Balloon-Expandable Valve Geometry After Transcatheter Aortic Valve Replacement in Low-Risk Patients With Bicuspid Versus Tricuspid Aortic Stenosis.

BACKGROUND: Prospective bicuspid low-risk transcatheter aortic valve replacement (TAVR) registries' data demonstrated encouraging short-term results. Detailed data on transcatheter heart valve (THV) geometry after deployment using contemporary devices are lacking. This study sought to examine valve geometry after TAVR in patients with bicuspid aortic stenosis (AS). METHODS: The study population was patients from the LRT (Low Risk TAVR) trial who underwent TAVR using the SAPIEN 3 THV for bicuspid and tricuspid AS. THV geometry measured on 30-day computed tomography (CT) included valve height, angle, depth, and eccentricity. Additionally, THV hemodynamics and outcomes post-TAVR were compared among patients with bicuspid and tricuspid AS. RESULTS: A total of 107 patients from the LRT trial using the SAPIEN 3 THV were included in our analysis. On 30-day CT, the valve height ratio (1.07 vs. 1.07; p = 0.348), depths (right [5.6 mm vs. 6.2 mm; p = 0.223], left [5.3 mm vs. 4.4 mm; p = 0.082] and non [4.8 mm vs. 4.5 mm; p = 0.589] coronary cusps), eccentricities (1.08 vs. 1.07; p = 0.9550), and angles (except the right [3.9 degrees vs. 6.3 degrees; p = 0.003] and left [3.6 degrees vs. 6.0 degrees; p = 0.007]) were similar between bicuspid and tricuspid patients. Hemodynamics, stroke, and mortality were similar at 1 year. CONCLUSION: Despite challenging bicuspid anatomy of the aortic valve, our comprehensive CT analysis supports similar THV geometry between patients with bicuspid and tricuspid AS undergoing TAVR using the SAPIEN 3 THV in low-risk patients. This translated to excellent short-term clinical outcomes and THV hemodynamics in both aortic valve morphologies. TRIAL REGISTRY: NCT02628899, https://clinicaltrials.gov/ct2/show/NCT02628899.

Transcatheter aortic valve replacement in low-risk patients: 2-year results from the LRT trial.

BACKGROUND: Previous studies from the Low Risk TAVR (LRT) trial demonstrated that transcatheter aortic valve replacement (TAVR) is safe and feasible in low-risk patients, with excellent 30-day and 1-year outcomes. The objective of this study was to report clinical outcomes and the impact of 30-day hypoattenuated leaflet thickening (HALT) on structural valve deterioration (SVD) 2 years after TAVR. METHODS: The LRT trial was the first Food and Drug Administration-approved Investigational Device Exemption trial in the United States to evaluate the safety and feasibility of TAVR in low-risk patients with symptomatic severe tricuspid aortic stenosis (AS). Valve hemodynamics and SVD by echo were recorded 30 days, 1 year, and 2 years post-TAVR. RESULTS: The LRT trial enrolled 200 low-risk patients to receive TAVR. Their mean age was 73.6 years and 61.5% were men. At 2-year follow-up, the mortality rate was 4.2%; the cardiovascular death rate was 1.6%. The disabling stroke rate was 1.1%, permanent pacemaker implantation rate was 8.6%, and 4 patients (2.2%) presented with endocarditis (2 between years 1 and 2). Of the 14% of TAVR subjects who had evidence of HALT at 30 days, there was no impact on valve hemodynamics, endocarditis or stroke at 2 years. CONCLUSIONS: TAVR for low-risk patients with symptomatic severe tricuspid AS is safe at 2 years. The presence of HALT at 30 days did not impact the early hemodynamic improvements nor the durability of the valve structure.

Randomized Trial of Aspirin Versus Warfarin After Transcatheter Aortic Valve Replacement in Low-Risk Patients.

BACKGROUND: The optimal antithrombotic regimen after transcatheter aortic valve replacement remains unclear. METHODS: In this randomized open-label study, low-risk patients undergoing transfemoral transcatheter aortic valve replacement at 7 centers in the United States were randomized 1:1 to low-dose aspirin or warfarin plus low-dose aspirin for 30 days. Patients who could not be randomized were enrolled in a separate registry. Computed tomography or transesophageal echocardiography was performed at 30 days. The primary effectiveness end point was a composite of the following at 30 days: hypoattenuated leaflet thickening, at least moderately reduced leaflet motion, hemodynamic dysfunction (mean aortic valve gradient ≥20 mm Hg, effective orifice area ≤1.0 cm2, dimensionless valve index <0.35, or moderate or severe aortic regurgitation), stroke, or transient ischemic attack. RESULTS: Between July 2018 and October 2019, 94 patients were randomly assigned, 50 to aspirin and 44 to warfarin plus aspirin, and 30 were enrolled into the registry. In the intention-to-treat analysis of the randomized cohort, the composite primary effectiveness end point was met in 26.5% for aspirin versus 7.0% for warfarin plus aspirin (P=0.014; odds ratio, 4.8 [95% CI, 1.3-18.3]). The rate of hypoattenuated leaflet thickening was 16.3% for aspirin versus 4.7% for warfarin plus aspirin (P=0.07; odds ratio, 4.0 [95% CI, 0.8-20.0]). There was no excess bleeding at 30 days with anticoagulation. In the as-treated analysis of pooled randomized and registry cohorts, the rate of hypoattenuated leaflet thickening was 16.7% for aspirin versus 3.1% for warfarin plus aspirin (P=0.011; odds ratio, 6.3 [95% CI, 1.3-30.6]). CONCLUSIONS: In low-risk transcatheter aortic valve replacement patients, anticoagulation with warfarin may prevent transcatheter heart valve dysfunction in the short term without excess bleeding. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03557242.

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.

Transcatheter Aortic Valve Replacement in Low-Risk Patients With Symptomatic Severe Bicuspid Aortic Valve Stenosis.

OBJECTIVES: The aim of this study was to evaluate clinical outcomes and transcatheter heart valve hemodynamic parameters after transcatheter aortic valve replacement (TAVR) in low-risk patients with bicuspid aortic stenosis (AS). BACKGROUND: TAVR is approved for low-risk patients in the United States. However, patients with bicuspid AS were excluded from the randomized cohorts of the pivotal low-risk trials. METHODS: The LRT (Low Risk TAVR) trial was an investigator-initiated, prospective, multicenter study and was the first and only U.S. Food and Drug Administration-approved investigational device exemption trial to evaluate the feasibility of TAVR with either balloon-expandable or self-expanding valves in low-risk patients with bicuspid AS. The primary endpoint was all-cause mortality at 30 days. Baseline and follow-up echocardiography and computed tomography to detect leaflet thickening were analyzed in an independent core laboratory. RESULTS: Sixty-one low-risk patients with symptomatic, severe AS and bicuspid aortic valves (78.3% Sievers type 1 morphology) underwent TAVR at 6 centers from 2016 to 2019. The mean age was 68.6 years, and 42.6% were men. At 30 days, there was zero mortality and no disabling strokes. The rate of new permanent pacemaker implantation was 13.1%; just 1 patient had a moderate paravalvular leak at 30 days. Hypoattenuated leaflet thickening was observed in 10% of patients at 30 days. CONCLUSIONS: TAVR appears to be safe in patients with bicuspid AS, with short length of hospital stay, zero mortality, and no disabling strokes at 30 days. Subclinical leaflet thrombosis was observed in a minority of patients at 30 days but did not appear to be associated with clinical events.

Impact of Transcatheter Aortic Valve Replacement on Risk Profiles of Surgical Aortic Valve Replacement Patients.

BACKGROUND: The advent of transcatheter aortic valve replacement (TAVR) has changed which patients undergo surgical aortic valve replacement (SAVR). We sought to understand the impact of TAVR on the characteristics of SAVR patients in the United States. METHODS: A cohort of 2959 patients who underwent isolated SAVR at 11 US hospitals that perform both TAVR and SAVR from 2013 through 2017 were grouped by the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database version (v)2.73 (2011-2014), v2.81 (2014-2017), and v2.9 (2017) to assess temporal trends in patient characteristics. RESULTS: Over time, SAVR patients were younger with fewer preoperative comorbidities. There was a significant decrease in median STS predicted risk of mortality (PROM) score (2.0 vs. 1.8 vs. 1.3, p < 0.001, in v2.73 vs. v2.81 vs. v2.9). Specifically, there were fewer high-risk (STS PROM > 8%: 4.3% vs. 4.7% vs. 1.2%, p = 0.03) and intermediate-risk (STS PROM 4% to 8%: 16.3% vs. 11.7% vs. 4.3%, p < 0.001) patients. The proportion of patients with bicuspid aortic valve disease increased significantly (11.2% vs. 26.9% vs. 36.6%, p < 0.001). There were no differences in operative mortality (1.9% vs. 2.1% vs. 1.4%, p = 0.75). CONCLUSIONS: The introduction of TAVR has already impacted the demographics, clinical characteristics and risk profiles of patients undergoing SAVR in the US. Now that TAVR is approved for low-risk patients, SAVR is likely to be reserved for younger patients who are willing to receive a mechanical valve and for patients with aortopathy, coronary artery disease, or concomitant mitral or tricuspid pathology.

Feasibility of Coronary Access and Aortic Valve Reintervention in Low-Risk TAVR Patients.

OBJECTIVES: The aim of this study was to evaluate the feasibility of coronary access and aortic valve reintervention in low-risk patients undergoing transcatheter aortic valve replacement (TAVR) with a balloon-expandable transcatheter heart valve (THV). BACKGROUND: Younger, low-risk TAVR patients are more likely than older, higher risk patients to require coronary angiography, percutaneous coronary intervention, or aortic valve reintervention, but their THVs may impede coronary access and cause coronary obstruction during TAVR-in-TAVR. METHODS: The LRT (Low Risk TAVR) trial (NCT02628899) enrolled 200 subjects with symptomatic severe aortic stenosis to undergo TAVR using commercially available THVs. Subjects who received balloon-expandable THVs and who had 30-day cardiac computed tomographic scans were included in this study. In a subgroup, the feasibility of intentional THV crimping on the delivery catheter to pre-determine commissural alignment was tested. RESULTS: In the LRT trial, 168 subjects received balloon-expandable THVs and had 30-day cardiac computed tomographic scans, of which 137 were of adequate image quality for analysis. The most challenging anatomy for coronary access (THV frame above and commissural suture post in front of a coronary ostium) was observed in 9% to 13% of subjects. Intentional THV crimping did not appear to meaningfully affect commissural alignment. The THV frame extended above the sinotubular junction in 21% of subjects, and in 13%, the distance between the THV and the sinotubular junction was <2 mm, signifying that TAVR-in-TAVR may not be feasible without causing coronary obstruction. CONCLUSIONS: TAVR may present challenges to future coronary access and aortic valve reintervention in a substantial number of low-risk patients.

Coronary Artery Disease Assessed by Computed Tomography-Based Leaman Score in Patients With Low-Risk Transcatheter Aortic Valve Implantation.

We aimed to evaluate the burden of coronary artery disease (CAD) using the computed tomography (CT) Leaman score in low-risk transcatheter aortic valve implantation (TAVI) patients. The extent of CAD in low-risk patients with aortic stenosis who are candidates for TAVI has not been accurately quantified. The CT Leaman score was developed to quantify coronary CT angiography (CCTA) atherosclerotic burden and has been validated to evaluate the extent of CAD. CT Leaman score >5 has been associated with an increase in major adverse cardiac events over long-term follow-up. The study population included patients enrolled in the Low Risk TAVI trial who underwent CCTA before the procedure. For the CT Leaman score, we used 3 sets of weighting factors: (1) location of coronary plaques, (2) type of plaque, and (3) degree of stenosis. A total of 200 patients were enrolled in the Low Risk TAVI trial. Excluded were 31 patients who had no analyzable CCTA imaging. For the remaining 169 patients, the mean CT Leaman score was 6.27 ± 0.27, of whom 102 (60.4%) had CT Leaman score >5. Nearly all analyzed patients (97%) had coronary plaques. Furthermore, 33 patients (19.5%) had potentially obstructive coronary plaques (>50% stenosis by CCTA) in proximal segments. Most low-risk TAVI patients have significant CAD burden by CCTA. It should be a priority for future TAVI devices to guarantee unimpeded access to the coronary arteries for selective angiography and interventions.

Hemodynamics and Subclinical Leaflet Thrombosis in Low-Risk Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: This analysis evaluated echocardiographic predictors of hypoattenuated leaflet thickening (HALT) in low-risk patients undergoing transcatheter aortic valve replacement and assessed 1-year clinical and hemodynamic consequences. HALT by computed tomography may be associated with early valve degeneration and increased neurological events. METHODS: Echocardiograms were performed at baseline, discharge, 30 days, and 1 year post-procedure. Four-dimensional contrast-enhanced computed tomography assessed HALT at 30 days. Independent core laboratories analyzed images. Doppler hemodynamic parameters were tested in a univariable regression model to identify HALT predictors. One-year clinical and hemodynamic outcomes were compared between HALT (+) and (-) patients. RESULTS: Analysis included 170 patients with Sapien 3 valves and diagnostic 30-day computed tomographies, of whom 27 (16%) had HALT. Baseline characteristics were similar between groups. After transcatheter aortic valve replacement, aortic flow was nonsignificantly reduced in patients who developed HALT. Regression analysis did not show significant association between baseline or discharge valve hemodynamics and development of HALT at 30 days. Patients with HALT had smaller aortic valve areas (1.4±0.4 versus 1.7±0.5 cm2; P=0.018) and Doppler velocity index (0.4±0.1 versus 0.5±0.1; P=0.003) than those without HALT at 30 days but not at 1 year. There was no difference in aortic mean gradient at 30 days. There was no difference between the groups in New York Heart Association class, 6-minute walk distance, and mortality at 1 year. CONCLUSIONS: There were no early hemodynamic predictors of HALT. At 30 days, patients with HALT had worse valve hemodynamics than those without HALT, but hemodynamic and clinical outcomes at 1 year were similar. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02628899.

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.

Transcatheter Aortic Valve Replacement in Low-Risk Patients With Symptomatic Severe Aortic Stenosis.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is now the standard of care for patients with symptomatic severe aortic stenosis who are extreme, high, or intermediate risk for surgical aortic valve replacement (SAVR). OBJECTIVES: The authors sought to evaluate TAVR in a prospective multicenter trial involving low-risk patients. METHODS: The Low Risk TAVR (Feasibility of Transcatheter Aortic Valve Replacement in Low-Risk Patients With Symptomatic, Severe Aortic Stenosis) trial was the first U.S. Food and Drug Administration-approved Investigational Device Exemption trial to enroll in the United States. This investigator-led trial was a prospective, multicenter, unblinded, comparison to historical controls from the Society of Thoracic Surgeons (STS) database. The primary endpoint was all-cause mortality at 30 days. RESULTS: The authors enrolled 200 low-risk patients with symptomatic severe aortic stenosis at 11 centers to undergo TAVR. The authors compared outcomes with an inverse probability weighting-adjusted control cohort of 719 patients who underwent SAVR at the same institutions using the STS database. At 30 days, there was zero all-cause mortality in the TAVR group versus 1.7% mortality in the SAVR group. There was zero in-hospital stroke rate in the TAVR group versus 0.6% stroke in the SAVR group. Permanent pacemaker implantation rates were similar between TAVR and SAVR (5.0% vs. 4.5%). The rates of new-onset atrial fibrillation (3.0%) and length of stay (2.0 ± 1.1 days) were low in the TAVR group. One patient (0.5%) in the TAVR group had >mild paravalvular leak at 30 days. Fourteen percent of TAVR patients had evidence of subclinical leaflet thrombosis at 30 days. CONCLUSIONS: TAVR is safe in low-risk patients with symptomatic severe aortic stenosis, with low procedural complication rates, short hospital length of stay, zero mortality, and zero disabling stroke at 30 days. Subclinical leaflet thrombosis was observed in a minority of TAVR patients at 30 days. (Feasibility of Transcatheter Aortic Valve Replacement in Low-Risk Patients With Symptomatic, Severe Aortic Stenosis [Low Risk TAVR; NCT02628899).