VOLUME 27, Issue 2

UPDATE ON TAVR: FIVE YEAR FOLLOW-UP DATA AND EXPANDING INDICATIONS

Surgical aortic valve replacement (SAVR) has been the standard treatment for the management of aortic valvular disease. However, transcatheter aortic valve replacement (TAVR) and its rapidly mounting body of evidence has grown exponentially in its role in the management of patients with aortic stenosis. Since 2002, when TAVR was first introduced in France, the engineering of the valves and their delivery systems have rapidly advanced.1 At least four manufacturers have brought devices to market of which only the Edwards Sapien and Medtronic Core Valves have received FDA approval for use in the United States. The original PARTNER (Placement of AoRtic TraNscathetER Valves) trial restricted TAVR to patients who were considered to be high-risk surgical candidates with aortic stenosis or inoperable due to comorbidities. However, recent early results from the PARTNER II trial suggest that TAVR may be a reasonable alternative to SAVR in an expanded lower risk pool of patients.

TAVR refers to the placement of a bioprosthetic valve into the aortic valve position via a catheter-based delivery system. Introduction of the delivery system into a patient’s arterial vasculature is accomplished via the femoral artery, subclavian artery, or directly through the aorta. The large size of the delivery system needed to transport and deploy the valve (historically as large as 25 French) sometimes eliminated the possibility of such approaches in patients with small-caliber peripheral arteries. In patients who have a contraindication to a transarterial approach, a transapical approach via a small anterior thoracotomy may be utilized. With the first generation of devices, the large introducer size often necessitated surgical cut-down even in the transfemoral approach. Vascular complications (commonly femoral or iliac artery injury) comprised a significant proportion of short-term TAVR complications and affected short-term mortality.

However, the pace with which the devices are evolving cannot be understated; introducers as small as 14 and 16 French are now utilized in Europe with an expected arrival in the United States in 2016. Once the smaller sized introducers are available, most routine TAVRs will be performed wholly percutaneously.

Early data from the PARTNER trial demonstrated the non-inferiority of TAVR to SAVR and its superiority to conservative medical management for the treatment of severe aortic stenosis.2 Recently published five year follow-up data from the PARTNER trial demonstrated no difference between TAVR and SAVR in terms of mortality, stroke, and hospital readmission after five years. Functional outcomes and valve hemodynamics are also equivalent at five years. Moderate to severe aortic regurgitation attributed to paravalvular leak was more common in TAVR and was associated with lower survival.3 Based on this latest encouraging evidence and the European experience, a growing body of evidence was presented at the American College of Cardiology Conference in March of 2015 that TAVR should be the preferred modality for many patients with aortic stenosis (not just the high-risk patients). Recent FDA approval of the Medtronic device for “valve-in-valve” use portends a future in which younger and healthier patients receive a series of TAVRs over the course of their lifetime. Continued advances in the procedure may make TAVR no more invasive than any other cardiac catheter based intervention. The cardiovascular community is anxiously awaiting further results of the PARTNER2 and SURTAVI trials for more definitive prospective data regarding this issue. (For more information on the PARTNER2 and SURTAVI trials, please visit www.edwards.com and www.corevalve.com)     

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