Patients with severe aortic stenosis that puts them at increased risk for surgery continue to do better at 3 years after receiving a self-expanding transcatheter aortic valve replacement than do similar patients who have an open surgical valve replacement, according to new results from a randomized trial presented at the annual meeting of the American College of Cardiology.
Two-year follow-up results from the same trial cohort, the CoreValve U.S. Pivotal High Risk Trial, showed superior survival and stroke outcomes for TAVR compared with open surgery (J Am Coll Cardiol. 2015;66[2]:113-21). The difference in outcomes was thought to stem mainly from fewer postprocedural complications and faster recovery in the TAVR group.
The new study, presented at the meeting and simultaneously published online April 3 in the Journal of the American College of Cardiology (doi: 10.1016/j.jacc.2016.03.506) aimed to determine whether the previously seen benefits extended into the third year and whether these were accompanied by differences in valve hemodynamics.
Dr. G. Michael Deeb, Herbert Sloan Collegiate Professor of Cardiac Surgery at the University of Michigan, Ann Arbor, and his colleagues evaluated three-year clinical and echocardiographic outcomes from the 391 patients who underwent TAVR and 359 who had SAVR. At baseline all patients had severe aortic stenosis and were considered to be at increased risk for SAVR, with an estimated 30-day mortality risk 15% or greater and a combined 30-day surgical mortality and major morbidity risk less than 50%.
At 3 years follow-up in the treated groups, combined all-cause mortality or stroke was significantly lower at 37% in TAVR patients as compared to nearly 47% in SAVR patients. All-cause mortality was 33% with TAVR and 39% with SAVR, a difference that did not reach statistical significance. Stroke rates were nearly 13% with TAVR and 19% with SAVR; major adverse cardiovascular or cerebrovascular events were 40% with TAVR and 48% for SAVR. Both were significant differences.
While mean aortic valve gradient measures were more favorable – 7.62 ± 3.57 mm Hg with TAVR and 11.40 ± 6.81 mm Hg with SAVR – regurgitation was significantly higher at nearly 7% with TAVR and no regurgitation with SAVR. Valve thrombosis and valve structural deterioration were not observed in either group.
While the findings show sustained 3-year clinical benefit of self-expanding TAVR over SAVR in patients with aortic stenosis at increased risk for surgery, longer studies are needed to determine whether the crimping and re-crimping of the transcatheter valve would have an impact on long-term bioprosthesis durability.
The study was funded by the device manufacturer Medtronic, and 21 of its 28 authors disclosed financial relationships with Medtronic and/or other manufacturers; one is a Medtronic employee. Dr. Deeb disclosed serving as an unpaid advisor to Medtronic.