Aortic valvular stenosis is a disease with a long latent period followed by rapid progression to death after the onset of symptoms. The classic series by Ross and Braunwald reports an average survival of 2 to 5 years after symptom onset (Figure 1).1 There is no medical therapy proven to extend survival. Fortunately, surgical aortic valve replacement (AVR) is now done with an operative mortality of 3% to 4% for isolated AVR and 5.5% to 6.8% for AVR combined with coronary artery bypass (CAB)2 and with a 10-year survival that averages a little over 60%. The success we have seen with surgical AVR is complicated by an increase in aortic stenosis with age combined with the aging of our population itself. It is estimated that by 85 years of age, 8% of the population will have aortic stenosis.3 Surgical series have been reported with operative mortality of 2% for AVR in patients 80 years and older,4 but increasing age is associated with increasing risk, and not all patients that meet guideline criteria for AVR are offered therapy.
It was recently reported in a survey of European centers that 31.8% of patients with severe, isolated, symptomatic aortic stenosis were not offered surgical therapy due to risk level, comorbidities, or patient refusal.5 A large academic medical center in the United States reported a review of echocardiographic results from their institution that showed only 453 out of 740 patients (61%) with severe aortic stenosis — defined as aortic valve area (AVA) of 0.8 cm2 or less — received surgery.6 In the United States, it is estimated that about 749,000 patients have aortic stenosis and, of these, 125,000 have severe stenosis. This can be compared to the estimated number of AVR operations done in the United States annually of 70,000. It is clear that there is a substantial population with severe, life-threatening aortic stenosis that is underserved. This has led to the search for less morbid treatment options for aortic stenosis.
How to Cite:
1. Kleiman N, Reardon MJ. TAVI: Transcatheter Aortic Valve Implantation. Methodist DeBakey Cardiovascular Journal. 2011;7(1):49-52. DOI: http://doi.org/10.14797/mdcvj.252