Hypoattenuated Leaflet Thickening-Associated Myocardial Infarction: A Rare Case Report and Literature Review.

Hypoattenuated leaflet thickening (HALT), a potential aftereffect of transcatheter aortic valve replacement (TAVR) procedure, may affect valve performance and clinical outcomes. At this moment we describe an elderly patient who, despite being on prophylactic antiplatelet medication for previous percutaneous intervention (PCI) for coronary artery disease (CAD) and a self-expanding valve in-situ for aortic stenosis (TAVR), presented to the emergency room with non-ST-segment elevation myocardial infarction (NSTEMI), probably as a result of a thromboembolic event from HALT. The case highlights the significance of considering HALT-associated thromboembolism as a potential cause of myocardial infarction (MI) in post-TAVR patients.

Periprocedural Thrombogenicity Change Is Associated With Subclinical Leaflet Thrombosis Progression in Patients Undergoing Transcatheter Aortic Valve Implantation.

Background: Subclinical leaflet thrombosis occasionally occurs after transcatheter aortic valve implantation (TAVI), but its exact etiology and relationship with thrombogenicity remain unknown. Methods and Results: This study enrolled 35 patients who underwent TAVI. Thrombogenicity was evaluated using a total thrombus-formation analysis system (T-TAS) to compute the thrombus-formation area under the curve (PL18-AUC10 and AR10-AUC30). Periprocedural thrombogenic parameters including T-TAS were investigated at pre-TAVI, 2 days, 7 days, and 3 months post-TAVI. Hypoattenuated leaflet thickening (HALT) and maximum leaflet thickness (MLT) were evaluated using contrast-enhanced computed tomography 7 days and 3 months post-TAVI. The associations between thrombogenicity and HALT or MLT were assessed. T-TAS parameters consistently decreased at 2 and 7 days post-TAVI, followed by improvement at 3 months. HALT was detected in 20% and 17% of patients at 7 days and 3 months, respectively, post-TAVI. The median MLT value was 1.60 mm at 7 days and 3 months post-TAVI. A significant positive correlation was observed between the decrease in the AR10-AUC30 and MLT at 7 days post-TAVI. Univariate linear regression analysis revealed a decrease in the AR10-AUC30 and an increase in the D-dimer level as a significant predictor of MLT deterioration. Conclusions: The findings suggested that a transient decrease in thrombogenicity following TAVI predicts leaflet thrombosis, implying that monitoring thrombogenicity may be useful for predicting progression of leaflet thrombosis.

Investigation of factors determining haemodynamic relevance of leaflet thrombosis after transcatheter aortic valve implantation.

AIMS: To determine the conditions under which early hypoattenuated leaflet thickening (HALT) after transcatheter aortic valve implantation (TAVI) becomes haemodynamically relevant. METHODS AND RESULTS: The study included 100 patients (age: 81.5 ± 5.5 years; female 63%), thereof 50 patients with HALT. After anonymization and randomization, blinded readers measured maximum thrombus thickness per prosthesis (MT_pr) and movement restriction (MR_pr) on electrocardiogram (ECG)-gated whole heart cycle computed tomography angiography. These measurements were compared with echocardiographic mean pressure gradient (mPG), its increase from baseline (ΔmPG), and Doppler velocity index (DVI). Haemodynamic valve deterioration (HVD) was defined as mPG > 20 mmHg. Age, body mass index, valve type, valve size, left ventricular ejection fraction, and atrial fibrillation were considered as influencing factors. Multiple regression analysis revealed that only valve size (P = 0.001) and MT_pr (P = 0.02) had a significant influence on mPG. In an interaction model, valve size moderated the effect of MT_pr on mPG significantly (P = 0.004). Sub-group analysis stratified by valve sizes showed a strong correlation between MT_pr and echocardiographic parameters for 23 mm valves (mPG: r = 0.57, ΔmPG: r = 0.68, DVI: r = 0.55, each with P < 0.001), but neither for 26 nor 29 mm valves (r < 0.2, P > 0.2 for all correlations). Six of seven prostheses with HVD had a 23 mm valve diameter, while one had 29 mm (P = 0.02). CONCLUSION: Early HALT rarely causes significant mPG increase. Our study shows that valve size is a key factor influencing the haemodynamic impact of HALT. In small valve sizes, mPG is more likely to increase. Our study is the first to offer in vivo evidence supporting previous in vitro findings on this topic.

Post-procedural structural heart CT imaging: TAVR, TMVR, and other interventions.

Transcatheter valve replacement has experienced substantial growth in the past decade and this technique can now be used for any of the four heart valves. Transcatheter aortic valve replacement (TAVR) has overtaken surgical aortic valve replacement. Transcatheter mitral valve replacement (TMVR) is often performed in pre-existing valves or after prior valve repair, although numerous devices are undergoing trials for replacement of native valves. Transcatheter tricuspid valve replacement (TTVR) is similarly under active development. Lastly, transcatheter pulmonic valve replacement (TPVR) is most often used for revision treatment of congenital heart disease. Given the growth of these techniques, radiologists are increasingly called upon to interpret post-procedural imaging for these patients, particularly with CT. These cases will often arise unexpectedly and require detailed knowledge of potential post-procedural appearances. We review both normal and abnormal post-procedural findings on CT. Certain complications-device migration or embolization, paravalvular leak, or leaflet thrombosis-can occur after replacement of any valve. Other complications are specific to each type of valve, including coronary artery occlusion after TAVR, coronary artery compression after TPVR, or left ventricular outflow tract obstruction after TMVR. Finally, we review access-related complications, which are of particular concern due to the requirement of large-bore catheters for these procedures.

Subclinical leaflet thrombosis and antithrombotic therapy post-TAVI: An LRT substudy.

BACKGROUND: Subclinical leaflet thrombosis (SLT) is characterized on computed tomography (CT) imaging as hypoattenuated leaflet thickening (HALT), reduced leaflet motion (RELM), and hypoattenuation affecting motion (HAM). How antithrombotic regimen type impacts SLT remains poorly understood. We evaluated how antithrombotic regimen type impacts SLT in low-risk subjects following transcatheter aortic valve implantation (TAVI). METHODS: This substudy is a post hoc analysis of the LRT 1.0 and 2.0 trials to assess SLT in subjects who underwent CT or transoesophageal echocardiogram (TOE) imaging at 30 days, stratified by antithrombotic regimen received (single antiplatelet therapy [SAPT], dual antiplatelet therapy [DAPT], or oral anticoagulation). We also utilized univariable logistic regression modelling to identify echocardiographic predictors of HALT. RESULTS: Rates of HALT, RELM, and HAM were all significantly lower with oral anticoagulation compared to SAPT or DAPT at 30 days (HALT: 2.6% vs 14.3% vs 17.2%, respectively, with p < 0.001; RELM: 1.8% vs 9.6% vs 13.1%, respectively, with p = 0.004; and HAM: 0.9% vs 8.5% vs 9.8%, respectively, with p = 0.011). Additionally, short-term oral anticoagulation was not associated with higher bleeding rates compared to SAPT or DAPT (0.8% vs. 1.8% vs. 3.6%, p = 0.291). The presence of HALT did not significantly impact echocardiographic haemodynamic parameters at 30 days. CONCLUSION: This is the largest study to date that evaluated the impact of different antithrombotic regimens on SLT in low-risk TAVI patients. Oral anticoagulation was associated with significantly lower rates of SLT at 30 days compared to DAPT or SAPT, and there was no apparent benefit of DAPT over SAPT.

Subclinical Leaflet Thrombosis in Supra-annular Transcatheter Aortic Valves: the Role of Leaflet Design.

Subclinical leaflet thrombosis has been increasingly observed in patients undergoing transcatheter aortic valve replacement. Intra-annular transcatheter aortic valves (TAVs) have a larger neo-sinus volume than supra-annular devices and are potentially at a higher risk of hypoattenuated leaflet thickening (HALT). However, clinical data from randomized clinical trials have shown that approximately one-third of patients undergoing TAVR with intra- or supra-annular devices develop HALT in 1 year. The findings point to the potential role of leaflet design in developing HALT. The study aimed to systematically investigate leaflet kinematics of a supra-annular TAV, Medtronic CoreValve, and determine regions of blood stasis. Fluid-solid interaction simulations demonstrated the limited movement of CoreValve leaflets in the lower belly region that created regions of blood stasis on the surface of the leaflets. The findings provide insights into potential improvements in leaflet design in the next generation of TAVs to reduce the risk of HALT and leaflet immobility.

Natural History of Leaflet Thrombosis After Transcatheter Aortic Valve Replacement: A 5-Year Follow-Up Study.

Background Subclinical leaflet thrombosis, characterized by hypoattenuated leaflet thickening (HALT) on multidetector computed tomography, is common after transcatheter aortic valve replacement (TAVR). Because little is known about the long-term natural history of subclinical HALT, we aimed to investigate this in patients who underwent TAVR without using additional anticoagulation. Methods and Results We retrospectively evaluated patients who underwent TAVR with the Edwards SAPIEN-XT at our institute between October 2013 and December 2015. Patients were grouped according to the presence or absence of HALT within 1 year after TAVR (HALT and No-HALT groups). The primary outcome, defined as the composite of all-cause mortality, heart failure readmission, and ischemic stroke, was compared. Valve performance was assessed over time by transthoracic echocardiography. Among 124 patients (men: 29.1%; median age, 85 years), 27 (21.8%) showed HALT on multidetector computed tomography within 1 year after TAVR. No patient required additional anticoagulation for treating HALT because of the absence of valve-related symptomatic deterioration. During the median follow-up period of 4.7 years (interquartile range, 4.0-5.6), the rate of primary outcome and valve performance was not statistically different between the 2 groups (37.0% versus 38.1%; log-rank test P=0.92; mean pressure gradient, 9 mm Hg [8-14 mm Hg] versus 10 mm Hg [7-15 mm Hg]; P=0.51, respectively). Conclusions Approximately 20% of patients after TAVR had HALT within 1 year; however, that did not change the risk of subsequent adverse cardiovascular events or the valve performance with statistical significance for up to 5 years despite no additional anticoagulation therapy.

Subclinical leaflet thrombosis after transcatheter aortic valve implantation is associated with silent brain injury on brain magnetic resonance imaging.

AIMS: Whether hypoattenuated leaflet thickening (HALT) following transcatheter aortic valve implantation (TAVI) carries a risk of subclinical brain injury (SBI) is unknown. We investigated whether HALT is associated with SBI detected on magnetic resonance imaging (MRI), and whether post-TAVI SBI impacts the patients' cognition and outcome. METHODS AND RESULTS: We prospectively enrolled 153 patients (age: 78.1 ± 6.3 years; female 44%) who underwent TAVI. Brain MRI was performed shortly post-TAVI and 6 months later to assess the occurrence of acute silent cerebral ischaemic lesions (SCIL) and chronic white matter hyperintensities (WMH). HALT was screened by cardiac computed tomography (CT) angiography (CTA) 6 months post-TAVI. Neurocognitive evaluation was performed before, shortly after and 6 months following TAVI. At 6 months, 115 patients had diagnostic CTA and 10 had HALT. HALT status, baseline, and follow-up MRIs were available in 91 cases. At 6 months, new SCIL was evident in 16%, new WMH in 66%. New WMH was more frequent (100 vs. 62%; P = 0.047) with higher median volume (319 vs. 50 mm3; P = 0.039) among HALT-patients. In uni- and multivariate analysis, HALT was associated with new WMH volume (beta: 0.72; 95%CI: 0.2-1.39; P = 0.009). The patients' cognitive trajectory from pre-TAVI to 6 months showed significant association with the 6-month SCIL volume (beta: -4.69; 95%CI: -9.13 to 0.27; P = 0.038), but was not related to the presence or volume of new WMH. During a 3.1-year follow-up, neither HALT [hazard ratio (HR): 0.86; 95%CI: 0.202-3.687; P = 0.84], nor the related WMH burden (HR: 1.09; 95%CI: 0.701-1.680; P = 0.71) was related with increased mortality. CONCLUSIONS: At 6 months post-TAVI, HALT was linked with greater WMH burden, but did not carry an increased risk of cognitive decline or mortality over a 3.1-year follow-up (NCT02826200).

Long-Term Follow-Up of Hypoattenuated Leaflet Thickening After Transcatheter Aortic Valve Replacement.

BACKGROUND: Early hypoattenuated leaflet thickening (HALT) occurs in at least 10% of all transcatheter aortic valve replacement (TAVR) patients. The long-term prognostic impact of HALT is uncertain. OBJECTIVES: The aim of this study was to assess the long-term risk of early HALT post-TAVR. METHODS: We report outcome data from our prospective observational registry with post-TAVR computed tomography angiography performed between May 2012 and December 2017. The outcomes were survival, cardiovascular mortality, ischemic cerebrovascular events, and symptomatic hemodynamic valve deterioration. RESULTS: Early HALT was diagnosed in 115 (16.0%) of 804 patients. During a median follow-up of 3.25 years, survival rates did not differ significantly between patients with and without HALT (Kaplan-Meier 3-year estimates for survival 70.1% vs 74.0%, P = 0.597). The 3-year cardiovascular mortality rate was 13.2% versus 11.3% (with vs without HALT, P = 0.733). The 3-year event rate for cerebrovascular events was 2.0% versus 4.4% (with vs without HALT, P = 0.246), and the 3-year event rate of symptomatic hemodynamic valve deterioration was 9.4% versus 1.5% (with vs without HALT, P < 0.001). Multivariable analysis revealed the following predictors of symptomatic hemodynamic valve deterioration: HALT (HR: 6.10; 95% CI: 2.59-14.29; P < 0.001), the mixed valve-type group (HR: 6.51; 95% CI: 2.38-17.81; P < 0.001), and prosthesis diameter (HR valve size per 3 mm [HR: 0.37; 95% CI: 0.17-0.79]; P = 0.011). CONCLUSIONS: During a median follow-up of more than 3 years, HALT was not associated with mortality or cerebrovascular events. However, we observed an association of HALT with symptomatic hemodynamic valve deterioration.

Transcatheter Aortic Valve Leaflet Thrombosis: Prevalence, Management, and Future Directions.

PURPOSE OF REVIEW: We review the pathology, prevalence, diagnosis, hemodynamics, risk factors, prognosis, and treatment of leaflet thrombosis (LT), and suggest future directions in this field. RECENT FINDINGS: The latest meta-analysis showed the prevalence of overall LT is 5.4% (clinical LT of 1.2% and subclinical LT of 15.1%). Either subclinical or clinical LT is not associated with risk of mortality; however, clinical LT is associated with increased risk of stroke. Although LT can be reduced by oral anticoagulation therapy (OAT), routine use of OAT as primary prevention for high-risk patients is not recommended due to increased risk of mortality. Four-dimensional computed tomography plays an important role in the diagnosis of LT and the accumulation of qualitative or qualitative assessments of hypoattenuated leaflet thickening would provide more clues to clarify effective OAT strategies. In addition, further studies are warranted to evaluate the efficacy of other anticoagulants in low-intermediate risk patients.

Subclinical Leaflets Thrombosis After Transcatheter Replacement of Bicuspid vs. Tricuspid Aortic Valve.

Background: Subclinical leaflet thrombosis (SLT) is an important sequela that compromises the durability of the bioprosthetic valve. Objectives: To better determine the effect of SLT in bicuspid aortic valve (BAV), we performed a retrospective assessment of CT-defined SLT in BAV and tricuspid aortic valve (TAV) stenotic patients. Methods: We consecutively collected patients undergoing the TAVR between August 2015 and March 2020 in our center. A total of 170 BAV and 201 TAV cases were enrolled. Multidetector computed tomography was performed within 30 days and at 1-year. Results: Twenty cases in the BAV group and 19 cases in the TAV group had hypoattenuated leaflet thickening (HALT) in 30 days (12.5 vs. 9.9%, p = 0.449), and 52 cases in BAV and 61 cases in TAV had the HALT (34.9 vs. 36.7%, p = 0.733) at 1-year follow-up. The mean aortic gradient (MAG) and effective orifice areas (EOA) values were comparable between the two groups at 30 days (HALT vs. no HALT; 10.8 ± 4.8 vs. 11.3 ± 6.0, p = 0.638; 1.6 ± 0.4 vs. 1.6 ± 0.3, p = 0.724), and still, no difference was observed in the MAG at 1-year (11.5 ± 5.6 vs. 10.6 ± 5.1, p = 0.164). However, the EOA at 1-year was statistically different between the two groups (1.5 ± 0.3 vs. 1.6 ± 0.4, p = 0.004). The multivariate logistic regression analysis demonstrated the anticoagulation and age as independent predictors both in the BAV and TAV groups at 1-year. There was no difference in clinical events between the HALT and no HALT group in relevant to BAV or TAV at 1-year follow-up. Conclusions: The presence of subclinical leaflet thrombosis defined by the CT was comparable between the BAV and TAV in the first year after the TAVR procedure. Age and anticoagulation were the independent predictors of the subclinical leaflet thrombosis at 1 year after the TAVR. There was no difference in relevant clinical events between the BAV and TAV groups at 1-year follow-up.

Anatomical Characteristics Associated With Hypoattenuated Leaflet Thickening in Low-Risk Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND/PURPOSE: This sub-analysis of the prospective Low Risk TAVR (LRT) trial determined anatomical characteristics associated with hypoattenuated leaflet thickening (HALT), which may contribute to early transcatheter heart valve (THV) degeneration. METHODS/MATERIALS: The LRT trial enrolled 200 low-risk patients between February 2016 and February 2018. All subjects underwent baseline and 30-day CT studies, analyzed by an independent core laboratory. Additional measurements, namely THV expansion, eccentricity, depth, and commissural alignment, were made by consensus of three independent readers. HALT was observed only in the Sapien 3 THV, so Evolut valves were excluded from this analysis. RESULTS: In the LRT trial, 177 subjects received Sapien 3 THVs, of whom 167 (94.3%) had interpretable 30-day CTs and were eligible for this analysis. Twenty-six subjects had HALT (15.6%). Baseline characteristics were similar between groups. There was no difference in THV size implanted and baseline aortic-root geometry between groups. In patients who developed HALT, THV implantation depth was shallower than in patients who did not develop HALT (2.6 ± 1.1 mm HALT versus 3.3 ± 1.8 mm no-HALT, p = 0.03). There were more patients in the HALT group with commissural malalignment (40% vs. 28%; p = 0.25), but this did not reach statistical significance. In a univariable regression model, no predetermined variables were shown to independently predict the development of HALT. CONCLUSIONS: This study did not find anatomical or THV implantation characteristics that predicted the development of HALT at 30 days. This study cannot exclude subtle effects or interaction between factors because of the small number of events.

Anticoagulation Therapy After Transcatheter Aortic Valve Replacement.

PURPOSE OF REVIEW: We review the prevalence; natural history; impact of subclinical clinical thrombosis on valve hemodynamics, clinical outcomes, and valve durability; and the role of anticoagulation after transcatheter aortic valve replacement (TAVR). RECENT FINDINGS: Subclinical leaflet thrombosis is a dynamic finding present in both transcatheter and surgical bioprosthetic aortic valves. This finding is less prevalent in patients on anticoagulation and resolves following initiation of anticoagulation. Routine anticoagulation after TAVR in high-surgical-risk patients was associated with increased mortality and thromboembolic complications. In the absence of a clinical indication for anticoagulation, there is no reason to initiate anticoagulation after TAVR for the prevention of subclinical leaflet thrombosis. In patients with an established indication for anticoagulation, for instance, atrial fibrillation, clinical or symptomatic valve thrombosis, or a clinical event related to valve thrombosis, anticoagulation should be initiated or continued after TAVR to treat the clinical indication.

Subclinical Leaflet Thrombosis in Transcatheter and Surgical Bioprosthetic Valves: PARTNER 3 Cardiac Computed Tomography Substudy.

BACKGROUND: Subclinical leaflet thrombosis, characterized by hypoattenuated leaflet thickening (HALT) and reduced leaflet motion observed on 4-dimensional computed tomography (CT), may represent a form of bioprosthetic valve dysfunction. OBJECTIVES: The U.S. Food and Drug Administration mandated CT studies to understand the natural history of this finding, differences between transcatheter and surgical valves, and its association with valve hemodynamics and clinical outcomes. METHODS: The PARTNER 3 (The Safety and Effectiveness of the SAPIEN 3 Transcatheter Heart Valve in Low-Risk Patients With Aortic Stenosis) CT substudy randomized 435 patients with low-surgical-risk aortic stenosis to undergo transcatheter aortic valve replacement (n = 221) or surgery (n = 214). Serial 4-dimensional CTs were performed at 30 days and 1 year and were analyzed independently by a core laboratory. RESULTS: The incidence of HALT increased from 10% at 30 days to 24% at 1 year. Spontaneous resolution of 30-day HALT occurred in 54% of patients at 1 year, whereas new HALT appeared in 21% of patients at 1 year. HALT was more frequent in transcatheter versus surgical valves at 30 days (13% vs. 5%; p = 0.03), but not at 1 year (28% vs. 20%; p = 0.19). The presence of HALT did not significantly affect aortic valve mean gradients at 30 days or 1 year. Patients with HALT at both 30 days and 1 year, compared with those with no HALT at 30 days and 1 year, had significantly increased aortic valve gradients at 1 year (17.8 ± 2.2 mm Hg vs. 12.7. ± 0.3 mm Hg; p = 0.04). CONCLUSIONS: Subclinical leaflet thrombosis was more frequent in transcatheter compared with surgical valves at 30 days, but not at 1 year. The impact of HALT on thromboembolic complications and structural valve degeneration needs further assessment.

Bioprosthetic Aortic Valve Leaflet Thickening in the Evolut Low Risk Sub-Study.

BACKGROUND: Subclinical leaflet thrombosis has been reported after bioprosthetic aortic valve replacement, characterized using 4-dimensional computed tomographic imaging by hypoattenuated leaflet thickening (HALT) and reduced leaflet motion (RLM). The incidence and clinical implications of these findings remain unclear. OBJECTIVES: The aim of this study was 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 computed tomographic imaging 30 days and 1 year after transcatheter aortic valve replacement (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 of 179 (17.3%) for TAVR and 23 of 139 (16.5%) for surgery; the frequency of RLM was 23 of 157 (14.6%) for TAVR and 19 of 133 (14.3%) for surgery. At 1 year, the frequency of HALT was 47 of 152 (30.9%) for TAVR and 33 of 116 (28.4%) for surgery; the frequency of RLM was 45 of 145 (31.0%) for TAVR and 30 of 111 (27.0%) for surgery. Aortic valve hemodynamic status was not influenced by the presence or severity of HALT or RLM at either time point. The rates of HALT and RLM were similar after the implantation of supra-annular, self-expanding transcatheter, or surgical bioprostheses. CONCLUSIONS: The presence of computed tomographic imaging abnormalities of aortic bioprostheses were frequent but dynamic in the first year after self-expanding transcatheter and surgical aortic valve replacement, but these findings did not correlate with aortic valve hemodynamic status after aortic valve replacement in patients at low risk for surgery. (Medtronic Evolut Transcatheter Aortic Valve Replacement in Low Risk Patients; NCT02701283).

TAVR in Low-Risk Patients: 1-Year Results From the LRT Trial.

OBJECTIVES: This study sought to evaluate clinical outcomes and transcatheter heart valve hemodynamics at 1 year after transcatheter aortic valve replacement (TAVR) in low-risk patients. BACKGROUND: Early results from the LRT (Low Risk TAVR) trial demonstrated that TAVR is safe in patients with symptomatic severe aortic stenosis who are at low risk for surgical valve replacement. METHODS: The LRT trial was an investigator-initiated, prospective, multicenter study and was the first Food and Drug Administration-approved Investigational Device Exemption trial to evaluate feasibility of TAVR in low-risk patients. The primary endpoint was all-cause mortality at 30 days. Secondary endpoints included clinical outcomes and valve hemodynamics at 1 year. RESULTS: The LRT trial enrolled 200 low-risk patients with symptomatic severe AS to undergo TAVR at 11 centers. Mean age was 73.6 years and 61.5% were men. At 30 days, there was zero mortality, zero disabling stroke, and low permanent pacemaker implantation rate (5.0%). At 1-year follow-up, mortality was 3.0%, stroke rate was 2.1%, and permanent pacemaker implantation rate was 7.3%. Two (1.0%) subjects underwent surgical reintervention for endocarditis. Of the 14% of TAVR subjects who had evidence of hypoattenuated leaflet thickening at 30 days, there was no impact on valve hemodynamics at 1 year, but the stroke rate was numerically higher (3.8% vs. 1.9%; p = 0.53). CONCLUSIONS: TAVR in low-risk patients with symptomatic severe aortic stenosis appears to be safe at 1 year. Hypoattenuated leaflet thickening, observed in a minority of TAVR patients at 30 days, did not have an impact on valve hemodynamics in the longer term.