Cardiac Computed Tomography Analysis Research Articles

Relationship between epicardial adipose tissue and ventricular fibrillation in Brugada syndrome by cardiac computed tomography analysis

Abstract Background Fibrofatty changes in the myocardium of the right ventricular (RV) to right ventricular outflow tract (RVOT) in patients with Brugada syndrome (BrS) may contribute to ventricular conduction delay and ultimately in the development of ventricular fibrillation (VF). In patients with atrial fibrillation (AF), inflammatory infiltration of epicardial adipose tissue (EAT) into the atrial muscle, along with reduced quantity and quality of EAT, has been demonstrated to be associated with the development of AF. We hypothesized that EAT in the RVOT from the RV in patients with BrS may lead to organic abnormalities in the ventricular muscle, resulting in VF. Purpose The purpose of this study was to evaluate the quantity and quality of EAT in patients with BrS using cardiac computed tomography (CT) and to determine the relationship with the occurrence of VF. Methods We retrospectively evaluated 61 of 82 patients with BrS regularly followed in our outpatient clinic from January 2000 to December 2023, who underwent cardiac CT scans. Patients were divided into two groups: those with VF events during follow-up (VF event group) and those without events (VF non-event group). Patient background, various parameters, volume of epicardial adipose tissue (EAT), and CT values from cardiac CT scans were compared between the two groups. EAT volume and CT values were measured for the entire heart and four specific regions: right ventricle (RV-EAT), right ventricular outflow tract (RVOT) to pulmonary artery bifurcation (RVOT-EAT), left ventricle (LV-EAT), and the left coronary artery main trunk circumference (LV summit-EAT) were measured for four specific sites. Results Median age at first diagnosis of BrS was 43 years, 98% were male patients, 41 patients (71%) had symptomatic BrS, and 18 patients (31%) had a family history. During a median follow-up of 72 months (30-136 months), 22 patients (38%) had VF events, including 2 arrhythmic sudden deaths. The median time from diagnosis to the first VF event was 14.3 months (4.3-24.5 months). The VF event group had more overall EAT volume (98.3 cm3 [range: 77.4 to 120.3 cm3] vs. 70.1 cm3 [range: 53.8 to 98.0 cm3], P=0.02) and significantly more RV-EAT volume (18.4 cm3 [range: 11.5 to 28.0 cm3] vs. 11.0 cm3 [range: 7.9 to 18.3 cm3], P=0.008). The CT value of RV-EAT was significantly lower in the VF event group (-83.1±6.1 vs -78.0±6.2, P=0.003), although the RV-EAT/LV-EAT density ratio was not different between the two groups (1.01±0.05 vs 0.99±0.07, P=0.14). On the other hand, the density ratio of RVOT-EAT/LV-EAT was significantly lower in the VF event group (0.95±0.08 vs. 1.00±0.08, P=0.03). Conclusions EAT analysis via CT in patients with BrS revealed that those experiencing VF events during follow-up tended to exhibit greater RV-EAT volume, lower CT values of RV-EAT, and higher CT values of RVOT-EAT density. These findings suggest EAT involvement in VF occurrence in patients with BrS.

Timing of the narrowest neoLVOT with trans-catheter mitral valve implantation, a cardiac computed tomography study

Abstract Funding Acknowledgements Type of funding sources: None. Background Trans-catheter mitral valve replacement (TMVR) procedures had emerged as an alternative solution for patients who have surgical high risk for mitral valve surgery. One of the main challenges faced during the percutaneous approach is the degree of left ventricular outflow tract (LVOT) narrowing after implanting the new percutaneous mitral prosthesis. The remaining LVOT area (NeoLVOT) can be estimated by a commercially available CT analysis software that allows the insertion of a virtual valve within the CT dataset in the native annulus and/or the degenerated bioproshesis and hence allows measurement of the NeoLVOT using the multi-planar reconstruction (MPR) mode. The systolic phase that shows the narrowest NeoLVOT is not fully understood, and hence there is a considerable variability between operators in choosing the best phase in systole at which they should insert the virtual valve within the mitral annulus in the CT dataset to measure the narrowest NeoLVOT. Purpose To detect the systolic phase that shows the narrowest NeoLVOT and hence standardize the way to use the software to decrease variability among operators. Methods A retrospective observational single center study, including 20 patients (age 62± 4 years, 70% men), who had undergone a clinically indicated cardiac computed tomography (CT). All these patients were in sinus rhythm, had no significant coronary artery disease bases on CT report, and had normal left ventricular systolic function with no regional wall motion abnormalities, we excluded patients who had previous cardiac surgeries, hypertrophic cardiomyopathy, significant pulmonary hypertension or congenital heart disease that may affect septal motion. CTs were performed using a 128 slice dual-source (Somatom Definition Flash, Siemens Healthineers, Erlangen, Germany) with a retrospective ECG-gated acquisition CT analysis was done by a single operator using the commercially available software (3mensio Structural Heart 10.3, Pie Medical Imaging, The Netherlands). Multiphase scans were used and mid-diastole (80%), early-systole (10%), mid-systole (20%), late-systole (30–40%) were identified and analysed. Measurements done were; mitral annulus (MA) antero-posterior (AP) diameter, inter-commissural (IC) diameter, annulus area (Area), annulus perimeter (Peri), aorto-mitral angel, and the NeoLVOT area. (Figure 1). Results All measurements were feasible in all phases for all patients. The neoLVOT area was significantly narrower at end-systole (224 ± 62mm²), compared to early-systole (299 ± 70mm²) & mid-systole (261 ± 75 mm²), (p = 0.005). All other measurement did not show statistically significant changes despite taking certain trends. (Figure 2). Conclusions End-systole is the cardiac phase that shows the narrowest predicted Neo-LVOT area and hence it should be the standard phase to be used during CT analysis before TMVR to predict the narrowest NeoLVOT.

Abstract 15120: Mechanistic Determinants of Atrial Functional Mitral Regurgitation

Introduction: Atrial functional mitral regurgitation (AFMR) is an increasingly recognized entity that is defined as MR in the absence of primary leaflet pathology and left ventricular dysfunction. Objectives: Identify the mechanistic determinants of AFMR by cardiac computed tomography (CT). Methods: We reviewed all consecutive CTs performed in atrial fibrillation (Afib) patients pre/post-ablation and appendage occlusion procedures starting in February 2017. We identified the first 50 patients with significant MR (≥2+) then 50 controls without MR that were age and gender-matched. Clinical and echo data were collected. A dedicated CT software (Aquarius, TeraRecon) was used to perform detailed annular measurements Results; The median age was 70.7 years, and 39% were females. There were no significant differences in baseline clinical comorbidities, including type and duration of Afib, and medication use, including rate control agents and antiarrhythmics (Table 1). On echo, patients with significant MR had larger LA volumes (mean +/- SD, 47.63 ml/m2 +/- 17.21 vs. 35.53 +/- 14.22, p<0.001) higher estimated RVSP (40.77 +/- 13.88 mmHg vs. 33.54 +/-6.92, p 0.004), and more frequent concomitant significant TR (32% vs 8%, p=0.006). On CT analysis, there were significant differences (all p<0.001) in the mitral annular measurements, including larger area, perimeter, and septo-lateral and inter-commissural distances in the MR group (Figure 1). Conclusion: Patients with Afib who develop significant AFMR have significantly larger annular and atrial sizes, higher RVSP, and more concomitant significant TR. The type and duration of Afib do not appear to be significant predictors.

Role of computed tomography in transcatheter aortic valve implantation and valve-in-valve implantation: complete review of preprocedural and postprocedural imaging.

: Since 2002, transcatheter aortic valve implantation (TAVI) has revolutionized the treatment and prognosis of patients with aortic stenosis. A preprocedural assessment of the patient is vital for achieving optimal outcomes from the procedure. Retrospective ECG-gated cardiac computed tomography (CT) today it is the gold-standard imaging technique that provides three-dimensional images of the heart, thus allowing a rapid and complete evaluation of the morphology of the valve, ascending aorta, coronary arteries, peripheral access vessels, and prognostic factors, and also provides preprocedural coplanar fluoroscopic angle prediction to obtain complete assessment of the patient. The most relevant dimension in preprocedural planning of TAVI is the aortic annulus, which can determine the choice of prosthesis size. CT is also essential to identify patients with increased anatomical risk for coronary artery occlusion in Valve in Valve (ViV) procedures.Moreover, CT is very useful in the evaluation of late complications, such as leakage, thrombosis and displacements. At present, CT is the cornerstone imaging modality for the extensive and thorough work-up required for planning and performing each TAVI procedure, to achieve optimal outcomes. Both the CT procedure and analysis should be performed by trained and experienced personnel, with a radiological background and a deep understanding of the TAVI procedure, in close collaboration with the implantation team. An accurate pre-TAVI CT and post-processing for the evaluation of all the points recommended in this review allow a complete planning for the choice of the valve dimensions and type (balloon or self-expandable) and of the best percutaneous access.

P6155Early computed tomographic evaluation for out-of-hospital cardiac arrest survivors: the CT-FIRST trial

Abstract Background Patients surviving an out-of-hospital cardiac arrest (OHCA) commonly present without an obvious etiology, but computed tomography (CT) can provide rapid, comprehensive anatomic evaluation of potential OHCA causes. Purpose To assess the diagnostic capabilities of whole body CT imaging in OHCA survivors. Methods From 11/2015 to 2/2018, the CT-FIRST (CT Feasibility In Resuscitated patient for Sudden death Triage) protocol enrolled 104 OHCA survivors without obvious OHCA cause to an early (<6 hours from hospital arrival) dual source Sudden Death CT (SDCT) scan protocol that included a non-contrast head, ECG-gated cardiac/thoracic angiography, and non-gated venous phase abdominal CT's. Cardiac CT analysis was blinded, but other SDCT findings were clinically available. Patients needing urgent cardiac catheterization or hemodynamically unable to tolerate CT were excluded. Primary endpoints were SDCT diagnosis compared to OHCA causes from adjudicated record review, and any significantly altered therapy based on SDCT. Acute coronary syndrome by SDCT was conservatively assumed if >50% stenosis was identified in major coronary artery(ies). Results SDCT scans identified 39% (41/104) of all OHCA causes and 95% (41/43) of causes potentially identifiable with SDCT (Table). No inappropriate treatments resulted from SDCT findings. SDCT changed or expedited treatments in 21/23 (95%) patients, including antibiotics, anticoagulants, and invasive evaluations or treatments. SDCT found or confirmed resuscitation complications including liver/spleen laceration (n=5), pneumothorax (n=7), and hemopericardium (n=1). N=104 OHCA Cause SDCT Diagnosis of OHCA Cause N (%) N (%) Acute coronary syndrome 13 (13%) 13 (100%) Cardiomyopathy 8 (8%) 7 (88%) Pneumonia 11 (11%) 11 (100%) Hemorrhagic stroke 3 (3%) 3 (100%) Pulmonary embolism 4 (3%) 4 (100%) Perforated viscus 2 (2%) 2 (100%) Gut necrosis 1 (1%) 1 (100%) Pulmonary hemorrhage 1 (1%) 1 (100%) Substance use 22 (21%) 0 (0%) Unknown 7 (7%) 0 (0%) Other 32 (31%) 0 (0%) Conclusion This pilot study suggests the SDCT protocol has considerable promise to diagnose OHCA causes and complications of resuscitation, as well as change clinical treatment. Acknowledgement/Funding Medic One Foundation

3255Characterization of the arrhythmogenic substrate with multimodality imaging in ischemic patients undergoing VT ablation: relationship between cardiac computed tomography and magnetic resonance

Abstract Background Cardiac magnetic resonance (CMR)-aided ventricular tachycardia (VT) substrate ablation has shown to improve VT recurrence-free survival, through a better identification of the arrhythmogenic substrate. However, the access to CMR may be limited in certain centers or sometimes Its use can be contraindicated in patients with cardiac implantable electronic device. Cardiac computed tomography (CT) has shown to improve the results of substrate ablation, correlating with low-voltage areas and local abnormal ventricular activity, and identifying ridges of myocardial tissue (CT-channels) that may be appropriate target sites for ablation. Purpose To evaluate the correlation between CT and CMR imaging in identifying anatomical heterogeneous tissue channels (CMR-channels) or CT-channels in ischemic patients undergoing VT substrate ablation. Methods The study included 30 post-myocardial infarction (MI) patients (mean age 69±10; 94% male, left ventricular ejection fraction 35±10%), who underwent both CMR and cardiac CT before VT substrate ablation. Using a dedicated post-processing software, the myocardium was segmented in 10 layers from endocardium to epicardium both for the CMR and CT, characterizing the presence of CMR-channels and CT-channels, respectively, by two blinded operators, assigned either to CMR or CT analysis. CMR-channels were classified as endocardial (CMR-channels in layer <50%), epicardial (CMR-channels in layers ≥50%) or transmural (in both endo and epicardial layers). Presence and location of CT and CMR-channels were compared. Results In 26/30 patients (86.7%) 91 CT-channels (mean 3.0±1.9 per patient) were identified while 30/30 (100%) showed CMR-channels (n=76; mean 2.4±1.2 per patient). We found 190 CT-channel entrances (mean 6.3±4.1 per patient), and 275 CMR-channel entrances (mean 8.9±4.9 per patient) on cardiac CT and CMR, respectively. There were 47/91 (51.6%) true positive CT-channels. On the contrary, 44/91 (48.4%) CT-channels were considered false positives [19/91 (20.9%) identified out of CMR scar], and 29/76 (38.2%) CMR-channels could not be identified on CT. Thirty-six out of 76 (47.4%) CMR-channels were considered as non-endocardial (epi- or transmural). Twenty-nine out of 36 (80.5%) non-endocardial CMR-channels were coincident with CT-channels. CT and CMR Channels Conclusion CT shows a modest sensitivity in identifying CMR-channels and fails in ascertain their complexity, underestimating the number of entrances; however, channels location at CT fit well with CMR for those classified as transmural or epicardial.

Added value of cardiac computed tomography for evaluation of mechanical aortic valve: Emphasis on evaluation of pannus with surgical findings as standard reference

The added value of cardiac computed tomography (CT) with transesophageal echocardiography (TEE) for evaluating mechanical aortic valve (AV) dysfunction has not yet been investigated. The purposes of this study were to investigate the added value of cardiac CT for evaluation of mechanical AVs and diagnoses of pannus compared to TEE, with surgical findings of redo-aortic valve replacement (AVR) used as a standard reference. 25 patients who underwent redo-AVR due to mechanical AV dysfunction and cardiac CT before redo-AVR were included. The presence of pannus, encroachment ratio by pannus, and limitation of motion (LOM) were evaluated on CT. The diagnostic performance of pannus detection was compared using TEE, CT, and CT+TEE, with surgical findings as a standard reference. The added value of CT for diagnosing the cause of mechanical AV dysfunction was assessed compared to TTE+TEE. In two patients, CT analysis was not feasible due to severe metallic artifacts. On CT, pannus and LOM were found in 100% (23/23) and 60.9% (14/23). TEE identified pannus in 48.0% of patients (12/25). CT, TEE, and CT+TEE correctly identified pannus with sensitivity of 92.0%, 48.0%, and 92.0%, respectively (P=0.002 for CT vs. TEE). In 11 of 13 cases (84.6%) with inconclusive or negative TEE results for pannus, CT detected the pannus. Among 13 inconclusive cases of TTE+TEE for the cause of mechanical AV dysfunction, CT suggested 6 prosthetic valve obstruction (PVO) by pannus, 4 low-flow low-gradient PVO, and one LOM without significant PVO. Cardiac CT showed added diagnostic value with TEE in the detection of pannus as the cause of mechanical AV dysfunction.

Dynamic intravenous contrast bolus in CT fluoroscopy guided biopsy

Dynamic intravenous contrast bolus in CT fluoroscopy guided biopsy