Prognostic impact of transcatheter mitral valve repair in patients with exercise-induced secondary mitral regurgitation

Stress echocardiography in valvular heart disease

Valvular heart disease (VHD) has been a significant health problem, particularly in developed countries, in relation to the aging population. Recent developments in the management of VHD require a more accurate assessment of disease severity to determine the need for transcatheter interventions or open heart surgery. Stress echocardiography is a crucial imaging modality for identifying the underlying pathology of VHD. Optimal administration of exercise or intravenous drugs may reveal hemodynamic abnormalities under stress without posing an invasive risk. Therefore, the implementation of stress echocardiography is recommended for determining interventional indications and risk stratification in mitral regurgitation and aortic stenosis. In addition, recent evidence has accumulated regarding the usefulness of stress echocardiography in various conditions including mitral stenosis, aortic regurgitation, and post-interventional VHD. Here, we summarize the current evidence and future perspectives on stress echocardiography in VHD.

The year 2021 in the European Heart Journal: Cardiovascular Imaging Part II

The European Heart Journal-Cardiovascular Imaging was launched in 2012 and has during these years become one of the leading multimodality cardiovascular imaging journals. The journal is currently ranked as Number 19 among all cardiovascular journals. It has an impressive impact factor of 9.130. The most important studies published in our Journal from 2021 will be highlighted in two reports. Part II will focus on valvular heart disease, heart failure, cardiomyopathies, and congenital heart disease, while Part I of the review has focused on studies about myocardial function and risk prediction, myocardial ischaemia, and emerging techniques in cardiovascular imaging.

The role of stress echocardiography in transcatheter aortic valve implantation and transcatheter edge-to-edge repair era: A systematic review

OBJECTIVES

In the last decade, percutaneous treatment of valve disease has changed the approach toward the treatment of aortic stenosis (AS) and mitral regurgitation (MR). The clinical usefulness of stress echocardiography (SE) in the candidates for transcatheter aortic valve implantation (TAVI) and transcatheter edge-to-edge repair (TEER) of MR remains to be established. Therefore, the key aim of this review is to assess the main applications of SE in patients undergoing TAVI or TEER.

METHODS

We searched for relevant studies to be included in the systematic review on PubMed (Medline), Cochrane library, Google Scholar, and Biomed Central databases. The literature search was conducted in February 2022. The inclusion criteria of the studies were: observational and clinical trials or meta-analysis involving patients with AS or MR evaluated with SE (excluding those in which SE was used only for screening of pseudo-severe stenosis) and treated with percutaneous procedures.

RESULTS

Thirteen studies published between 2013 and 2021 were included in the review: five regarding candidates for TEER and eight for TAVI. In TEER candidates, seeing an increase in MR grade, and stroke volume of >40% during SE performed before treatment was, respectively, related to clinical benefits (p = 0.008) and an increased quality of life. Moreover, overall, 25% of patients with moderate secondary MR at rest before TEER had the worsening of MR during SE. At the same time, in SE performed after TEER, an increase in mean transvalvular diastolic gradient and in systolic pulmonary pressure is expected, but without sign and symptoms of heart failure. Regarding TAVI, several studies showed that contractile reserve (CR) is not predictive of post-TAVI ejection fraction recovery and mortality in low-flow low-gradient AS either at 30 days or at long-term.

CONCLUSION

This systematic review shows in TEER candidates, SE has proved useful in the optimization of patient selection and treatment response, while its role in TAVI candidates is less defined. Therefore, larger trials are needed to test and confirm the utility of SE in candidates for percutaneous procedures of valve diseases.

Exercise echocardiography for a differential diagnosis in a patient with radiation-induced heart disease: A case report

Advances in radiation therapy (RT) have dramatically improved the survival rates of patients with cancer, but radiation-induced heart disease (RIHD) has become an emerging problem, which is complex and multifaceted.

A 65-year-old man with a medical history of chemoradiotherapy for esophageal cancer, who had multiple admissions for acute heart failure (AHF), was readmitted to our hospital. Transthoracic echocardiography at rest revealed left ventricular diastolic dysfunction, moderate aortic stenosis with mild aortic regurgitation, and mild mitral regurgitation (MR). A diagnosis of RIHD was obtained, however, the main cause of the AHF was not clearly understood. Exercise echocardiography (ExE) revealed an exacerbation of the MR and exercise-induced pulmonary hypertension (EIPH), and the severe dynamic MR was considered to be the main cause of the AHF. A transcatheter edge-to-edge repair (TEER) with a MitraClip (Abbott Vascular, Menlo Park, CA, USA) was performed, and the post-procedural ExE showed the mitigation of the dynamic MR and EIPH. He had no further heart failure admissions for more than one year.

Our case showed that ExE may be useful in the management of patients with RIHD, and a TEER with a MitraClip may be an effective treatment for RT-related dynamic MR.

Learning objective

Radiation therapy (RT) has improved the survival rates of patients with cancer, but which involves radiation-induced heart disease (RIHD). RIHD is complex and multifaceted, and RT-related valvular disease may be underestimated with transthoracic echocardiography at rest alone. Then exercise echocardiography may be useful in the management. It is important to perform an individualized approach including medical therapy, surgery, and percutaneous intervention by a heart team.

Treatment of secondary mitral regurgitation by transcatheter edge-to-edge repair using MitraClip

Transcatheter edge-to-edge repair (TEER) is becoming the standard invasive treatment for ventricular functional mitral regurgitation (MR). It is necessary to determine the severity of MR before treatment with MitraClip; however, the severity of secondary MR is usually underestimated compared with that of primary MR and varies temporally. Therefore, to accurately determine the severity of MR, it is important to correctly use the algorithm of the guidelines for valvular heart disease and aggressively perform stress echocardiography. Before performing TEER, the difficulty of the procedure should be evaluated. First, morphological features that make TEER unsuitable, such as cleft of the mitral leaflet, mitral stenosis (MS), or perforation of the mitral leaflet, should be checked. The mitral valve orifice area, transmitral valve pressure gradient, coaptation depth, coaptation length, and posterior leaflet length should be measured to determine the difficulty of the procedure based on the inclusion criteria of Endovascular Valve Edge-to-Edge Repair Study II and the German consensus. After MitraClip implantation, in addition to assessing the severity of MS and residual MR, the pulmonary venous flow pattern and stroke volume should be evaluated to comprehensively assess whether TEER improves the hemodynamics. MitraClip has also been used to treat atrial functional MR, another type of secondary MR. Several reports suggest that MitraClip is effective for atrial functional MR; however, evidence is still being accumulated.

Change in Lung Fluid Volume during Exercise in Patients with Exercise-Induced Mitral Regurgitation

Exercise-induced mitral regurgitation (MR) can be diagnosed during stress echocardiography testing. Remote dielectric sensing (ReDS^TM) is a noninvasive electromagnetic-based modality to measure lung fluid levels. The change in lung fluid levels in patients with MR during stress echocardiography remains unknown. Patients with symptomatic MR at baseline and suspected worsening exercise-induced MR underwent stress echocardiography. ReDS values were measured before and after the tests. A total of four patients (ages ranging between 74 and 84 years old, three women) underwent stress echocardiography testing using a bicycle ergometer. In patient A, MR effective regurgitant orifice area (EROA) remained unchanged and ReDS values decreased. EROA increased significantly with a small incremental change in ReDS values in patient B and patient C, who underwent valve repair with MitraClip later. Patient D had a mild increase in MR EROA but a considerable increase in ReDS values (from 22% to 32%), and eventually received valve repair with MitraClip. The ReDS system may be a complementary tool to conventional stress echocardiography in the evaluation of clinically significant MR and considering mitral valve intervention.

Dynamic Secondary Mitral Regurgitation: Current Evidence and Challenges for the Future

Heart failure (HF) is a challenging situation in healthcare worldwide. Secondary mitral regurgitation (SMR) is a common condition in HF patients with reduced ejection fraction (HFrEF) and tends to be increasingly associated with unfavorable clinical outcomes as the severity of SMR increases. It is worth noting that SMR can deteriorate dynamically under stress. Over the past three decades, the characteristics of dynamic SMR have been studied. Dynamic SMR contributes to the reduction in exercise capacity and adverse clinical outcomes. Current guidelines refer to the indication of transcatheter edge-to-edge repair (TEER) for significant SMR based on data from the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial if symptomatic despite optimal guideline-directed medical therapy (GDMT) and cardiac resynchronization therapy (CRT), but nonpharmacological treatment for dynamic SMR remains challenging. In HFrEF patients with LV dyssynchrony and dynamic SMR, CRT can improve LV dyssynchrony and subsequently attenuate SMR at rest and during exercise. Also, a recent study suggests that TEER with GDMT and CRT is more effective in symptomatic patients with HFrEF and dynamic SMR than GDMT and CRT alone. Further studies are needed to evaluate the safety and efficacy of nonpharmacological treatments for dynamic SMR. In this review, current evidence and challenges for the future of dynamic SMR are discussed.

Predictors of outcomes in patients with mitral regurgitation undergoing percutaneous valve repair

Percutaneous mitral valve repair has been increasingly performed worldwide after approval. We sought to investigate predictors of clinical outcome in patients with mitral regurgitation undergoing percutaneous valve repair. The MITRA-UMG study, a single-centre registry, retrospectively collected consecutive patients with symptomatic moderate-to-severe or severe MR undergoing MitraClip therapy. The primary endpoint was the composite of cardiovascular death or rehospitalization for heart failure. Between March 2012 and July 2018, a total of 150 consecutive patients admitted to our institution were included. Procedural success was obtained in 95.3% of patients. The composite primary endpoint of cardiovascular death or rehospitalization for HF was met in 55 patients (37.9%) with cumulative incidences of 7.6%, 26.2%, at 30 days and 1-year, respectively. In the Cox multivariate model, NYHA functional class and left ventricular end-diastolic volume index (LVEDVi), independently increased the risk of the primary endpoint at long-term follow-up. At Kaplan–Meier analysis, a LVEDVi > 92 ml/m² was associated with an increased incidence of the primary endpoint. In this study, patients presenting with dilated ventricles (LVEDVi > 92 ml/m²) and advanced heart failure symptoms (NYHA IV) at baseline carried the worst prognosis after percutaneous mitral valve repair.