Transcatheter aortic valve implantation viable in some patients
MedWire News: Transcatheter aortic valve implantation (TAVI) is a feasible non-invasive strategy for the treatment of aortic stenosis, results of the PARTNER trial suggest.
However the trial investigators say that surgical valve replacement remains the "gold standard" treatment for aortic surgery and recommend reserving TAVI for patients who are unsuitable for surgery and have a decreased life expectancy.
The Placement of Aortic Transcatheter Valves (PARTNER) trial was a prospective, randomized, multicenter trial to determine the optimal treatment of critical aortic stenosis.
The present analysis reports outcomes on a prespecified cohort of patients who were considered unsuitable for surgery in view of their high risk and comorbidities. These 358 individuals were randomly assigned to either standard therapy (including balloon aortic valvuloplasty) or transfemoral transcatheter implantation of a balloon-expandable bovine pericardial valve.
The primary endpoint was all-cause mortality at 1 year. This endpoint was met by 30.7% in the TAVI group versus 50.7% of the standard therapy group, giving a hazard ratio (HR) of 0.55 in favor of TAVI.
Some secondary endpoints also favoured TAVI, including the combined rate of all-cause mortality or repeat hospitalization (42.5% vs 71.6%, HR=0.46), the rate of cardiac symptoms at 1 year (25.2% vs 58.0%), and the improvement in 6-minute walk test between baseline and 1 year.
Conversely, TAVI was associated with a significantly higher incidence of major strokes (5.0% vs 1.1%) and major vascular complications (16.2% vs 1.1%) at 30 days.
Finally, echocardiographic findings indicated that the hemodynamic performance of the bioprosthetic valve was "excellent" and that there was no evidence of deterioration in the first year.
Writing in the New England Journal of Medicine, Martin Leon (Columbia University Medical Center, New York, USA) and fellow investigators say that TAVI "should be the new standard of care for patients with aortic stenosis who are not suitable candidates for surgery."
However, they warn that their results should not be extrapolated to other patients with aortic stenosis and add that further trials are needed to compare TAVI with surgery in high-risk patients for whom surgery is a viable option.
Harold Lazar (Boston Medical Center, Massachusetts), the author of an accompanying Editorial, agrees that in patients who cannot undergo surgery, TAVI is effective in improving survival. However, he says that more data are needed on other important long-term outcomes, such as health-related quality of life.
He also stresses that TAVI "should be reserved for patients at inordinately high risk who are not suitable for surgery and who have decreased life expectancy," noting that the durability of these prostheses is currently unknown.
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By Joanna Lyford