“The rate of severe aortic regurgitation is very low after THV implantation,” Dr. John G. Webb from University of British Columbia, Vancouver, British Columbia, Canada told Reuters Health in an email. “In most cases it is treatable by implantation of a second valve at the time of the procedure.”
Dr. Webb and colleagues evaluated their experience with THV-in-THV implantation for acute THV failure, which was attempted in 21 (2.8%) of 760 patients who underwent balloon-expandable TAVR.
THV-in-THV was carried out at the time of the initial procedure in 17 patients and after 3 to 6 days in the remaining 4 patients. For the second THV, the same access route and the same diameter THV were used in all cases.
Nineteen (90%) of the 21 THV-in-THV implantations were successful. Both unsuccessful procedures were associated with low implantation of the initial valve followed by embolization of both valves into the ventricle, requiring emergent open heart surgery.
Three of 21 (14.3%) patients undergoing THV-in-THV died in the first 30 days, compared with 54 of 739 (7.3%) patients undergoing conventional TAVR. Survival rates at 1 year were 76% of patients undergoing THV-in-THV and 78% in patients undergoing conventional TAVR (p=0.37).
All but 1 surviving patient undergoing THV-in-THV was in NYHA functional class I or II at 1-year follow-up. [p.
None of the 19 patients with successful THV-in-THV implantation had transvalvular aortic regurgitation after the second TAVR. Mean aortic valve gradient fell and aortic valve area improved after implantation of the second valve. Ejection fraction did not change. None of these outcomes differed from those in patients undergoing conventional TAVR.
By 1-year follow-up, only 1 patient had a moderate paravalvular leak, and the other patients had no or mild paravalvular leaks.
“THV-in-THV implantation for failed balloon-expandable TAVR is feasible and results in satisfactory short- and mid-term outcomes,” the investigators conclude. “This may have important implications for patients who develop late failure of transcatheter valves.”
“The fact that THV implantation inside THVs is readily possible means that when THVs eventually wear out surgery will not be necessary,” Dr. Webb said. “A percutaneous procedure is more repeatable than surgery.”