SAN FRANCISCO—Mid-term valve-related complications are “exceptionally low,” and the gradient release after transcatheter aortic valve prosthesis implantation is stable up to one year of follow up, according to a study presented this week at the 2009 Transcatheter Cardiovascular Therapeutics meeting.
Sabine Bleiziffer, MD, a cardiac surgeon at the German Heart Center Munich in Munich, Germany, and lead author of the study said that “transcatheter aortic valve implantation with the self-expandable prosthesis is an effective and durable treatment for patients with aortic stenosis not eligible for surgical aortic valve replacement.”
She reported on a single-center experience with transcatheter aortic valve prosthesis (CoreValve, Medtronic), and provided echocardiographic data, in addition to findings on valve-related events in one year of follow up.
Between June 2007 and April 2009 clinicians implanted 179 prostheses (164 transfemoral, five transapical, seven via subclavian artery, three via ascending aorta) in non-surgical candidates (mean age 81, mean STS score 19 percent) with symptomatic high-grade aortic stenosis (mean valve orifice area 0.7 m², mean aortic gradient 48-mm Hg).
Peri-procedural complications included femoral access site complications in 13 percent of the patients, dialysis for postoperative renal failure in 8 percent, neurologic events in 7 percent, and permanent pacemaker implantation in 26 percent. She reported that 30 day-, six month- and one-year survival was 88 percent, 78 percent and 78 percent, respectively.
Freedom from bleeding events, thromboembolic events, structural valve deterioration and prosthetic endocarditis was 83 percent, 97 percent, 99 percent and 97 percent at one year.
The researchers also found that non-structural valve deterioration or valve thrombosis did not occur. Mean aortic gradient decreased to 11-mm Hg (valve size 26) and 12-mm Hg (valve size 29), and valve orifice area increased to 1.4 cm² (valve size 26) and 1.5 cm² without change up to one-year follow-up.
The authors concluded that “multiple vascular access sites are feasible for implantation of the prosthesis because of the small diameter of the delivery sheath.”
While peri-procedural complications are considerable, according to Bleiziffer, they are related to the high-risk patient population.
"A close and careful follow-up of patients treated with the new technology of transcatheter valve implantation, including history of valve-related complications and echocardiographic assessment, is crucial to improve the quality of the technique and to redefine indications for future patients," Bleiziffer said.