At least 30% of patients with severe symptomatic aortic stenosis are not deemed surgical candidates owing to advanced age, left ventricular dysfunction, or the presence of multiple coexisting conditions. In the perceived absence of effective alternative treatment options, Transcatheter Aortic-Valve Implantation (TAVI), which was first demonstrated in 2002, has been rapidly adopted as a treatment for these high-risk patients despite a lack of rigorous prospective clinical trials data regarding either safety or effectiveness.
To redress this, the prospective, multicenter PARTNER trial recruited 358 patients between 2007 and 2009 not considered candidates for surgery due to an estimated procedural mortality of 50% or more, and randomised them to either TAVI via a transfemoral approach or to standard care. The primary end point was the rate of death from any cause and secondary end-points included cardiovascular death and NYHA functional class with safety end-points including vascular complications and major stroke. In the standard therapy group, the majority (83%) of patients underwent balloon valvuloplasty. At 1 year, the rate of death from any cause was 30.7% with TAVI, as compared with 50.7% with standard therapy (HR with TAVI, 0.55; 95% CI, 0.40 to 0.74; P<0.001). The rate of death from cardiovascular causes at 1 year was also lower in the TAVI group than in the standard-therapy group (20.5% vs 44.6%; HR, 0.39; 95% CI, 0.27 to 0.56; P<0.001) and among survivors at 1-year, the rate of cardiac symptoms (New York Heart Association class III or IV) was lower among patients who had undergone TAVI than among those who had received standard therapy (25.2% vs 58.0%, P<0.001). At 30 days, TAVI, as compared with standard therapy, was associated with a higher incidence of major strokes (5.0% vs 1.1%, P=0.06) and major vascular complications (16.2% vs 1.1%, P<0.001; figure 1).
In patients with severe aortic stenosis who were not suitable candidates for surgery, TAVI, as compared with standard therapy, significantly reduced the rates of death from any cause, and cardiac symptoms, despite the higher incidence of major strokes and major vascular events.
▶ Leon MB, Smith CR, Mack M, et al; for the PARTNER Trial Investigators. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med2010;363 (e-pub ahead of print).