Transcatheter mitral valve repair for inotrope dependent cardiogenic shock - Design and rationale of the CAPITAL MINOS trial

Transcatheter Structural Heart Interventions in the Acute Setting: An Emerging Indication

Structural heart disease is increasingly prevalent in the general population, especially in patients of increased age. Recent advances in transcatheter structural heart interventions have gained a significant following and are now considered a mainstay option for managing stable valvular disease. However, the concept of transcatheter interventions has also been tested in acute settings by several investigators, especially in cases where valvular disease comes as a result of acute ischemia or in the context of acute decompensated heart failure. Tested interventions include both the mitral and aortic valve, mostly evaluating mitral transcatheter edge-to-edge repair and transcatheter aortic valve implantation, respectively. This review is going to focus on the use of acute structural heart interventions in the emergent setting, and it will delineate the available data and provide a meaningful discussion on the optimal patient phenotype and future directions of the field.

Mitral Regurgitation Complicated by Cardiogenic Shock: Reassessing Risk Stratification and Therapeutic Strategies

Mitral regurgitation complicated by cardiogenic shock creates a unique and devastating risk profile for patients and poses significant difficulties for physicians who lack a comprehensive range of effective management strategies. Supportive measures such as intravenous vasodilators, intra-aortic balloon pumps, and percutaneous ventricular assist devices are often necessary to stabilize patients prior to definitive treatment with surgical mitral valve replacement or trans-catheter edge-to-edge repair. This review evaluates the evidence for the available supportive and definitive management strategies in patients with mitral regurgitation complicated by cardiogenic shock and presents a framework to aid clinicians in navigating the complex clinical decision-making process. Additionally, the authors review emerging transcatheter mitral valve replacement technologies that hold promise for expanding the therapeutic armamentarium and improving patient outcomes.

Functional Mitral Regurgitation: Patient Selection and Optimization

Functional mitral regurgitation appears commonly among all heart failure phenotypes and can affect symptom burden and degree of maladaptive remodeling. Transcatheter mitral valve edge-to-edge repair therapies recently became an important part of the routine heart failure armamentarium for carefully selected and medically optimized candidates. Patient selection is considering heart failure staging, relevant comorbidities, as well as anatomic criteria. Indications and device platforms are currently expanding.

Evolving indications for transcatheter mitral edge-to-edge repair

Transcatheter mitral edge-to-edge repair (TEER) is an established procedure for managing mitral regurgitation (MR) in high-risk patients. It is effective in treating both primary and secondary MR, as reported in the surgical and interventional literature. Over time, TEER has gained popularity and achieved procedural success in various anatomies. The less invasive nature of TEER, along with its high safety profile and immediate haemodynamic improvement suggest potential benefits in high-risk populations who are not normally included in major trials. These patients, often deemed unsuitable for surgical intervention, are typically managed conservatively, despite accumulating evidence suggesting the potential of clinical improvement by reducing MR through TEER. Examples include post-myocardial infarction MR, patients with hypertrophic obstructive cardiomyopathy and patients experiencing recurrent MR after surgical intervention. This review discusses the utilisation of TEER beyond recognised indications, examining outcomes and limitations in diverse patient populations. Further studies are warranted to evaluate the benefits of TEER in clinical scenarios beyond the current indications.

Transcatheter edge-to-edge mitral valve repair for mitral regurgitation in patients with cardiogenic shock: A systematic review and meta-analysis

BACKGROUND

There is currently little evidence for transcatheter edge-to-edge mitral valve repair (TEER) for mitral regurgitation (MR) in patients with cardiogenic shock (CS). Therefore, this study investigated the characteristics and outcomes of CS patients who underwent TEER for MR.

METHODS

PubMed, EMBASE were searched in July 2023. Case series and observational studies reporting clinical characteristics and outcomes in CS patients with MR who underwent TEER were included. We performed a one-group meta-analysis using a random effects model.

RESULTS

A total of 4060 patients from 7 case series and 5 observational studies were included. The mean age was 68.2 (95% confidence interval [CI]: 64.1-72.2) years, and 41.4% of patients (95% CI: 39.1%-43.7%) were female. Pre-TEER, severe MR was present in 85.3% (95% CI: 76.1%-91.3%) of patients. Mean left ventricular ejection fraction was 36.7% (95% CI: 29.2%-44.2%), and 54.6% (95% CI: 36.9%-71.2%) of patients received mechanical circulatory support. The severity of MR post-TEER was less than 2+ in 88% (95% CI: 87%-89%) of patients. In-hospital mortality was 11% (95% CI: 10%-13%), whereas 30-day and 1-year mortality rates were 15% (95% CI: 13%-16%), and 36% (95% CI: 21%-54%), respectively.

CONCLUSIONS

This systematic review and meta-analysis assessed the clinical characteristics and outcomes of TEER in CS patients with MR. TEER for MR in patients with CS has been successful in reducing MR in most of the patients, but with a high mortality rate. Randomized controlled trials of TEER for MR and CS are needed.

Mitral Interventions in Heart Failure

Patients with heart failure with reduced ejection fraction who have secondary mitral regurgitation (SMR) have poorer outcomes and quality of life than those without SMR. Guideline-directed medical therapy is the cornerstone of SMR treatment. Careful evaluation of landmark trials using mitral transcatheter edge-to-edge repair in SMR has led to an improved understanding of who will benefit from percutaneous interventions with emphasis on a multidisciplinary approach. The success with mitral transcatheter edge-to-edge repair in SMR has also spurred the evaluation of its role in populations that were not initially studied, such as end-stage heart failure and cardiogenic shock. A spectrum of transcatheter devices in development and clinical trials promise to further provide a growing array of management options for heart failure with reduced ejection fraction patients with symptomatic SMR.

Acute mitral regurgitation with and without acute heart failure

Acute severe mitral regurgitation (MR) is rare, but often leads to cardiogenic shock, pulmonary edema, or both. Most common causes of acute severe MR are chordae tendineae (CT) rupture, papillary muscle (PM) rupture, and infective endocarditis (IE). Mild to moderate MR is often seen in patients with acute myocardial infarction (AMI). CT rupture in patients with floppy mitral valve/mitral valve prolapse is the most common etiology of acute severe MR today. In IE, native or prosthetic valve damage can occur (leaflet perforation, ring detachment, other), as well as CT or PM rupture. Since the introduction of percutaneous revascularization in AMI, the incidence of PM rupture has substantially declined. In acute severe MR, the hemodynamic effects of the large regurgitant volume into the left atrium (LA) during left ventricular (LV) systole, and in turn back into the LV during diastole, are profound as the LV and LA have not had time to adapt to this additional volume. A rapid, but comprehensive evaluation of the patient with acute severe MR is essential in order to define the underline cause and apply appropriate management. Echocardiography with Doppler provides vital information related to the underlying pathology. Coronary arteriography should be performed in patients with an AMI to define coronary anatomy and need for revascularization. In acute severe MR, medical therapy should be used to stabilize the patient before intervention (surgery, transcatheter); mechanical support is often required. Diagnostic and therapeutic steps should be individualized, and a multi-disciplinary team approach should be utilized.