Percutaneous balloon mitral valvuloplasty with shockwave lithotripsy for the treatment of calcific mitral valve stenosis.

BACKGROUND: Calcific mitral stenosis (calcific MS) presents a challenge for surgical treatment and is a contraindication for most contemporary transcatheter mitral valve replacement devices (TMVR), rendering patients with very limited therapeutic options. AIMS: This study aims to assess the clinical and hemodynamic follow-up after mitral valve lithotripsy (MVL). METHODS: All consecutive patients who underwent MVL to treat symptomatic calcific MS at St Michael's Hospital, Toronto, Canada, were included. Patients were deemed unsuitable for mitral surgery or TMVR after heart team assessment. Patients with rheumatic MS or ≥moderate mitral regurgitation (MR) were excluded. The primary endpoint was a reduction in the invasive mitral gradient by ≥50% without significant (≥moderate) MR. RESULTS: Fifteen patients underwent MVL between 2021 and 2023 with a mean age of 74 ± 9 years; 53% were female, with a mean STS score of 10% ± 0.1%. Following MVL, there was a reduction in the invasively measured mean trans-mitral gradient compared to baseline (14 mmHg vs. 6 mmHg; p < 0.05). The primary endpoint was achieved in 8 patients (53%) with no major procedural complications. At follow-up (median 90 days, IQR 58-115 days), 14 (93%) patients reported improved symptoms from New York Heart Association (NYHA) Class III-IV to NYHA Class I-II (p < 0.01) with stable echo-derived mean gradient (7.7 mmHg ± 2 mmHg vs. 8.4 mmHg ± 2.9 mmHg (p = 0.7). CONCLUSIONS: In selected patients with symptomatic inoperable calcific MS, MVL was safe and associated with significant short-term clinical and hemodynamic improvement. MVL may represent a new compassionate therapy for this challenging cohort. Further studies are needed to determine the long-term outcomes and help define the role of IVL technology in treating calcific valvular conditions.

Mitral annular calcification and valvular dysfunction: multimodality imaging evaluation, grading, and management.

Mitral annular calcification (MAC) refers to calcium deposition in the fibrous skeleton of the mitral valve. It has many cardiovascular associations, including mitral valve dysfunction, elevated cardiovascular risk, arrhythmias, and endocarditis. Echocardiography conventionally is the first-line imaging modality for anatomic assessment, and evaluation of mitral valve function. Cardiac computed tomography (CT) has demonstrated importance as an imaging modality for the evaluation and planning of related procedures. It also holds promise in quantitative grading of MAC. Currently, there is no universally accepted definition or classification system of MAC severity. We review the multimodality imaging evaluation of MAC and associated valvular dysfunction and propose a novel classification system based on qualitative and quantitative measurements derived from echocardiography and cardiac CT.

Mitral Annular Calcification and Calcific Mitral Stenosis: Role of Echocardiography in Hemodynamic Assessment and Management.

As the life expectancy of the population continues to increase, mitral annular calcification has emerged as an important cause of mitral stenosis (MS), commonly referred to as calcific or degenerative MS. Mitral annular calcification results in valvular stenosis when calcification extends into the base of the mitral leaflet(s) and displaces the mitral valve hinge point(s) into the left ventricular inlet. Echocardiographic determination of mitral vale area is fraught with difficulties and often precludes using planimetry or the Hatle formula. Given the numerous confounders that affect transmitral flow in calcific MS, evaluation of lesion severity should incorporate flow-independent methods such as the continuity equation and the mitral valve dimensionless index. In light of the significant risks entailed, there is little enthusiasm for mitral valve replacement in patients with calcific MS. Transcatheter mitral valve replacement is generally offered on a compassionate use basis to patients deemed to be at high surgical risk.

Advances in Rheumatic Mitral Stenosis: Echocardiographic, Pathophysiologic, and Hemodynamic Considerations.

Echocardiography is the primary imaging modality used in patients with mitral stenosis. Doppler-derived measurements of mitral pressure half-time are commonly used to calculate mitral valve area, but a number of hemodynamic confounders associated with advanced age limit its utility. Planimetry remains the gold standard for determining mitral valve area and may be performed using two- or three-dimensional imaging. Although the Wilkins score has been used for >30 years to predict balloon mitral valvuloplasty outcomes, newer scoring systems have been proposed to improve predictive accuracy. Some patients undergoing technically successful balloon mitral valvuloplasty may not have satisfactory clinical outcomes. These individuals may be identified by the presence of reduced net atrioventricular compliance, which can be measured echocardiographically. Exercise testing may be useful in patients with mitral stenosis whose symptomatic status is incongruous their mitral valve area. Last, reduced left atrial systolic strain, an indicator of poor left atrial compliance, has been shown to reliably predict adverse outcomes in patients with mitral stenosis. The author discusses the hemodynamics and path ophysiology of mitral stenosis and reviews current and emerging roles of echocardiography in its evaluation.

Mitral Annular Calcification and Calcific Mitral Stenosis: Therapeutic Challenges and Considerations.

PURPOSE OF REVIEW: Mitral annular calcification (MAC) and associated calcific mitral stenosis (MS) are frequent in the aging population, although optimal management remains debated and outcomes are poor. This article summarizes challenges in the diagnosis and therapy of calcific MS, the indications for valve intervention, procedural concerns, and emerging treatment options. RECENT FINDINGS: Surgical mitral valve replacement is the procedure of choice in symptomatic patients at acceptable surgical risk, with transcatheter mitral valve replacement (TMVR) being evaluated in clinical trials as an alternative for patients at prohibitive surgical risk. Significant challenges exist with the currently available technology and outcomes have been suboptimal. Optimizing the patient-selection process by using multimodality imaging tools has proven to be essential. MAC and calcific MS is an increasingly prevalent, challenging issue with poor outcomes. While surgical valve replacement can be performed in patients with acceptable surgical risk, TMVR can be considered for patients at higher risk. Clinical trials are underway to optimize outcomes. Dedicated device designs and techniques to minimize risk of left ventricular outflow tract obstruction, paravalvular leakage, and device embolization are to be awaited.

Short-term results of alcohol septal ablation as a bail-out strategy to treat severe left ventricular outflow tract obstruction after transcatheter mitral valve replacement in patients with severe mitral annular calcification.

OBJECTIVES: To evaluate the outcomes of the early experience of percutaneous alcohol septal ablation in patients with severe left ventricular outflow tract (LVOT) obstruction post transcatheter mitral valve replacement (TMVR). BACKGROUND: Severe LVOT obstruction with hemodynamic compromise is a complication of TMVR associated with high mortality. Percutaneous alcohol septal ablation has recently been described as a therapeutic option in this setting. METHODS: Multicenter retrospective review of clinical outcomes of patients undergoing alcohol septal ablation to treat LVOT obstruction after TMVR for severe mitral stenosis with severe mitral annular calcification. RESULTS: Six patients underwent percutaneous alcohol septal ablation to treat LVOT obstruction post-TMVR at six different centers. Five patients had immediate significant reduction in LVOT obstruction with improvement in hemodynamic status while one had persistent LVOT gradient but hemodynamic instability improved. The first patient died on postoperative day 4 due to complete heart block. One patient had initial improvement in LVOT gradient with recurrence on postoperative day 1 thought to be secondary to septal edema, was treated with surgical removal of the transcatheter valve and resection of the anterior mitral leaflet followed by transatrial TMVR and died 3 weeks later due to multi-organ failure. The remaining four patients improved clinically after alcohol septal ablation, were discharged from the hospital and were clinically stable at 30-day follow-up. CONCLUSIONS: Percutaneous alcohol ablation provides acute relief of TMVR-induced LVOT obstruction when septal hypertrophy is a contributing factor. This may be a safer alternative to bail-out surgery in this extremely high-risk patient population. © 2017 Wiley Periodicals, Inc.

Transcatheter Mitral Valve Replacement in Native Mitral Valve Disease With Severe Mitral Annular Calcification: Results From the First Multicenter Global Registry.

OBJECTIVES: This study sought to evaluate the outcomes of the early experience of transcatheter mitral valve replacement (TMVR) with balloon-expandable valves in patients with severe mitral annular calcification (MAC) and reports the first large series from a multicenter global registry. BACKGROUND: The risk of surgical mitral valve replacement in patients with severe MAC is high. There are isolated reports of successful TMVR with balloon-expandable valves in this patient population. METHODS: We performed a multicenter retrospective review of clinical outcomes of patients with severe MAC undergoing TMVR. RESULTS: From September 2012 to July of 2015, 64 patients in 32 centers underwent TMVR with compassionate use of balloon-expandable valves. Mean age was 73 ± 13 years, 66% were female, and mean Society of Thoracic Surgeons score was 14.4 ± 9.5%. The mean mitral gradient was 11.45 ± 4.4 mm Hg and the mean mitral area was 1.18 ± 0.5 cm(2). SAPIEN valves (Edwards Lifesciences, Irvine, California) were used in 7.8%, SAPIEN XT in 59.4%, SAPIEN 3 in 28.1%, and Inovare (Braile Biomedica, Brazil) in 4.7%. Access was transatrial in 15.6%, transapical in 43.8%, and transseptal in 40.6%. Technical success according to Mitral Valve Academic Research Consortium criteria was achieved in 46 (72%) patients, primarily limited by the need for a second valve in 11 (17.2%). Six (9.3%) had left ventricular tract obstruction with hemodynamic compromise. Mean mitral gradient post-procedure was 4 ± 2.2 mm Hg, paravalvular regurgitation was mild or absent in all. Thirty-day all-cause mortality was 29.7% (cardiovascular = 12.5% and noncardiac = 17.2%); 84% of the survivors with follow-up data available were in New York Heart Association functional class I or II at 30 days (n = 25). CONCLUSIONS: TMVR with balloon-expandable valves in patients with severe MAC is feasible but may be associated with significant adverse events. This strategy might be an alternative for selected high-risk patients with limited treatment options.