PARIS – In inoperable patients with severe aortic stenosis, their EuroSCORE – a predicted operative mortality from cardiac surgery – consistently predicted outcomes from transcatheter aortic valve implantation in a prospective, single-center study.
Among 177 consecutive patients declined for surgery, the procedural success rate was 100% in patients with a EuroSCORE of less than 20% and 95.7% in those with a EuroSCORE of more than 20%.
Moreover, there were no deaths at 30 days in the low-risk group, but mortality was 11.1% in the high-risk group. This result was maintained at 1 year (5% vs. 25%), and both differences were highly significant, Dr. Matthieu Godin reported at the annual congress of the European Society of Cardiology.
"This may be the first step towards a broader assessment of percutaneous techniques in populations at lower surgical risk, but without forgetting that surgery is currently the ... standard," he said.
Transcatheter aortic valve implantation (TAVI) is not commercially avaliable in the United States. In Europe, however, TAVI is considered a less invasive therapeutic option for severe aortic stenosis among nonsurgical and high–surgical-risk patients, as defined by a logistic EuroSCORE (European System for Cardiac Operative Risk) of more than 20% or a Society of Thoracic Surgeons risk score of more than 10%.
TAVI is frequently performed, however, in patients with low to intermediate logistic EuroSCOREs and contraindications to conventional valve replacement due to comorbidities not included in the surgical risk models, said Dr. Godin of Rouen (France) University Hospital–Charles Nicolle Hospital, where the first TAVI was performed in 2002 by coinvestigator Dr. Alain Cribier (Circulation 2002;106:3006-8).
In an effort to address this evolution and an eager marketplace, the American College of Cardiology and Society of Thoracic Surgeons released an expert consensus document that explores key components that will be necessary for successful integration of transcatheter valve therapy into clinical practice (J. Am. Coll. Cardiol. 2011;58:445-55). While praising the "transformational technology," the societies cite limited evidence from only one randomized trial in aortic stenosis (PARTNER) and one in mitral insufficiency (EVEREST II) in stating that "adoption of these techniques to populations beyond those studied in these randomized trials, therefore, is not appropriate at the current time."
Dr. Godin stressed that his results should not be interpreted to suggest that the indication for TAVI should be expanded to low-risk surgical candidates and said that this would require a large-scale trial like PARTNER and long-term follow-up on the durability of the prostheses.
The Placement of Aortic Transcatheter Valves (PARTNER) trial enrolled two distinct cohorts. Cohort A included 699 patients (median age 84 years) who were candidates for conventional surgery but were at high surgical risk based on an STS score of at least 10% or on coexisting conditions that would be associated with at least a 15% predicted risk of death by 30 days after surgery. Cohort B included 358 patients (median age 83 years) who were deemed unsuitable for conventional surgery because of coexisting conditions that would be associated with at least a 50% predicted probability of death by 30 days after surgery or a serious irreversible complication (N. Engl. J. Med. 2010;363:1597-607).
Dr. Godin’s analysis included 177 patients who presented between 2006 and 2011 with degenerative aortic stenosis and were implanted with the Edwards Sapien valve up to October 2009 and the Edwards Sapien-XT prosthesis thereafter. A transfemoral approach was used in 72% and a transapical approach in 28%.
In all, 60 patients had a EuroSCORE of less than 20% (mean 12%) and 117 had a EuroSCORE of at least 20% (mean 32%). Their mean ages were 80 years and 84 years, respectively.
Contraindications to conventional surgery in the low-risk group included porcelain aorta in 15%, chest irradiation in 20%, and chest deformity in 8.3%.
The low- and high-risk groups had similar rates of major stroke (1.7% and 0.9%, respectively), major vascular complications (5% and 6%), and definitive pacemaker implantation (5% and 6%), Dr. Godin reported.
The low-risk group had significantly less life-threatening bleeding (7% vs. 21%) and significantly shorter mean ICU stays (2 days vs. 3 days) and mean hospital stays (9 days vs. 11 days).
Dr. Godin reported no conflicts. Dr. Cribier is a consultant for Edwards Lifesciences, and two additional coauthors are proctors for the company.