volume (RVol) to LAV was calculated from baseline transthoracic echocardiograms. The primary endpoint was 2-year covariate-adjusted rate of HF hospitalization (HFH). Among 567 patients, the median RVol/LAV was 0.67 (interquartile range 0.48-0.91). In patients randomized to GDMT alone, lower RVol/LAV was independently associated with an increased 2-year risk of HFH (adjHR: 1.77; 95% CI: 1.20-2.63). RVol/LAV was a stronger predictor of adverse outcomes than RVol or LAV alone. Treatment with TEER plus GDMT compared with GDMT alone was associated with lower 2-year rates of HFH both in patients with low and high RVol/LAV (Pinteraction = 0.28). Baseline RVol/LAV ratio was unrelated to 2-year mortality, health status, or functional capacity in either treatment group.

CONCLUSION

Low RVol/LAV ratio was an independent predictor of 2-year HFH in HF patients with severe MR treated with GDMT alone in the COAPT trial. TEER improved outcomes regardless of baseline RVol/LAV ratio.

CLINICAL TRIAL REGISTRATION

Trial Name: Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation (The COAPT Trial) (COAPT) ClinicalTrial.gov Identifier NCT01626079URL https://clinicaltrials.gov/ct2/show/NCT01626079.

Economic Burden of Inpatient Care for Mitral Regurgitation in Maryland

BACKGROUND

Mitral regurgitation (MR) is the most common valvular disease in the United States and increases the risk of death and hospitalization. The economic burden of MR in the United States is not known.

METHODS AND RESULTS

We analyzed inpatient hospitalization data from the 1 221 173 Maryland residents who had any in-state admissions from October 1, 2015, to September 30, 2019. We assessed the total charges for patients without MR and for patients with MR who underwent medical management, transcatheter mitral valve repair or replacement, or surgical mitral valve repair or replacement. During the study period, 26 076 inpatients had a diagnosis of MR. Compared with patients without MR, these patients had more comorbidities and higher inpatient mortality. Patients with medically managed MR incurred average total charges of $23 575 per year; MR was associated with $10 559 more in charges per year and an incremental 3.1 more inpatient days per year as compared with patients without MR. Both surgical mitral valve repair or replacement and transcatheter mitral valve repair or replacement were associated with higher charges as compared with medical management during the year of intervention ($47 943 for surgical mitral valve repair or replacement and $63 108 for transcatheter mitral valve repair or replacement). Annual charges for both groups were significantly lower as compared with medical management in the second and third years postintervention.

CONCLUSIONS

MR is associated with higher mortality and inpatient charges. Patients who undergo surgical or transcatheter intervention incur lower charges compared with medically managed MR patients in the years after the procedure.

Revisiting predictors of worse atrioventricular valve and left ventricular systolic function following pacemaker therapy

BACKGROUND

Predictors of worsening atrioventricular valve regurgitation and left ventricular (LV) systolic function after implantation of a leadless pacemaker (LPM) remain unclear compared with those of a transvenous pacemaker (TPM).

METHODS

We retrospectively analyzed 205 patients who were newly implanted with a permanent pacemaker (119 LPMs and 86 TPMs) and underwent transthoracic echocardiography before and 8 ± 5 months after implantation. We evaluated the worsening of tricuspid and mitral regurgitation (TR and MR), defined as at least one-grade aggravation in severity, and changes in LV ejection fraction (LVEF).

RESULTS

Worsening TR occurred more frequently in the LPM group compared to the TPM group (33% vs. 20%, p = .04); however, there was no significant difference between the two groups regarding worsening MR (26% vs. 18%, p = .18) and LVEF change (-2 ± 10% vs. -3 ± 8%, p = .40). In multivariable analysis, independent predictors for worsening TR, MR, and LVEF after implantation were found to be (1) the change from sinus rhythm at baseline to atrioventricular asynchronous right ventricular (RV) pacing (odds ratio [OR]: 5.68, 95% confidence interval [CI]: 1.94-16.70, p < .01); (2) the change from non-pacing ventricular contraction at baseline to RV pacing (OR: 2.42, 95% CI: 1.12-5.24, p = .02); and (3) a higher RV pacing burden (β: -0.05, 95% CI: -0.08--0.02, p < .01), respectively.

CONCLUSION

Worsening TR, MR, and LVEF after pacemaker implantation were not associated with the type of pacing device but loss of atrioventricular synchrony or dependency on RV pacing.

Diagnosis, Classification, and Management Strategies for Mitral Annular Calcification: A Heart Valve Collaboratory Position Statement

Mitral annular calcium (MAC) with severe mitral valvular dysfunction presents a complex problem, as valve replacement, either surgical or transcatheter, is challenging because of anatomy, technical considerations, concomitant comorbidities, and advanced age. The authors review the clinical and anatomical features of MAC that are favorable (green light), challenging (yellow light), or prohibitive (red light) for surgical or transcatheter mitral valve interventions. Under the auspices of the Heart Valve Collaboratory, an expert working group of cardiac surgeons, interventional cardiologists, and interventional imaging cardiologists was formed to develop recommendations regarding treatment options for patients with MAC as well as a proposed grading and staging system using both anatomical and clinical features.

New Perspective on Pathophysiology and Management of Functional Mitral Regurgitation

Functional mitral regurgitation (FMR) occurs as a result of global or segmental left ventricular (LV) dysfunction or left atrial dilatation, leading to mitral annular dilatation, papillary muscle displacement, mitral valve (MV) leaflet tethering, and leaflet remodeling. The prevalence of FMR continues to rise in the United States. Even mild FMR is associated with adverse clinical outcomes. Echocardiography is the primary imaging modality used to assess the type and severity of mitral regurgitation. FMR treatment depends on the etiology. Evidence-based pharmacologic and cardiac resynchronization therapies for underlying LV dysfunction remain the mainstay of treatment. Patients who remain symptomatic despite optimal medical therapy can be considered for surgical or percutaneous MV intervention. This article reviews the pathophysiology, imaging evaluation, and therapeutic options of FMR, highlighting the most recent developments in a rapidly evolving field.

[Update Valvular Heart Disease: Heart Team Decision-Making Based on Patient Examples]

INTRODUCTION

In Europe, mitral regurgitation and aortic stenosis are the most common valve lesions requiring interventions. In advanced stages, these valve pathologies affect patients' quality of life and prognosis. The prevalence of mitral regurgitation and aortic stenosis is increasing with age. In view of an aging population and the comorbidities associated with age, these valve defects represent an increasing challenge to health care providers. Nowadays, surgical as well as catheter-based treatment options are available to treat affected patients. Therapeutic strategies suitable to the individual patient should be discussed in interdisciplinary heart teams. The aim of the present article is to give an overview of possible guideline-conform heart team decisions based on patient examples.

The Role of Cardiac Resynchronization Therapy for the Management of Functional Mitral Regurgitation

Valve leaflets and chordae structurally normal characterize functional mitral regurgitation (FMR), which in heart failure (HF) setting results from an imbalance between closing and tethering forces secondary to alterations in the left ventricle (LV) and left atrium geometry. In this context, FMR impacts the quality of life and increases mortality. Despite multiple medical and surgical attempts to treat FMR, to date, there is no univocal treatment for many patients. The pathophysiology of FMR is highly complex and involves several underlying mechanisms. Left ventricle dyssynchrony may contribute to FMR onset and worsening and represents an important target for FMR management. In this article, we discuss the mechanisms of FMR and review the potential therapeutic role of CRT, providing a comprehensive review of the available data coming from clinical studies and trials.

Managing acute cardiac valvular emergencies in the emergency department

Valvular heart disease is becoming more prevalent as the United States' population ages, with aortic and mitral valves most commonly affected. Complications, including syncope, heart failure, dyspnea, and chest pain, can arise from slow progression of stenosis and regurgitation, though acute regurgitation from an ischemic or traumatic event can be life-threatening. Patients with valvular disease may present with cardiogenic shock, and vasoactive agent treatment will depend on determination of the valvular etiology. This issue reviews aortic and mitral valvular disease as potential causes of a patient's emergency department presentation, including history, diagnostic testing, and physical examination findings that can help guide treatment.

Burden, treatment use, and outcome of secondary mitral regurgitation across the spectrum of heart failure: observational cohort study

OBJECTIVES

To define prevalence, long term outcome, and treatment standards of secondary mitral regurgitation (sMR) across the heart failure spectrum.

DESIGN

Large scale cohort study.

SETTING

Observational cohort study with data from the Viennese community healthcare provider network between 2010 and 2020, Austria.

PARTICIPANTS

13 223 patients with sMR across all heart failure subtypes.

MAIN OUTCOME MEASURES

Association between sMR and mortality in patients assigned by guideline diagnostic criteria to one of three heart failure subtypes: reduced, mid-range, and preserved ejection fraction, was assessed.

RESULTS

Severe sMR was diagnosed in 1317 patients (10%), correlated with increasing age (P<0.001), occurred across the entire spectrum of heart failure, and was most common in 656 (25%) of 2619 patients with reduced ejection fraction. Mortality of patients with severe sMR was higher than expected for people of the same age and sex in the same community (hazard ratio 7.53; 95% confidence interval 6.83 to 8.30, P<0.001). In comparison with patients with heart failure and no/mild sMR, mortality increased stepwise with a hazard ratio of 1.29 (95% confidence interval 1.20 to 1.38, P<0.001) for moderate and 1.82 (1.64 to 2.02, P<0.001) for severe sMR. The association between severe sMR and excess mortality was consistent after multivariate adjustment and across all heart failure subgroups (mid-range ejection fraction: hazard ratio 2.53 (95% confidence interval 2.00 to 3.19, P<0.001), reduced ejection fraction: 1.70 (1.43 to 2.03, P<0.001), and preserved ejection fraction: 1.52 (1.25 to 1.85, P<0.001)). Despite available state-of-the-art healthcare, high volume heart failure, and valve disease programmes, severe sMR was rarely treated by surgical valve repair (7%) or replacement (5%); low risk transcatheter repair (4%) was similarly seldom used.

CONCLUSION

Secondary mitral regurgitation is common overall, increasing with age and associated with excess mortality. The association with adverse outcome is significant across the entire heart failure spectrum but most pronounced in those with mid-range and reduced ejection fractions. Despite these poor outcomes, surgical valve repair or replacement are rarely performed; similarly, low risk transcatheter repair, specifically in the heart failure subsets with the highest expected benefit from treatment, is seldom used. The current data suggest an increasing demand for treatment, particularly in view of an expected increase in heart failure in an ageing population.

The mechanism and prognosis of acute and late improvement in mitral regurgitation after cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) improves functional mitral regurgitation (MR); however, the mechanism and differences in acute and late improvement in MR are unclear. We aimed to evaluate the factors associated with the acute and late MR improvements and the prognosis of MR improvement after CRT. This retrospective study included 121 patients who underwent CRT implantation with full echocardiography assessment at baseline, 1 week, and 6 months after implantation. MR severity was classified into five grades (0: none to 4: severe). Two-dimensional speckle-tracking echocardiography with radial strain was used to assess dyssynchrony, and the time difference between the lateral and inferior segments at papillary muscle levels (TD_late-inf) was calculated. The MR improved 1 week and 6 months after CRT in 40 (33%) and 45 (37%) patients, respectively. On multivariate analyses, TD_late-inf (baseline-1 week) and SPWMD were independently associated with acute MR improvement. The %reduction in left ventricular end-systolic volume (LVESV) (baseline-6 months) and TD_late-inf (baseline-1 week) were independently correlated with late MR improvement. The patients with pre-MR grades 2-4 and improved MR after CRT showed significantly better prognosis in heart failure hospitalization. Cutoff values of ≥ 19.5 ms of the reduction of TD_late-inf and ≥ 30.8% of the %reduction of LVESV were significantly associated with the decrease in heart failure hospitalization. The improved interpapillary muscle activation time delay and volume reduction after CRT were associated with acute and late MR improvements. There may be different time course of recovery and distinct causes for late MR improvement.

Paroxysmal Severe Mitral Regurgitation

OBJECTIVE

To investigate the clinical presentation, pathophysiology, and treatment for "paroxysmal severe mitral regurgitation" (MR), which is an underappreciated cause of heart failure with preserved left ventricular ejection fraction.

METHODS

We retrospectively reviewed cases of transient severe MR that were evaluated at Mayo Clinic in Rochester, Minnesota, between January 1, 2006, and December 31, 2019. Paroxysmal severe MR was defined as the appearance of transient severe MR in patients with mild MR at rest, normal left ventricle (LV) size, left ventricular ejection fraction greater than 40%, and absence of obstructive coronary artery disease.

RESULTS

We identified 6 patients (5 women) with a median age of 68 years. There were 3 distinct mechanisms of paroxysmal severe MR, which we labeled types 1, 2, and 3. Type 1 MR was caused by LV dyssynchrony from a rate-dependent left bundle branch block, which led to apical leaflet tenting and incomplete coaptation. Type 2 MR occurred from mitral annular dilatation during maneuvers that increased left-sided volume. Type 3 MR was caused by coronary artery vasospasm with apical leaflet tenting. Treatments varied depending on the underlying cause and included cardiac resynchronization therapy for type 1, surgical valve replacement for type 2, and medical therapy for type 3.

CONCLUSION

Paroxysmal severe MR is a rare cause of heart failure in patients with preserved LV function. We have identified 3 distinct mechanisms that can lead to this dynamic process, with treatments varying based on the underlying cause.

[New treatments for systolic heart failure]

New treatments for systolic heart failure. Cardioprotective pharmacological treatments, cardiac resynchronization and defibrillators, percutaneous interventional and surgical treatments have led to a dramatic improvement in survival, quality of life and decrease of hospitalizations of heart failure (HF) patients. At the same time, major diagnostic progress has been made in imaging and genetics, allowing early etiological diagnosis and the implementation of preventive or curative strategies before irreversible cardiac remodeling. However, morbidity and mortality remain significant at the most advanced stages when the pathophysiological processes responsible for the alteration of cardiac function cannot be prevented or effectively reversed. After a prolific period during the 1980's - 2000's when therapeutic trials laid the foundations for modern cardioprotective treatment, they then stalled for about ten years with the failure of many new molecules that did not demonstrate a reduction in mortality. But since 2010, new molecules acting on complementary pathophysiological processes have been showing positive results. Recalling the recommended algorithm for optimizing the treatment of HF, we discuss in this article the mechanisms of action and the results of the latest clinical trials with SGLT2 inhibitors (gliflozines), vericiguat and percutaneous treatment of functional mitral regurgitation that will in the very short term modify the prescriptions of our HF patients.

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.

Mitral Stenosis After MitraClip: How to Avoid and How to Treat

PURPOSE OF REVIEW

The goal of the paper is to highlight the importance of procedural planning and patient selection when using the MitraClip device in treating severe mitral regurgitation (MR).

RECENT FINDINGS

Following the recent results of the COAPT trial and FDA approval for functional MR patients, the indications for mitral clip are continuing to expand. Because of this, mitral stenosis from mitral clip can become a problem if the appropriate patients are not selected. Proper valve imaging, utilizing 3D transesophageal echocardiography to identify the pathology, is important to prevent iatrogenic mitral stenosis. In the unfortunate event of severe mitral stenosis as a result of the MitraClip device, surgery is the only treatment.

Predictors of functional improvement in the short term after MitraClip implantation in patients with secondary mitral regurgitation

Background and objectives

MitraClip implantation is an established therapy for secondary mitral regurgitation (MR) in high-risk patients and has shown to improve several important outcome parameters such as functional capacity. Patient selection is both challenging and crucial for achieving therapeutic success. This study investigated baseline predictors of functional improvement as it was quantified by the six-minute walk distance (6MWD) after transcatheter mitral valve repair.

Methods and results

We retrospectively analyzed 79 patients with secondary MR treated with MitraClip implantation at an academic tertiary care center. Before and four weeks after the procedure, all patients underwent comprehensive clinical assessment, six-minute walk tests and echocardiography. 6MWD significantly improved after MitraClip therapy (295 m vs. 265 m, p < 0.001). A linear regression model including seven clinical baseline variables significantly predicted the change in 6MWD (p = 0.002, R² = 0.387). Female gender, diabetes mellitus and arterial hypertension were found to be significant negative predictors of 6MWD improvement. At baseline, female patients had significant higher left ventricular ejection fraction (49% vs. 42%, p = 0.019) and lower 6MWD (240 m vs. 288 m, p = 0.034) than male patients.

Conclusion

MitraClip implantation in secondary MR significantly improves functional capacity in high-risk patients even in the short term of four weeks after the procedure. Female gender, diabetes mellitus and arterial hypertension are baseline predictors of a less favourable functional outcome. While further validation in a larger cohort is recommended, these parameters may improve patient selection for MitraClip therapy.

Injectable Shear-Thinning Hydrogels Prevent Ischemic Mitral Regurgitation and Normalize Ventricular Flow Dynamics

Injectable hydrogels are known to attenuate left-ventricular (LV) remodeling following myocardial infarction (MI), dependent on material mechanical properties. The effect of hydrogel injection on ischemic mitral regurgitation (IMR) resultant from LV remodeling remains relatively unexplored. This study uses multiple imaging methods to evaluate the efficacy of injectable hydrogels with tunable modulus to prevent post-MI development of IMR. Posterolateral MI was induced in 20 sheep with subsequent epicardial injection of saline (control (MI); n = 7), soft hydrogel (guest-host crosslinking, modulus <1 kPa, n = 7), or stiff hydrogel (dual-crosslinking, modulus = 41.4 ± 4.3 kPa, n = 6) within the infarct region and 8-week follow-up. IMR and valve geometry were assessed by echocardiography. LV geometry (long-axis dimension, posterior chordae length) and ventricular flow dynamics were assessed by magnetic resonance imaging. IMR developed in MI controls at 8 weeks and was attenuated with hydrogel treatment (IMR grade for MI: 1.86 ± 0.69; guest-host crosslinking: 1.29 ± 1.11; dual-crosslinking: 0.50 ± 0.55, P = 0.02 vs MI). Tethering of the posterior leaflet increased in MI controls, but not with stiff hydrogel treatment. Across cohorts, IMR was correlated with changes in the long-axis dimension (Spearman R = 0.77) and posterior chordae length (Spearman R = 0.64). Intraventricular flow dynamics were highly disturbed in MI controls, but stiff hydrogel treatment normalized flow patterns and reduced the prevalence of large (≥2+ MR, >5 mL) regurgitant volumes. Injectable hydrogels attenuated subvalvular remodeling and leaflet tethering, preventing IMR development and normalizing LV flow dynamics. Hydrogels with a supraphysiological modulus yielded best outcomes.

Diagnosis and Management of Ischemic Mitral Regurgitation: Evidence-Based Clinical Decision Making at the Point of Care

Anatomical, functional, and pathophysiologic mechanisms of ischemic mitral regurgitation (IMR) are markedly different from the primary mitral regurgitation. The older and ubiquitous cutoff of EROA (effective regurgitant orifice area) and Rvol (regurgitant volume) for IMR has been reinstated in the new guideline after a brief hiatus. There had always been a lack of good-quality evidence for its introduction for guiding IMR severity in the previous guideline, and we still do not have quality evidences that could justify its reintroduction. Unlike primary MR, IMR is usually associated with reduced ejection fraction. Therefore, it appears unrealistic to keep the similar cutoff for primary MR and IMR. The cutoff of severity can be modified according to projected values of Rvol normalized to ejection fraction and EROA normalized to Rvol. In addition, the treatment outcome in these patients is determined by factors (left ventricular dyssynchrony, annular dilatation, tenting area, tenting height, tenting volume, and myocardial viability) other than the simple grading. In this review article, a series of graph have been constructed from the numerical data derived from the literatures on IMR to depict the relationship between EROA, Rvol, left ventricular end diastolic volume, and ejection fraction in order to obtain a reasonable projection formula for EROA and Rvol. Furthermore, a management algorithm has been proposed for patients with IMR undergoing coronary artery bypass grafting based on echocardiographic predictors that influence the postoperative outcome.

[Percutaneous mitral interventions]

After aortic valve diseases, mitral valve diseases represent the most numerous indications of surgical or percutaneous valvular intervention. Surgical management is favoured in severe symptomatic mitral regurgitation. In case of high or prohibitive surgical risk, new techniques are developed to allow percutaneous, less invasive management. In these circumstances, MitraClip® allows the treatment of mitral regurgitation in case of adequate valve morphology. Percutaneous balloon valvuloplasty is currently the first-line treatment of mitral stenosis related to rheumatic disease when anatomical features are favourable. Alongside the Inoue technique, which remains the classical procedure, other approaches are available with encouraging results.

Safety of centrifugal left ventricular assist device in patients previously treated with MitraClip system

INTRODUCTION

No data regarding the safety of continuous-flow left ventricular assist device (CF-LVAD) implantation in patients with previous MitraClip have been reported. Thus, it remains unknown whether an initial treatment strategy with MitraClip therapy might complicate future heart failure management in patients who are also considered for CF-LVAD.

METHODS

We retrospectively identified 6 patients (median age of 62 years; 2 women) who had been treated with MitraClip, that were eventually implanted with a CF-LVAD (all Heartware HVAD) in 3 hospitals between 2013 and 2018.

RESULTS

Patients were treated in 4 cases with 2 clips, and in 2 cases with 1 clip. Median time from MitraClip implantation to CF-LVAD implant was 282 days (interquartile range 67 to 493), and median time on CF-LVAD support was 401 days (interquartile range 105 to 492 days). Two patients underwent a heart transplant, 3 patients died on support, and 1 is alive on support. In all cases, there was a reduction of functional mitral regurgitation without MitraClip-related complications.

CONCLUSIONS

Based on this small case series, implantation of a CF-LVAD appears safe in patients with a previously positioned MitraClip system, at least, with 1 or 2 clips in place, with no need for additional mitral valve surgery.

A meta-analysis of MitraClip combined with medical therapy vs. medical therapy alone for treatment of mitral regurgitation in heart failure patients

AIMS

Survival benefit of percutaneous mitral valve repair with the MitraClip over conservative treatment of functional mitral regurgitation (MR) remains unclear. The purpose of this meta-analysis is to compare survival outcomes of MitraClip with those of medical therapy in patients with functional MR.

METHODS AND RESULTS

A comprehensive literature search of PubMed, MEDLINE, and Google Scholar was conducted including studies evaluating MitraClip vs. medical therapy with multivariate adjustment and with >80% of patients with functional MR. Death from any cause was the primary endpoint, while freedom from readmission was the secondary one, evaluated with random effects. These analyses were performed at study level and at patient level including only functional MR when available, evaluating the effect of MitraClip in different subgroups according to age, ischaemic aetiology, presence of implantable cardioverter defibrillator/cardiac resynchronization therapy, and left ventricular ejection fraction and volumes. We identified six eligible observational studies including 2121 participants who were treated with MitraClip (n = 833) or conservative therapy (n = 1288). Clinical follow-up was documented at a median of 400 days. At study-level analysis, MitraClip, when compared with medical therapy (P = 0.005), was associated with significant reduction of death (P = 0.002) and of readmission due to cardiac disease. At patient-level analysis, including 344 patients, MitraClip confirmed robust survival benefit over medical therapy for all patients with functional MR and among the most important subgroups.

CONCLUSIONS

Compared with conservative treatment, MitraClip is associated with a significant survival benefit. Importantly, this superiority is particularly pronounced among patients with functional MR and across all the main subgroups.

[Surgical Cardiac Resynchronization Therapy for Patients with Severe Left Ventricular Systolic Dysfunction]

We applied cardiac resynchronization therapy with an implantable cardioverter-defibrillator( CRT-D) and with concomitant cardiac surgery to 2 patients with left ventricular (LV) systolic dysfunction and dyssynchronous ventricular activation. A patient had severe ischemic dilated cardiomyopathy with coronary artery aneurysms (LV ejection fraction 12%, LV diastolic dimension 81 mm, LV systolic dimension 75 mm and atrial fibrillation, with complete left bundle branch block). Another patient had severe dilated cardiomyopathy with mitral valve regurgitation (LV ejection fraction 25%, LV diastolic dimension 75 mm, LV systolic dimension 61 mm atrial fibrillation, and complete left bundle branch block). Both epicardial LV leads were surgically implanted on the posterolateral wall. CRT-D achieved the resynchronization of the LV contraction, and improved cardiac function. The patients had an uneventful postoperative course and were discharged from hospital after operation. A key advantage of surgical epicardial lead placement is that lead placement is not confined to anatomic branches of the LV venous circulation as is the case with transvenous placement. CRT-D combined with cardiac surgery might be available for patients with LV systolic dysfunction.

Outcome and undertreatment of mitral regurgitation: a community cohort study

BACKGROUND

Mitral regurgitation is the most common valve disease worldwide but whether the community-wide prevalence, poor patient outcomes, and low rates of surgical treatment justify costly development of new therapeutic interventions remains uncertain. Therefore, we did an observational cohort study to assess the clinical characteristics, outcomes, and degree of undertreatment of mitral regurgitation in a community setting.

METHODS

We used data from Mayo Clinic electronic health records and the Rochester Epidemiology Project to identify all cases of moderate or severe isolated single-valvular mitral regurgitation (with no other severe left-sided valvular disease or previous mitral surgery) diagnosed during a 10-year period in the community setting in Olmsted County (MN, USA). We assessed clinical characteristics, mortality, heart failure incidence, and results of cardiac surgery post-diagnosis.

FINDINGS

Between Jan 1, 2000, and Dec 31, 2010, 1294 community residents (median age at diagnosis 77 years [IQR 66-84]) were diagnosed with moderate or severe mitral regurgitation by Doppler echocardiography (prevalence 0·46% [95% CI 0·42-0·49] overall; 0·59% [0·54-0·64] in adults). Left-ventricular ejection fraction below 50% was frequent (recorded in 538 [42%] patients), and these patients had a slightly lower regurgitant volume than those with an ejection fraction of 50% or higher (mean 39 mL [SD 16] vs 45 mL [21], p<0·0001). Post-diagnosis mortality was mainly cardiovascular in nature (in 420 [51%] of 824 patients for whom the cause of death was available) and higher than expected for residents of the county for age or sex (risk ratio [RR] 2·23 [95% CI 2·06-2·41], p<0·0001). This excess mortality affected all subsets of patients, whether they had a left-ventricular ejection fraction lower than 50% (RR 3·17 [95% CI 2·84-3·53], p<0·0001) or of 50% or higher (1·71 [1·53 -1·91], p<0·0001) and with primary mitral regurgitation (RR 1·73 [95% CI 1·53-1·96], p<0·0001) or secondary mitral regurgitation (2·72 [2·48-3·01], p<0·0001). Even patients with a low comorbidity burden combined with favourable characteristics such as left-ventricular ejection fraction of 50% or higher (RR 1·28 [95% CI 1·10-1·50], p<0·0017) or primary mitral regurgitation (1·29 [1·09-1·52], p=0·0030) incurred excess mortality. Heart failure was frequent (mean 64% [SE 1] at 5 years postdiagnosis), even in patients with left-ventricular ejection fraction of 50% or higher (49% [2] at 5 years postdiagnosis) or in those with primary mitral regurgitation (48% [2]). Mitral surgery was ultimately done in only 198 (15%) of 1294 patients, of which the predominant type of surgery was valve repair (in 149 [75%] patients). Mitral surgery was done in 28 (5%) of 538 patients with left-ventricular ejection fraction below 50% and in 170 (22%) of 756 patients with ejection fraction of 50% or higher, and in 34 (5%) of 723 with secondary mitral regurgitation versus 164 (29%) of 571 with primary regurgitation. All other types of cardiac surgery combined were performed in only 3% more patients (237 [18%] patients) than the number who underwent mitral surgery.

INTERPRETATION

In the community, isolated mitral regurgitation is common and is associated with excess mortality and frequent heart failure postdiagnosis in all patient subsets, even in those with normal left-ventricular ejection fraction and low comorbidity. Despite these poor outcomes, only a minority of affected patients undergo mitral (or any type of cardiac) surgery even in a community with all means of diagnosis and treatment readily available and accessible. This suggests that in a wider population there might be a substantial unmet need for treatment for this disorder.

FUNDING

Mayo Clinic Foundation.

Iatrogenic Atrial Septal Defect After Percutaneous Mitral Valve Repair With the MitraClip System

This study examines the incidence of iatrogenic atrial septal defect (iASD) after the MitraClip procedure and its influence on echocardiographic and clinical outcomes. We examined 96 patients who underwent a successful MitraClip procedure and who also had baseline and 1-year postprocedure transthoracic echocardiograms. At 1-year follow-up, iASD were observed in 24% of cases. Compared with the patients without iASD, the patients with iASD had a larger right atrium and greater severity of tricuspid regurgitation (TR) at baseline. After the MitraClip procedure, mitral regurgitation lessened significantly in both groups. Although right atrial area and right ventricular diameters increased significantly in patients with iASD (25.3 ± 8.0 to 28.3 ± 9.5 cm², 39.7 ± 7.1 to 42.2 ± 8.1 mm, p <0.05 for both comparisons), these variables did not change in patients without iASD. In addition, patients with iASD had worse TR at follow-up. The incidence of stroke was comparable between the 2 groups during 1-year follow-up (4.3% vs 4.1%). However, patients with iASD had a markedly higher re-hospitalization rate for heart failure (26% vs 2.7%, p <0.05). In conclusion, iASD occurred in 24% of patients who underwent the MitraClip therapy and the presence of iASD was associated with right-sided heart enlargement, worse TR, and a higher re-hospitalization rate for heart failure.

Valvular Heart Disease

This article outlines the diagnosis and management of commonly occurring valvular heart diseases for the primary care provider. Basic understanding of pathologic murmurs is important for appropriate referral. Echocardiography is the gold standard for diagnosis and severity grading. Patients with progressive valvular heart disease should be followed annually by cardiology and imaging should be performed based on the severity of valvular dysfunction. Surgery or intervention is recommended only when symptoms dictate or when changes in left ventricular function occur. Surgery or intervention should be performed after discussion by a heart team, including cardiologists and cardiac surgeons.

Survival Advantage of MitraClip® Over Medical Treatment in Patients with Mitral Regurgitation: A Meta-Analysis

BACKGROUND

The MitraClip® system is a percutaneous treatment for mitral regurgitation (MR) that has shown promising results in patients who are inoperable or at high risk for mitral surgery. Data on the efficacy of the system over optimal medical therapy, above all in patients with functional MR, are scarce. The study aim was to assess the effect of MitraClip on the survival of patients with moderate/severe or severe MR compared to medical therapy, using meta-analytical techniques.

METHODS

Independently, reviewers searched electronically for relevant articles based on predefined criteria and end-points. Only articles with a comparison between MitraClip and conservative therapy were included. Standard meta-analysis techniques were used. The primary outcomes were 30-day and one-year mortalities.

RESULTS

Five observational reports were included that enrolled a total of 1,271 patients: 720 patients underwent percutaneous mitral valve repair (PMVR) with the MitraClip device, and 551 were managed conservatively. A total of 49 all-cause mortality events was reported at 30 days: 3.05% (22/720) in the PMVR arm, and 4.90% (27/510) in the conservative group, with no significant differences in all-cause mortality (OR 0.64; 95% CI 0.36-1.14). A total of 269 all-cause mortality events at one year was reported: 15.14% (109/720) in the PMVR arm, and 29.04% (160/551) in the conservative group. A significant difference favoring PMVR with the MitraClip system over medical therapy alone was observed (OR 0.44; 95% CI 0.30-0.64, p <0.0001). Neither significance between study heterogeneity (p = 0.18) nor publication bias was detected (p = 0.3).

CONCLUSIONS

PMVR with the MitraClip system may be associated with an improvement in one-year survival compared to stand-alone medical management.

Early Improvement in Mitral Regurgitation after Cardiac Resynchronization Therapy in Cardiomyopathy Patients

BACKGROUND

The study aim was to investigate factors affecting the improvement of mitral regurgitation (MR) severity within 48 hours after cardiac resynchronization therapy (CRT) in patients with cardiomyopathy.

METHODS

Sixty-nine cardiomyopathy patients (48 males, 21 females; mean age 59.12 ± 9.66 years) in NYHA functional class ≥III, with left ventricular ejection fraction (LVEF) ≤35%, and QRS duration >120 ms, with MR ≥moderate, were included in the study. Conventional echocardiography was performed before and within 48 h after CRT, and all patients underwent tissue Doppler imaging prior to CRT. Improved MR was defined as a reduction of at least one grade in MR severity.

RESULTS

After CRT, 49 patients (71%) showed MR improvement but 20 (29%) had no MR improvement. The mean MR severity grade was reduced significantly, from 2.70 ± 0.77 before CRT to 1.90 ± 0.94 after CRT (p<0.001). The group with improved MR had a significantly higher rate of left bundle branch block (75.5% versus 45%; p = 0.015), a higher QRS duration (172.00 ± 31.98 versus 147.25 ± 28.75 ms; p = 0.001), a higher median septal lateral delay (70 versus 35 ms, p = 0.035), and a higher median anteroseptal to posterior-wall delay by M mode (200 versus 130 ms, p = 0.041). Older age, longer QRS duration, and septallateral delay remained significant independent predictors of MR improvement. A greater proportion of patients with improved MR showed ≥5% increase in LVEF (55.1% versus 30.0%, p = 0.058).

CONCLUSIONS

CRT acutely reduced the severity of functional MR in the majority of cardiomyopathy patients. Those patients with improved MR showed a higher frequency of ≥5% increase in LVEF after CRT. Older age, longer QRS duration, and septallateral delay were independent predictors of MR improvement after CRT.

Computational virtual evaluation of the effect of annuloplasty ring shape

Mitral regurgitation (MR) is a result of mitral valve (MV) pathology. Its etiology can be categorized as degenerative or functional MR. Ring annuloplasty aims to reconfigure a dilated mitral annulus to its normal size and shape. We investigated the effect of annuloplasty ring shape on MR outcome using our established 3-dimensional (3-D) echocardiography-based computational MV evaluation protocols. Virtual patient MV models were created from 3-D transesophageal echocardiographic data in patients with MR because of mitral annular dilation. Two distinct annuloplasty rings (Physio II and GeoForm) were designed and virtually implanted to the patient MVs. Dynamic finite element simulations of MV function were performed for each MV after virtual ring annuloplasty of either ring, and physiologic and biomechanical characteristics of MV function were compared. Excessive stress values appeared primarily in the midanterior and midposterior regions, and lack of leaflet coaptation was found in pre-annuloplasty patient MVs. Both rings demonstrated marked reduction of stresses and efficient leaflet coaptation. The Physio II ring demonstrated more evenly distributed stress reduction across the leaflets and annulus compared with the GeoForm ring. Conversely, the highly nonplanar curvature of the GeoForm ring more effectively increased leaflet coaptation compared with the Physio II ring. This indicates that the shape of annuloplasty ring affects post-annuloplasty physiologic and biomechanical conditions, which can lead to tissue alteration over a longer period after ring annuloplasty. This virtual ring annuloplasty simulation strategy provides detailed physiologic and biomechanical information and may help better plan the optimal ring selection and improved patient-specific MV repairs.

[Malignant bileaflet mitral valve prolapse syndrome in otherwise idiopathic ventricular fibrillation]

A 32-year-old, otherwise healthy woman was admitted after successful out-of-hospital resuscitation due to ventricular fibrillation. Established cardiac, pulmonary, metabolic, and toxicological causes were excluded. However, persisting (biphasic) negative T waves in the inferior ECG leads and premature ventricular contractions (PVC) were noted. PVC morphology indicated a focus alternating between the posterior papillary muscle/the left posterior fascicle and the left ventricular outflow tract region/anterior papillary muscle. Echocardiography revealed a bileaflet mitral prolapse with mild mitral valve regurgitation. This case is a typical presentation of the recently described malignant bileaflet mitral valve prolapse syndrome. The patient was discharged without overt neurological deficit after implantation of a cardioverter-defibrillator.

Percutaneous Closure of 2 Paravalvular Leaks and a Gerbode Defect after Mitral Valve Replacement for Infective Endocarditis

Surgical valve replacement after infective endocarditis can result in local destructive paravalvular lesions. A 30-year-old woman with infective endocarditis underwent mitral valve replacement that was complicated postoperatively by 2 paravalvular leaks. During percutaneous closure of the leaks, a Gerbode defect was also found and closed. We discuss our patient's case and its relation to others in the relevant medical literature. To our knowledge, we are the first to describe the use of a percutaneous approach to close concomitant paravalvular leaks and a Gerbode defect.

Initial Results of Combined MitraClip® Implantation and Left Atrial Appendage Occlusion

BACKGROUND

Atrial fibrillation is present in 30-50% of patients undergoing percutaneous mitral valve repair. The presence of a formal contraindication to oral anticoagulation is also very common in these patients. In this context, percutaneous left atrial appendage occlusion (LAAO) may be a valid alternative for these patients. The study aim was to assess the feasibility, safety, and technical considerations of the combination of percutaneous mitral valve repair using the MitraClip system and LAAO. The present study describes the multicenter experience of combined MitraClip and LAAO procedures.

METHODS

Between April 2012 and April 2016, six patients were successfully treated with the combined procedure.

RESULTS

In all patients, mitral valve repair was performed before LAAO. Both procedures were successfully performed in all cases without any relevant procedural complication or mortality.

CONCLUSIONS

According to the results of the present study, a combination of both techniques appears to be feasible and safe, with favorable in-hospital outcomes.

Young Patient with Advanced Heart Failure No Longer a Candidate for Heart Transplantation after MitraClip® Procedure

In Europe, mitral regurgitation (MR) is the second most common form of valvular heart disease requiring surgical treatment. The case is presented of a 36-year-old woman with end-stage heart failure secondary to chemotherapy-induced cardiotoxicity, complicated by severe MR. She was listed for heart transplantation and underwent percutaneous MitraClip® implantation in order to preclude further clinical deterioration while awaiting a suitable donor. The one-year follow-up showed a strong improvement of symptoms and mostly reverse left ventricular remodelling, with consequent removal from the heart transplantation list. Video 1: Four-chamber view at baseline. Video 2: Four-chamber view at one-year follow up. Video 3: Tricuspid regurgitation and right ventricle at baseline. Video 4: Tricuspid regurgitation and right ventricle at one-year follow up.

Incidence and Clinical Impact of Cerebral Lesions after the MitraClip® Procedure

BACKGROUND

Clinically silent brain injury detected with cerebral magnetic resonance imaging (MRI) is well known after various cardiovascular interventions. Thus far, only one study has examined the periprocedural risk of cerebral ischemic events in patients undergoing percutaneous mitral valve reconstruction. The study aim was to examine the incidence and clinical impact of cerebral embolic events in patients undergoing percutaneous mitral valve reconstruction using the MitraClip® system.

METHODS

Thirteen eligible high-risk patients without contraindications for MRI underwent MitraClip treatment at the authors' institution. Neurological testing with the assessment of global cognitive function was performed three days before and two days after the procedure. All patients underwent cerebral diffusion-weighted MRI (DWI) two days after the procedure.

RESULTS

In nine patients, post-interventional MRI revealed newly acquired microembolic cerebral lesions. At follow up MRI scans recorded at 307 ± 270 days after the procedure, ischemic scars were not detectable in any patient. Two patients with five or more new cerebral lesions in DW-MRI showed a significant decline in their test scores.

CONCLUSIONS

The MitraClip procedure results in acute cerebral lesions in the vast majority of patients. All lesions seen on DWI post-procedure resolved completely, but the number of lesions may have had an impact on cognitive function.

Quadricuspid Aortic Valve Associated with Aortic Regurgitation, Mitral Regurgitation, and Aortic Dilatation

The quadricuspid aortic valve (QAV) is a very uncommon congenital malformation with an estimated incidence of 0.003% to 0.043% of all congenital heart diseases. Combinations of QAV with several different congenital malformations have been described. The case is reported of a type A QAV associated with moderate aortic regurgitation, mild mitral regurgitation, and ascending aorta dilatation. This interesting case was referred for close follow up.

Assessment and Management of Acute Severe Mitral Regurgitation in the Intensive Care Unit

BACKGROUND AND AIM OF THE STUDY

Acute severe mitral regurgitation (MR) is a serious medical condition. Whilst clear guidelines exist regarding the management of chronic MR, acute severe MR is usually treated on an individual basis. Currently, few data exist regarding acute MR in the era of primary coronary interventions (PCI). The present study included patients admitted to the Department of Cardiology during recent years with acute severe MR of different etiologies, and an analysis of these data in the light of previous investigations.

METHODS

The digital database of the present authors' hospital was searched for patients diagnosed with severe MR between 2008 and 2015. From a total of 228 patients identified, 19 with primary MR and 17 with secondary (functional) MR were admitted to the Department of Cardiology. The clinical data and outcome of these patients were analyzed.

RESULTS

Among patients with MR due to acute myocardial infarction (MI), 13 had functional MR and six had MR due to mechanical complications, namely rupture of the papillary muscle or chordae tendineae. Among patients with MR not in the setting of MI, 13 had primary MR and four had functional MR. Patients with MR due to acute MI were more often in cardiogenic shock or had pulmonary edema and had a higher mortality. The strongest predictor of mortality was the presence of shock, followed by female gender, hypertension, age ≥68 years; previous MI and pulmonary edema were also predictors of mortality. In patients with acute MI and secondary MR, PCI to the culprit coronary artery was associated with a lesser degree of MR on follow up.

CONCLUSIONS

Patients with severe MR are at high risk of in-hospital death. Patients with functional MR are likely to benefit from prompt PCI to the culprit artery, and for those with primary MR urgent surgery is life-saving.

[Thoughts about valvular abnormalities yesterday and today]

The article deals with the problems of acquired valvular disorders. It mainly focuses on the new findings regarding ethiopathogenesis, diagnostics, evaluation and treatment, especially catheterization. In advanced countries, post-rheumatic abnormalities have almost disappeared, their current etiology has substantially changed (mitral stenosis). The earlier relatively rare degenerative changes now predominate, mainly affecting older patients (aortic stenosis). Also the treatment methods for acquired abnormalities have substantially changed - currently catheterization approaches are used more frequently in their correction.Key words: aortic regurgitation - aortic stenosis - echocardiography for valvular abnormalities - magnetic resonance abnormalities - mitral regurgitation - mitral stenosis - valve replacement.

[Interdisciplinary differential treatment of structural heart disease : When operation and when catheter-based intervention?]

The demographic changes in society lead to an increasing number of patients with aortic valve stenosis and mitral regurgitation. Simultaneously the higher age of patients is associated with an increase in multimorbidity with a high surgical risk so that they cannot be referred to surgery. Besides the current gold standard of surgery, minimally invasive therapeutic options are increasingly becoming established for these patients. For the differentiated indications and therapeutic success, a multidisciplinary heart team assumes an important role. The next generation of transcatheter aortic valve implantation (TAVI) systems will lead to improvement in the results, lower complication rates and mortality and as a result there is a general trend towards expanding the indications. New innovative minimally invasive mitral valve devices are still undergoing clinical trials and will define future therapy options.

A case of dilated cardiomyopathy and severe mitral regurgitation treated using a combined percutaneous approach of MitraClip followed by CARILLON® mitral contour system

Functional mitral regurgitation (FMR) is common in severe heart failure. Medical therapy is the standard of care since the role of surgery is less established. Various trans-catheter percutaneous techniques may avoid the risks of surgery; such as edge-to-edge repair using MitraClip system (Abbott Vascular, Illinois, USA) and CARILLON® Mitral Contour System® (Model XE2; Cardiac Dimensions., Kirkland, WA, USA). We present the case of a 41-year-old man with severe dilated cardiomyopathy, NYHA IIIb, and grade 3 MR. Due to high surgical risk (logistic EuroScore 35.1) he initially underwent single MitraClip insertion with significant echocardiographic and clinical improvement (MR reduced from 3+ to 1+, NYHA classes III to II). Fifteen months later, he developed heart failure symptoms due to recurrence of severe MR and was retreated with percutaneous CARILLON® Mitral Contour System® with resolution of MR and doing well at nine-month follow-up. A combined approach of MitraClip followed by percutaneous mitral annuloplasty demonstrated clinically meaningful reduction of MR and resulted in significant symptomatic improvement for up to 6months. Follow-up for longer period is warranted to ensure sustained favorable outcome.

Mitral Valve Regurgitation with a Rotary Left Ventricular Assist Device: The Haemodynamic Effect of Inlet Cannulation Site and Speed Modulation

Mitral valve regurgitation (MVR) is common in patients receiving left ventricular assist device (LVAD) support, however the haemodynamic effect of MVR is not entirely clear. This study evaluated the haemodynamic effect of MVR with LVAD support and the influence of inflow cannulation site and LVAD speed modulation. Left atrial (LAC) and ventricular (LVC) cannulation was evaluated in a mock circulation loop with no, mild, moderate and severe MVR with constant speed and speed modulation (±600 RPM) modes. The use of an LVAD relieved pulmonary congestion during severe MVR, by reducing left atrial pressure from 20.5 to 10.8 (LAC) and 11.5 (LVC) mmHg. However, LAC resulted in decreased left ventricular stroke work (-0.08 J), ejection fraction (-7.9%) and higher MVR volume (+12.7 mL) and pump speed (+100 RPM) compared to LVC. This suggests that LVC, in addition to reducing MVR severity, also improves ventricular washout over LAC. LVAD speed modulation in synchrony with ventricular systole reduced MVR volume and increased ejection fraction with LAC and LVC, thus demonstrating the potential benefits of this mode, despite a reduction in cardiac output.

Practice gaps in the care of mitral valve regurgitation: Insights from the American College of Cardiology mitral regurgitation gap analysis and advisory panel

BACKGROUND

The revised 2014 American College of Cardiology (ACC)/American Heart Association valvular heart disease guidelines provide evidenced-based recommendations for the management of mitral regurgitation (MR). However, knowledge gaps related to our evolving understanding of critical MR concepts may impede their implementation.

METHODS

The ACC conducted a multifaceted needs assessment to characterize gaps, practice patterns, and perceptions related to the diagnosis and treatment of MR. A key project element was a set of surveys distributed to primary care and cardiovascular physicians (cardiologists and cardiothoracic surgeons). Survey and other gap analysis findings were presented to a panel of 10 expert advisors from specialties of general cardiology, cardiac imaging, interventional cardiology, and cardiac surgeons with expertise in valvular heart disease, especially MR, and cardiovascular education. The panel was charged with assessing the relative importance and potential means of remedying identified gaps to improve care for patients with MR.

RESULTS

The survey results identified several knowledge and practice gaps that may limit implementation of evidence-based recommendations for MR care. Specifically, half of primary care physicians reported uncertainty regarding timing of intervention for patients with severe primary or functional MR. Physicians in all groups reported that quantitative indices of MR severity were frequently not reported in clinical echocardiographic interpretations, and that these measurements were not consistently reviewed when provided in reports. In the treatment of MR, nearly 30% of primary care physician and general cardiologists did not know the volume of mitral valve repair surgeries by their reference cardiac surgeons and did not have a standard source to obtain this information. After review of the survey results, the expert panel summarized practice gaps into 4 thematic areas and offered proposals to address deficiencies and promote better alignment with the 2014 ACC/American Heart Association valvular disease guidelines.

CONCLUSION

Important knowledge and skill gaps exist that may impede optimal care of the patient with MR. Focused educational and practice interventions should be developed to reduce these gaps.

Use of Computed Tomography to Guide Mitral Interventions

With increasing utilization of cardiac computed tomographic angiography (CTA) and widespread adoption of fusion imaging technology allowing the merger of pre-procedural CTA with fluoroscopy, the ability of CTA to guide structural heart interventions has evolved significantly. It has opened new possibilities in mitral valve (MV) interventions with improved pre-procedural planning and intra-procedural guidance. Given the lack of fluoroscopic landmarks of the mitral apparatus and continued growth of native MV device technologies, the value of CTA will continue to develop. The goal of this chapter is to detail the role of CTA in MV imaging and support for transcatheter therapies.