Early outcomes following transatrial transcatheter mitral valve replacement in patients with severe mitral annular calcification.

OBJECTIVE: Implantation of a transcatheter valve-in-mitral annular calcification (ViMAC) has emerged as an alternative to traditional surgical mitral valve (MV) replacement. Previous studies evaluating ViMAC aggregated transseptal, transapical, and transatrial forms of the procedure, leaving uncertainty about each technique's advantages and disadvantages. Thus, we sought to evaluate clinical outcomes specifically for transatrial ViMAC from the largest multicenter registry to-date. METHODS: Patients with symptomatic MV dysfunction and severe MAC who underwent ViMAC were enrolled from 12 centers across the United States and Europe. Clinical characteristics, procedural details, and clinical outcomes were abstracted from the electronic record. The primary end point was all-cause mortality. RESULTS: We analyzed 126 patients who underwent ViMAC (median age 76 years [interquartile range {IQR}, 70-82 years], 28.6% female, median Society of Thoracic Surgeons score 6.8% [IQR, 4.0-11.4], and median follow-up 89 days [IQR, 16-383.5]). Sixty-one (48.4%) had isolated mitral stenosis, 25 (19.8%) had isolated mitral regurgitation (MR), and 40 (31.7%) had mixed MV disease. Technical success was achieved in 119 (94.4%) patients. Thirty (23.8%) patients underwent concurrent septal myectomy, and 8 (6.3%) patients experienced left ventricular outflow tract obstruction (7/8 did not undergo myectomy). Five (4.2%) patients of 118 with postprocedure echocardiograms had greater than mild paravalvular leak. Thirty-day and 1-year all-cause mortality occurred in 16 and 33 patients, respectively. In multivariable models, moderate or greater MR at baseline was associated with increased risk of 1-year mortality (hazard ratio, 2.31; 95% confidence interval, 1.07-4.99, P = .03). CONCLUSIONS: Transatrial ViMAC is safe and feasible in this selected, male-predominant cohort. Patients with significant MR may derive less benefit from ViMAC than patients with mitral stenosis only.

Imaging in patients with severe mitral annular calcification: insights from a multicentre experience using transatrial balloon-expandable valve replacement.

AIMS: To investigate valve sizing and the haemodynamic relevance of the predicted left ventricular outflow tract (LVOT) in patients with mitral annular calcification (MAC) undergoing transatrial transcatheter valve implantation (THV). METHODS AND RESULTS: In total, 21 patients undergoing transatrial THV, multiplanar reconstruction (MPR), maximum intensity projection (MIP), and cubic spline interpolation (CSI) were compared for MA sizing during diastole. In addition, predicted neo-LVOT areas were measured in 18 patients and correlated with the post-procedural haemodynamic dimensions. The procedure was successful in all patients (100%). Concomitant aortic valve replacement was performed in eight patients (43%) (AVR group). Sizing using MPR and MIP yielded comparable results in terms of area, perimeter, and diameter, whereas the dimensions obtained with CSI were systematically smaller. The simulated mean systolic neo-LVOT area was 133.4 ± 64.2 mm2 with an anticipated relative LVOT area reduction (neo-LVOT area/LVOT area × 100) of 59.3 ± 14.7%. The systolic relative LVOT area reduction, but not the absolute neo-LVOT area, was found to predict the peak (r = 0.69; P = 0.002) and mean (r = 0.65; P = 0.004) post-operative aortic gradient in the overall population as well as separately in the AVR (peak: r = 0.91; P = 0.002/mean: r = 0.85; P = 0.002) and no-AVR (peak: r = 0.89; P = 0.003/mean: r = 0.72; P = 0.008) groups. CONCLUSION: In patients with severe MAC undergoing transatrial transcatheter valve implantation, MPR, and MIP yielded comparable annular dimensions, while values obtained with CSI tended to be systematically smaller. Mitral annular area and the average annular diameter appear to be reliable parameters for valve selection. Simulated relative LVOT reduction was found to predict the post-procedural aortic gradients.

Transatrial implantation of a transcatheter heart valve for severe mitral annular calcification.

OBJECTIVE: To assess the outcomes of transatrial implantation of a transcatheter heart valve (THV) for the treatment of mitral valve disease with severe mitral annular calcification (MAC). METHODS: Implantation of a balloon-expandable THV was performed on cardiopulmonary bypass via left atrial exposure in patients considered at risk for left ventricular outflow tract obstruction. The anterior mitral valve leaflet was systematically resected and pledgeted sutures were placed to enhance stability and reduce paravalvular leak. RESULTS: Twenty-six consecutive symptomatic patients with severe MAC (mean age, 78 ± 7 years; 92% female; mean Society of Thoracic Surgeons score, 9.4 ± 4.8) were included at 6 different centers. Two patients (8%) received an Edwards Sapien XT (Edwards Lifesciences, Irvine, Calif), and 24 (92%) an Edwards Sapien 3 bioprosthesis (Edwards Lifesciences). Concomitant aortic valve replacement was performed in 11 patients. Technical success according to the criteria of the Mitral Valve Academic Research Consortium was achieved in all patients. The mean transmitral gradient decreased from 10 ± 5 to 4 ± 2 mm Hg (P < .001) with trace or mild regurgitation in all patients. An elevated mean transaortic gradient (30 mm Hg) was observed in 1 patient (4%). Five patients died during hospital stay (19%) and 2 additional between discharge and 30 days (30-day mortality: 27%). Sustained functional improvement was observed in the remaining patients. CONCLUSIONS: Transatrial implantation of a THV for the treatment of MAC is associated with high technical success despite unfavorable anatomy. In this early experience of very high surgical risk patients, 30-day all-cause mortality was high. Patients at particular risk appear to be those with chronic kidney disease requiring multiple valve surgery.