The frequency of hypoattenuated leaflet thickening was similar after TAVR and surgery at 30 days (17.3% vs 16.5%) and 1 year (30.9% vs 28.4%), and did not correlate with valve hemodynamics.
RCT (n=318)
Randomized
Does TAVR compared to surgical aortic valve replacement affect the frequency of hypoattenuated leaflet thickening (HALT) and reduced leaflet motion (RLM) in low-risk patients not on oral anticoagulation?
Subclinical leaflet thrombosis (HALT and RLM) is frequent but dynamic in the first year after both TAVR and surgical aortic valve replacement in low-risk patients, without affecting valve hemodynamics.
Absolute Event Rate: 17.3% vs 16.5%
BACKGROUND Subclinical leaflet thrombosis has been reported after bioprosthetic aortic valve replacement, characterized using 4-dimensional computed tomographic (CT) imaging by hypoattenuated leaflet thickening (HALT) and reduced leaflet motion (RLM). The incidence and clinical implications of these findings remain unclear. OBJECTIVE This study sought to determine the frequency, predictors and hemodynamic and clinical correlates of HALT and RLM after aortic bioprosthetic replacement. METHODS A prospective subset of patients not on oral anticoagulation enrolled in the Evolut Low Risk randomized trial underwent CT imaging 30 days and 1 year after TAVR or surgery. The primary endpoint was the frequency of HALT at 30 days and 1 year, analyzed by an independent core laboratory using standardized definitions. Secondary endpoints included RLM, mean aortic gradient, and clinical events at 30 days and 1 year. RESULTS At 30 days, the frequency of HALT was 31/179 (17.3%) for TAVR and 23/139 (16.5%) for surgery; the frequency of RLM was 23/157 (14.6%) for TAVR and 19/133 (14.3%) for surgery. At 1 year, the frequency of HALT was 47/152 (30.9%) for TAVR and 33/116 (28.4%) for surgery; the frequency of RLM was 45/145 (31.0%) in TAVR and 30/111 (27.0%) for surgery. Aortic valve hemodynamics were not influenced by the presence or severity of HALT or RLM at either time point. The rates of HALT and RLM were similar after implantation of supraannular, self-expanding transcatheter or surgical bioprostheses. CONCLUSIONS We found that the presence of CT imaging abnormalities of aortic bioprostheses were frequent but dynamic in the first year after self-expanding transcatheter and surgical aortic valve replacement, but that these findings did not correlated with aortic valve hemodynamics after aortic valve replacement in patients at low risk for surgery.
“no one knows how much subclinical valve thrombosis truly matters. Even in low-risk patients, these cases come and go. The rate is definitely higher than what we probably should be seeing—it's over 20%—[but] some disappear, and some appear. So we just don't know what kind of conditions, whether it's patient, anatomic, device-related, or procedure factors, we can pinpoint to better prevent this from happening.”
Blanke et al. (2020) conducted an RCT in Aortic valve replacement in patients at low surgical risk (n=318). Self-expanding transcatheter aortic valve replacement (TAVR) vs. Surgical aortic valve replacement was evaluated on Frequency of hypoattenuated leaflet thickening (HALT) at 30 days and 1 year. The frequency of hypoattenuated leaflet thickening was similar after TAVR and surgery at 30 days (17.3% vs 16.5%) and 1 year (30.9% vs 28.4%), and did not correlate with valve hemodynamics.