TAVI Results Published as US Gears Up for Sapien Review

Shelley Wood

July 14, 2011

July 13, 2011 (London, United Kingdom) — One-year outcomes from the European SOURCE registry, tracking postcommercialization outcomes for patients who underwent transcatheter aortic-valve implantation (TAVI) with the Sapien bioprosthesis (Edwards Lifesciences), can be used as a "benchmark against which future TAVI cohorts and devices can be measured," say the authors of the now-published results [1].

Their paper, published online July 11, 2011 in Circulation, comes as the US readies for the FDA circulatory system devices panel review of the Sapien's premarket approval application next week.

Dr Martyn Thomas (Kings College Hospital, London, UK) first presented the one-year results from the initial SOURCE cohort (cohort 1) at EuroPCR 2010, as reported by heartwire , and this week's published results are nearly identical to those presented last year. At EuroPCR 2011, Dr Olaf Wendler (Kings College Hospital) presented an update on SOURCE, including a second cohort of patients (cohort 2) enrolled in the second year of postcommercialization.

The original SOURCE cohort included 1038 consecutive patients at 32 centers, treated with a transfemoral approach (n=463) or a transapical approach (n=575). Transapical patients had a higher baseline logistic EuroSCORE than did transfemoral patients (29% vs 25.8%).

One-year survival was 76.1% in the overall cohort and higher in the transfemoral patients, at 81.1%, than the transapical group, at 72.1%. By way of comparison, one-year survival in PARTNER cohort B was 69.3%; however, the EuroSCORE in that group was 26.4%.

One-Year Survival Rates in SOURCE

Time point All (%) Transapical (%) Transfemoral (%)
12 mo 76.1 72.1 81.1

For both groups, half of all deaths were noncardiac in nature (most commonly pulmonary complications, renal failure, cancers, and stroke). One-quarter of the deaths were cardiac, something the authors say needs to be taken into account when deciding on a patient's eligibility for a TAVI procedure. Also of note, in multivariate analyses, factors most commonly associated with increased mortality were high EuroSCORE, renal disease, liver disease, and smoking.

Contacted by heartwire today, Thomas underscored the high survival rates among a large group of consecutive patients. "Even with a first-generation device using 22F and 24F sheaths, the transfemoral patients have a survival of >80% in a real-world setting. This is a higher survival than the patients in cohort B (nonsurgical candidates) of the PARTNER US randomized trial."

SOURCE patients, he points out, were not required to be declared surgery-ineligible and so were likely slightly lower risk--a point that will no doubt be debated at next week's FDA meeting. But of note, Thomas stressed, "there has been very little 'risk creep' within the SOURCE registry," with average surgical risk level, by EuroSCORE, among the year-two patients being very similar to those of the year-one group.

"I think this demonstrates that the technology is being introduced in a responsible manner by multidisciplinary teams in Europe, with surgeons being an important member of this team and in many instances continuing to be the gatekeeper of the technology. It can be hoped that data from the SOURCE XT registry--currently under way, with more than 1000 patients already included--using the latest device with 16F and 18F sheaths, will demonstrate yet further improvement in outcomes because of improved patient selection and reduced vascular complications."

Authors of the Circulation paper also express the hope that the registry results, in addition to data from other series, could lead to the development of a more precise risk score to be used in weighing a patient's eligibility for a TAVI procedure. Both the EuroSCORE and the STS score were created to help gauge mortality risk in patients undergoing open-heart surgery, Thomas et al note. "Unfortunately, their utility in TAVI is very much open to question, resulting in an urgent need to produce a TAVI risk score that will have a similar utility for TAVI patients."

The FDA advisory committee meeting will take place one week from today, on July 20, and will be covered by heartwire . Briefing documents from the FDA will be published a few days prior, giving a glimpse of the FDA's position prior to hearing from its expert reviewers. For minute-by-minute updates and insights into how the meeting next week is unfolding, follow theheart.org on twitter.


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