PARIS – Hemodynamic values were sustained up to 3 years after CoreValve transcatheter aortic valve implantation among 393 patients with severe symptomatic aortic stenosis.
Importantly, there were no signs of unexpected early degeneration of the CoreValve prosthesis, lead author Dr. Anke Opitz reported at the annual congress of the European Society of Cardiology.
One of the fundamental questions facing transcatheter aortic valve implantation (TAVI) is whether the durability of transcatheter aortic valves is comparable to that of conventional biological aortic valves, which typically start degenerating at about 10-15 years.
"We expect that the duration will be as long as the conventional biological aortic valves, but this is a completely new style of valve," Dr. Opitz said in an interview. "It’s very different from the conventional valves because you have to crimp these valves [on to the catheter] and sometimes you do post dilation, so there’s a lot more stress on the valves than on the conventional ones."
The CoreValve (Medtronic) and Edwards Sapien (Edwards Lifesciences) transcatheter valves are limited to investigational use in the United States but have been available in Europe since 2007. U.S. approval of the Edwards Sapien valve is expected, however, following a July 20, 2011 U.S. Food and Drug Administration advisory panel vote in favor of the valve for treatment of certain inoperable patients.
Dr. Opitz reported on 393 consecutive patients implanted from June 2007 to June 2011 at the German Heart Center in Munich with the CoreValve device, which consists of a self-expandable nitinol stent with a porcine pericardium valve. Femoral access was possible in 87% of patients; 63% of patients were implanted with a 29-mm prosthesis and 37% with a 26-mm prosthesis.
The patients’ mean age was 80 years, mean EuroSCORE was 19.1%, and mean Society of Thoracic Surgeons risk score was 5.8%.
Transthoracic echocardiography revealed that the effective orifice area increased significantly, from 0.7 cm2 at baseline to 1.55 cm2 after TAVI, and remained unchanged through 36 months at 1.57 cm2 in 20 evaluable patients, Dr. Opitz reported.
The peak aortic valve gradient decreased significantly after TAVI (78 mm Hg vs. 21 mm Hg), as did the mean aortic valve gradient. Both gradients remained low through the 36 months. Severity of stenosis rises with the gradients.
Septal wall thickness also significantly decreased from 14.9 mm preoperatively to 13.1 mm at 36 months.
Left ventricular end diastolic diameter remained unchanged from baseline at 12-, 24-, and 36-month follow-ups. The percentage of patients with a left ventricular ejection fraction less than 35% decreased significantly, from 19% at baseline to 4% at 12 months, 6% at 24 months, and 7% at 36 months, Dr. Opitz said.
Paravalvular aortic valve regurgitation occurred in 64% of patients after TAVI but was trivial or mild in 65%, mild to moderate in 20%, and moderate in 15%, she noted.
Dr. Opitz reported no conflicts of interest.