November 11th, 2011
TAVI at TCT: Enthusiasm Tempered by Poor Transapical Outcomes
Continued enthusiasm for transcatheter aortic valve implantation (TAVI) with the Edwards’ Sapien device was tempered somewhat by poor outcomes observed in the group of patients for whom the procedure was performed using the transapical instead of the transfemoral approach. Results of 3 new studies from the PARTNER trials and a controversial new trial, STACCATO, were presented on Thursday at the TCT conference in San Francisco.
The overall good news for TAVI came from the 2-year results of the PARTNER B trial. In this trial of patients who were not eligible for open heart surgery, the advantages for TAVI over medical therapy previously observed at 1 year have now been extended out to 2 years. The rate of all-cause mortality at 2 years was 18.2% in the TAVI group versus 35.1% in the control group. Repeat hospitalization was cut in half from 72.5% in the control group to 35% in the TAVI group. However, the stroke rate at 2 years remained higher in the TAVI group: 13.8% versus 5.5%. Three strokes and 2 TIAs occurred in TAVI patients in the second year.
“The ultimate value of TAVR in ‘inoperable’ patients will depend on careful selection of patients who are not surgical candidates, and yet do not have extreme co-morbidities that overwhelm the benefits of TAVR and render the intervention futile,” concluded Raj Makkar, who presented the results at TCT.
Transapical Approach Under Scrutiny
Two other PARTNER studies presented at TCT cast a shadow on the value of TAVI in patients who require the transapical approach. The quality-of-life study of the PARTNER A trial, presented by David Cohen, found an improvement in quality of life in patients whose TAVI was performed via the transferal approach but not via the transapical approach, when compared with surgery. In fact, said Cohen, the results raised the possibility of a worse quality of life in the transapical TAVI group.
A cost-effectiveness study of PARTNER A presented by Matthew Reynolds found a small but significant gain in 12-month quality-adjusted life-years (QALY) for TAVI performed via the transfemoral approach. For the transapical approach, by contrast, there was no increase — and a possible decrease — in QALY. Total expenses in the transapical group were also significantly higher than in the surgical group.
“Current results for transcatheter aortic valve replacement via the transapical approach, compared with surgical aortic valve replacement, are unattractive from a health economic perspective,” said Reynolds in a TCT press release. “Whether the transapical approach can be refined to provide faster recovery and better results from a cost perspective should be the subject of further study.”
On their CardioExchange interventional cardiology blog, Rick Lange and David Hillis ask whether these findings cast a shadow on the future of the transapical approach.
Finally, a study performed in Denmark, called STACCATO, attempted to compare transapical TAVI with surgery in elderly patients but was discontinued early after only 70 out of a planned 200 patients had been enrolled. The discontinuation was due to an excess of events in the transapical TAVI group.
“In its present phase of development, transapical transcatheter aortic valve implantation may be inferior to surgical aortic valve replacement in operable elderly patients,” said Leif Thuesen, the lead investigator of the trial, in a TCT press release.
Lange and Hillis also scrutinize STACCATO and write:
It’s critical that we find out what went wrong in STACCATO before Edwards embarks on its ambitious efforts to roll out TAVI to 150-250 sites in the first year of commercialization.