Cardiac Computed Tomography Research Articles

Extracellular volume measured by whole body CT scans predicts chronic cardiotoxicity in breast cancer patients treated with neoadjuvant therapies based on anthracyclines: A retrospective study

IntroductionNeoadjuvant chemotherapies for breast cancer (BC) are effective but potentially cardiotoxic, and expose long survivors at risk of chemotherapy-related cardiac dysfunction (CTRCD). Unfortunately, early screening for CTRCD has actual diagnostic limits. Myocardial extracellular volume (mECV) is a radiological marker used in cardiac CT scans and cardiac magnetic resonance for diagnosis and follow-up of CTRCD. It can be measured in whole-body CT (WB-CT) scan, routinely performed in patients at high risk of relapse, to evaluate CTRCD occurrence during oncological follow-up. Methods82 WB-CT scans were examined at baseline (T0) and during oncological follow-up at first year (T1) and fifth year (T5) after the end of neoadjuvant treatment. mECV was measured at 1 min (PP) and 5 min (DP) after contrast injection. 31 echocardiograms were retrieved in T1 to perform a linear correlation between mECV and left ventricular ejection fraction (LVEF). ResultsmECV values in T0 were similar between the two groups both in PP and in DP. Significant results were found for PP values in T1 (37.0 % vs 32 %, p = 0.0005) and in T5 (27.2 % vs 31.2 %, p = 0.025). A cut-off value of 35 % in PP proved significant in T1 (OR = 12.4, p = 0.004), while mECV was inversely correlated with LVEF both in PP (adj-S = −3.54, adj-p = 0.002) and in DP (adj-S = −2.51, adj-p = 0.0002), suggesting a synergistic action with the age at diagnosis (p < 0.0001, respectively). ConclusionsWB-CT scans performed during oncological reassessment in patients at high-risk of recurrence could be used for CTRCD screening in cardiovascular low-risk patients, especially in aging patients with mECV values above 35 %.

Validation of CT in comparison to TEE in routine workflow for detection of LAA thrombus in patients under oral anticoagulation presenting for left atrial ablation

Abstract Background Left atrial (LA) thrombus in patients (pts) presenting for LA ablation is an absolute contraindication to ablation. Although thrombi can still form despite the use of oral anticoagulation (OAC) in advance of the procedure. Transesophageal echocardiography (TEE) has been considered the gold standard for LAA thrombus detection. Additional cardiac computer tomography (CT) is often performed in pts with persistent atrial fibrillation (AF) or atrial tachycardia (AT). The aim of the study was in routine workflow 1) to identify the incidence of LAA thrombi in TEE and CT, 2) to search for an association in detecting LAA thrombi in the 2 methods and 3) to find out if the LAA flow velocity/ LA volume influences the thrombus detection. Methods Between 05/2018 and 10/2023 patients with AF/AT under OAC which were scheduled for a LA ablation were included. TEE and CT searching for LAA thrombus were carried out at intervals of up to 7 days. LAA flow velocity measured in the TEE. The LA volume which included LAA and excluded the pulmonary veins were obtained from the CT at the end-systole. Results Patients characteristics: 283 pts were included, mean age of 66y (+9y), 182 male, mean CHA2DS2-VASc score 3 [0-7]. All patients, mostly on NOACs (n=265), were orally anticoagulated. Mean LA volume (LA + LAA) was 158 ml (+45ml), LAA flow velocity was reduced (&amp;lt; 40 cm/s) in 119 pts (42%). In the majority of cases (73%), TEE and CT were performed at the same day or with an interval of 1 day. In 16 pts a LAA thrombus was detected using TEE,42 pts had SEC/Sludge but no solid thrombus. An LAA thrombus in the CT was described in 26 pts (10%), 6% couldn't definitively diagnose thrombi due to contrast recesses/flow phenomena in 16 pts. In 8 out of 34 events (23%) TEE and CT agreed on the diagnosis of a thrombus, in 6 cases during same-day examinations. 18 pts: LAA thrombus on CT, not on TEE (mean interval: 2d). 8 pts: LAA thrombus on TEE, not on CT (mean interval: 1.5d). In 71% (200 out of 283) of cases, CT and TEE agreed in ruling out a thrombus (p=0.358). LAA flow velocity and thrombus verification by TEE showed a significant correlation (p &amp;lt; 0.001). No correlation was found between the presence of a thrombus on CT and LA volume (p= 0.964). Discussion In 12% of the patients, all treated with OAC, a thrombus was described in at least one of the examinations or in both. Only in one out of four pts TEE and CT agreed on the diagnosis of a thrombus. It was notable that both examinations excluded thrombi in 70%. LAA flow velocity and thrombus verification in the TEE are significant correlated. LA volume and thrombus notification in CT are not related. Conclusion Routine diagnosis of LAA thrombus remains challenging, with frequent discrepancies between TEE, the gold standard, and CT. TEE results depend on the examining physician, while CT is limited by flow phenomena and scan timing.

Scar tissue characterization to predict arrhythmia recurrence in patients undergoing ventricular tachycardia ablation: cardiac computed tomography compared with cardiac magnetic resonance

Abstract Background The role of imaging in evaluating patients undergoing ventricular tachycardia (VT) ablation is crucial for planning, procedural success, and clinical outcomes. In daily practice, cardiac computed tomography (CCT) assessing wall thinning and late iodine uptake (LI) and cardiac magnetic resonance (CMR) assessing late-gadolinium enhancement (LGE) are most commonly implemented. However, data comparing the two imaging modalities for scar tissue characterization is scarce. Aims To compare the performance of both imaging modalities for scar tissue characterization in ischemic (ICM) and non-ischemic (NICM) patients undergoing VT ablation and predict procedural outcomes. Methods In a retrospective analysis, consecutive patients undergoing both CCT and LGE-CMR before scheduled VT ablation were included. The presence and extent of scar was assessed by means of each imaging modality using dedicated softwares (MUSIC and ADAS). To compare scar distribution and agreement between the two modalities, a scar classification scheme was used for all 17 AHA segments: 0 points (no scar present), 1 point (scar &amp;lt;50% of total segment area), 2 points (scar representing 50-99% of total segment area) or 3 points (scar present in 100% of the segment area).&amp;lt;scar&amp;lt;100%)&amp;gt;&amp;lt;scar&amp;lt;100%&amp;gt; Results 36 patients (67±10 years; 97% male; LVEF 39±10%; 72% ischemic) undergoing CCT and LGE-CMR before scheduled VT ablation were included. In the ICM group, mean detected scar burden was higher than in the NICM group on LGE-CMR (total volume: 62.3±32.9g vs. 32.8±9.5g, p&amp;lt;0.001), using wall thinning model (WT)(mean scar area 69.0±45.6 cm2 vs. 23.4±23.6cm2, p=0.005) as well as LI (dense scar area: 39.2±28.1 cm2 vs. 11.0±6.3 cm2 , p=0.005). The absolute score difference per segment and patient between CCT and LGE-CMR was calculated and summed for all patients divided by the number of patients. Differences were more pronounced for NICM compared to ICM and LGE-CMR showed better concordance to LI than WT in both NICMP and ICM (Figure). Total procedure time was 205±68 min (ablation time 28±16 min; fluoroscopy time 15 ± 12 min). During a follow-up period of 19±7 months, 87 sustained VT episodes in 12 patients (33%) were documented. Three patients (8%) underwent a second VT ablation and one patient (3%) died during follow-up. In ICM, total scar volume on LGE-CMR and scar area on LI showed numerically higher predictive value for VT recurrence than total scar area by means of WT (AUC: LGE 0.76, LI 0.78 and WT 0.65 respectively), while in NICM scar characterization by means of WT yielded higher performance to predict VT recurrence than LI or LGE-CMR (AUC: LGE 0.67, LI 0.58, WT 0.83 respectively). Conclusions In patients undergoing VT ablation, both LGE-CMR and CCT are valuable for scar tissue characterization. Late iodine uptake on CCT showed a high concordance with LGE-CMR in both NICM and ICM.&amp;lt;/scar&amp;lt;100%&amp;gt;&amp;lt;/scar&amp;lt;100%)&amp;gt;

Volumetric quantification of epicardial fat using semiautomated atrial CT segmentation in patients with atrial fibrillation: the Prospective AFAT study

Abstract Background Epicardial fat or epicardial adipose tissue (EAT) is most commonly defined as adipose tissue between the myocardium and the visceral pericardium. Previous studies have suggested EAT to be an important contributor to the pathogenesis of atrial fibrillation (AF) as well as a plausible predictor for AF recurrences after ablation. However, data on EAT using precise volumetric quantification is limited. Methods and Results AFAT is a prospective observational study conducted at a heart centre in our city with 200 patients aimed to be included. We conducted an interim analysis of the first 75 patients enrolled in the AFAT study. All patients received delayed dual source cardiac computer tomography (CT) imaging which was analysed using semi-automated 3D segmentation (Figure 2) to quantify left atrial (LA) and right atrial (RA) EAT prior to ablation (52.5 % persistent AF). The mean age was 67 ± 8.7 years with 46.9 % (n=35) being female. Mean BMI was 28 ± 4.5. The Mean LA EAT was 33.1 ml ± 13.2 ml and RA EAT was 32.7 ml ± 12.2ml. Median follow up after AF catheter ablation was 163 days. The optimal cut point for the total atrial EAT was estimated at 50.2 ml. In patients with total atrial EAT ≤ 50 ml recurrence of any atrial arrythmia after catheter ablation occurred in 8% (6 patients) compared to 25.3% (19 patients) recurrence rates in patients with a total atrial EAT &amp;gt; 50 ml. Kaplan-Meyer estimates showed no statistical difference between groups (log rank p=0.063) as this analysis is under-powered with more patients being enrolled for the final results (Figure 1). Conclusion The use of semi-automated CT based atrial segmentation presents a novel highly accurate and reproducible method to reliably identify atrial EAT. Increased atrial EAT is likely to play an important role for arrythmia recurrences after catheter ablation. Final results of the AFAT study will provide further evidence to this important subject.Arrhythmia recurrences depending on EATBiatrial 3D Segmentation of EAT

Left atrial strain defines functional and structural remodeling in patients with persistent atrial fibrillation

Abstract Background Left atrial (LA) strain is an echocardiographic method to detect atrial dysfunction as a process of structural and functional remodeling of the atria. In patients with persistent atrial fibrillation (AF), functional changes and an enlargement of the LA due to structural remodeling has been described. The aim of our study was 1) the echocardiographic assessment of LA function using LA strain and 2) to investigate the correlation between LA strain and left atrial size index (LAVI) using 3D reconstruction of the LA from multi-detector computed tomography (CT). Methods This study includes patients with persistent AF who underwent LA catheter ablation without prior treatment. All subjects underwent measurement of reservoir (LASr), conduit (LAScd) and contraction (LASct) LA strain using imaging using two-dimensional speckle tracking echocardiography (2D-STE) and cardiac CT. A 3D reconstruction of the LA from the CT was done using EnSite Verismo (Abbott, USA). The LA volume obtained at the end-systole included LA appendage reconstruction and excluded the pulmonary veins. LAVI was calculated by dividing LA volume by body surface area. Results The study included 36 patients (mean age 69 yrs [49 to 80 yrs], 27 male, mean LV-EF 56% [40 to 78%). We found the following LA strain measurement: mean LASr 21% [6 to 52%], mean LAScd -12% [-32 to -0,25%] and mean LASct -9% [-32 to -1%]. LAVI: mean 82 ml/m² [38 to 127 ml/m²]. There is a statistically significant negative correlation between LASr (p = 0.002, r = -0.503) and a statistically positive correlation between LASct (p = 0.003, r = 0.482) compared to the LA volume, whereas there is no statistically significant correlation between LAScd and the LA volume (p = 0.088, r = 0.288). Discussion LA strain in patients with persistent AF as an expression of functional remodeling is reduced compared to normal values in literature. Correlation of LA strain and LAVI are statistically significant for LASr as well as LASct. The correlation between LAScd and LAVI did not reach statistical significance but shows a trend towards a positive correlation. Whether early treatment of AF could prevent further fibrotic remodeling with reducing LA volume and improving LA strain needs further research.

Association between left atrial wall thickness and residual potential after first-pass pulmonary vein isolation using very high-power short-duration ablation in patients with atrial fibrillation

Abstract Background In this study, we evaluated efficacy, efficiency, and safety of pulmonary vein isolation (PVI) applying vHPSD ablation strategy in patients with atrial fibrillation (AF) and explored the association between left atrial wall thickness (LAWT) and the residual potential after first-pass PVI. Methods Between April 2, 2023 and October 6, 2023, drug refractory symptomatic AF patients who underwent AF ablation using vHPSD ablation strategy with QDOT MICRO catheter were prospectively enrolled. All patients took cardiac computed tomography (CT) a day before procedure. Using CT image, LAWT map was created. PV segments were categorized into prespecified 14 segments, and LAWT of each segment, segments with residual potential (RP) after first-pass PVI and early reconnection after 20-minute waiting after PVI were evaluated. Total procedure time, ablation time for PVI, and occurrence of procedure-related complication were collected. Results A total of 40 patients were included (mean age 64 years, 45% of persistent AF). Additional ablation other than PV was performed in 48% of patients, total procedure time was 77 minutes, and total PVI time was 9.9 minutes. With vHPSD PVI, all PVs first pass isolation rate was 60%; in terms of per PV, RSPV first-pass isolation was 88%, followed by LSPV and LIPV 85%, RIPV showed lowest first-pass isolation rate, 75% (Figure A). Most common RP sites was right carina, followed by left carina (Figure A). Compared to historical comparator, vHPSD PVI showed shorter procedure time, shorter ablation time for PVI, with numerically lower but statistically comparable first-pass PVI rate (Figure B). In total 560 PV segments in 40 patients, RSPV anterior, left carina, and right carina showed higher prevalence to be thick PV segments (over 60% of patients), followed by RPSV posterior, LSPV posterior, and RIPV anterior (over 40% of patients). Looking into ablation parameter detail, mean contact force was 10g, mean temperature was 47°C, and mean impedance drop was 8.4Ω. Compared to segments without RP, segments with RP showed thicker mean left atrial wall thickness grades, lower minimum contact force, higher maximum temperature, and lower minimum impedance drop. According to the left atrial wall thickness, thick PV segments showed higher prevalence of RP after first-pass PVI with vHPSD ablation. In segments with LAWT grade 3 or more, the RP rate was 9.1%. This thickness means thicker than 1.5 to 2.0 mm of thickness (Figure C). In 10% of patients (n=4) had audible or tactile steam-pops, visible char was confirmed in 5% of patients (n=2). There were no clinical complications. Conclusion PVI using vHPSD achieved shorter procedure time, shorter ablation time for PVI, and comparable first-pass PVI rate compared to historical comparator using ablation-index guided conventional power ablation. Thick segments had higher chance to have residual potential after first-pass PVI with vHPSD.

Management of peri-device leaks after left atrial appendage closure using endovascular coils and/or amplatzer plugs and radiofrequency ablation

Abstract Background Peri-device leaks (PDLs) after left atrial appendage closure (LAAC) portend a higher residual risk of thromboembolism in patients with Atrial Fibrillation (AF). Therefore, closure of PDLs has evolved as a procedural strategy to mitigate this residual thromboembolic risk. Objective To present our procedural experience and outcome data in patients who underwent PDL-closure after prior LAAC. Methods We performed a retrospective review of patients with follow-up imaging data (either transesophageal echocardiograms or Cardiac CT scans) performed at ∼1 year after LAAC between the time-period 5/2015 – 10/2022 to assess PDLs. Results We included a total of 532 patients with follow-up imaging data. At a mean follow up of 696±359 days post-LAAC, 63 of 532 (11.8%) patients underwent PDL closure. These PDL closure cohort was age 73.1±9.5 years, 41 of 62 (65%) had paroxysmal AF, and the CHA2DS2-Vasc was 3.7±1.5. In 42 of 62 (67.7%) patients, the initial LAAC device was Watchman, and in 21 (33.8%) patients, it was Watchman-FLX. Of the PDL closure cohort, 8 of 62 (12.9%) had a post-LAAC thromboembolic event (transient ischemic attack [TIA], stroke or systemic embolism). The PDL size was 3.8±2.0 mm. PDL closure was performed using endovascular coils alone in 23 (37.1%), plugs (Amplatzer devices, Abbott) alone in 18 (29%), and combinations of both in 13 (19.4%) patients. In 8 (14.5%) patients, radiofrequency ablation was used in concert with both coils and plugs (Figure). There was only 1 complication (pericardial effusion drained percutaneously) during the PDL closure procedure. During follow-up post-PDL closure, no patient sustained a stroke and only 1 patient had a TIA (Table). Conclusions Our data indicate that PDL closure after LAAC is feasible and safe, with a low risk of procedural complications. Such a strategy can be used in a subset of high-risk patients with PDL after LAAC who are at an elevated residual risk of thromboembolism.Table summarizing procedural strategies

Spatial relationship between left peri-atrial fat with underlying arrhythmogenic substrate in patients with atrial fibrillation - innocent bystander or culprit?

Abstract Introduction Peri-atrial fat may have pro-inflammatory and pro-fibrotic effects on atrial myocardium and increase the risk of developing atrial fibrillation. Consistent with prior evidence, we have previously shown that peri-atrial fat volume, but not fat attenuation (an imaging biomarker of inflammation), was associated with prevalent atrial fibrillation. Whether this association is secondary to "outside-to-inside" tissue cross talk with local adverse electrical remodelling of adjacent atrial cardiomyocytes is not known. Purpose In this novel proof of concept study, we aimed to identify a spatial relationship between left peri-atrial fat and potentially arrhythmogenic substrate (low voltage areas and slow conduction pathways) in the left atrial myocardium. Methods Contrast-enhanced cardiac computed tomography (CT) imaging and electroanatomic mapping, during coronary sinus pacing, were performed pre-ablation in atrial fibrillation patients (n=27). The left atrium and surrounding peri-atrial fat were segmented and quantified using seg3D2 and CEMRGapp. We performed registration of the electroanatomic map onto the CT-derived left atrial mesh using OpenEP and EP Workbench. Mean fat volume and attenuation around each electroanatomic point (within a 3mm radial region of interest) were correlated with local voltage and conduction velocity. Results A total of 24,839 electroanatomic points were registered onto the 3D CT-derived left atrial mesh, with a median of 935 points (range 673 to 1150) per patient. The average bipolar voltage and conduction velocity in the left atrium was 1.92±1.91 mV and 0.66±0.47 ms-1 respectively. In comparison to areas with little/no surrounding periatrial fat (Quartile 1, ≤0.93 mm3 fat per electroanatomic point), areas with the highest burden of fat (Quartile 4, ≥17.6 mm3) had significantly lower bipolar voltage (1.69±1.7 vs 2.09±2.0 mV, p&amp;lt;0.001) and conduction velocity (0.627±0.43 vs 0.700±0.47 ms-1, p&amp;lt;0.001). However, the overall correlation between periatrial fat volume with bipolar voltage (r=-0.06, p&amp;lt;0.001) and conduction velocity (r=-0.07, p&amp;lt;0.001) was weak. High, not low, fat attenuation (Quartile 4; &amp;gt;-46.5HU vs Quartile 1; ≤-75.5HU) was associated with increased bipolar voltage (2.23±2.1 vs 1.63±1.6 mV) and conduction velocity (0.703±0.42 vs 0.623±0.39 ms-1 respectively). Conclusion There is a weak correlation between periatrial fat and localized adverse electrical remodelling. The relationship between fat attenuation and electrophysiological properties was inverted. These findings confirm an association between peri-atrial fat burden but call question as to whether peri-atrial fat inflammation is implicated in atrial fibrillation pathogenesis.

Associations between atrial epicardial fat quantified by semi-automated CT segmentation and gender, BMI, cholesterol levels in AF patients: results from the prospective AFAT study

Abstract Background Epicardial adipose tissue (EAT) is defined as adipose tissue (epicardial fat) between the myocardium and the visceral pericardium. Recent evidence suggests that EAT may play important roles in regard to atrial fibrillation (AF) burden as well as other cardiovascular diseases through complex inflammatory mechanisms. Current evidence regarding the relationship of atrial EAT and BMI, gender or cardiovascular risk factors is mixed. Methods and Results We conducted a prospective observational study (AFAT) at the German Heart centre in Munich with 200 patients aimed to be included. This represents an interim analysis of the first 75 patients enrolled in the AFAT study. All patients received delayed dual source cardiac computer tomography (CT) imaging which was analysed using 3D segmentation (Figure 1) to quantify left atrial (LA) and right atrial (RA) EAT prior to receiving catheter ablation for AF. The mean age was 67 ± 8.7 years with 46.9 % being female (n=35) and the mean BMI was 28 ± 4.5. Mean LA EAT was 33.1 ml ± 13.2 ml and RA EAT was 32.7 ml ± 12.2ml with a total mean atrial EAT volume of 65.4 ml ± 10.2 ml. Volumes of the left- and right atrial EAT were significantly correlated in our sample (p &amp;lt; 0.001; Pearson correlation coefficient r=0.9). The mean total EAT Volume was significantly larger in males than in females (74 ml vs. 52 ml, p &amp;lt; 0.001) (Figure 2). Linear regression analysis adjusted for cofounders demonstrated significantly larger mean atrial EAT volumes in patients with higher body mass index (p = 0.001) and with increased age (p=0.006). Increased HbA1c levels or increased total cholesterol levels were not associated with higher total atrial EAT Levels (respectively, p=0.066 and p=0.22). Conclusion Semi-automated CT based atrial segmentation is a novel highly accurate and reproducible way to reliably identify atrial EAT. Left and right atrial EAT volumes are significantly intercorrelated. In this study BMI, Age and male gender were independently associated with higher EAT levels.Visualization of atrial EATGender differences in atrial EAT (ml)

Computed tomography as a predictive tool for ventricular tachycardia

Abstract Background Sudden cardiac death is the main cause of mortality worldwide. It is often linked with ventricular tachycardia (VT). To prevent VT, high-risk patients are typically equipped with intracardiac defibrillators (ICDs). Currently, left ventricular ejection fraction (LVEF) is the standard for determining a patient's risk level. Objective We hypothesized that the use of imaging software analyzing cardiac CT-scans could enhance the detection of patients with an increased risk of VT. Methods and Results In this study, 132 patients with ischemic cardiomyopathy (average age 66.2±11.4 years, with an average LVEF of 36.6±10.3%), all with implanted cardiac devices, underwent CT scans. We developed software to automatically analyze the heart's wall tissue thickness, cardiac fat, and calcification levels (Figure.1.A). A viable cardiac wall thickness of less than 3mm typically indicates a ventricular wall predominantly composed of scar tissue with minimal viable tissue remaining. In contrast, a viable wall thickness of less than 5mm includes regions with more viable tissue and therfore represents the total scar. Over an average follow-up of 6.6 years (79.8 ± 30.5 months) via live telemedicine, we observed that patients with VT had a significant difference in wall thickness ratio (3mm/5mm; no VT 0.31±0.18 vs, VT 0.44±0.18, p&amp;lt;0.01)) and higher calcification (0.10±0.38ml vs. 0.47±1.57ml, p=0.039). The amount of cardiac fat did not significantly differ between the no VT and VT groups (1.14±1.38ml vs.1.21±1.01ml, p=0.771). Logistic regression determined a critical cutoff for wall thickness at a ratio of 0.3 for 3mm and 5mm thickness. Kaplan Meyer analysis contrasted this wall thickness ratio of 0.3 (figure.1.B) against the established LVEF threshold of 35% (figure.1.C) for predicting VT-free survival, revealing a notable disparity favoring wall thickness ratio (p&amp;lt;0.01) over LVEF (p=0.77). Conclusions The findings suggest that a higher proportion of regions of thin viable tissue or dense scar in the total scar is a more effective predictor of VT-free survival than LVEF, potentially improving the identification of patients at risk for sudden cardiac death.Figure. 1

Computed tomography imaging in preprocedural planning of transcatheter valvular heart interventions.

Cardiac Computed Tomography (CCT) has become a reliable imaging modality in cardiology providing robust information on the morphology and structure of the heart with high temporal and isotropic spatial resolution. For the past decade, there has been a paradigm shift in the management of valvular heart disease since previously unfavorable candidates for surgery are now provided with less-invasive interventions. Transcatheter heart valve interventions provide a real alternative to medical and surgical management and are often the only treatment option for valvular heart disease patients. Successful transcatheter valve interventions rely on comprehensive multimodality imaging assessment. CCT is the mainstay imaging technique for preprocedural planning of these interventions. CCT is critical in guiding patient selection, choice of procedural access, device selection, procedural guidance, as well as allowing postprocedural follow-up of complications. This article aims to review the current evidence of the role of CCT in the preprocedural planning of patients undergoing transcatheter valvular interventions.

Complete Transposition of the Great Arteries in the Pediatric Field: A Multimodality Imaging Approach.

The complete transposition of the great arteries (C-TGA) is a congenital cardiac anomaly characterized by the reversal of the main arteries. Early detection and precise management are crucial for optimal outcomes. This review emphasizes the integral role of multimodal imaging, including fetal echocardiography, transthoracic echocardiography (TTE), cardiovascular magnetic resonance (CMR), and cardiac computed tomography (CCT) in the diagnosis, treatment planning, and long-term follow-up of C-TGA. Fetal echocardiography plays a pivotal role in prenatal detection, enabling early intervention strategies. Despite technological advances, the detection rate varies, highlighting the need for improved screening protocols. TTE remains the cornerstone for initial diagnosis, surgical preparation, and postoperative evaluation, providing essential information on cardiac anatomy, ventricular function, and the presence of associated defects. CMR and CCT offer additional value in C-TGA assessment. CMR, free from ionizing radiation, provides detailed anatomical and functional insights from fetal life into adulthood, becoming increasingly important in evaluating complex cardiac structures and post-surgical outcomes. CCT, with its high-resolution imaging, is indispensable in delineating coronary anatomy and vascular structures, particularly when CMR is contraindicated or inconclusive. This review advocates for a comprehensive imaging approach, integrating TTE, CMR, and CCT to enhance diagnostic accuracy, guide therapeutic interventions, and monitor postoperative conditions in C-TGA patients. Such a multimodal strategy is vital for advancing patient care and improving long-term prognoses in this complex congenital heart disease.

Automatic 3D left atrial strain extraction framework on cardiac computed tomography

Background and objectiveStrain analysis provides insights into myocardial function and cardiac condition evaluation. However, the anatomical characteristics of left atrium (LA) inherently limit LA strain analysis when using echocardiography. Cardiac computed tomography (CT) with its superior spatial resolution, has become critical for in-depth evaluation of LA function. Recent studies have explored the feasibility of CT-derived strain; however, they relied on manually selected regions of interest (ROIs) and mainly focused on left ventricle (LV). This study aimed to propose a first-of-its-kind fully automatic deep learning (DL)-based framework for three-dimensional (3D) LA strain extraction on cardiac CT. MethodsA total of 111 patients undergoing ECG-gated contrast-enhanced CT for evaluating subclinical atrial fibrillation (AF) were enrolled in this study. We developed a 3D strain extraction framework on cardiac CT images, containing a 2.5D GN-U-Net network for LA segmentation, axis-oriented 3D view extraction, and LA strain measure. The segmentation accuracy was evaluated using Dice similarity coefficient (DSC). The model-extracted LA volumes and emptying fraction (EF) were compared with ground-truth measurements using intraclass correlation coefficient (ICC), correlation coefficient (r), and Bland-Altman plot (B-A). The automatically extracted LA strains were evaluated against the LA strains measured from 2D echocardiograms. We utilized this framework to gauge the effect of AF burden on LA strain, employing the atrial high rate episode (AHRE) burden as the measurement parameter. ResultsThe GN-U-Net LA segmentation network achieved a DSC score of 0.9603 on the test set. The framework-extracted LA estimates demonstrated excellent ICCs of 0.949 (95 % CI: 0.93–0.97) for minimal LA volume, 0.904 (95 % CI: 0.86–0.93) for maximal LA volume, and 0.902 (95 % CI: 0.86–0.93) for EF, compared with expert measurements. The framework-extracted LA strains demonstrated moderate agreement with the LA strains based on 2D echocardiography (ICCs >0.703). Patients with AHRE > 6 min had significantly lower global strain and LAEF, as extracted by the framework than those with AHRE ≤ 6 min. ConclusionThe promising results highlighted the feasibility and clinical usefulness of automatically extracting 3D LA strain from CT images using a DL-based framework. This tool could provide a 3D-based alternative to echocardiography for assessing LA function.

Relationship Between Clinical Parameters and Histological Features of Epicardial Adipose Tissue and Aortic Valve Calcification Assessed on Computed Tomography.

The relationships of the clinical and biological attributes of epicardial adipose tissue (EAT) with aortic valve calcification (AVC) have not been characterized. We evaluated the relationships of the clinical and histological features of EAT with AVC assessed using computed tomography (CT).Methods and Results: We enrolled 43 patients undergoing cardiac CT examination prior to elective cardiac surgery in whom AVC was identified on CT. EAT volume and density, coronary calcium score (CCS), AVC score (AVCS), and coronary atherosclerosis on CT angiography were evaluated in each patient. During cardiac surgery, 2 EAT samples were obtained for immunohistochemistry. The number of CD68- and CD11c-positive macrophages and osteocalcin-positive cells was counted in 6 random high-power fields of EAT sections. EAT density, but not EAT volume normalized to body surface area, was positively correlated with the number of macrophages and osteocalcin-positive cells in EAT. There was a positive correlation between ln(AVCS), but not ln(CCS+1), and the number of macrophages and osteocalcin-positive cells in EAT. Multivariate analysis revealed significant positive correlations for ln(AVCS) with EAT density (β=0.42; P=0.0072) and the number of CD68-positive macrophages (β=0.57; P=0.0022), CD11c-positive macrophages (β=0.62; P=0.0003), and osteocalcin-positive cells (β=0.52; P=0.0021) in EAT. Inflammation and osteogenesis in EAT, reflected by high CT density, are associated with the severity of AVC representing aortic valve degeneration.

Diagnostic performance of unenhanced electrocardiogram-gated cardiac CT for detecting myocardial edema.

To assess the diagnostic performance of unenhanced electrocardiogram (ECG)-gated cardiac computed tomography (CT) for detecting myocardial edema, using MRI T2 mapping as the reference standard. This retrospective study protocol was approved by our institutional review board, which waived the requirement for written informed consent. Between December 2017 to February 2019, consecutive patients who had undergone T2 mapping for myocardial tissue characterization were identified. We excluded patients who did not undergo unenhanced ECG-gated cardiac CT within 3 months from MRI T2 mapping or who had poor CT image quality. All patients underwent unenhanced ECG-gated cardiac CT with an axial scan using a third-generation, 320 × 0.5 mm detector-row CT unit. Two radiologists together drew regions of interest (ROIs) in the interventricular septum on the unenhanced ECG-gated cardiac CT images. Using T2 mapping as the reference standard, the diagnostic performance of unenhanced cardiac CT for detecting myocardial edema was evaluated by using the area under the receiver operating characteristic curve with sensitivity and specificity. Youden index was used to find an optimal sensitivity-specificity cutoff point. A cardiovascular radiologist independently performed the measurements, and interobserver reliability was assessed using intraclass correlation coefficients for CT value measurements. A P value of <.05 was considered statistically significant. We included 257 patients who had undergone MRI T2 mapping. Of the 257 patients, 35 patients underwent unenhanced ECG-gated cardiac CT. One patient was excluded from the study because of poor CT image quality. Finally, 34 patients (23 men; age 64.7 ± 14.6 years) comprised our study group. Using T2 mapping, we identified myocardial edema in 19 patients. Mean CT and T2 values for 34 patients were 46.3 ± 2.7 Hounsfield unit and 49.0 ± 4.9 ms, respectively. Mean CT values moderately correlated with mean T2 values (Rho = -0.41; P < .05). Mean CT values provided a sensitivity of 63.2% and a specificity of 93.3% for detecting myocardial edema, with a cutoff value of ≤45.0 Hounsfield unit (area under the receiver operating characteristic curve = 0.77; P < .01). Inter-observer reproducibility in measuring mean CT values was excellent (intraclass correlation coefficient = 0.93; [95% confidence interval: 0.86, 0.96]). Myocardial edema could be detected by CT value of myocardium in unenhanced ECG-gated cardiac CT.

Delayed Enhancement in Cardiac CT: A Potential Alternative to Cardiac MRI? Technical Updates and Clinical Considerations

Despite cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) being the current gold standard for non-invasive myocardial characterization and fibrosis quantification, its accessibility is limited, particularly in acute settings and in certain patient populations with contraindications to magnetic resonance imaging. Late iodine enhancement (LIE) in computed tomography (CT) imaging has emerged as a potential alternative, capitalizing on the similarities in the contrast kinetics between gadolinium and iodinated contrast agents. Studies have investigated LIE-CT’s effectiveness in myocardial infarction (MI) detection, revealing promising outcomes alongside some disparities compared to LGE-CMR. LIE-CT also proves beneficial in diagnosing non-ischemic heart diseases such as myocarditis, hypertrophic cardiomyopathy, and sarcoidosis. While LIE-CT demonstrates good accuracy in detecting certain myocardial pathologies, including acute MI and chronic fibrotic changes, it has limitations, such as the inability to detect diffuse myocardial enhancement. Nonetheless, thanks to the availability of optimized protocols with minimal radiation doses and contrast medium administration, integrating LIE-CT into cardiac CT protocols could enhance its clinical utility, particularly in acute settings, providing valuable prognostic and management insights across a spectrum of cardiac ischemic and non-ischemic conditions.

Four-dimensional computed tomography is useful for detection of apical sparing of cardiac amyloidosis.

A 73-year-old male was admitted because of recurrent syncope. He was diagnosed with transient bradycardia caused by a 2:1 atrioventricular block, and he underwent cardiac computed tomography (CT) using 320 detector-row CT to screen for coronary artery disease. Significant coronary artery stenosis was not detected, but diffuse late iodinate enhancement was found on the epi-myocardium and endo-myocardium of the interventricular septum, and endo-myocardium of the anterior and lateral left ventricular (LV) myocardium (LVM) on CT. The ejection fraction and global longitudinal strain (LS) of LVM were 53.97% and - 9.87% on CT. Apical sparing was present, meaning the LS of LV apical segments were preserved compared with basal segments on CT. Pathological findings of LVM demonstrated loss of myocardial cells and extra-cellular amyloid deposition on the direct fast scarlet staining. He was finally diagnosed with transthyretin amyloidosis.

Long-Term Clinical Implications of High-Risk Cardiac Computed Tomography Findings in Patients With Acute Ischemic Stroke.

Cardiac computed tomography (CT) acquired during the initial acute stroke imaging protocol (acute cardiac CT) is increasingly used to screen for cardioembolism, but information on the long-term clinical implications of its findings is lacking. We performed a prospective, single-center cohort study in which consecutive patients with ischemic stroke underwent ECG-gated acute cardiac CT and were followed up for 2 years. The primary outcome was functional outcome assessed using the modified Rankin Scale. Secondary outcomes were death and occurrence of major adverse cardiovascular events (composite of recurrent ischemic stroke, myocardial infarction, and cardiovascular death). We compared patients with and without a high-risk structural source of embolism on acute cardiac CT. Of 452 included patients, 55 (12.2%) had a high-risk source of embolism, predominantly cardiac thrombi (38 patients) and signs of endocarditis (8 patients). Follow-up at 2 years was complete for 430 (95.1%) patients. Patients with a high-risk source of embolism had a worse functional outcome (median modified Rankin Scale, 6 [IQR, 2-6] versus 2 [IQR, 1-5]; adjusted common odds ratio, 2.92 [95% CI, 1.62-5.25]), increased mortality rate (52.7% versus 23.7%; adjusted hazard ratio [HR], 3.28 [95% CI, 1.94-5.52]), and major adverse cardiovascular events (38.9% versus 17.5%; adjusted HR, 3.20 [95% CI, 1.80-5.69]). A high-risk source of embolism was not associated with recurrent ischemic stroke (11.1% versus 9.6%; adjusted HR, 1.30 [95% CI, 0.49-3.44]). Structural high-risk sources of embolism on acute cardiac CT in patients with ischemic stroke were associated with poor long-term functional outcome and occurrence of major adverse cardiovascular events but not with recurrent stroke.

Pre- and post-procedural cardiac imaging (computed tomography and magnetic resonance imaging) in electrophysiology: a clinical consensus statement of the European Heart Rhythm Association and European Association of Cardiovascular Imaging of the European Society of Cardiology.

Imaging using cardiac computed tomography (CT) or magnetic resonance (MR) imaging has become an important option for anatomic and substrate delineation in complex atrial fibrillation (AF) and ventricular tachycardia (VT) ablation procedures. Computed tomography more common than MR has been used to detect procedure-associated complications such as oesophageal, cerebral, and vascular injury. This clinical consensus statement summarizes the current knowledge of CT and MR to facilitate electrophysiological procedures, the current value of real-time integration of imaging-derived anatomy, and substrate information during the procedure and the current role of CT and MR in diagnosing relevant procedure-related complications. Practical advice on potential advantages of one imaging modality over the other is discussed for patients with implanted cardiac rhythm devices as well as for planning, intraprocedural integration, and post-interventional management in AF and VT ablation patients. Establishing a team of electrophysiologists and cardiac imaging specialists working on specific details of imaging for complex ablation procedures is key. Cardiac magnetic resonance (CMR) can safely be performed in most patients with implanted active cardiac devices. Standard procedures for pre- and post-scanning management of the device and potential CMR-associated device malfunctions need to be in place. In VT patients, imaging-specifically MR-may help to determine scar location and mural distribution in patients with ischaemic and non-ischaemic cardiomyopathy beyond evaluating the underlying structural heart disease. Future directions in imaging may include the ability to register multiple imaging modalities and novel high-resolution modalities, but also refinements of imaging-guided ablation strategies are expected.

Dual energy for pulmonary vein isolation using dual-energy focal ablation technology integrated with a three-dimensional mapping system: SmartfIRE 3-month results.

Contact force (CF)-sensing radiofrequency (RF) catheters with an ablation index have shown reproducible outcomes for the treatment of atrial fibrillation (AF) in large multicentre studies. A dual-energy (DE) focal CF catheter to deliver RF and unipolar/biphasic pulsed field ablation (PFA), integrated with a three-dimensional (3D) mapping system, can provide operators with additional flexibility. The SmartfIRE study assessed the safety and efficacy of this novel technology for the treatment of drug-refractory, symptomatic paroxysmal AF. Results at 3 months post-ablation are presented here. Pulmonary vein isolation (PVI) was performed using a DE focal, irrigated CF-sensing catheter with the recommendation of PFA at posterior/inferior and RF ablation at the anterior/ridge/carina segments. Irrespective of energy, a tag size of 3 mm; an inter-tag distance ≤6 mm; a target index of 550 for anterior, roof, ridge, and carina; and a target index of 400 for posterior and inferior were recommended. Cavotricuspid isthmus ablation was permitted in patients with documented typical atrial flutter. The primary effectiveness endpoint was acute procedural success. The primary safety endpoint was the rate of primary adverse events (PAEs) within 7 days of the procedure. A prespecified patient subset underwent oesophageal endoscopy (EE; 72 h post-procedure), neurological assessment (NA; pre-procedure and discharge), and cardiac computed tomography (CT)/magnetic resonance angiogram (MRA) imaging (pre-procedure and 3 months post-procedure) for additional safety evaluation, and a mandatory remapping procedure (Day 75 ± 15) for PVI durability assessment. Of 149 patients enrolled between February and June 2023, 140 had the study catheter inserted (safety analysis set) and 137 had ablation energy delivered (per-protocol analysis set). The median (Q1/Q3) total procedure and fluoroscopy times were 108.0 (91.0/126.0) and 4.2 (2.3/7.7) min (n = 137). The acute procedural success rate was 100%. First-pass isolation was achieved in 89.1% of patients and 96.8% of veins. Cavotricuspid isthmus ablations were successfully performed in 12 patients [pulsed field (PF) only: 6, RF only: 5, and RF/PF: 1]. The PAE rate was 4.4% [6/137 patients; 2 pulmonary vein (PV) stenoses, 2 cardiac tamponades/perforations, 1 stroke, and 1 pericarditis]. No coronary artery spasm was reported. No oesophageal lesion was seen in the EE subset (0/31, 0%). In the NA subset (n = 30), microemboli lesions were identified in 2 patients (2/30, 6.7%), both of which were resolved at follow-up; only 1 was symptomatic (silent cerebral lesion, 3.3%). In the CT/MRA subset (n = 30), severe PV narrowing (of >70%) was detected in 2 patients (2/30, 6.7%; vein level 2/128, 1.6%), of whom 1 underwent dilatation and stenting and 1 was asymptomatic; both were associated with high index values and a small inter-tag distance. In the PV durability subset (n = 30), 100/115 treated PVs (87%) were durably isolated and 18/30 patients (60.0%) had all PVs durably isolated. A DE focal CF catheter with 3D mapping integration showed a 100% acute success rate with an acceptable safety profile in the treatment of paroxysmal AF. Prespecified 3-month remapping showed notable PVI durability. ClinicalTrials.gov Identifier: NCT05752487.