CardioExchange Archive

What is TAVI?

During Transcatheter Aortic Valve Implantation (TAVI), a bioprosthetic valve is inserted through a catheter and implanted within the native stenotic aortic valve. The self-expanding CoreValve (Medtronic) and balloon-mounted Edwards SAPIEN (Edwards Lifesciences) valve are approved in Europe and under investigation in the U.S. for TAVI and can be implanted via the transfemoral, subclavian, or transapical route.

Is one valve better than the other?

Don’t know, as no comparison has been performed.

Are there randomized trials of TAVI, or is all experience to date anecdotal?

In PARTNER A, patients with severe, symptomatic AS who were considered candidates for aortic valve replacement (AVR) but had an increased surgical risk (i.e., a predicted perioperative mortality >15%) were randomized to TAVI or surgical AVR.  The results will be presented at the 2011 ACC meeting. 

In PARTNER B, “high risk” elderly patients with severe, symptomatic AS who were thought not to be candidates for AVR (i.e., a predicted perioperative mortality > 50%) were randomized to TAVI or “standard therapy” (which included balloon valvuloplasty in 84%). When compared with standard therapy at 1 year, TAVI significantly reduced the rate of death as well as the composite of death and repeat hospitalization, despite higher incidences of major stroke and other major vascular events.

PARTNER B: Outcomes at 1 yr

Who was not a candidate for TAVI in PARTNER? 

Patients with any of the following:
– bicuspid aortic valve
– CAD requiring revascularization
– left ventricular EF <20%
– severe (> 3+) MR or AR
– TIA or stroke in the previous 6 months
– severe renal insufficiency
– severe iliofemoral arterial or aortic (abdominal or thoracic) disease

What are the concerns with TAVI?

1. The incidence of permanent pacemaker placement within 30 days of TAVI is ≈14% (range, 0%-34%).  The incidence is higher with the CoreValve (mean, 21%; range 9–30%) than with the Edwards SAPIEN valve (mean, 5%; range 0%–10%).
2. Although the incidence of periprocedural major strokes is only 1.5%-3.0%, the incidence of cerebral silent embolic lesions is very high (70%-90%) with TAVI. The impact of these lesions on neurocognitive dysfunction needs to be assessed.
3. Durability of the valves is unknown.  Since TAVI has been used only in older patients, valve durability has not been an issue.  However, it will be an important consideration if they’re implanted in younger patients (who expect to live a long time with the valve).
4. Is TAVI as good as AVR in patients who are suitable for conventional surgery but considered to be high risk?  We’ll know soon, when the PARTNER A results are presented at the ACC.

Are the cardiac surgeons worried about TAVI?

Not really — at least not yet — because it’s only performed in patients who are considered unsuitable or high risk for conventional AVR (i.e., patients whom they try to avoid).  In addition, the surgeons are actually doing the procedure, especially the subclavian and transapical approaches.

For more of our ACC.11 coverage of late-breaking clinical trials, interviews with the authors of the most important research, and blogs from our fellows on the most interesting presentations at the meeting, check out our Coverage Roundup.