Extending the Reach of Transcatheter Therapies
With the completion of the PARTNER 3 clinical trial, which demonstrated that transcatheter aortic valve replacement performs better than open-heart surgery in patients with severe aortic stenosis at low surgical risk, TAVR has earned its position as the standard of care for aortic stenosis. As pioneers in the TAVR journey that is enabling patients to benefit from less invasive options for aortic stenosis, Columbia and Weill Cornell faculty are now taking the lead investigating new approaches to expand the transcatheter repertoire and additional methods to improve outcomes even further.
Automated CT versus Standard CT for TAVR Sizing and Outcomes
Weill Cornell researchers reviewed the preprocedural CT scans of 60 patients to compare the value of automated CT software to CT manual measurement for aortic annular sizing and the impact on paravalvular leak and major adverse cardiovascular events. When reclassifying valve size using dynamic automated values, 12 patients were undersized and 3 patients were oversized. Undersized patients were more likely to have mild-to-moderate paravalvular leak at 30 days. The five undersized patients with at least mild paravalvular leak all had balloon-expandable valves. The results indicate that dynamic CT annular measurements have the potential to reclassify patients with paravalvular leak with larger TAVR valve size, particularly balloon-expandable valves.
Addressing Aortic Stenosis and Regurgitation
Columbia faculty led the initial U.S. clinical trial evaluating the use of JenaValve in high-risk patients with either aortic stenosis or aortic regurgitation. The JenaValve is designed to treat symptomatic, severe aortic stenosis and aortic regurgitation using a single valve prosthesis. Unlike other TAVR designs, this technology allows transcatheter replacement in a patient with pure aortic regurgitation.
Initial findings of the trial have demonstrated excellent hemodynamics and superior paravalvular leakage results. In January 2020, the JenaValve Transcatheter Aortic Valve Replacement System was designated a breakthrough device by the FDA. It is the first transcatheter device to receive this designation for severe aortic regurgitation (AR) and AR-dominant mixed aortic valve disease.
Identifying the Potential for Pacemaker Implantation
The proximity to structures vital to cardiac conduction may put some patients undergoing TAVR at higher risk for developing atrioventricular conduction disease requiring permanent pacemaker implantation. Researchers at Weill Cornell hypothesized that aortomitral continuity calcification (AMCC) may help identify patients at highest risk for this complication. To this end, the research team analyzed 136 patients who did not have a preexisting intracardiac device or prior valve surgery for the presence of AMCC, aortic valve calcification, and mitral annular calcification. Their AMCC score was stratified into 3 categories: 0, 1 to 300, and >300.
Of the 136 patients, 51 required permanent pacemaker implantation (PPMI) with a median time to PPMI of five days. Patients who underwent PPMI had a higher prevalence of AMCC than patients without PPMI (69 percent versus 32 percent, as well as higher median AMCC score, 263 versus 0). There was no difference in aortic valve and mitral annular calcification. Patients with AMCC had a 4-fold increase in odds for PPMI and those with an AMCC score >300 had greater than a 5-fold increase in odds. The authors conclude that aortomitral continuity calcification, particularly with a score >300, is associated with the need for permanent pacemaker implementation after TAVR.
Investigating the Application of Intermediate Devices for Heart Failure
Two new therapies are being investigated by Columbia researchers as an intermediate solution between medical therapy and ventricular assist devices. AccuCinch is a device consisting of a series of connected anchors placed percutaneously that can be cinched to help remodel the left ventricle in patients with heart failure and reduced ejection fraction. This device is now in early feasibility studies.
The second study is a pivotal clinical trial for an interatrial shunt device for patients with heart failure and preserved ejection fraction. With heart failure, the pressures in the left side of the heart are elevated. The Columbia team is evaluating the placement of a shunt between the left and the right atrium to help balance the pressure levels and reduce symptoms.
Does Left Ventricular Chamber Remodeling Affect MitraClip Response?
Weill Cornell faculty undertook a study, with a particular focus on left ventricular geometry, to clarify why the response varies among patients undergoing MitraClip percutaneous therapy for mitral regurgitation. Using two-dimensional transthoracic echocardiography and intra-procedural three-dimensional transesophageal echocardiography, the researchers evaluated 67 patients with degenerative mitral regurgitation who underwent the MitraClip procedure. Both 2D and 3D mitral annular size yielded good diagnostic performance for optimal MitraClip response. Sub-optimal response was associated with left ventricular end-diastolic diameter independent of left atrial size.
Their findings demonstrate that left ventricular and mitral annular dilation predict sub-optimal procedural success, augment the risk for residual or recurrent mitral regurgitation, and link therapeutic response to MitraClip to sub-valvular remodeling. Future larger scale studies are necessary to further validate current findings and determine whether extent of LV remodeling can be used to guide therapeutic decision making for patients being considered for percutaneous mitral valve repair.
Left Atrial Appendage Closure
This procedure eliminates the need for long-term oral anticoagulation in patients with atrial fibrillation and is emerging as a strategy for stroke prevention. The Left Atrial Appendage Closure Team at Columbia performed the first human case using the Conformal Left Atrial Appendage (LAA) Seal, which is designed to conform to each patient’s unique anatomy and to reduce the need for anticoagulation. The case served to initiate a multicenter study investigating the effectiveness of LAA occlusion with the Conformal device for prevention of stroke in patients with AFib.