Background: Patients with severe aortic stenosis being considered for transcatheter aortic valve replacement (TAVR) undergo aortoiliac computed tomographic angiography (CTA) of the chest/abdomen/pelvis. Despite the increasing number of TAVR procedures worldwide, little is known regarding the clinical significance of non-cardiovascular incidental findings (IFs) on TAVR-CTA scans. Objective: To determine the frequency, clinical significance and impact on survival of non-cardiovascular IFs detected on TAVR-CTA scans. Methods: CTA studies for 424 consecutive patients being evaluated for TAVR were reviewed for non-cardiovascular IFs (62% male, median age 82±8.3 years). The electronic medical record was reviewed to assess for subsequent clinical management and survival. Results: An IF was present in nearly all patients (99%). The mean number of IFs per patient was 5.3 (±2.8; range 0-14). After excluding obviously benign IFs, 67% had at least one potentially pathologic IF (mean 1.1±1.0). Factors associated with higher numbers of IFs were age (p<0.0001) and use of IV contrast (p=0.03). IFs prompted clinical work-up in 39 patients (9.2%) and delayed or cancelled procedures in 7 patients (1.7%). The number needed to image to diagnose a new malignancy or medical condition was 19. The number of IFs was predictive of poor overall survival before (HR 1.09; 95% CI (1.02 to 1.70), p=0.02) and after adjustment for baseline clinical variables (HR 1.07; (1.0 to 1.15); p=0.04). Conclusions: This investigation demonstrates that IFs are present in nearly all TAVR-CTA scans, commonly require further clinical evaluation, and are associated with poorer survival. TAVR institutions should have mechanisms in place to ensure communication and follow-up of IFs.
Segmental analysis of aortic basal ring dimensions in normal and dilated tricuspid aortic roots
Abstract OBJECTIVES In patients with aortic root aneurysm, the aortic basal ring is frequently dilated. It has been speculated that the muscular part of the basal ring dilates most. The purpose of this study was to analyse the segmental dilatation of the basal ring, comparing normal and dilated roots in patients with tricuspid aortic valves. METHODS Retrospective analysis of computed tomography studies in patients with normal and dilated aortic roots was performed. Lengths of segments of the basal ring corresponding to each of the 3 sinuses, and to the muscular and fibrous parts were measured. Fractions of these segments relative to the total basal ring perimeter were calculated. RESULTS We analysed 152 normal and 126 dilated aortic roots and 86 propensity-matched pairs. Basal ring dilatation was present in all segments of dilated aortic roots with subtle differences between the segments corresponding to the 3 sinuses. The muscular part of the basal ring dilated proportionately to its fibrous part, with no difference in fractions of measured muscular part in normal and dilated roots [42.2% (interquartile range 4.3%) vs 42.1% (interquartile range 6.3%)]. CONCLUSIONS Basal ring dilatation was present in all segments corresponding to the 3 sinuses in dilated aortic roots. Both muscular and fibrous parts dilated equally, supporting the need to stabilize the entire basal ring when performing aortic valve repair surgery.
Motion artifact correction in cardiac CT using cross-phase temporospatial information and synergistic attention gate and spatial transformer sub-networks
Abstract Objectives. To improve quality of coronary CT angiography (CCTA) images using a generalizable motion-correction algorithm. Approach . A neural network with attention gate and spatial transformer (ATOM) was developed to correct coronary motion. Phantom and patient CCTA images (39 males, 32 females, age range 19–92, scan date 02/2020 to 10/2021) retrospectively collected from dual-source CT were used to create training, development, and testing sets corresponding to 140- and 75 ms temporal resolution, with 75 ms images as labels. To test generalizability, ATOM was deployed for locally adaptive motion-correction in both 140- and 75 ms patient images. Objective metrics were used to assess motion-corrupted and corrected phantom and patient images, including structural-similarity-index (SSIM), dice-similarity-coefficient (DSC), peak-signal-noise-ratio (PSNR), and normalized root-mean-square-error (NRMSE). In objective quality assessment, ATOM was compared with several baseline networks, including U-net, U-net plus attention gate, U-net plus spatial transformer, VDSR, and ResNet. Two cardiac radiologists independently interpreted motion-corrupted and -corrected images at 75 and 140 ms in a blinded fashion and ranked diagnostic image quality (worst to best: 1–4, no ties). Main results . ATOM improved quality metrics ( p < 0.05) before/after correction: in phantom, SSIM 0.87/0.95, DSC 0.85/0.93, PSNR 19.4/22.5, NRMSE 0.38/0.27; in patient images, SSIM 0.82/0.88, DSC 0.88/0.90, PSNR 30.0/32.0, NRMSE 0.16/0.12. ATOM provided more consistent improvement of objective image quality, compared to the presented baseline networks. The motion-corrected images received better ranks than un-corrected at the same temporal resolution ( p < 0.05): 140 ms images 1.65/2.25, and 75 ms images 3.1/3.2. The motion-corrected 75 ms images received the best rank in 65% of testing cases. A fair-to-good inter-reader agreement was observed (Kappa score 0.58). Significance . ATOM reduces motion artifacts, improving visualization of coronary arteries. This algorithm can be used to virtually improve temporal resolution in both single- and dual-source CT.
Abstract 13645: Prognostic Value of Aortic Valve Calcification in Asymptomatic Patients With Non-Severe Aortic Valve Stenosis and Preserved Ejection Fraction
Introduction: Criteria for aortic valve intervention (AVI) in severe aortic stenosis (AS) rely on symptoms, left ventricular ejection fraction (LVEF) and AS severity. Computed tomography-based aortic valve calcification (CT-AVC) scores associated with severe AS also have prognostic value, but this remains unexplored in patients with non-severe AS. We aimed to assess the prognostic value of AVC in asymptomatic patients with nonsevere AS and preserved LVEF. Methods: We retrospectively identified 395 patients with ≥mild AS but less-than-severe AS by echocardiography, who had CT-AVC assessed within six months. AVCscore was quantified offline by Agatston method (TeraRecon software), and also indexed by LV outflow track area, i.e., AVCdensity. Patients were followed until AVI or death. The primary outcome was all-cause death under medical surveillance. Results: In 395 patients, mean age was 73±12 years, 61% were men, mean aortic valve area 1.2±0.3cm2, mean gradient 28±9 mmHg, peak velocity 3.4±0.5 m/s, LVEF 64±6%. During a follow-up of 2.2[0.74-4.94] years, 220 patients had AVI and 82 patients died. Both AVCscore and AVCdensity were associated with AVI-free survival and the best AVCscore thresholds associated with mortality were 853 in women and 1183 in men by log-rank test (both p<0.001). High AVCscore and high AVCdensity were associated with increased hazard for all-cause death in unadjusted and adjusted analyses (Figure), and after further adjustment for echocardiographic severity (all p ≤0.01). Conclusions: In asymptomatic patients with less-than-severe AS, sex-specific CT-AVC scores differentiate those at higher risk for death versus lower risk. Whether AVI could modify this risk remains to be proven.
Computed tomography calcium scoring in aortic stenosis: bicuspid versus tricuspid morphology
Objective CT aortic valve calcium score (AVCscore) and density (AVCdensity) thresholds have been recommended for aortic stenosis (AS) severity assessment in tricuspid aortic valve (TAV). We aimed to compare AVCscore and AVCdensity in bicuspid aortic valve (BAV) versus TAV. Methods Retrospective single-centre study of patients with echocardiographic AS-severity and CT-AVC assessments within 6 months, and left ventricular ejection fraction ≥50%, all referred for clinical AS evaluation. Severe AS was defined as aortic valve area (AVA) ≤1 cm2 or indexed AVA ≤0.6cm2/m2 plus mean gradient ≥40 mm Hg or peak velocity ≥4 m/s. AVC was assessed by Agatston method. Results Of the 1957 patients, 328 had BAV and 1629 had TAV, age 65±11 vs 80±9 years (p<0.001), men 65% vs 56% (p=0.006), respectively. BAV morphology was associated with higher AVCscore and AVCdensity independent of age, comorbidities and AS severity (p<0.001) in men only (sex and BAV interaction p<0.001). In patients with severe AS, mean AVCscore and AVCdensity were higher in BAV-men than that in TAV-men (both p<0.001), but similar in BAV-women and TAV-women (both p≥0.4). Such patterns remained the same after adjustment for clinical covariates and AS severity. Best thresholds for severe AS diagnosis in BAV-men were 2916 AU by AVCscore and 600 AU/cm2 by AVCdensity which were higher than the guideline-recommended thresholds, while thresholds in BAV-women (1036 AU and 282 AU/cm2) were similar to guideline-recommended ones. Conclusion Valve calcification in AS differs according to valve morphology and sex. BAV-men with severe AS exhibit greater AVCscore and AVCdensity than TAV-men. This presents a diagnostic challenge to the current guidelines, which needs confirmation in larger studies.
Utility of CT and MRI in Tricuspid Valve Interventions
Introduction: Aortic valve calcification (AVC) is the key pathophysiology underlying aortic stenosis (AS). We aimed to assess computed tomography AVC in AS by valve morphology (bicuspid [BAV] vs. tricuspid aortic valve[TAV]) and sex. Methods: Retrospective study of patients with echocardiographic AS severity and AVC assessments within six months. Patients with > moderate aortic regurgitation, prosthetic aortic valve, or indeterminate aortic valve morphology were excluded. Severe AS with high mean gradient (MG) was defined as aortic valve area (AVA)≤1cm2 or indexed AVA≤0.6 cm2/m2 + MG≥40 mmHg. Results: Of 2647 patients, 361(65% men) had BAV and 2286(59% men) had TAV, age 65±11 vs. 80±9 years(p<0.001), AVA 1.07±0.42 vs. 0.90±0.25 cm2(p<0.001), MG 41±16 vs.42±14 mmHg(p=0.4) for BAV and TAV, respectively. For both BAV and TAV groups, age, MG, and severe AS frequency were similar between women and men(all p≥0.06). BAV morphology affected AVC-AS severity and AVC-sex associations (p for interactions <0.001): as AS severity increased, mean AVC difference became larger between BAV-men and TAV-men, but smaller between BAV-women and TAV-women. Similar patterns were observed in AVC density (AVCd, AVC divided by left ventricular outflow tract diameter)-AS severity and AVCd-sex associations (p for interactions < 0.001). In patients with concordant AS severity and MG levels, the best BAV AVC-cutoff for detecting severe AS + high MG by area-under-the-curve analysis was 924 AU for BAV-women and 2851 AU for BAV-men, different from guideline-recommended AVC-thresholds (1200 for women and 2000 for men). The best BAV AVCd cutoff was 289 for BAV-women and 476 for BAV-men, similar to the cutoffs for patients predominantly with TAV (292 for women and 476 for men from Clavel MA JACC 2013). The BAV-AVC threshold identified more patients with severe AS than guideline-recommended threshold in BAV-women (84% vs 74%, p<0.001), but not in BAV-men. Conclusions: Valvular calcium accretion in AS was different by valve morphology and sex. As compared to TAV, BAV-women exhibited the least calcification while BAV-men exhibited the highest. Such patterns may impact the sensitivity of guideline-recommended AVC thresholds for detecting severe AS in BAV patients.
Abstract 10766: Analysis of Cardiac Ct Anatomy in Patients With Severe Tricuspid Regurgitation Considered for Transcatheter Intervention
Introduction: Severe tricuspid regurgitation (TR) is associated with considerable morbidity/mortality in an elderly population with multiple comorbidities. There is interest in transcatheter interventions to manage severe TR in this population. Understanding right heart (RH) anatomy has implications for patient/device selection for transcatheter intervention. Hypothesis: We analyzed RH anatomy by CT of patients referred for TR therapy to determine transcatheter tricuspid intervention device sizing needs. Methods: Retrospective Mayo Clinic study of 29 patients considered for intervention of severe TR from 3/1/2016-12/15/2020; echocardiogram and CT angiogram obtained in all patients. Results: Mean age was 83±8 (83% female), 100% had atrial fibrillation, and 62% had chronic kidney disease ≥3a. 97% were symptomatic, 93% were prescribed loop diuretics, and 24% had device leads. Mean tricuspid annular plane systolic excursion 16.8±4.5 mm, effective regurgitant orifice area (EROA) 81±33 mm 2 , and cardiac index 2.6±0.6 L/min/m 2 . 41% had at least moderate right ventricular (RV) dysfunction with a mean RV systolic pressure of 46±16 mmHg. Patients receiving intervention had significantly larger EROA (101±33 v. 63±22 mm 2 , P=0.033), shorter tricuspid leaflet tenting length (6.5±3.0 v. 8.9±2.7 mm, P=0.042), and smaller annuloplasty diagnostic perimeter during diastole (120.1±16.6 v. 131.1±7.4 mm, P=0.041). Intervention patients tended to have better right ventricular function, smaller RV and IVC size, and more severe symptoms. Max tricuspid annulus diameter in systole and diastole was 51±5 and 53±7 mm, respectively. Conclusions: Severe TR patients referred for transcatheter intervention present with severe RH enlargement with a large proportion having tricuspid annulus dimensions outside the range for current devices available in clinical trials. These data have implications for device development/selection and procedural feasibility.
Pre- and Postprocedure Imaging of Transcatheter Pulmonary Valve Implantation