Transcatheter valve implantation is a newly developed technique for the curative treatment of high-grade aortic stenosis. It is likely to be of benefit especially to elderly, multimorbid patients for whom the risk of open heart surgery would be too great. The initial results obtained with this technique at the German Heart Center in Munich are presented in the current issue of Deutsches Ärzteblatt International by Sabine Bleiziffer and her colleagues (Dtsch Arztebl Int 2009; 106(14): 235-41).
From June 2007 to September 2008, aortic valvular prostheses were successfully implanted with the transcatheter technique in 150 patients with high-grade aortic stenosis. The 30-day mortality was 11.8%, which can be compared to a figure of 24% for conventional aortic valve replacement surgery. The most common post-procedural complications were cardiac arrhythmia, vascular problems, and cerebrovascular events. Six months after the procedure, the patients' clinical condition had markedly improved, and the authors were able to demonstrate good hemodynamic functioning of the new prostheses.
Calcific aortic stenosis is the most common acquired heart valve defect in Western countries, with a prevalence of more than 3% in persons over age 75. Up to the present time, the treatment of choice for high-grade aortic stenosis has been surgical aortic valve replacement. As many as 60% of patients, however, cannot be operated on because of advanced age and major comorbidities, even though they suffer from severe symptoms and have a poor prognosis under conservative treatment.
The advantage of transcatheter valve implantation is that it can be performed on the beating heart without the need for a heart-lung machine. In the procedure, an aortic valve prosthesis crimped to fit inside the catheter is brought into aortic position and then unfolded. The catheter can be inserted transarterially, usually by way of a femoral artery puncture, or transapically, i.e., through the left ventricular apex. The technical feasibility of the procedure has already been demonstrated at multiple centers around the world.