PARTNER CAP Data Show Transapical Outcomes Improve With Practice

Reed Miller

January 31, 2012

January 31, 2012 (Fort Lauderdale, Florida)— Results from the continued-access program (CAP) of the PARTNER A trial of the Sapien transcatheter aortic valve (Edwards Lifesciences) show improvements in transapical-delivery compared with those patients treated transapically in the trial [1].

At the Society of Thoracic Surgeons (STS) 2012 Annual Meeting, Dr Todd Dewey (Medical City Hospital, Dallas, TX) presented results from 822 patients implanted with a Sapien transapically since 2009 as part of the post-PARTNER trial CAP at 22 centers in Europe. The results confirm that "transapical transcatheter valve replacement is a safe, reproducible, and effective procedure for the treatment of critical aortic stenosis in a high-risk population that is not a candidate for a transfemoral procedure," Dewey said.

Dewey said that the CAP patients have had generally better results than the transapical patients in the PARTNER A trial, because the operators are getting better at performing the procedure and selecting patents who are better suited to this technique than the transfemoral approach and because of improvements in postprocedure patient care.

PARTNER A stratified surgery-eligible high-risk patients by their suitability for a percutaneous transfemoral intervention. Patients deemed unsuitable for the transfemoral approach due to poor vascular access were randomized to either a Sapien implant via transapical delivery (104 patients) or standard surgical valve replacement (103).

The transapical patients in CAP were slightly older, with less pulmonary hypertension and cerebrovascular disease than the transapical patients in the PARTNER A trial, but otherwise the CAP patients were very similar to those in the PARTNER A trial. For example, the CAP patients' average STS predicted risk of mortality score was 12.4 compared with 11.8 for the PARTNER A transapical patients, and their average logistic EuroSCORE was 29.1 compared with 29.8 in the PARTNER A trial.

Clinical Outcomes at 30 Days

Outcome PARTNER transapical, n=104 (%) PARTNER surgery, n=92 (%) CAP transapical, n=822 (%)
All-cause mortality 8.7 7.6 8.2
Stroke 7.0 5.5 2.0
Death or stroke 15.4 12.0 9.9

 

Clinical Outcomes at One Year

Outcome PARTNER transapical, n=104 (%) PARTNER surgery, n=92 (%) CAP transapical, n=822 (%)
All-cause mortality 29.1 25.3 23.6
Stroke 10.8 7.0 3.7
Death or stroke 34.8 29.7 25.7

Kaplan-Meier estimates show that the one-year all-cause mortality for the CAP group was 5.5% lower than that of the transapical patients in PARTNER A. The one-year stroke risk for the patients in the CAP group was 3.3% lower than that of the surgery patients in the trial and 7.1% better than the stroke risk of the transapical patients in PARTNER A.

The Learning Curve Can Transcend Centers

The average number of patients treated per site in CAP was about 38, compared with fewer than eight per site in the PARTNER A trial.

Early on, when we were learning [this procedure] from our colleagues in Europe, we were learning not only how to make the clock but to tell time. Now we're just teaching people how to tell time.

The study showed a learning curve not only for individual implanting centers, but for all of the implanting centers as a group. "The transmission of accumulated knowledge to later-adopting sites through training and education can lead to early results that are comparable and in some cases somewhat better than slightly experienced centers," Dewey said. "Early on, when we were learning [this procedure] from our colleagues in Europe, we were learning not only how to make the clock but to tell time. Now we're just teaching people how to tell time," Dewey said. "With the training and education of centers, you can see even people with limited experience have excellent results."

The centers that began transapical implants of Sapien after September 2009 had a 3.4% better 30-day mortality than the early-adopting sites that participated in the trial. The difference in one-year mortality between the late- and early-adopting sites was 7.9%. "Clearly, the learning curve was bent in a significant and positive direction for the later-adopting sites based on the dispersal of accumulated knowledge that was gained from the early-adopting centers," Dewey said. The stroke data also showed a small improvement between the early- and late-adopting centers.

Dewey is a consultant for the PARTNER trial sponsored by Edwards Lifesciences and has received honoraria from and is on the speaker's bureau for Edwards Lifesciences. He has ownership interest in Cardiapex. Disclosures for the coauthors are listed in the abstract.

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