Shelley Wood

May 22, 2013

PARIS, France (corrected) — One-year results from the SOURCE XT postapproval registry for the next-generation Sapien XT valve (Edwards Lifesciences) in Europe show that mortality rates are edging downward, while moderate or severe aortic regurgitation appears much lower than in other series.

In an intriguing new finding, survival rates were actually better for women than for men.

Presenting the results here at EuroPCR 2013 , Dr Stephan Windecker (University Hospital Inselspital Bern, Switzerland) stressed that comparing one-year results for the newer valve with that of its predecessor, the Sapien (in the SOURCE registry) is fraught with problems, including the fact that patients in SOURCE XT had a slightly lower mean EuroSCORE. Nevertheless, all-cause mortality at one year in SOURCE XT was 19.5% and cardiac mortality was just 10.8%--one of the highest, if not the highest, survival rate for transcatheter aortic-valve replacement (TAVR) ever reported, Dr Martyn Thomas (St Thomas' Hospital, London, UK) observed during the hotline session yesterday.

SOURCE XT Patients and Results

Windecker presented one-year results for 2166 SOURCE XT patients (out of 2688 originally treated patients) from 93 sites in 17 countries. In the registry, 62.7% of devices were implanted via the transfemoral route, followed by 33.3% via the transapical approach, 3.7% via a transaortic route, and 0.3% via the subclavian approach.

In one of the more striking slides of his presentation, Windecker showed that survival in the transfemorally treated patients was highest, at 85%, a number that was significantly higher than both the transapical group at 72.8% and the transaortic group at 73.9%.

Those findings prompted Thomas to remark that while he's "always been a great defender of transapical," the numbers make it impossible to ignore the question: "Is it the procedure or the patient?" To this, Windecker replied: "It has less to do with the access route and more to do with the patient's condition," since these patients have comorbidities that make the transfemoral route a no-go.

Paravalvular Leaks

Also impressive in the SOURCE XT 12-month results was a clear signal that the problem of paravalvular regurgitation with this device is clearly improving, although not gone altogether. At one year, the majority of SOURCE XT patients had no or mild regurgitation, with just 6.2% having moderate or severe "leaks." In PARTNER 2 , by contrast, the randomized trial using the XT device, moderate to severe paravalvular regurgitation was more than 29%, while in the original PARTNER trial, with Sapien, aortic regurgitation hovered at around 12%. One-year results from the ADVANCE registry with CoreValve (Medtronic), reported yesterday, also documented a moderate paravalvular leak rate of 12% (with no cases of severe leak).

Asked what was driving the improvement in the new Sapien XT regurgitation results, Windecker cited new design features of XT that make it possible to implant with more precision; better use of multimodal imaging; and a heightened awareness on the part of implanting physicians that limiting paravalvular leaks is critically important. Of note, however, paravalvular regurgitation did not emerge in SOURCE XT as a driver of worse outcomes. Indeed, in multivariate analyses, only porcelain aorta and liver disease emerged as predictors of mortality--neither of which are captured in the EuroSCORE--yet paravalvular regurgitation did not. Windecker acknowledged, however, that paravalvular leaks were adjudicated in-house at each hospital and not by an independent core lab.

Other Findings

Asked why survival was better in women than men, Windecker speculated that this might simply reflect that women are not adversely affected by the procedure itself (despite concerns about large sheath sizes, etc), so that for those who survive the initial procedure, their greater longevity kicks in and allows them to "beat out the men."

Other key insights from SOURCE XT at one year:

  • Stroke at one year was 6.3%.

  • Proportion of patients in NYHA class 3 or 4 dropped from 75.3% at baseline to 9.7% at one year.

  • Quality of life (by EQ-5D scale) improved from 49.3 to 69.5.

  • Survival free from all-cause and cardiac events in women was 82.5% and 90.6%, respectively, while for men those numbers were 77.9% and 87.6%.

  • All-cause survival among patients with mean EuroSCORE of >15 or greater was 78.9%, rising to 83.4% among patients with mean EuroSCORE <15.

Commenting on the findings, Dr Christoph K Naber (Elisabeth Hospital, Essen, Germany) observed that the findings will not necessarily change his practice. On the contrary, he said, "this trial rather confirms and reassures me that we are on the right track."

Windecker disclosed receiving institutional grants/research support from Abbott, Biosensors, Biotronik, Boston Scientific, Cordis, Edwards Lifesciences, Medtronic, and St Jude.

An earlier version of this story incorrectly stated that survival in the transaortic group was 23.9%.

 

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