Research Presentation Session: Cardiac

RPS 2303 - Pre- and periprocedural imaging and new techniques

March 3, 09:30 - 11:00 CET

7 min
Early myocardial extracellular volume at CT imaging: prognostic value in patients undergoing transcatheter aortic valve implantation
Francesco Rizzetto, Rho / Italy
Author Block: M. L. Lampus1, F. Rizzetto2, C. B. Monti2, D. Artioli2, P. Pedrotti2, F. Musca2, A. Vanzulli2; 1Sassari/IT, 2Milan/IT
Purpose: The objective of this study was to investigate the prognostic value of early myocardial extracellular volume (eECV) at CT imaging in patients undergoing transcatheter aortic valve implantation (TAVI).
Methods or Background: Consecutive patients who underwent angio-CT examinations for TAVI procedure planning between January 2021 and December 2022 were retrospectively identified. Pre-TAVI CT scans, demographics, and death records, when present, were retrieved for each patient. Region-of-interests in the septal midventricular wall and left ventricular blood pool were delineated on axial images from unenhanced scan and venous phase (acquired 70-90 seconds after contrast injection). Myocardial eECV was calculated as the ratio between myocardium and blood pool differential attenuations, adjusted for patient hematocrit. Myocardial relative enhancement (MRE), computed as the ratio between myocardium and blood pool attenuation at venous phase, and septal wall thickness were also calculated. The correlation between eECV and MRE was assessed with Spearman's rho. Kaplan-Meier analysis and hazard ratios (HR) were used to evaluate the association of eECV and MRE with overall survival to all-cause mortality during a 30-month follow-up period.
Results or Findings: The study included 244 patients, with median (1st-3rd quartile) eECV, MRE, and septal wall thickness of 32% (29-36%), 68% (64-73%), and 15 mm (13-17 mm), respectively. A strong positive correlation was observed between eECV and MRE (rho=0.67; p<0.001). Patients with eECV≥34% had an increased risk of mortality (HR=2.7, 95% confidence interval: 1.3-5.4, p=0.006), as well as those with MRE≥74% (HR=3.3, 95% confidence interval: 1.4-7.5, p=0.005). No significant difference in demographics and septal wall thickness was observed between high- and low-risk patients.
Conclusion: Myocardial eECV and MRE obtained from venous phase CT images are associated with all-cause mortality in patients undergoing TAVI.
Limitations: The main study limitation is the retrospective single-centre design.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Institutional Review Board approved the retrospective data collection in an anonymous, aggregated form.
7 min
Interrater variability of ML-based CT-FFR during TAVR-planning: influence of image quality and coronary artery calcifications
Robin F. Gohmann, Leipzig / Germany
Author Block: R. F. Gohmann, A. Schug, C. Lücke, P. Seitz, M. Gutberlet; Leipzig/DE
Purpose: The purpose of this study was to compare machine learning (ML)-based CT-derived fractional flow reserve (CT-FFR) in patients before transcatheter aortic valve replacement (TAVR) by observers with differing training and to assess the influence of image quality and coronary artery calcium score (CAC).
Methods or Background: Patients considered for TAVR have a high prevalence of coronary artery disease (CAD). Coronary computed tomography angiography (cCTA) can effectively exclude CAD, but remains limited by its specificity. CT-FFR may mitigate this limitation also in patients prior to TAVR. While a high reliability of CT-FFR is presumed, little is known about the reproducibility of ML-based CT-FFR.
Results or Findings: CT-FFR was successfully performed on 214/272 examinations by both observers. The median difference of CT-FFR was -0.05(-0.12-0.02) (p<0.001). Differences were smaller with high values and larger with low values. Categorization into CAD was different in 37/214 examinations, resulting in a net recategorizations of Δ13 (13/214) examinations and a difference in accuracy of Δ6.1%. Categorization into CAD was independent of quantitative image quality or CAC.
Conclusion: CT-FFR values measured by two observers with different experience were different, with smaller differences of high and much larger differences of low values. Categorization into CAD was different in several patients, but only led to a small net difference and ultimately had a moderate influence on diagnostic accuracy, independently of image quality or CAC.
Limitations: Retrospective study. Assessment of coronary artery disease (CAD) is recommended prior to transcatheter aortic valve replacement (TAVR). Invasive coronary angiography (ICA) may be omitted, if significant CAD can be excluded on coronary computed tomography angiography (cCTA). Despite its high sensitivity, cCTA is limited by relatively low specificity and positive predictive value, particularly in high-risk patients. CT-derived fractional flow reserve (CT-FFR) is a promising technique with the potential to increase the diagnostic accuracy and specificity of cCTA for ruling-out CAD during pre-TAVR evaluation. However, the significance of the segmentation process and reader experience on the reliability of CT-FFR is not well investigated.
Funding for this study: No information was provided for this section by the submitter.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The local ethics committee approved the study and written informed consent was waived.
7 min
CT fluoroscopy-guided percutaneous biopsy of cardiac and pericardial masses
Patrik Rogalla, Toronto / Canada
Author Block: P. Rogalla, M. Pourafkari, B. Karasfi, S. Kandel, C. O'Brien, R. Cusimano; Toronto, ON/CA
Purpose: Multiple routes exist for obtaining tissue samples from cardio-pericardial masses (CPM), including percutaneous transvenous catheter biopsy techniques, minimally invasive methods such as mediastinoscopy and open surgical approaches. This study aims to assess the feasibility, success rate, and complications of CT-guided biopsy of CPM.
Methods or Background: Institutional Research Ethics Board approval was obtained. Twenty-four biopsies of cardio-pericardial masses and pericardial thickening were performed in 23 patients under CT-fluoroscopy guidance with or without EKG gating on a 320-slice scanner (Canon Medical Systems) under conscious sedation. 3D mapping of the coronary arteries prior to the intervention, mediastinal widening and capnothorax techniques were applied when appropriate. The clinical presentation, details of the procedure, the success rate of obtaining diagnostic tissue, and potential complications and mitigation strategies, and in-room time were recorded.
Results or Findings: Twenty-three patients (12 women, 11 men; mean age, 52.3 years) were included in this study. The CT fluoroscopy-guided procedure was successful in obtaining diagnostic tissue samples in all patients. The target lesions ranged from 1 cm of pericardial thickening to a 15 cm intrapericardial mass. Histology revealed 12 malignant and 12 benign diagnoses. One patient developed a small hemothorax, and another patient developed a small pneumomediastinum immediately post-procedure, both of which were successfully treated conservatively. Post-procedure hemopericardium or arrhythmia were not observed in any of the patients. One patient with encasing sarcomatoid mesothelioma passed away from cardiac arrest in the ICU two hours after the procedure. The mean in-room time was 34.2 min.
Conclusion: CT-guided percutaneous biopsy of cardio-pericardial masses is a safe procedure that provides an accurate diagnosis and may be considered when a histological diagnosis is crucial for clinical management decisions.
Limitations: Single-centre evaluation, no alternative sampling methods tested in comparison.
Funding for this study: No funding was obtained for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Institutional Research Ethics Board approval was obtained for this study.
7 min
Diagnostic accuracy of detecting significant mitral valve regurgitation on non-contrast thoracic CT
Benedicta Mutiara Suwita, Uxbridge / United Kingdom
Author Block: B. M. Suwita1, R. Khattar2, K. Vakalis1, W. Banya2, T. Mittal1, A. Baltabaeva1, S. Mirsadraee2; 1Harefield/UK, 2London/UK
Purpose: Previous studies suggested that mitral regurgitation (MR) is an under-diagnosed disease. Earlier detection results in appropriate management and a better prognosis. Non-contrast thoracic CT for non-cardiovascular indications may be used for mitral annulus measurement. This study aimed to assess CT markers of MR on non-contrast thoracic CT and to determine cut-off values for detecting moderate/severe MR on this modality.
Methods or Background: This is a retrospective study of adult subjects who underwent non-contrast thoracic CT and echocardiography between 2013 and 2023. Exclusion criteria were poor image quality, prior intervention on mitral/aortic valve, and >12 months period between CT and echocardiography. Using double-oblique multiplanar projects, 4 parameters were measured on the thoracic CT: mitral valve anterior-posterior (MVAP), mitral valve septal-lateral (MVSL), left ventricle anterior-posterior (LVAP) and left ventricle apical-basal diameters. The left ventricle sphericity index (LVSI) was measured by dividing LVAP and LV apical-basal. Subjects were divided into “normal”, “mild MR”, “moderate MR”, and “severe MR” categories based on echocardiography.
Results or Findings: 220 subjects were included (120 normal, 44 mild, 27 moderate, 29 severe). Kruskal-Wallis test and Bonferroni post-hoc analysis showed no statistically significant difference between the normal and mild MR. However, there is a significant difference between normal and moderate/severe MR groups in all CT parameters. Cut-off points to detect moderate/severe MR were: MVAP 41.5 mm, MVSL 37.5 mm, LVAP 72.5 mm, LV apical-basal 87.5 mm, and LVSI 0.83. The accuracy (with 95% confidence interval) for each cut-off point was: 84% (78–89%), 82% (76–87%), 78% (72–84%), 63% (55–70%) and 72% (66–79%).
Conclusion: Simple measurements on non-contrast thoracic CT can predict the presence of moderate/severe MR with good diagnostic accuracy. These results are important for early detection of undiagnosed significant MR.
Limitations: The limitations of the study are no sub-group analysis for different MR causes.
Funding for this study: No funding was provided for this study
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: The study is retrospective.
7 min
Impact of postprocedural CT evaluation of lead to valve angle on the development of cardiac implantable electrical devices related tricuspid regurgitation
Vincenzo Scialò, Milan / Italy
Author Block: A. Caracciolo, C. Lisi, F. Catapano, L. Monti, M. Francone; Milan/IT
Purpose: Research shows that direct injury from CIED leads is related to the development of tricuspid regurgitation (TR), with a prevalence of up to 40% of patients. This study aimed to explore the role of CT in identifying predictors of the development or worsening of TR secondary to CIED.
Methods or Background: 374 patients who underwent CIED implantation between January 2014 and December 2021 and had at least one chest CT after implantation and repeated transthoracic echocardiograms (TTE) were selected. The angle between the tricuspid valve plane and the lead was measured in a two-chamber view CT scan. Worsening TR was defined as an increased TR severity compared to baseline while worsening right ventricular (RV) function was defined as the new occurrence of RV dysfunction, as indicated by a tricuspid annular plane excursion (TAPSE) <18 mm. Univariate and multivariate regression analyses were performed to identify the predictors of development or TR worsening.
Results or Findings: After implantation, 169 individuals (45.18%) had new-onset or worsening TR and 60 (16.04%) had a worse RV function. Regression analysis reported that statistically significant predictors of development or worsening of TR were a lead-valve angle >90° (HR 2.03, CI 1.09-3.76; p 0.025) and worsening right ventricular function (HR 2.22, CI 1.26-3.91; p 0.006); other strongly related variables, although without a statistical significance were moderate-to-severe mitral regurgitation (HR 0.74, CI 0.47 - 1.16; p 0.184), baseline RV dysfunction (HR 1.36; CI 0.83-2.24; p 0.2).
Conclusion: Our study demonstrates that lead positioning has a significant impact on patient outcomes, with a two-fold increased risk of worsening TR when the lead-valve angle exceeds 90°. Postimplantation CT scans may help identify patients at risk of developing TR due to suboptimal lead positioning.
Limitations: No limitations were identified.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Not applicable because the study is retrospective.
7 min
Myocardial tissue characterisation with late contrast enhancement (LCE-CT) in patients presenting with acute symptoms and mild troponin rise
Davide Vignale, Milan / Italy
Author Block: D. Vignale1, A. Palmisano1, M. Gatti2, R. Faletti2, A. Esposito1; 1Milan/IT, 2Turin/IT
Purpose: This study aimed to investigate the added diagnostic value of myocardial tissue characterisation with Late Contrast Enhancement (LCE) scan in patients with acute symptoms, slight troponin increases but no acute myocardial infarction diagnosis.
Methods or Background: A total of 144 patients (M: F=80:64; median age=67, IQR 50-77) with elevated troponin but no ECG or lab signs of acute myocardial infarction were enrolled. Initial CT angiography (CTA) screened for coronary artery disease (CAD), pulmonary embolism, and thoracic aortic conditions. Those with negative CTA results underwent a low kVp LCE scan 7 min after an iodinated contrast injection to detect myocardial damage. A subset of patients with obstructive CAD underwent LCE too. Diagnoses were mostly confirmed through gold-standard methods.
Results or Findings: Median troponin was 69 ng/L (IQR 39-200; normal <14 ng/L). Out of 144 patients, 64 (44%) had CAD, two (1%) aortic syndrome, and eight (6%) pulmonary embolism. LCE was performed in the remaining 70 (49%) with negative CTA, diagnosing myocarditis in 35/70 (50%), Takotsubo in 8/70 (11%), MINOCA in 4/70 (6%), dilated cardiomyopathy in 4/70 (6%), and amyloidosis in 3/70 (4%). For 16/70 (23%), LCE was normal. Among the 27 with CAD also imaged with LCE, 12 (44%) had no LCE, four (15%) had subendocardial LCE, and 11 (41%) had transmural LCE, with 3/11 (27%) showing microvascular obstruction.
Conclusion: In patients with acute symptoms and elevated troponin but negative CTA, supplementary LCE improved diagnostic accuracy from 51% to 89% (p<0.001), mainly identifying myocarditis as the aetiology. In patients with CAD, LCE revealed different extents of myocardial damage, offering valuable insights into the severity of acute coronary syndromes.
Limitations: This study had a relatively small sample size and not all patients underwent CMR. There was also a lack of follow-up data on LCE capabilities of risk stratification.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by protocol CT-MyoC.
7 min
Feasibility of T2 mapping for the detection of myocardial injury in hypertrophic cardiomyopathy
Jiaxin Wang, Beijing / China
Author Block: S. Yang, S. Zhao, J. Wang; Beijing/CN
Purpose: This study aimed to explore the association between T2 value and myocardial injury in patients with hypertrophic cardiomyopathy (HCM).
Methods or Background: All patients underwent laboratory testing and CMR. Hs-cTnI was obtained as a marker of myocardial injury (>0.016 ng/mL). Global T2 values were quantified for three LV short-axis slices. The maximum T2 value and ConSept T2 were measured from the maximal value of 16 segments and the middle septum, respectively.
Results or Findings: In the HCM group, elevated hs-cTn I was found in 25 (20 males, 50±13 years) and normal hs-cTn I in 25 (17 males, 49±14 years). The hs-cTnI elevated group had higher T2 global, ConSept T2, T2 max, T1 global, ConSept T1 values, and LGE extent (P<0.05) than the normal hs-cTnI group. The ConSept T2 value (r=0.52, P<0.001) and LGE extent (r=0.52, P<0.001) were all moderately correlated with hs-cTnI. Among all parametric parameters, the ConSept T2 value showed the best performance in identifying myocardial injury (AUC=0.83). In multivariate logistic regression analyses, after adjusting LV ejection fraction, LV end-diastolic volume index, maximal ventricular wall thickness, LV myocardial mass index, LGE extent, T1 global, and ConSept T1 values, respectively, ConSept T2 value was still significantly associated with elevated hs-cTnI (P<0.01).
Conclusion: We confirmed the feasibility of T2 mapping for detecting myocardial injury in HCM. T2 value was associated with an elevated hs-cTnI, which provided in-vivo evidence by CMR for the ongoing myocardial injury in HCM.
Limitations: The study was conducted at a tertiary referral centre with a small sample size. Since the mapping values depend on the sequence and vendor, the results observed in our study might not be generalised to the other centres.
Funding for this study: This study was supported by grants from the National Key Research and Development Program of China (No. 2021YFF0501404, No. 2021YFF0501400) and the key projects of the National Natural Science Foundation of China (No. 81930044).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study complied with the Declaration of Helsinki and was approved by the institutional review boards of Fuwai Hospital.
7 min
Fractal analysis on CMR: trabecular complexity as a new marker to predict outcomes in patients with dilated cardiomyopathy
Xiaorui Xiang, Beijing / China
Author Block: X. Xiang, S. Yu, K. Yang, C. Cui, X. Chen, M. Lu, S. Zhao; Beijing/CN
Purpose: Trabecular complexity is a unique biometric marker like a fingerprint, but its prognostic impact in dilated cardiomyopathy (DCM) remains unclear. This study investigated the prognostic value of trabecular complexity by fractal analysis in patients with DCM.
Methods or Background: Consecutive 276 patients with DCM were enrolled in this study. Comprehensive clinical evaluation and cardiovascular magnetic resonance (CMR) imaging investigation were obtained. Trabecular complexity was quantified with fractal analysis of cine images to estimate the global, basal, and apical fractal dimensions (FD). All patients were followed up for major adverse cardiac events (MACE) of all-cause mortality, aborted sudden cardiac death, and heart transplantation.
Results or Findings: Over a 5.37-year median follow-up, 103 (37.32%) patients experienced MACE. All left ventricular FD parameters were higher in patients with events than those without events (all P<0.05). Max Basal FD emerged as the strongest MACE prognosticator among FD parameters (AUC: 0.84 [95% CI, 0.78–0.88]), and the optimal cutoff value was 1.27. Furthermore, Cox hazards analysis revealed that Max Basal FD was independently associated with MACE (HR: 1.07 per %, p=0.002) after adjustment for clinical and imaging risk factors including NT-proBNP, LVEF, and LGE presence. By Kaplan-Meier analysis, the risk of MACE increased significantly with increased Global FD, Mean Basal FD, and Max Basal FD (all log-rank p<0.001).
Conclusion: LV max basal FD was an independent predictor of adverse outcomes, and fractal analysis may contribute to improving the risk stratification for patients with DCM.
Limitations: This was a single-centre study with no genetic characterization of the subjects. Despite the limitations, it is the first study to apply Fractal Analysis to predict outcomes in DCM, demonstrating that myocardial trabecular complexity as a new marker has the potential to improve DCM risk stratification algorithms.
Funding for this study: This study was funded by the National Key Research and Development Program of China (No. 2021YFF0501400) and the Key Project of the National Natural Science Foundation of China (No. 81930044).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the hospital’s Institutional Review Board (IRB).
7 min
Computed tomography angiography reconstructed with MBIR for TAVR planning as a comprehensive tool for the assessment of coronary arteries
Cammillo Roberto Giovanni Leopoldo Oreste Massimiliano Talei Franzesi, Milan / Italy
Author Block: C. R. G. L. O. M. Talei Franzesi, C. Maino, D. G. Gandola, M. Ragusi, T. P. Giandola, P. N. Franco, R. Corso, D. Ippolito; Milan/IT
Purpose: This study aimed to evaluate the diagnostic performance of a model-based iterative algorithm (MBIR) in the assessment of coronary arteries in an angiographic-CT (CTA) study during TAVR planning.
Methods or Background: A total of 82 patients who underwent CTA for TAVR planning were included in this study. All exams were obtained using a 256-slice MDCT scanner with low-dose and low-contrast media volume CTA protocol (80 kV, 50 mL) with ECG-gated technique and reconstructed with MBIR algorithm. All coronary arteries were divided into 3 segments and evaluated in terms of image quality and contrast enhancement. Mean attenuation values (HU) of coronary arteries and thoracic aorta were calculated by drawing a manual region of interest (ROI) in the lumen of vessels.
Results or Findings: The mean attenuation value in the thoracic aorta was 478 HU and in the abdominal aorta was 447 HU. The proximal segment of the left anterior descending artery was identified and analysed in all (100%) cases, while the medium segment was identified in 89% and the distal tract only in 65%.
The proximal segment of the left circumflex artery was recognisable in 89%, the medium segment in 70%, and only in 29% it was possible to assess the distal segment. In 95% of CT scans, we were able to evaluate the proximal segment of the right coronary artery, in 79% of the medium and 52% of the distal segment.
Conclusion: Low-dose and low-contrast media volume CTA performed for TAVR planning offers important insight information on coronary status when combined with the IMR reconstruction algorithm.
Limitations: This was a retrospective and a single-centre study.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: This was a retrospective study.

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