Low- or standard-dose edoxaban versus antiplatelet therapy for leaflet thrombus and cerebral thromboembolism after TAVR: A prespecified analysis of randomized ADAPT-TAVR trial

BACKGROUND

The risks of leaflet thrombosis and the associated cerebral thromboembolism are unknown according to different anticoagulation dosing after transcatheter aortic valve replacement (TAVR). The aim was to evaluate the incidence of leaflet thrombosis and cerebral thromboembolism between low-dose (30 mg) or standard-dose (60 mg) edoxaban and dual antiplatelet therapy (DAPT) after TAVR.

METHODS

In this prespecified subgroup analysis of the ADAPT-TAVR trial, the primary endpoint was the incidence of leaflet thrombosis on 4-dimensional computed tomography at 6-months. Key secondary endpoints were new cerebral lesions on brain magnetic resonance imaging and neurological and neurocognitive dysfunction.

RESULTS

Of 229 patients enrolled in this study, 118 patients were DAPT group and 111 were edoxaban group (43 [39.1%] 60 mg vs 68 [61.3%] 30 mg). There was a significantly lower incidence of leaflet thrombosis in the standard-dose edoxaban group than in the DAPT group (2.4% vs 18.3%; odds ratio [OR] 0.11; 95% confidence interval [CI], 0.01-0.55; P = .03). However, no significant difference was observed between low-dose edoxaban and DAPT (15.0% vs 18.3%; OR 0.79; 95% CI, 0.32-1.81; P = .58). Irrespective of different antithrombotic regiments, the percentages of patients with new cerebral lesions on brain MRI and worsening neurological or neurocognitive function were not significantly different.

CONCLUSIONS

In patients without an indication for anticoagulation after TAVR, the incidence of leaflet thrombosis was significantly lower with standard-dose edoxaban but not with low-dose edoxaban, as compared with DAPT. However, this differential effect of edoxaban on leaflet thrombosis was not associated with a reduction of new cerebral thromboembolism and neurological dysfunction.

[Effect of dexmedetomidine on the intraoperative and early postoperative complications of patients undergoing orthotopic liver transplantation]

Objective: To investigate the effect of dexmedetomidine on the intraoperative and early postoperative complications of patients undergoing orthotopic liver transplantation. Methods: This is a retrospective cohort study. The clinical data of 399 patients who underwent orthotopic liver transplantation at the First Affiliated Hospital of Nanjing Medical University from January 2016 to September 2020 were retrospectively collected. There were 319 males and 80 females, aged (50.9±10.2) years (range: 10 to 73 years). These patients were divided into the control group (369 cases) and the dexmedetomidine group (30 cases) according to whether dexmedetomidine was continuously pumped intravenously during the operation until the operation ended. The 1∶2 propensity score matching was used to match the preoperative and intraoperative conditions of the two groups of patients, and the caliper width was 0.2. Outcome indicators included intraoperative postreperfusion syndrome, acute kidney injury and pulmonary complications within 7 days after surgery, length of hospital stay, time of stay in ICU, duration of assisted mechanical ventilation, rate of reintubation, 6-month and 1-year survival and recurrence-free survival rate after surgery. The independent sample t test, χ2 test, Mann-Whitney U test or Fisher exact test was used to statistically analyze the data of the two groups of patients, respectively. Survival curves of overall survival and disease-free-survival were plotted by Kaplan-Meier method, and the survival rate and recurrence-free survival rate were compared by Log-rank test. Results: A total of 78 patients were included after propensity score matching, including 26 in the dexmedetomidine group and 52 in the control group. The incidence of acute kidney injury in the dexmedetomidine group within 7 days after surgery was 0 (0/26), significantly lower than that of the control group (21.2%,11/52)(corrected χ2=4.776, P=0.029). There were no significant differences in the incidence of intraoperative postreperfusion syndrome and pulmonary complications within 7 days after surgery, length of hospital stay, ICU time, the duration of assisted mechanical ventilation, rate of reintubation, 6-month and 1-year survival, and recurrence-free survival rate after surgery between the two groups (all P>0.05). Conclusion: Continuous infusion of dexmedetomidine via intravenous pump during operation may be beneficial in reducing the incidence of acute kidney injury within 7 days after orthotopic liver transplantation.

Tailored Planning of Surgical Myectomy in Obstructive Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic myocardial disease characterized by abnormal thickening of the myocardium caused by myocardial disarray and interstitial fibrosis. HCM is associated with sudden cardiac-related events, such as ventricular fibrillation, tachycardia, and syncope. Moreover, left ventricular or midcavity obstruction due to the thickened myocardium can result in severe heart failure and mortality in patients with HCM. Surgical myectomy is a standard treatment option for patients with symptomatic obstructive HCM; however, it is a complex procedure that requires careful planning and execution to avoid complications, such as residual flow obstruction, persistent obliteration of the left ventricular cavity in systole, or iatrogenic ventricular septal defects. Therefore, a thorough understanding of the mechanics of HCM and precise evaluation of the location and extent of the hypertrophic myocardium to be removed are crucial for preoperative planning. Multiphase cardiac CT postprocessing is important for preoperative evaluation and planning of surgical myectomy in patients with HCM. In this review, the authors highlight use of multiphase cardiac CT with step-by-step postprocessing methods to simulate successful surgical myectomy. The transaortic surgeon's view on end-diastolic phase images accurately represents the surgical field. Moreover, myocardial segmentation can be used to generate volume-rendered images and three-dimensional printing. CT evaluation can also assist in identifying concurrent abnormalities, such as mitral valve or papillary muscle abnormalities. In addition to CT, other imaging modalities for preoperative evaluation of HCM and postmyectomy evaluation methods are presented. ©RSNA, 2023 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

A Thrombus within an Interventricular Membranous Septal Aneurysm Leading to Cerebral Infarction: A Case Report

Interventricular membranous septal aneurysms are rare. Since these aneurysms can lead to complications such as obstruction of right ventricular outflow and thromboembolism, the detection of this aneurysm has clinical significance. Herein, we report a case of an interventricular membranous septal aneurysm with an internal thrombus thought to be the cause of a cerebral infarction.

Impact of new-onset arrhythmia on cardiac reverse remodeling following transcatheter aortic valve replacement: computed tomography-derived left ventricular and atrial strains

OBJECTIVE

Patients who undergo transcatheter aortic valve replacement (TAVR) are at risk for new-onset arrhythmia (NOA) that may require permanent pacemaker (PPM) implantation, resulting in decreased cardiac function. We aimed to investigate the factors that are associated with NOA after TAVR and to compare pre- and post-TAVR cardiac functions between patients with and without NOA using CT-derived strain analyses.

METHODS

We included consecutive patients who underwent pre- and post-TAVR cardiac CT scans six months after TAVR. New-onset left bundle branch block, atrioventricular block, and atrial fibrillation/flutter lasting over 30 days after the procedure and/or the need for PPM diagnosed within 1 year after TAVR were regarded as NOA. Implant depth and left heart function and strains were analyzed using multi-phase CT images and compared between patients with and without NOA.

RESULTS

Of 211 patients (41.7% men; median 81 years), 52 (24.6%) presented with NOA after TAVR, and 24 (11.4%) implanted PPM. Implant depth was significantly deeper in the NOA group than in the non-NOA group (- 6.7 ± 2.4 vs. - 5.6 ± 2.6 mm; p = 0.009). Left ventricular global longitudinal strain (LV GLS) and left atrial (LA) reservoir strain were significantly improved only in the non-NOA group (LV GLS,  - 15.5 ± 4.0 to  - 17.3 ± 2.9%; p < 0.001; LA reservoir strain, 22.3 ± 8.9 to 26.5 ± 7.6%; p < 0.001). The mean percent change of the LV GLS and LA reservoir strains was evident in the non-NOA group (p = 0.019 and p = 0.035, respectively).

CONCLUSIONS

A quarter of patients presented with NOA after TAVR. Deep implant depth on post-TAVR CT scans was associated with NOA. Patients with NOA after TAVR had impaired LV reserve remodeling assessed by CT-derived strains.

CLINICAL RELEVANCE STATEMENT

New-onset arrhythmia (NOA) following transcatheter aortic valve replacement (TAVR) impairs cardiac reverse remodeling. CT-derived strain analysis reveals that patients with NOA do not show improvement in left heart function and strains, highlighting the importance of managing NOA for optimal outcomes.

KEY POINTS

• New-onset arrhythmia following transcatheter aortic valve replacement (TAVR) is a concern that interferes with cardiac reverse remodeling. • Comparison of pre-and post-TAVR CT-derived left heart strain provides insight into the impaired cardiac reverse remodeling in patients with new-onset arrhythmia following TAVR. • The expected reverse remodeling was not observed in patients with new-onset arrhythmia following TAVR, given that CT-derived left heart function and strains did not improve.

Evaluation of Chylothorax Using Dynamic Contrast-Enhanced Magnetic Resonance Lymphangiography After Lung Cancer Surgery

Background: To determine the role of dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) in the management of postoperative chylothorax after lung cancer surgery. Methods and Results: Between July 2017 and November 2021, patients who developed postoperative chylothorax following pulmonary resection and mediastinal lymph node dissection were assessed and those who underwent DCMRL for the evaluation of chyle leak were evaluated. The findings of DCMRL and conventional lymphangiography were compared. The incidence of postoperative chylothorax was 0.9% (50/5587). Among the patients with chylothorax, a total of 22 patients (44.0% [22/50]; mean age, 67.6 ± 7.9 years; 15 men) underwent DCMRL. Treatment outcomes were compared between patients with conservative management (n = 10) and those with intervention (n = 12). The patients demonstrated unilateral pleural effusion, ipsilateral to the operation site, and showed right-sided dominance. The most frequent site of thoracic duct injury showing contrast media leakage was visualized at the subcarinal level. No DCMRL-related complication occurred. DCMRL showed comparable performance to conventional lymphangiography in visualizing the central lymphatics, including cisterna chyli (DCMRL vs. conventional lymphangiography, 72.7% vs. 45.5%, p = 0.25) and thoracic duct (90.9% vs. 54.5%, p = 0.13), and in localizing thoracic duct injury (90.9% vs. 54.5%, p = 0.13). On follow-up, the amount of chest tube drainage after lymphatic intervention showed a significant difference over time from that after medical treatment only (p = 0.02). Conclusion: DCMRL can provide detailed information about the leak site and the central lymphatic anatomy in patients with chylothorax after lung cancer surgery. The findings of DCMRL can guide subsequent treatment planning for optimal outcomes.

CT Coronary Angiography and Dynamic CT Myocardial Perfusion for Detection of Cardiac Allograft Vasculopathy

BACKGROUND

Cardiac allograft vasculopathy (CAV) is a major obstacle limiting long-term graft survival. Effective noninvasive surveillance modalities reflecting both coronary artery and microvascular components of CAV are needed.

OBJECTIVES

The authors evaluated the diagnostic performance of dynamic computed tomography-myocardial perfusion imaging (CT-MPI) and coronary computed tomography angiography (CCTA) for CAV.

METHODS

A total of 63 heart transplantation patients underwent combined CT-MPI and CCTA plus invasive coronary angiography (ICA) with intravascular ultrasonography (IVUS) between December 2018 and October 2021. The median interval between CT-MPI and heart transplantation was 4.3 years. Peak myocardial blood flow (MBF) of the whole myocardium (MBF_global) and minimum MBF (MBF_min) among the 16 segments according to the American Heart Association model, except the left ventricular apex, were calculated from CT-MPI. CCTA was assessed qualitatively, and the degree of coronary artery stenosis was recorded. CAV was diagnosed based on both ICA (ISHLT criteria) and IVUS. Patients were followed up for a median time of 2.3 years after CT-MPI and a median time of 5.7 years after transplantation.

RESULTS

Among the 63 recipients, 35 (55.6%) had diagnoses of CAV. The median MBF_global and MBF_min were significantly lower in patients with CAV (128.7 vs 150.4 mL/100 mL/min; P = 0.014; and 96.9 vs 122.8 mL/100 mL/min; P < 0.001, respectively). The combined use of coronary artery stenosis on CCTA and MBF_min showed the highest diagnostic performance with an area under the curve of 0.886 (sensitivity: 74.3%, specificity: 96.4%, positive predictive value: 96.3%, and negative predictive value: 75.0%).

CONCLUSIONS

The combination of CT-MPI and CCTA demonstrated excellent diagnostic performance for the detection of CAV. One-stop evaluation of the coronary artery and microvascular components involved in CAV using combined CCTA and CT-MPI may be a potent noninvasive screening method for early detection of CAV.

Myocardial Scar and Revascularization on Mortality in Ischemic Cardiomyopathy (from the Late Gadolinium Enhancement Cardiac Magnetic Resonance Study)

Myocardial viability test to guide revascularization remains uncertain in patients with ischemic cardiomyopathy. We evaluated the different impacts of revascularization on cardiac mortality according to the extent of myocardial scar assessed by cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) in patients with ischemic cardiomyopathy. A total of 404 consecutive patients with significant coronary artery disease and an ejection fraction ≤35% were assessed by LGE-CMR before revascularization. Of them, 306 patients underwent revascularization and 98 patients received medical treatment alone. The primary outcome was cardiac death. During a median follow-up of 6.3 years, cardiac death occurred in 158 patients (39.1%). Revascularization was associated with a significantly lower risk of cardiac death than medical treatment alone in the overall population (adjusted hazard ratio [aHR] 0.29, 95% confidence interval (CI) 0.19 to 0.45, p <0.001). There was a significant interaction between the number of segments with >75% transmural LGE and revascularization on the risk of cardiac death (p = 0.037 for interaction). In patients with limited myocardial scar (<6 segments with >75% transmural LGE, n = 354), revascularization had a significantly lower risk of cardiac death than medical treatment alone (aHR 0.24, 95% CI 0.15 to 0.37, p <0.001); in patients with extensive myocardial scar (≥6 segments with >75% transmural LGE, n = 50), there was no significant difference between revascularization and medical treatment alone regarding the risk of cardiac death (aHR 1.33, 95% CI 0.46 to 3.80, p = 0.60). In conclusion, the assessment of myocardial scar by LGE-CMR may be helpful in the decision-making process for revascularization in patients with ischemic cardiomyopathy.

Dynamic Contrast-Enhanced Magnetic Resonance Lymphangiography and Lymphatic Interventions for Pediatric Patients with Various Lymphatic Diseases

Background: To demonstrate the magnetic resonance lymphangiography (MRL) imaging findings of lymphatic diseases and the clinical outcomes of lymphatic embolization in pediatric patients. Methods and Results: This retrospective study included 10 consecutive pediatric patients who underwent MRL for lymphatic diseases between June 2017 and June 2021. Nine patients underwent dynamic contrast-enhanced MRL with bilateral inguinal lymph node injection of diluted gadolinium, and one patient underwent nonenhanced MRL with a heavily T2-weighted image. The etiology of lymphatic disease was classified into three categories based on the magnetic resonance findings. The resolution of chylous fluid and weight-adjusted amounts of chylous fluid collected from a drainage tube were evaluated as outcomes. Patients were classified as postoperative lymphatic leak (n = 3), pulmonary lymphatic perfusion syndrome (n = 3), central lymphatic flow disorder (CLFD; n = 3), and primary lymphatic dysfunction (Gorham-Stout syndrome; n = 1). Three patients underwent radiological lymphatic intervention, and one CLFD patient underwent surgical intervention. In patients with postoperative lymphatic leak, the median chest tube drainage decreased significantly after the intervention [from 87.9 to 12.4 mL/(kg·d); p = 0.02]. However, in one CLFD patient, the amount of chylous fluid did not decrease until 7 days after intervention. Conclusion: The etiology of lymphatic disease in pediatrics can be recognized on MRL, and lymphatic intervention can be performed for cessation of lymphatic leak, even though the treatment outcomes may differ according to the underlying etiology. MRL can play an important role in classifying lymphatic disease, and in planning treatment on the basis of the lymphatic anatomy and underlying etiology.

Comparison of Coronary Computed Tomography Angiography Image Quality With High-concentration and Low-concentration Contrast Agents: The Randomized CONCENTRATE Trial

PURPOSE

To confirm that the image quality of coronary computed tomography (CT) angiography with a low tube voltage (80 to 100 kVp), iterative reconstruction, and low-concentration contrast agents (iodixanol 270 to 320 mgI/mL) was not inferior to that with conventional high tube voltage (120 kVp) and high-concentration contrast agent (iopamidol 370 mgI/mL).

MATERIALS AND METHODS

This prospective, multicenter, noninferiority, randomized trial enrolled a total of 318 patients from 8 clinical sites. All patients were randomly assigned 1: 1: 1 for each contrast medium of 270, 320, and 370 mgI/mL. CT scans were taken with a standard protocol in the high-concentration group (370 mgI/mL) and with 20 kVp lower protocol in the low-concentration group (270 or 320 mgI/mL). Image quality and radiation dose were compared between the groups. Image quality was evaluated with a score of 1 to 4 as subject image quality.

RESULTS

The mean HU, signal-to-noise ratio, and contrast-to-noise ratio of the 3 groups were significantly different (all P<0.0001). The signal-to-noise ratio and contrast-to-noise ratio of the low-concentration groups were significantly lower than those of the high-concentration group (P<0.05). However, the image quality scores were not significantly different among the 3 groups (P=0.745). The dose length product and effective dose of the high-concentration group were significantly higher than those of the low-concentration group (P<0.0001 and 0.003, respectively).

CONCLUSIONS

The CT protocol with iterative reconstruction and lower tube voltage for low-concentration contrast agents significantly reduced the effective radiation dose (mean: 3.7±2.7 to 4.1±3.1 mSv) while keeping the subjective image quality as good as the standard protocol (mean: 5.7±3.4 mSv).

Differences in aortic valve area measured on cardiac CT and echocardiography in patients with aortic stenosis

BACKGROUND

A certain proportion of patients with severe aortic stenosis (AS) present with discordant grading between different diagnostic modalities, which raises uncertainty about the true severity of AS. The aim of this study was to compare the aortic valve area (AVA) measured on CT and echocardiography and demonstrate the factors affecting AVA discrepancies.

METHODS

Between June 2011 and March 2016, 535 consecutive patients (66.83±8.80 years, 297 men) with AS who underwent pre-operative cardiac CT and echocardiography for aortic valve replacement were retrospectively included. AVA was obtained by AVA on echocardiography (AVAecho) and CT (AVACT) using a measurement of the left ventricular outflow tract on each modality and correlations between those measures were evaluated. Logistic regression analysis was performed to identify factors affecting the discordance for grading severe AS.

RESULTS

The AVACT and AVAecho showed a high correlation (r: 0.79, P <0.001) but AVACT was larger than the AVAecho (difference 0.26 cm2, P <0.001). By using the cut-off values of AVACT (<1.2 cm2) and AVAecho (<1.0 cm2) for diagnosing severe AS, the BSA (odds ratio [OR]: 68.03, 95% confidence interval [CI]: 5.45-849.99; P = 0.001), AVAecho (OR: 1.19, 95%CI: 1.14-1.24; P <0.001), tricuspid valve morphology (OR: 2.83, 95%CI: 1.23-6.50; P = 0.01), and normalized annulus area (OR: 1.02; 95%CI:1.02-1.03; P <0.001) were significant factors associated with the discordance between the AVAecho and AVACT.

CONCLUSION

Patients with larger BSA, AVAecho, and annulus, and tricuspid valve morphology were associated with the AVA discordance between the echocardiography and CT. Complementary use of CT with echocardiography for grading severe AS could be helpful in such conditions.

Edoxaban Versus Dual Antiplatelet Therapy for Leaflet Thrombosis and Cerebral Thromboembolism After TAVR: The ADAPT-TAVR Randomized Clinical Trial

BACKGROUND

It is unknown whether the direct oral anticoagulant edoxaban can reduce leaflet thrombosis and the accompanying cerebral thromboembolic risk after transcatheter aortic valve replacement. In addition, the causal relationship of subclinical leaflet thrombosis with cerebral thromboembolism and neurological or neurocognitive dysfunction remains unclear.

METHODS

We conducted a multicenter, open-label randomized trial comparing edoxaban with dual antiplatelet therapy (aspirin plus clopidogrel) in patients who had undergone successful transcatheter aortic valve replacement and did not have an indication for anticoagulation. The primary end point was an incidence of leaflet thrombosis on 4-dimensional computed tomography at 6 months. Key secondary end points were the number and volume of new cerebral lesions on brain magnetic resonance imaging and the serial changes of neurological and neurocognitive function between 6 months and immediately after transcatheter aortic valve replacement.

RESULTS

A total of 229 patients were included in the final intention-to-treat population. There was a trend toward a lower incidence of leaflet thrombosis in the edoxaban group compared with the dual antiplatelet therapy group (9.8% versus 18.4%; absolute difference, -8.5% [95% CI, -17.8% to 0.8%]; P=0.076). The percentage of patients with new cerebral lesions on brain magnetic resonance imaging (edoxaban versus dual antiplatelet therapy, 25.0% versus 20.2%; difference, 4.8%; 95% CI, -6.4% to 16.0%) and median total new lesion number and volume were not different between the 2 groups. In addition, the percentages of patients with worsening of neurological and neurocognitive function were not different between the groups. The incidence of any or major bleeding events was not different between the 2 groups. We found no significant association between the presence or extent of leaflet thrombosis with new cerebral lesions and a change of neurological or neurocognitive function.

CONCLUSIONS

In patients without an indication for long-term anticoagulation after successful transcatheter aortic valve replacement, the incidence of leaflet thrombosis was numerically lower with edoxaban than with dual antiplatelet therapy, but this was not statistically significant. The effects on new cerebral thromboembolism and neurological or neurocognitive function were also not different between the 2 groups. Because the study was underpowered, the results should be considered hypothesis generating, highlighting the need for further research.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT03284827.

Classification of severe aortic stenosis and outcomes after aortic valve replacement

Aortic valve calcium scoring by cardiac computed tomographic (CT) has been recommended as an alternative to classify the AS (aortic stenosis) severity, but it is unclear that whether CT findings would have additional value to discriminate significant AS subtypes including high gradient severe AS, classic low-flow, low gradient (LF-LG) AS, paradoxical LF-LG AS, and moderate AS. In this study, we examined the preoperative clinical and cardiac CT findings of different subtypes of AS in patients with surgical aortic valve replacement (AVR) and evaluated the subtype classification as a factor affecting post-surgical outcomes. This study included 511 (66.9 ± 8.8 years, 55% men) consecutive patients with severe AS who underwent surgical AVR. Aortic valve area (AVA) was obtained by echocardiography (AVA_echo) and by CT (AVA_CT) using each modalities measurement of the left ventricular outflow tract. Patients with AS were classified as (1) high-gradient severe (n = 438), (2) classic LF-LG (n = 18), and (3) paradoxical LF-LG (n = 55) based on echocardiography. In all patients, 455 (89.0%) patients were categorized as severe AS according to the AVA_CT. However, 56 patients were re-classified as moderate AS (43 [9.8%] high-gradient severe AS, 5 [27.8%] classic LF-LG AS, and 8 [14.5%] paradoxical LF-LG AS) by AVA_CT. The classic LF-LG AS group presented larger AVA_CT and aortic annulus than those in high-gradient severe AS group and one third of them had AVA_CT ≥ 1.2 cm². After multivariable adjustment, old age (hazard ratio [HR], 1.04, P = 0.049), high B-type natriuretic peptide (BNP) (HR, 1.005; P < 0.001), preoperative atrial fibrillation (HR, 2.75; P = 0.003), classic LF-LG AS (HR, 5.53, P = 0.004), and small aortic annulus on CT (HR, 0.57; P = 0.002) were independently associated with major adverse cardiac and cerebrovascular events (MACCE) after surgical AVR.

Aortic annulus sizing in bicuspid and tricuspid aortic valves using CT in patients with surgical aortic valve replacement

The purpose of this study was to evaluate whether bicuspid anatomy affects the discrepancy between CT-derived annular size and intraoperative size. We retrospectively analyzed annular measurements in 667 patients who underwent surgical aortic valve replacement (AVR). Preoperative CT measurements of the aortic annulus were compared to surgically implanted valve sizes. To evaluate whether the bicuspid valve affects the differences between CT annulus diameter and surgical AVR size, patients with diameter larger by > 10% (CT-Lg group) on CT, compared to surgical AVR size, were compared with those having size difference < 10% (CT-Sim group). Propensity score matching yielded 183 matched patients from each group. Bicuspid aortic valve annulus parameters significantly correlated with surgical aortic valve size (r = 0.52-0.71; for all, p < 0.01). The most representative measurements corresponded to surgical aortic valve size were area-derived diameters in tricuspid aortic valve (r = 0.69, p < 0.001) and bicuspid without raphe (r = 0.71, p < 0.001), and perimeter-derived diameter in bicuspid with raphe (r = 0.63, p < 0.001). After propensity score matching, native valve type was not different between CT-Sim and CT-Lg groups. In multivariable analysis, the difference between CT-derived diameter and surgical AVR size was affected by the operator factor and types of prosthesis. Bicuspid aortic annulus diameters measured on CT showed a significant correlation with surgical aortic valve size. The difference between CT-derived diameter and surgical AVR size is affected by operator factor and the types of prosthesis but not affected by the bicuspid valve.

Tricuspid Valve Imaging and Right Ventricular Function Analysis Using Cardiac CT and MRI

Cardiac computed tomography (CT) and cardiac magnetic resonance imaging (CMR) can reveal the detailed anatomy and function of the tricuspid valve and right ventricle (RV). Quantification of tricuspid regurgitation (TR) and analysis of RV function have prognostic implications. With the recently available transcatheter treatment options for diseases of the tricuspid valve, evaluation of the tricuspid valve using CT and CMR has become important in terms of patient selection and procedural guidance. Moreover, CT enables post-procedural investigation of the causes of valve dysfunction, such as pannus or thrombus. This review describes the anatomy of the tricuspid valve and CT and CMR imaging protocols for right heart evaluation, including RV function and TR analyses. We also demonstrate the pre-procedural planning for transcatheter treatment of TR and imaging of postoperative complications using CT.

Angiographic patterns and temporal changes of arterial lesions in Behcet's disease

BACKGROUND

Behcet's disease (BD) can entail vascular involvement in various forms including aneurysm. We evaluated the angiographic patterns and changes in arterial lesions over time in BD patients with arterial involvement.

METHODS

We reviewed the medical records of BD patients diagnosed with arterial lesions between 1995 and 2018. Angiographic patterns were categorized as stenosis, occlusion, dilatation, or aneurysm. Patients were divided according to symptom duration (<5, 5-10, >10 years). Cox proportional-hazards model was used to evaluate the risk factors for vascular progression.

RESULTS

47 BD patients had arterial involvement in the following patterns: aneurysm (n = 31), stenosis (n = 17), dilatation (n = 13), and occlusion (n = 8). Aneurysm (70.8%) was the most common pattern in 24 patients with short (<5 years) symptom duration. Stenosis was more common (50.0%) in 12 patients with longer symptom durations (>10 years). In 23 patients with follow-up imaging (median, 5.7 years), eight (34.8%) developed 11 new lesions: stenosis (n = 5), dilatation (n = 1), and aneurysm (n = 5). One stenotic lesion progressed to occlusion, and two dilated lesions progressed to aneurysms. Lower extremity involvement and methotrexate use were associated with arterial progression, with hazard ratios of 5.716 (p = 0.029) and 0.101 (p = 0.049), respectively.

CONCLUSION

In BD patients with arterial involvement, aneurysm was the most common pattern in earlier stages of BD, while stenosis was more common in later stages of BD. Methotrexate use was associated with lower risk of arterial lesion progression.

Empirical assessment of biases in cerebrospinal fluid biomarkers of Alzheimer's disease: an umbrella review and re-analysis of data from meta-analyses

OBJECTIVE

Alzheimer's disease (AD) is a leading cause of years lived with disability in older age, and several cerebrospinal fluid (CSF) markers have been proposed in individual meta-analyses to be associated with AD but field-wide evaluation and scrutiny of the literature is not available.

MATERIALS AND METHODS

We performed an umbrella review for the reported associations between CSF biomarkers and AD. Data from available meta-analyses were reanalyzed using both random and fixed effects models. We also estimated between-study heterogeneity, small-study effects, excess significance, and prediction interval.

RESULTS

A total of 38 meta-analyses on CSF markers from 11 eligible articles were identified and reanalyzed. In 14 (36%) of the meta-analyses, the summary estimate and the results of the largest study showed non-concordant results in terms of statistical significance. Large heterogeneity (I2≥75%) was observed in 73% and small-study effects under Egger's test were shown in 28% of CSF biomarkers.

CONCLUSIONS

Our results suggest that there is an excess of statistically significant results and significant biases in the literature of CSF biomarkers for AD. Therefore, the results of CSF biomarkers should be interpreted with caution.

Cholesterol Control for Subclinical Coronary Atherosclerosis in Subjects Without Indication for Statin Therapy

Low-risk individuals still experience adverse cardiac events. We sought to evaluate long-term cardiac events and predictors for subclinical coronary atherosclerosis in subjects without indication for statin therapy. We analyzed 3,272 individuals without indication for statin therapy who voluntarily underwent coronary computed tomography angiography as part of a general health examination. A cardiac event was defined as a composite of cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, or late coronary revascularization. The prevalence of normal coronary arteries, nonobstructive coronary artery disease (CAD) (diameter stenosis < 50%), and obstructive CAD (diameter stenosis ≥50%) was 2,338 (71.5%), 809 (24.7%), and 125 (3.8%), respectively. During the follow-up period (median 5.3 [interquartile range, 4.3-6.3] years), the 6-year event-free survival rates were 99.2%±0.2% in subjects with normal coronary arteries, 98.2%±0.6% in those with nonobstructive CAD, and 90.2%±2.7% in those with obstructive CAD (log-rank p < 0.001). Multivariable regression analysis showed that low-density lipoprotein cholesterol (LDL-C, odds ratio [OR]: 1.012; 95% confidence interval (CI): 1.005-1.019) and high-density lipoprotein cholesterol (HDL-C, OR: 0.968; 95% CI: 0.952-0.984) levels were associated with subclinical obstructive CAD, together with age (OR: 1.080; 95% CI: 1.040-1.121) and male sex (OR: 3.102; 95% CI: 1.866-5.155) (all p < 0.05). In conclusion, LDL-C and HDL-C are significantly associated with the presence of subclinical obstructive CAD with a worse prognosis in subjects without indication for statin therapy. These findings suggest that stricter control of LDL-C and HDL-C levels may be necessary for primary prevention even in a relatively low-risk population.

Increased salivary syndecan-1 level is associated with salivary gland function and inflammation in patients with Sjögren's syndrome

Objectives: Syndecan-1 (SDC-1), a transmembrane heparin sulphate proteoglycan predominantly expressed on epithelial cells, also exists in a soluble form through ectodomain shedding. SDC-1 expression and shedding may be modulated in the inflammatory milieu of primary Sjögren's syndrome (SS). We investigated SDC-1 expression in minor salivary glands (MSGs) and analysed the association between salivary or plasma levels of SDC-1 and clinical parameters in SS.Method: We measured salivary and plasma SDC-1 levels via an enzyme-linked immunosorbent assay and assessed the salivary flow rates (SFRs) in 70 patients with SS and 35 healthy subjects. Disease activity indices, serological markers, salivary gland scintigraphy, and MSG biopsy were evaluated in patients with SS.Results: SDC-1 expression was upregulated on ductal epithelial cells in inflamed salivary glands. Salivary SDC-1 levels in patients significantly exceeded those in healthy subjects [median (interquartile range) 49.0 (20.7-79.1) vs 3.7 (1.7-6.3) ng/mL, p < 0.001] and inversely correlated with SFRs (r = -0.358, p = 0.032) and ejection fractions of the parotid (r = -0.363, p = 0.027) and submandibular (r = -0.485, p = 0.002) glands in salivary gland scintigraphy. Plasma SDC-1 levels were significantly correlated with the EULAR Sjögren's Syndrome Disease Activity Index (r = 0.507, p < 0.001) and EULAR Sjögren's Syndrome Patient Reported Index (r = 0.267, p = 0.033). Focus scores were correlated with salivary SDC-1 levels (r = 0.551, p = 0.004).Conclusion: Salivary and plasma SDC-1 levels may constitute potential biomarkers for salivary gland function and disease activity, respectively, in SS.

Impact of coronary calcium score and lesion characteristics on the diagnostic performance of machine-learning-based computed tomography-derived fractional flow reserve

AIMS

To evaluate the impact of coronary artery calcium (CAC) score, minimal lumen area (MLA), and length of coronary artery stenosis on the diagnostic performance of the machine-learning-based computed tomography-derived fractional flow reserve (ML-FFR).

METHODS AND RESULTS

In 471 patients with coronary artery disease, computed tomography angiography (CTA) and invasive coronary angiography were performed with fractional flow reserve (FFR) in 557 lesions at a single centre. Diagnostic performances of ML-FFR, computational fluid dynamics-based CT-FFR (CFD-FFR), MLA, quantitative coronary angiography (QCA), and visual stenosis grading were evaluated using invasive FFR as a reference standard. Diagnostic performances were analysed according to lesion characteristics including the MLA, length of stenosis, CAC score, and stenosis degree. ML-FFR was obtained by automated feature selection and model building from quantitative CTA. A total of 272 lesions showed significant ischaemia, defined by invasive FFR ≤0.80. There was a significant correlation between CFD-FFR and ML-FFR (r = 0.99, P < 0.001). ML-FFR showed moderate sensitivity and specificity in the per-patient analysis. Diagnostic performances of CFD-FFR and ML-FFR did not decline in patients with high CAC scores (CAC > 400). Sensitivities of CFD-FFR and ML-FFR showed a downward trend along with the increase in lesion length and decrease in MLA. The area under the curve (AUC) of ML-FFR (0.73) was higher than those of QCA and visual grading (AUC = 0.65 for both, P < 0.001) and comparable to those of MLA (AUC = 0.71, P = 0.21) and CFD-FFR (AUC = 0.73, P = 0.86).

CONCLUSION

ML-FFR showed comparable results to MLA and CFD-FFR for the prediction of lesion-specific ischaemia. Specificities and accuracies of CFD-FFR and ML-FFR decreased with smaller MLA and long lesion length.

Acute Seymour fractures in children/adolescents overlooked as a simple nail injury: Reduction without pinning

We retrospectively report the outcomes of several cases in which acute Seymour fractures were treated by open reduction of displaced distal bony fragments with concurrent nail repair, following complete incision and drainage without K-wire fixation. Among 21 patients surgically treated between March 2004 and December 2018, the final 12 were evaluated after at least 2 years of follow-up. All children/adolescents presented more than 24 h after the injury. All injuries were unreduced in the emergency department, with typical features of skin disruption around the eponychium/perionychium. Reduction was maintained without a K-wire after repairing the bone-periosteum-nail bed-nail plate of the distal fragment and the corresponding physis-periosteum-germinal matrix-proximal nail-fold of the proximal stump. Dorsal angulation, finger length, postoperative pain on visual analog scale (VAS), Disabilities of the Arm, Shoulder, and Hand (DASH) score, and active range of motion (ROM) were evaluated at the final follow-up. The mean patient age was 9.3 years (range, 3-13 years) and the mean time from injury to surgery was 35 h (range, 28-44 h). Only one child suffered a superficial infection; however, it resolved with 1 week of oral antibiotic treatment. At the final follow-up, mean dorsal angulation was 0.50° ± 1.24°; the length ratio compared with the corresponding contralateral phalanx was 98% (both, P >  0.05). The final pain on VAS, DASH score, and ROM ratio were 0.25 ± 0.45, 0.83 ± 1.34, and 99 ± 2%, respectively. Unreduced Seymour fractures presenting more than 24 h after the injury were treated by proper debridement and reduction of the fracture without the use of a K-wire. However, to determine whether the infection rate is definitively lower, this procedure should be compared with the conventional procedure using a K-wire. Level of Evidence: Therapeutic level IV.

Characteristics of Genetic Variations Associated With Lennox-Gastaut Syndrome in Korean Families

Lennox-Gastaut syndrome (LGS) is a severe type of childhood-onset epilepsy characterized by multiple types of seizures, specific discharges on electroencephalography, and intellectual disability. Most patients with LGS do not respond well to drug treatment and show poor long-term prognosis. Approximately 30% of patients without brain abnormalities have unidentifiable causes. Therefore, accurate diagnosis and treatment of LGS remain challenging. To identify causative mutations of LGS, we analyzed the whole-exome sequencing data of 17 unrelated Korean families, including patients with LGS and LGS-like epilepsy without brain abnormalities, using the Genome Analysis Toolkit. We identified 14 mutations in 14 genes as causes of LGS or LGS-like epilepsy. 64 percent of the identified genes were reported as LGS or epilepsy-related genes. Many of these variations were novel and considered as pathogenic or likely pathogenic. Network analysis was performed to classify the identified genes into two network clusters: neuronal signal transmission or neuronal development. Additionally, knockdown of two candidate genes with insufficient evidence of neuronal functions, SLC25A39 and TBC1D8, decreased neurite outgrowth and the expression level of MAP2, a neuronal marker. These results expand the spectrum of genetic variations and may aid the diagnosis and management of individuals with LGS.

Rationale and design of the ADAPT-TAVR trial: a randomised comparison of edoxaban and dual antiplatelet therapy for prevention of leaflet thrombosis and cerebral embolisation after transcatheter aortic valve replacement

INTRODUCTION

Optimal antithrombotic strategy following transcatheter aortic valve replacement (TAVR) is still unknown. We hypothesised that the direct factor Xa inhibitor edoxaban can potentially prevent subclinical leaflet thrombosis and cerebral embolisation compared with conventional dual antiplatelet therapy (DAPT) in patients undergoing TAVR.

METHODS AND ANALYSIS

The ADAPT-TAVR trial is an international, multicentre, randomised, open-label, superiority trial comparing edoxaban-based strategy and DAPT strategy in patients without an indication for oral anticoagulation who underwent successful TAVR. A total of 220 patients are randomised (1:1 ratio), 1-7 days after successful TAVR, to receive either edoxaban (60 mg daily or 30 mg daily if patients had dose-reduction criteria) or DAPT using aspirin (100 mg daily) plus clopidogrel (75 mg daily) for 6 months. The primary endpoint was an incidence of leaflet thrombosis on four-dimensional, volume-rendered cardiac CT imaging at 6 months post-TAVR. The key secondary endpoints were the number of new lesions and new lesion volume on brain diffusion-weighted MRI and the changes in neurological and neurocognitive function assessment between immediate post-TAVR and 6 months of study drug administration. Detailed clinical information on thromboembolic and bleeding events were also assessed.

ETHICS AND DISSEMINATION

Ethic approval has been obtained from the Ethics Committee/Institutional Review Board of Asan Medical Center (approval number: 2017-1317) and this trial is also approved by National Institute of Food and Drug Safety Evaluation of Republic of Korea (approval number: 31511). Results of this study will be disseminated in scientific publication in reputed journals.

TRIAL REGISTRATION NUMBER

NCT03284827.

Independent role of low-density lipoprotein cholesterol in subclinical coronary atherosclerosis in the absence of traditional cardiovascular risk factors

AIMS

Individuals without traditional cardiovascular risk factors (CVRFs) still experience adverse events in clinical practice. This study evaluated the predictors of subclinical coronary atherosclerosis in individuals without traditional CVRFs.

METHODS AND RESULTS

A total of 1250 (52.8 ± 6.5 years, 46.9% male) asymptomatic individuals without CVRFs who underwent coronary computed tomographic angiography for a general health examination were analysed. The following were considered as traditional CVRFs: systolic/diastolic blood pressure ≥140/90 mmHg; fasting glucose ≥126 mg/dL; total cholesterol ≥240 mg/dL; low-density lipoprotein cholesterol (LDL-C) ≥160 mg/dL; high-density lipoprotein cholesterol <40 mg/dL; body mass index ≥25.0 kg/m2; current smoking status; and previous medical history of hypertension, diabetes, and dyslipidaemia. Subclinical atherosclerosis, defined as the presence of any coronary plaque, was present in 20.6% cases; the incidences of non-calcified, calcified, and mixed plaque were 9.6%, 12.6%, and 2.6%, respectively. Multivariate regression analysis showed that LDL-C level [odds ratio (OR): 1.008; 95% confidence interval (CI): 1.001-1.015], together with age (OR: 1.101; 95% CI: 1.075-1.128) and male sex (OR: 5.574; 95% CI: 3.310-9.388), was associated with the presence of subclinical atherosclerosis (All P < 0.05). LDL-C level was significantly associated with an increased risk of calcified plaques rather than non-calcified or mixed plaques.

CONCLUSION

LDL-C, even at levels currently considered within normal range, is independently associated with the presence of subclinical coronary atherosclerosis in individuals without traditional CVRFs. Our results suggest that a stricter control of LDL-C levels may be necessary for primary prevention in individuals who are conventionally considered healthy.

Association of gamma-glutamyl transferase with subclinical coronary atherosclerosis and cardiac outcomes in non-alcoholics

In an asymptomatic population, we determined the relationship between serum gamma-glutamyl transferase (GGT) and subclinical atherosclerosis, using coronary computed tomography angiography (CCTA). This was a retrospective observational cohort study which analyzed 5120 consecutive asymptomatic individuals with no prior history of coronary artery disease or significant alcohol intake who voluntarily underwent CCTA as part of a general health examination. All subjects were stratified into tertiles based on GGT levels. Degree and extent of subclinical coronary atherosclerosis were evaluated using CCTA. Cardiac events were a composite of all-cause death, myocardial infarction, unstable angina, and coronary revascularization. After adjustment for cardiovascular risk factors, there were no significant differences among GGT tertiles in terms of adjusted odds ratios for non-calcified and mixed plaques. The risk of any atherosclerotic and calcified plaques, significant stenosis, multi-vessel disease, and significant stenosis in the left main or proximal left anterior descending artery was higher in the third GGT tertile than in the first tertile (all p < 0.05). Over a median 5.4-year follow-up, the third GGT tertile had significant adjusted hazards ratios for cardiac events than did the first GGT tertile, even after stepwise adjustment for cardiovascular risk factors (all p < 0.01). In asymptomatic individuals, elevated GGT was independently associated with high-risk feature atherosclerosis and poorer cardiac outcomes.

Practice Pattern, Diagnostic Yield, and Long-Term Prognostic Impact of Coronary Computed Tomographic Angiography

Background Although guidelines recommend the use of coronary computed tomographic angiography (CTA) in patients with stable pain syndromes, the clinical benefits of the use of coronary CTA in a broad spectrum of patients is unknown. We evaluated the contemporary practice pattern and diagnostic yield of coronary CTA and their impact on the subsequent diagnostic-therapeutic cascade and clinical outcomes. Methods and Results We identified 39 906 patients without known coronary artery disease (CAD) who underwent coronary CTA between January 2007 and December 2013. The patients' demographic characteristics, risk factors, symptoms, results of coronary CTA, the appropriateness of downstream diagnostic and therapeutic interventions, and long-term outcomes (death or myocardial infarction) were evaluated. The number of coronary CTAs had increased over time, especially in asymptomatic patients. Coronary CTA revealed that 6108 patients (15.3%) had obstructive CAD (23.7% of symptomatic and 9.3% of asymptomatic patients). Subsequent cardiac catheterization was performed in 19.2% of symptomatic patients (appropriate, 80.6%) and in 3.9% of asymptomatic patients (appropriate, 7.9%). The 5-year rate of death or myocardial infarction was significantly higher in patients with obstructive CAD on CTA than those without (7.2% versus 3.0%; P<0.001; adjusted hazard ratio [95% CI], 1.34 [1.17-1.54]). However, obstructive CAD on CTA had limited added value over conventional risk factors for predicting death or myocardial infarction. Conclusions Although the use of coronary CTA had substantially increased, CTA had a low diagnostic yield for obstructive CAD, especially in asymptomatic patients. The use of CTA in asymptomatic patients seemed to have led to inappropriate subsequent diagnostic or therapeutic interventions without clinical benefit.

Association between serum phosphorus and subclinical coronary atherosclerosis in asymptomatic Korean individuals without kidney dysfunction

BACKGROUND

There are limited data regarding the relation between serum phosphorus concentration (SPC) and subclinical coronary atherosclerosis in the asymptomatic healthy population without kidney dysfunction.

OBJECTIVES

We aimed to investigate the relation between SPC and characteristics of atherosclerotic plaques and cardiac events according to SPCs using a large cohort of asymptomatic Korean individuals.

METHODS

We evaluated 6329 asymptomatic Korean individuals [mean age: 53.6 ± 7.6 y, 4611 men (72.9%)] without kidney dysfunction and coronary artery disease who voluntarily underwent coronary computed tomography angiography (CCTA) as part of a general health examination. Study participants were stratified into quartiles according to their SPCs (≤3.0, 3.1-3.3, 3.4-3.7, ≥3.8 mg/dL). The degree and extent of subclinical coronary atherosclerosis were evaluated with CCTA. Stenosis of diameter ≥50% was defined as significant. A cardiac event was defined as a composite of all-cause death, myocardial infarction, unstable angina, and coronary revascularization.

RESULTS

After adjustment for cardiovascular disease risk factors, the risk of any atherosclerotic plaque was significantly higher with increasing SPC quartiles (P = 0.001). In particular, the risk of calcified plaque increased in the second (OR: 1.27; 95% CI: 1.07, 1.51; P = 0.006), third (OR: 1.39; 95% CI: 1.17, 1.64; P < 0.001), and fourth SPC quartiles (OR: 1.50; 95% CI: 1.24, 1.82; P < 0.001) compared with that in the first quartile. However, there were no significant differences in the adjusted ORs for noncalcified plaque, mixed plaque, or significant stenosis. During a follow-up of median 5.4 y, there was no significant difference in cardiac events between the SPC quartiles.

CONCLUSIONS

In asymptomatic Korean individuals without kidney dysfunction, a high SPC was an independent predictor of calcified plaques without any difference in cardiac events. Further long-term prospective studies are required to validate these results.

Determinants of effective orifice area in aortic valve replacement: anatomic and clinical factors

Background

Obtaining adequate effective orifice area (EOA) in surgical aortic valve replacement (SAVR) is important to minimize pressure gradients across the prosthetic aortic valve (AV) and improve clinical outcomes. However, the predictors of EOA are unclear.

Methods

From July 2011 to March 2016, patients undergoing SAVR who were preoperatively evaluated using a computed tomography (CT) on the aortic root were enrolled. Indexed EOA (iEOA) was used as an indicator of prosthetic AV opening area. The aortic root parameters investigated were the annular diameter (max and min), annular perimeter, annular area, and maximal dimensions of the proximal ascending aorta. These variables were evaluated as predictors of EOA, and an individual surgeon was incorporated in analysis for verifying surgeon dependent factors.

Results

Among the 710 patients included in this study [age: 64.9±10.8 years; females: n=285 (40.1%)], 370 (52.1%) were implanted with bio-prosthesis. Mean prosthetic iEOA was 1.1±0.3 cm²/m². Univariable linear regression analysis showed that all indexed aortic root parameters (maximal and minimal annular diameters, annular perimeter, annular area, and sinus dimensions) were significantly associated with iEOA (P<0.001). Multivariable analysis showed that indexed aortic annular area, indexed maximal diameter of the Valsalva sinus, female sex, and bio-prosthesis, supra-annular type prosthesis and surgeon were significant and independent determinants of iEOA (adjusted R²=0.513, P<0.001).

Conclusions

Aortic annular area and Valsalva sinus diameter are independent determinants for iEOA measured by preoperative CT; surgeon-dependent factors are also significant determinants in SAVR.

Homocysteine is not a risk factor for subclinical coronary atherosclerosis in asymptomatic individuals

BACKGROUND

Homocysteine has been known as a risk factor for cardiovascular disease. This study sought to evaluate the influence of homocysteine on the risk of subclinical coronary atherosclerosis in asymptomatic individuals.

METHODS

We reviewed 3,186 asymptomatic individuals (mean age 53.8 ± 8.0 years, 2,202 men [69.1%]) with no prior history of coronary artery disease who voluntarily underwent coronary computed tomographic angiography (CCTA) and laboratory tests as part of a general health examination. The subjects were stratified into tertiles according to their homocysteine levels. The degree and extent of subclinical coronary atherosclerosis were assessed by CCTA. Logistic regression analysis was used to determine the association between homocysteine levels and subclinical coronary atherosclerosis.

RESULTS

The prevalence of significant coronary artery stenosis, any atherosclerotic, calcified, mixed, and non-calcified plaques increased with homocysteine tertiles (all p < 0.05). However, after adjustment for cardiovascular risk factors, there were no statistically significant differences in the adjusted odds ratios (ORs) for any atherosclerotic plaque (OR 1.06; 95% CI [confidence interval] 0.85-1.32; p = 0.610), calcified plaques (OR 1.17; 95% CI 0.92-1.48; p = 0.199), non-calcified plaques (OR 0.80; 95% CI 0.61-1.04; p = 0.089), and mixed plaques (OR 1.42; 95% CI 0.96-2.11; p = 0.077) between the third and first homocysteine tertiles. In addition, the adjusted OR for significant coronary artery stenosis (OR 0.92; 95% CI 0.63-1.36; p = 0.687) did not differ between the first and third tertiles.

CONCLUSIONS

In asymptomatic individuals, homocysteine is not associated with an increased risk of subclinical coronary atherosclerosis.

Computed Tomography Features of Cuspal Thrombosis and Subvalvular Tissue Ingrowth after Transcatheter Aortic Valve Implantation

Post-transcatheter aortic valve implantation (TAVI) computed tomography (CT) findings have not been fully elucidated, except hypoattenuating leaflet thickening (HALT). The objective of this study was to describe cardiac CT findings after TAVI, and investigate factors associated with HALT. This retrospective study included patients who underwent TAVI and post-TAVI cardiac CT scans. On CT, abnormal findings such as hypoattenuating subvalvular thickening (HAST), thrombus within the sinus of Valsalva, HALT, and leaflet motion limitation were thoroughly reviewed. Clinical and CT findings were compared between patients with HALT and those without HALT. Logistic regression analysis was performed to determine factors associated with HALT. A total of 138 patients (64 male, mean 78.5 ± 5.2 years of age) with post-TAVI CT scans were included. The median duration from TAVI to CT was 17.5 days (interquartile range, 3 to 390.8 days). HAST and thrombus within the sinus of Valsalva were detected in 32 (23%) and 5 (4%) patients, respectively. HALT and leaflet motion limitations were found in 25 (18%) and 20 (14%) of patients, respectively. Pannus was diagnosed in 2 patients. TAVI device implant duration (odds ratio [OR], 1.5; p = 0.01), hypertension (OR, 0.2; p = 0.03), and HAST (OR, 4.9; p = 0.003) were associated with HALT. Implant durations were longer in patients with HAST, HALT, or leaflet motion limitation (p < 0.05, for all). In conclusion, HAST, HALT, thrombus within the sinus of Valsalva, and leaflet motion limitation are not uncommon after TAVI. Implant duration, hypertension, and HAST are associated with HALT.

Triglyceride glucose index is a useful marker for predicting subclinical coronary artery disease in the absence of traditional risk factors

BACKGROUND

Atherosclerotic cardiovascular (CV) events commonly occur in individuals with a low CV risk burden. This study evaluated the ability of the triglyceride glucose (TyG) index to predict subclinical coronary artery disease (CAD) in asymptomatic subjects without traditional CV risk factors (CVRFs).

METHODS

This retrospective, cross-sectional, and observational study evaluated the association of TyG index with CAD in 1250 (52.8 ± 6.5 years, 46.9% male) asymptomatic individuals without traditional CVRFs (defined as systolic/diastolic blood pressure ≥ 140/90 mmHg; fasting glucose ≥126 mg/dL; total cholesterol ≥240 mg/dL; low-density lipoprotein cholesterol ≥160 mg/dL; high-density lipoprotein cholesterol < 40 mg/dL; body mass index ≥25.0 kg/m²; current smoking; and previous medical history of hypertension, diabetes, or dyslipidemia). CAD was defined as the presence of any coronary plaque on coronary computed tomographic angiography. The participants were divided into three groups based on TyG index tertiles.

RESULTS

The prevalence of CAD increased with elevating TyG index tertiles (group I: 14.8% vs. group II: 19.3% vs. group III: 27.6%; P < 0.001). Multivariate logistic regression models showed that TyG index was associated with an increased risk of CAD (odds ratio [OR] 1.473, 95% confidence interval [CI] 1.026-2.166); especially non-calcified (OR 1.581, 95% CI 1.002-2.493) and mixed plaques (OR 2.419, 95% CI 1.051-5.569) (all P < 0.05). The optimal TyG index cut-off for predicting CAD was 8.44 (sensitivity 47.9%; specificity 68.5%; area under the curve 0.600; P < 0.001). The predictive value of this cut-off improved after considering the non-modifiable factors of old age and male sex.

CONCLUSIONS

TyG index is an independent marker for predicting subclinical CAD in individuals conventionally considered healthy.

Extent of Subprosthetic Pannus after Aortic Valve Replacement: Changes Over Time and Relationship with Echocardiographic Findings

Purpose

This study aimed to evaluate changes of subprosthetic pannus on cardiac CT and determine its relationship to echocardiographic findings in patients with mechanical aortic valve replacement (AVR).

Materials and Methods

Between April 2011 and November 2017, 17 AVR patients (56.8 ± 8.9 years, 12% male) who showed pannus formation on CT and had undergone both follow-up CT and echocardiography were included. The mean interval from AVR to the date of pannus detection was 10.5 ± 7.1 years. In the initial and follow-up CT and echocardiography, the pannus extent and echocardiographic parameters were compared using paired t-tests. The relationship between the opening angle of the prosthetic valve and the pannus extent was evaluated using Pearson correlation analysis.

Results

The pannus extent was significantly increased on CT (p < 0.05). The peak velocity (3.9 ± 0.8 m/s vs. 4.2 ± 0.8 m/s, p = 0.03) and mean pressure gradient (36.4 ± 15.5 mm Hg vs. 42.1 ± 15.8 mm Hg, p = 0.03) were significantly increased. The mean opening angles of the mechanical aortic leaflets were slightly decreased, but there was no statistical significance (73.1 ± 8.3° vs. 69.4 ± 12.1°, p = 0.12). The opening angle of the prosthetic leaflets was inversely correlated with the pannus extent (r = −0.57, p < 0.001).

Conclusion

The pannus extent increases over time, increasing transvalvular peak velocity and the pressure gradient. CT can be used to evaluate the pannus extent associated with hemodynamic changes that need to be managed by surgical intervention.

A Novel X-Linked Variant of IQSEC2 is Associated with Lennox-Gastaut Syndrome and Mild Intellectual Disability in Three Generations of a Korean Family

Aim: Lennox-Gastaut syndrome (LGS) is a severe type of childhood-onset epilepsy with multiple types of seizures, specific discharges on electroencephalography, and intellectual disability. However, LGS-related genes are largely unknown. To identify causative genes related to LGS, we collected and analyzed data from a three-generation Korean family in which one member had LGS and two had intellectual disability. Methods: Genomic DNAs were extracted from blood samples of all participants and used in whole-exome sequencing (WES). Genetic variants were detected by the Genome Analysis Toolkit and confirmed by Sanger sequencing. Variant pathogenicity was evaluated by prediction programs and the American College of Medical Genetics criteria. The LGS patient had generalized slow spike-and-wave discharges, multiple types of seizures, and developmental delay. Results: Analyses of the WES data from the family revealed a novel variant (c.1048G>A, p.Ala350Thr) in the IQ motif and Sec7 domain 2 (IQSEC2). This variant is within a highly evolutionarily conserved IQ-like motif, indicating a decrease in the calmodulin-binding capacity or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid transmission. The hemizygous variant in the male with LGS was a maternally inherited X-linked variant from the heterozygous maternal grandmother and mother, both of whom had intellectual disability. Conclusion: These findings indicate that the variant of IQSEC2 triggered both LGS and intellectual disability dependent on sex in this family. We report a novel X-linked inherited IQSEC2 variant for LGS and intellectual disability, which enhances the spectrum of variants in the IQ-like motif of IQSEC2.

Reduction in radiation exposure in cardiovascular computed tomography imaging: results from the PROspective multicenter registry on radiaTion dose Estimates of cardiac CT angIOgraphy iN daily practice in 2017 (PROTECTION VI)

Aims

Advances of cardiac computed tomography angiography (CTA) have been developed for dose reduction, but their efficacy in clinical practice is largely unknown. This study was designed to evaluate radiation dose exposure and utilization of dose-saving strategies for contrast-enhanced cardiac CTA in daily practice.

Methods and results

Sixty one hospitals from 32 countries prospectively enrolled 4502 patients undergoing cardiac CTA during one calendar month in 2017. Computed tomography angiography scan data and images were analysed in a central core lab and compared with a similar dose survey performed in 2007. Linear regression analysis was performed to identify independent predictors associated with dose. The most frequent indication for cardiac CTA was the evaluation of coronary artery disease in 89% of patients. The median dose-length product (DLP) of coronary CTA was 195 mGy*cm (interquartile range 110-338 mGy*cm). When compared with 2007, the DLP was reduced by 78% (P < 0.001) without an increase in non-diagnostic coronary CTAs (1.7% in 2007 vs. 1.9% in 2017 surveys, P = 0.55). A 37-fold variability in median DLP was observed between the hospitals with lowest and highest DLP (range of median DLP 57-2090 mGy*cm). Independent predictors for radiation dose of coronary CTA were: body weight, heart rate, sinus rhythm, tube voltage, iterative image reconstruction, and the selection of scan protocols.

Conclusion

This large international radiation dose survey demonstrates considerable reduction of radiation exposure in coronary CTA during the last decade. However, the large inter-site variability in radiation exposure underlines the need for further site-specific training and adaptation of contemporary cardiac scan protocols.

Association between insulin resistance, hyperglycemia, and coronary artery disease according to the presence of diabetes

This study evaluated the relationship of insulin resistance (IR) and glycemic control status to the presence and severity of coronary artery disease (CAD) according to diabetes. The relationship of IR parameters including homeostatic model assessment of IR (HOMA-IR), triglyceride-glucose (TyG) index, and triglyceride-to-high density lipoprotein cholesterol ratio (TG/HDL), and hemoglobin A1C (HbA1C) level to CAD and obstructive CAD was evaluated in 5,764 asymptomatic subjects who underwent coronary computed tomographic angiography. Non-diabetics (n = 4768) and diabetics (n = 996) were stratified into four groups based on the quartiles of HOMA-IR and the TyG index and were grouped based on the TG/HDL cut-offs of 3.5, respectively. CAD and obstructive CAD were defined as the presence of any plaques and plaques with ≥50% stenosis, respectively. The prevalence of CAD (59.0% vs. 39.0%) and obstructive CAD (15.0% vs. 6.6%) was higher in diabetic than in non-diabetic patients (p < 0.001, respectively). In non-diabetic patients, the adjusted odds ratio for both CAD and obstructive CAD significantly increased, but only with higher TyG index quartiles. Unlike non-diabetics, the adjusted odds ratio for obstructive CAD significantly increased in diabetic patients with a TG/HDL level ≥ 3.5. The HbA1C, rather than IR parameters, was independently associated with both CAD and obstructive CAD in diabetics. In conclusion, among IR parameters, TyG index was independently associated with the presence of CAD and obstructive CAD in non-diabetic patients. In contrast, the glycemic control status, rather than IR, was importantly related to both CAD and obstructive CAD in established diabetic patients.

Impact of coronary lumen reconstruction on the estimation of endothelial shear stress: in vivo comparison of three-dimensional quantitative coronary angiography and three-dimensional fusion combining optical coherent tomography

Aims

It is not clearly elucidated how the fusion technique improves the accuracy of endothelial shear stress (ESS) prediction, in comparison with that of three-dimensional (3D) quantitative coronary angiography (QCA) alone. We aimed to evaluate the difference in geometric measurements and haemodynamic estimation between 3D QCA and a 3D fusion model combining 3D QCA and optical coherence tomography (OCT).

Methods and results

Computational fluid dynamics was assessed in the coronary models of 20 patients. In the plane-per-plane comparison, the difference and agreement were assessed using a generalized linear mixed model and concordance correlation coefficient (CCC), respectively. The haemodynamic feature around minimum-lumen-diameter (MLD) was characterized using CCC values calculated for 1-mm segments. In comparison with the 3D fusion model, 3D QCA showed a shorter maximum lumen diameter (2.54 ± 0.67 mm vs. 2.78 ± 0.73 mm, P < 0.001) and smaller lumen area (4.81 ± 2.56 mm2 vs. 5.66 ± 2.97 mm2, P < 0.001), resulting in a significantly higher ESS (4.64 Pa vs. 3.78 Pa, p = 0.029). A more asymmetric lumen shape of the 3D fusion model was more likely associated with under- and over-estimation of the maximum and minimum lumen diameters in the 3D QCA model, respectively. The circumferential ESS variations, which were blunted by 3D QCA, showed the worst concordance near the MLD site (CCC = 0.370) on segment-based comparison.

Conclusion

The 3D fusion technique may be a more relevant tool for the haemodynamic simulation of coronary arteries through providing more accurate lumen characterization than 3D QCA.

High-density lipoprotein cholesterol and the risk of obstructive coronary artery disease beyond low-density lipoprotein cholesterol in non-diabetic individuals

AIMS

The relationship between high-density lipoprotein cholesterol and the severity of coronary artery disease beyond low-density lipoprotein cholesterol, the primary target of cholesterol-lowering therapy, remains uncertain. We evaluated the association between high-density lipoprotein cholesterol and obstructive coronary artery disease using parameters of any obstructive plaque, obstructive plaque in the left main coronary artery or proximal left anterior descending artery, and obstructive plaque in multi-vessels, according to low-density lipoprotein cholesterol levels.

METHODS AND RESULTS

We analyzed 5130 asymptomatic non-diabetics who underwent coronary computed tomography angiography for general health examination. Obstructive plaque was defined as a plaque with ≥50% luminal diameter stenosis. The participants were divided into three groups based on low-density lipoprotein cholesterol levels of ≤129, 130-159, and ≥160 mg/dl. The prevalence of any obstructive plaque (5.9% vs 6.4% vs 10.6%) and obstructive plaque in the left main coronary artery or proximal left anterior descending artery (2.1% vs 2.1% vs 4.3%) significantly increased with low-density lipoprotein cholesterol category (all p < 0.05). Compared with subjects with high-density lipoprotein cholesterol level ≥40 mg/dl, those with high-density lipoprotein cholesterol level <40 mg/dl had a significantly higher prevalence of any obstructive plaque (10.4% vs 5.1%), obstructive plaque in the left main coronary artery or proximal left anterior descending artery (3.6% vs 1.8%), and obstructive plaque in multi-vessels (4.3% vs 1.1%), only in the group with low-density lipoprotein cholesterol level ≤129 mg/dl (all p < 0.05). Multiple regression analysis showed that increased high-density lipoprotein cholesterol levels were associated with a reduced risk of all obstructive coronary artery disease parameters only in the group with low-density lipoprotein cholesterol level ≤129 mg/dl (all p < 0.05).

CONCLUSION

Increased high-density lipoprotein cholesterol levels were independently associated with a lower risk of obstructive coronary artery disease in asymptomatic non-diabetics with low low-density lipoprotein cholesterol levels.

Impact of Subtended Myocardial Mass Assessed by Coronary Computed Tomographic Angiography-Based Myocardial Segmentation

Although decision-making for revascularization is based on the extent of ischemic myocardium, the prognostic implication of supplying myocardial territories has not yet been studied. To evaluate the clinical impact of the coronary artery-based myocardial segmentation (CAMS)-derived myocardial volume subtended to the poststenotic segment, and to determine clinically relevant coronary lesions, coronary computed tomography angiography, invasive coronary angiography, and preprocedure fractional flow reserve (FFR) data were analyzed in 664 deferred lesions (in 577 patients) and 401 treated lesions (in 369 patients) with drug-eluting stent implantation, respectively. Using CAMS method, the myocardial volume subtended to a stenotic coronary segment (V_sub) was assessed. The primary composites included target vessel-related major adverse cardiac event (MACE) including cardiac death, myocardial infarction, and target vessel revascularization over 3 years. Independent predictors of 3-year MACE in deferred lesions were V_sub (adjusted hazard ratio [HR] 1.02), FFR (adjusted HR per 0.1 = 0.60), and distal reference luminal diameter (adjusted HR 2.04, all p < 0.05). A V_sub ≥ 36.2cc was predictive of MACE in deferred lesions with a sensitivity 72% and a specificity 67% (area under curve 0.71, 95% confidence interval 0.67 to 0.74, p < 0.001). V_sub was not associated with target vessel-related MACE. For the prediction of FFR < 0.80, the area under curve of V_sub/MLD⁴ > 6.3 was greater than those of angiographic diameter stenosis (0.78 vs 0.69) and minimal luminal diameter (0.78 vs 0.71), (all p < 0.05). CAMS-derived V_sub predicted 3-year clinical outcomes in untreated coronary lesions, and improved the diagnostic performance of angiography-derived parameters to identify ischemia-producing lesions.

On the mechanism of dendritic fragmentation by ultrasound induced cavitation

A dedicated solidification device and high speed camera were used to capture dendritic fragmentation of pure succinonitrile (SCN) induced by oscillating ultrasonic bubbles. Theoretical analysis of the melting behavior of the dendrite was performed based on local solidification thermodynamics. The dendritic growth or the evolution of the solid-liquid interface is closely related to both thermodynamics of the cavitation bubble and the local geometry of the dendrite. Accordingly, for the first time, a dimensionless scaling formulation was developed by fitting both theoretical and experimental data to determine the variational pressure exerted by the cavitation bubble.

Demonstration of infective endocarditis by cardiac CT and transoesophageal echocardiography: comparison with intra-operative findings

Aims

We aimed to compare imaging findings of infective endocarditis between computed tomography (CT) and transoesophageal echocardiography (TEE) using surgical inspection as a reference standard.

Methods and results

Forty-nine patients (aged 54 ± 17 years, 69% men) who underwent pre-operative CT and TEE for infective endocarditis were included. Twelve of these patients had prosthetic valve endocarditis. Imaging findings of infective endocarditis were classified as vegetation, leaflet perforation, abscess/pseudoaneurysm, and paravalvular leakage. Diagnostic performances of CT and TEE were evaluated using surgical inspection as a reference standard. Interobserver agreements for CT findings were obtained using Cohen's κ test. The detection rates of infective endocarditis per patient with CT and TEE were 93.9% (46/49) and 95.9% (47/49), respectively. In per-imaging analysis, the sensitivities of CT and TEE were not significantly different for both native and prosthetic valve infective endocarditis (sensitivity: vegetation, 100% in TEE and 90.9% in CT; leaflet perforation, 87.5% in TEE and 50.0% in CT; abscess/pseudoaneurysm, 40.0% in TEE and 60.0% in CT; paravalvular leakage, 100% in TEE and 50.0% in CT). Interobserver agreements for CT findings were substantial or excellent (0.79-0.88).

Conclusion

Cardiac CT can accurately demonstrate infective endocarditis in pre-operative patients with a similar diagnostic accuracy to TEE. The interobserver agreements for the CT findings of infective endocarditis were excellent.

Machine learning assessment of myocardial ischemia using angiography: Development and retrospective validation

BACKGROUND

Invasive fractional flow reserve (FFR) is a standard tool for identifying ischemia-producing coronary stenosis. However, in clinical practice, over 70% of treatment decisions still rely on visual estimation of angiographic stenosis, which has limited accuracy (about 60%-65%) for the prediction of FFR < 0.80. One of the reasons for the visual-functional mismatch is that myocardial ischemia can be affected by the supplied myocardial size, which is not always evident by coronary angiography. The aims of this study were to develop an angiography-based machine learning (ML) algorithm for predicting the supplied myocardial volume for a stenosis, as measured using coronary computed tomography angiography (CCTA), and then to build an angiography-based classifier for the lesions with an FFR < 0.80 versus ≥ 0.80.

METHODS AND FINDINGS

A retrospective study was conducted using data from 1,132 stable and unstable angina patients with 1,132 intermediate lesions who underwent invasive coronary angiography, FFR, and CCTA at the Asan Medical Center, Seoul, Korea, between 1 May 2012 and 30 November 2015. The mean age was 63 ± 10 years, 76% were men, and 72% of the patients presented with stable angina. Of these, 932 patients (assessed before 31 January 2015) constituted the training set for the algorithm, and 200 patients (assessed after 1 February 2015) served as a test cohort to validate its diagnostic performance. Additionally, external validation with 79 patients from two centers (CHA University, Seongnam, Korea, and Ajou University, Suwon, Korea) was conducted. After automatic contour calibration using the caliber of guiding catheter, quantitative coronary angiography was performed using the edge-detection algorithms (CAAS-5, Pie-Medical). Clinical information was provided by the Asan BiomedicaL Research Environment (ABLE) system. The CCTA-based myocardial segmentation (CAMS)-derived myocardial volume supplied by each vessel (right coronary artery [RCA], left anterior descending [LAD], left circumflex [LCX]) and the myocardial volume subtended to a stenotic segment (CAMS-%Vsub) were measured for labeling. The ML for (1) predicting vessel territories (CAMS-%LAD, CAMS-%LCX, and CAMS-%RCA) and CAMS-%Vsub and (2) identifying the lesions with an FFR < 0.80 was constructed. Angiography-based ML, employing a light gradient boosting machine (GBM), showed mean absolute errors (MAEs) of 5.42%, 8.57%, and 4.54% for predicting CAMS-%LAD, CAMS-%LCX, and CAMS-%RCA, respectively. The percent myocardial volumes predicted by ML were used to predict the CAMS-%Vsub. With 5-fold cross validation, the MAEs between ML-predicted percent myocardial volume subtended to a stenotic segment (ML-%Vsub) and CAMS-%Vsub were minimized by the elastic net (6.26% ± 0.55% for LAD, 5.79% ± 0.68% for LCX, and 2.95% ± 0.14% for RCA lesions). Using all attributes (age, sex, involved vessel segment, and angiographic features affecting the myocardial territory and stenosis degree), the ML classifiers (L2 penalized logistic regression, support vector machine, and random forest) predicted an FFR < 0.80 with an accuracy of approximately 80% (area under the curve [AUC] = 0.84-0.87, 95% confidence intervals 0.71-0.94) in the test set, which was greater than that of diameter stenosis (DS) > 53% (66%, AUC = 0.71, 95% confidence intervals 0.65-0.78). The external validation showed 84% accuracy (AUC = 0.89, 95% confidence intervals 0.83-0.95). The retrospective design, single ethnicity, and the lack of clinical outcomes may limit this prediction model's generalized application.

CONCLUSION

We found that angiography-based ML is useful to predict subtended myocardial territories and ischemia-producing lesions by mitigating the visual-functional mismatch between angiographic and FFR. Assessment of clinical utility requires further validation in a large, prospective cohort study.

Pulmonary Artery Intimal Sarcoma versus Pulmonary Artery Thromboembolism: CT and Clinical Findings

Objective

To describe CT and clinical findings of pulmonary artery intimal sarcoma (PAIS) compared with those of pulmonary thromboembolism (PTE), to investigate MRI and positron emission tomography (PET)-CT findings of PAIS, and to evaluate the effect of delayed diagnosis of PAIS on survival outcomes.

Materials and Methods

Twenty-six patients with PAIS were retrospectively identified and matched for sex, with patients with PTE at a ratio of 1:2. CT and clinical findings of the two groups were compared using Student's t test or chi-square test. The effect of delayed diagnosis on survival was investigated using Kaplan-Meier analysis.

Results

The most common tumor pattern in PAIS was tumoral impaction. Heterogeneous attenuation, wall eclipse signs, intratumoral vessels, acute interphase angles, single location, presence of lung ischemia, and central location were significantly more common in PAIS than in PTE (all p < 0.01). Levels of D-dimers and brain natriuretic peptide were lower in PAIS than in PTE (p < 0.05). In three patients of PAIS, long inversion time sequence MRI showed intermingled dark signal intensity foci suggestive of intermingled thrombi. All nine patients who had undergone PET-CT displayed hypermetabolism. Diagnosis was delayed in 42.3% of the PAIS patients and those patients had a significantly shorter overall survival than patients whose diagnosis was not delayed (p < 0.05).

Conclusion

The characteristic CT and clinical findings of PAIS may help achieve early diagnosis of PAIS and make better survival outcomes of patients. MRI and PET-CT can be used as second-line imaging modalities and could help distinguish PAIS from PTE and to plan clinical management.

Effect of pannus formation on the prosthetic heart valve: In vitro demonstration using particle image velocimetry

Although hemodynamic influence of the subprosthetic tissue, termed as pannus, may contribute to prosthetic aortic valve dysfunction, the relationship between pannus extent and hemodynamics in the prosthetic valve has rarely been reported. We investigated the fluid dynamics of pannus formation using in vitro experiments with particle image velocimetry. Subvalvular pannus formation caused substantial changes in prosthetic valve transvalvular peak velocity, transvalvular pressure gradient (TPG) and opening angle. Maximum flow velocity and corresponding TPG were mostly affected by pannus width. When the pannus width was 25% of the valve diameter, pannus formation elevated TPG to >2.5 times higher than that without pannus formation. Opening dysfunction was observed only for a pannus involvement angle of 360°. Although circumferential pannus with an involvement angle of 360° decreased the opening angle of the valve from approximately 82° to 58°, eccentric pannus with an involvement angle of 180° did not induce valve opening dysfunction. The pannus involvement angle largely influenced the velocity flow field at the aortic sinus and corresponding hemodynamic indices, including wall shear stress, principal shear stress and viscous energy loss distributions. Substantial discrepancy between the velocity-based TPG estimation and direct pressure measurements was observed for prosthetic valve flow with pannus formation.