Can stress echocardiography identify patients who will benefit from percutaneous mitral valve repair?

Prognostic impact of vasopressor test in transcatheter edge-to-edge repair of secondary mitral regurgitation: The PETIT study

BACKGROUND

Vasopressor test (VPT) might be useful in patients with functional mitral regurgitation (MR) and left ventricular dysfunction (MITRA-FR-like patients) during transcatheter edge-to-edge repair (TEER).

AIMS

We aimed to evaluate the prognostic impact of VPT.

METHODS

MR treated with TEER were included in a multicenter prospective registry. VPT was used intraprocedurally in patients with left ventricular dysfunction and/or hypotension. The 1-year echocardiographic and clinical outcomes were compared according to the use of VPT. The primary endpoint was a combination of mortality + heart failure (HF) readmission at 1-year.

RESULTS

A total of 1115 patients were included, mean age was 72.8 ± 10.5 years and 30.4% were women. VPT was performed in 128 subjects (11.5%), more often in critically ill patients with biventricular dysfunction. Postprocedurally the VPT group had greater rate of MR ≥ 2+ (46.9% vs. 31.7%, p = 0.003) despite greater number of devices (≥2 clips, 52% vs. 40.6 p = 0.008) and device repositioning or new clip in 12.5%. At 1-year, the primary endpoint occurred more often in the VPT group (27.3% vs. 16.9%, p = 0.002) as well as all-cause mortality (21.9% vs. 8.1%, p ≤ 0.001) but no differences existed in HF readmission rate (14.8% vs. 13.2%, p = 0.610), cardiovascular mortality (4.4% vs. 3.9%, p = 0.713) or residual MR ≥ 2+ (51.1% vs 51.7%, p = 0.371).

CONCLUSIONS

Dynamic evaluation of MR during TEER procedure through VPT was performed in patients with worse baseline risk who also presented higher all-cause mortality at 1-year follow-up. However, 1-year residual MR, cardiovascular mortality and HF readmission rate remained comparable suggesting that VPT might help in the management of MITRA-FR-like patients.

The evolution of technical prerequisites and local boundary conditions for optimization of mitral valve interventions-Emphasis on skills development and institutional risk performance

This viewpoint report describes how the evolution of transcatheter mitral valve intervention (TMVI) is influenced by lessons learned from three evolutionary tracks: (1) the development of treatment from mitral valve surgery (MVS) to transcutaneous procedures; (2) the evolution of biomedical engineering for research and development resulting in predictable and safe clinical use; (3) the adaptation to local conditions, impact of transcatheter aortic valve replacement (TAVR) experience and creation of infrastructure for skills development and risk management. Thanks to developments in computer science and biostatistics, an increasing number of reports regarding clinical safety and effectiveness is generated. A full toolbox of techniques, devices and support technology is now available, especially in surgery. There is no doubt that the injury associated with a minimally invasive access reduces perioperative risks, but it may affect the effectiveness of the treatment due to incomplete correction. Based on literature, solutions and performance standards are formulated with an emphasis in technology and positive outcome. Despite references to Heart Team decision making, boundary conditions such as hospital infrastructure, caseload, skills training and perioperative risk management remain underexposed. The role of Biomedical Engineering is exclusively defined by the Research and Development (R&D) cycle including the impact of human factor engineering (HFE). Feasibility studies generate estimations of strengths and safety limitations. Usability testing reveals user friendliness and safety margins of clinical use. Apart from a certification requirement, this information should have an impact on the definition of necessary skills levels and consequent required training. Physicians Preference Testing (PPT) and use of a biosimulator are recommended. The example of the interaction between two Amsterdam heart centers describes the evolution of a professional ecosystem that can facilitate innovation. Adaptation to local conditions in terms of infrastructure, referrals and reimbursement, appears essential for the evolution of a complete mitral valve disease management program. Efficacy of institutional risk management performance (IRMP) and sufficient team skills should be embedded in an appropriate infrastructure that enables scale and offers complete and safe solutions for mitral valve disease. The longstanding evolution of mitral valve therapies is the result of working devices embedded in an ecosystem focused on developing skills and effective risk management actions.

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.

Isometric Handgrip Stress Test during Right Heart Catheterization in Patients with Mitral Regurgitation -A Case Series Study

Objective The severity of mitral regurgitation (MR) dynamically changes during a stress test. Isometric handgrip is a readily-available stress test in daily practice; however, little is known regarding the response to isometric handgrip in MR patients during right heart catheterization. We aimed to evaluate this issue from our case-series study. Methods We retrospectively investigated consecutive MR patients using the isometric handgrip stress test during right heart catheterization at our institution between October 2019 and April 2021. After resting measurements were obtained, sustained maximum-effort hand dynamometer grasping was maintained for about 2-3 minutes. We investigated the differences in right heart catheterization data between at rest and during handgrip, and evaluated the individual response to the isometric handgrip stress test. Results We investigated a total of 15 patients (mean age: 75±6 years, moderate/severe MR: 7/8, primary/secondary MR: 8/7, mean left ventricular ejection fraction: 56±16%, exertional dyspnea: 10). During the handgrip test, the pulmonary capillary wedge pressure (PCWP) significantly increased [9 (8, 13) mmHg at rest to 20 (15, 27) mmHg during handgrip; p<0.001]. PCWP changes varied among individuals (range 2-22 mmHg) and were not correlated with patients' backgrounds including age, the natriuretic peptide levels, left ventricular ejection fraction, left atrial diameter or E/e' (all p>0.05). Patients with PCWP ≥25 mmHg during handgrip had a higher prevalence of exertional dyspnea than those without [6 (100%) vs. 4 (44%); p=0.04]. Conclusion We observed dynamic and varied hemodynamic changes during isometric handgrip in MR patients, suggesting that further research is needed to evaluate the clinical value of this maneuver.

Transcatheter mitral valve repair for the treatment of severe mitral regurgitation and exertional pre-syncope in a patient with non-obstructive hypertrophic cardiomyopathy: a case report

Background

Hypertrophic cardiomyopathy (HCM) has a complex pathophysiology and heterogeneous phenotypic expression. In obstructive HCM with significant mitral regurgitation (MR), MitraClip device implantation reduces MR severity and symptoms. There are no data regarding MitraClip implantation in patients with non-obstructive HCM and significant MR.

Case summary

A 78-year-old woman with non-obstructive HCM and significant functional MR (3+) was admitted to our centre for dyspnoea and episodes of pre-syncope under light stress. Transthoracic and transoesophageal echocardiography showed a normal left ventricular ejection fraction and normal right heart pressures, an inverted mitral filling pattern, and a central prevalent jet (A2-P2 origin) of MR. Exercise echocardiography performed to verify exercise tolerance was interrupted at the 50-W stage due to severe hypotension and pre-syncope. After transcatheter edge-to-edge repair using the MitraClip system, the patient exhibited a reduction in MR Grade from 3+ to 1+. Follow-up up to 1-year post-procedure revealed noticeable improvements in exercise tolerance and symptoms. There were no further episodes of pre-syncope.

Discussion

In non-obstructive HCM, the pathophysiological role of MR in symptom generation is unknown. In this patient, we speculated that significant MR contributed to the mechanisms responsible for severe hypotension and pre-syncope during exercise. A reduction in MR after MitraClip implantation was associated with symptomatic improvements. Our findings further highlight the potential utility of the exercise stress test in therapeutic decision-making for patients with non-obstructive HCM and MR.

Impact of Post-Procedural Change in Left Ventricle Systolic Function on Survival after Percutaneous Edge-to-Edge Mitral Valve Repair

OBJECTIVES

To investigate how the changes of left ventricle ejection fraction (LVEF) between admission and discharge affected the long-term outcome in patients who underwent percutaneous edge-to-edge mitral valve repair for secondary mitral regurgitation.

BACKGROUND

An acute impairment of LVEF after surgical repair of mitral regurgitation, known as afterload mismatch, has been associated with increased all-cause mortality. Afterload mismatch after percutaneous edge-to-edge mitral valve repair has been postulated to be a transient phenomenon.

METHODS

This study is based on a single-center, retrospective, observational registry of patients who underwent percutaneous edge-to-edge mitral valve repair with the MitraClip (Abbot Vascular) system for the treatment of symptomatic, moderate-to-severe mitral regurgitation. We included data on 399 patients who underwent percutaneous edge-to-edge mitral valve repair for secondary mitral regurgitation. Expert echocardiographers assessed LVEF before the procedure and at discharge. The patients were divided into three groups according to the difference of periprocedural LVEF measurements: unchanged (n = 318), improved (n = 40), and decreased (n = 41) LVEF.

RESULTS

The median follow-up time was 2.0 years. When adjusted for gender, NYHA class and estimated glomerular filtration rate, decreased postprocedural LVEF was associated with an increased risk of death (adjusted HR 2.05, 95% CI 1.26-3.34) and increased postprocedural LVEF with a reduced risk of death (adjusted HR 0.47, 95% CI 0.24-0.91) compared to unchanged LVEF. Conclusion: Among patients who underwent percutaneous edge-to-edge mitral valve repair, decreased postprocedural LVEF was associated with increased mortality, while improved LVEF was associated with lower mortality compared to unchanged LVEF.

Selection of the Optimal Candidate to MitraClip for Secondary Mitral Regurgitation: Beyond Mitral Valve Morphology

Secondary mitral regurgitation (MR) occurs despite structurally normal valve apparatus due to an underlying disease of the myocardium leading to disruption of the balance between tethering and closing forces with ensuing failure of leaflet coaptation. In patients with heart failure (HF) and left ventricular dysfunction, secondary MR is independently associated with poor outcome, yet prognostic benefits related to the correction of MR have remained elusive. Surgery is not recommended for the correction of secondary MR outside coronary artery bypass grafting. Percutaneous mitral valve repair (PMVR) with MitraClip implantation has recently evolved as a new transcatheter treatment option of inoperable or high-risk patients with severe MR, with promising results supporting the extension of guideline recommendations. MitraClip is highly effective in reducing secondary MR in HF patients. However, the derived clinical benefit is still controversial as two randomized trials directly comparing PMVR vs. optimal medical therapy in severe secondary MR yielded virtually opposite conclusions. We reviewed current evidence to identify predictors of PMVR-related outcomes in secondary MR useful to improve the timing and the selection of patients who would derive maximal benefit from MitraClip intervention. Beyond mitral valve anatomy, optimal candidate selection should rely on a comprehensive diagnostic workup and a fine-tuned risk stratification process aimed at (i) recognizing the substantial heterogeneity of secondary MR and its complex interaction with the myocardium, (ii) foreseeing hemodynamic consequences of PMVR, (iii) anticipating futility and (iv) improving symptoms, quality of life and overall survival.

Dynamic handgrip exercise for the evaluation of mitral valve regurgitation: an echocardiographic study to identify exertion induced severe mitral regurgitation

Handgrip exercise (HG) has been occasionally used as a stress test in echocardiography. The effect of HG on mitral regurgitation (MR) is not well known. This study aims to evaluate this effect and the possible role of HG in the echocardiographic evaluation of MR. 722 patients with MR were included (18% primary, 82% secondary disease). We calculated effective regurgitant orifice area (EROA) and regurgitant volume (RVOL) at rest and during dynamic HG. Increase in MR was defined as any increase in EROA or RVOL. We analyzed the data to identify possible associations between clinical or echocardiographic parameters and the effect of HG on MR. MR increased during dynamic HG in 390 of 722 patients (54%) (∆EROA = 25%, ∆RVOL = 27%). Increase of regurgitation occurred in 66 of 132 patients with primary MR (50%) and in 324 of 580 patients with secondary MR (55%). This increase was associated with larger baseline EROA and RVOL, but it was independent from other clinical or echocardiographic parameters. In secondary MR, dynamic HG led to a reclassification of regurgitation severity from non-severe at rest to severe MR during HG in 104 of 375 patients (28%). There was a significant association between this upgrade in MR classification and higher New York Heart Association (NYHA) class (OR 1.486, 95%-CI 1.138-1.940, p = 0.004). Dynamic HG exercise increases MR in about half of patients independent of the etiology. Dynamic HG may be used to identify symptomatic patients with non-severe secondary MR at rest but severe MR during exercise.