Cardiac MRI In Patients Research Articles

Abstract 4137534: Troponin Can Predict Late Gadolinium Enhancement on Cardiac MRI in COVID-19 Vaccine-Associated Myocarditis

Background/Aim: We previously reported that late gadolinium enhancement (LGE) on cardiac MRI (CMR) was as high as 82% in pediatric patients with COVID-19 vaccine-associated myocarditis (C-VAM) despite mild clinical symptoms and normal left ventricular function. As LGE can be a harbinger for future adverse events including arrhythmias, heart failure or sudden cardiac death, we sought to identify predictors for LGE in C-VAM, specifically assessing troponin as a screening marker for C-VAM patients at risk for myocardial scarring who could then be referred for a confirmatory CMR with LGE. Methods: In this longitudinal multicenter retrospective observational study across 38 U.S. member institutions of the M yocarditis A fter C OVID V accination (MACiV) study network, 333 patients with C-VAM based on CDC criteria were included from April 2021 to November 2022. Data collected included demographics, laboratory values, clinical and cardiac imaging characteristics and outcomes. Using logistic regression, troponin levels at presentation were assessed as a log transformed continuous variable and categorized into tertiles. Results: The C-VAM patients were predominantly white (67%) adolescent males (91%, 15.7± 2.8 years). There were 216/333 (65%) patients who had both a reported troponin value and had a CMR. On univariate analysis, elevated troponin increased the probability of having LGE (OR=1.29, 95% CI: 1.06, 1.58, p=0.012). Even after controlling for age, race, sex, number of vaccine doses and left ventricular ejection fraction (OR=1.32, 95% CI: 1.06, 1.65, p=0.013). Patients >15 years compared to those ≤15 years of age were 2.94 (95% CI: 1.28, 6.75, p=0.011) times more likely to have LGE at presentation. Patients with troponin levels in the highest tertile compared to lowest tertile were 2.66 times (95% CI: 1.04, 6.83, p=0.042) more likely to have LGE along with a greater involvement > 4 AHA myocardial segments with LGE (p=0.004) Conclusions: Higher troponin values are associated with presence of late gadolinium enhancement on cardiac MRI in patients with COVID-19 vaccine-associated myocarditis. Troponin levels at presentation may facilitate risk stratification and function as a screening tool to identify those C-VAM patients with the greatest likelihood of myocardial scarring, who may benefit from undergoing CMR for tissue characterization.

Flow quantification within the aortic ejection tract using 4D flow cardiac MRI in patients with bicuspid aortic valve: Implications for the assessment of aortic regurgitation

PurposeThe purpose of this study was to evaluate the performance of four-dimensional (4D) flow cardiac MRI in quantifying aortic flow in patients with bicuspid aortic valve (BAV). Materials and methodsPatients with BAV who underwent transthoracic echocardiography (TTE) and 4D flow cardiac MRI were prospectively included. Aortic flow was quantified using two-dimensional phase contrast velocimetry at the sinotubular junction and in the ascending aorta and using 4D flow in the regurgitant jet, in the left ventricular outflow tract, at the aortic annulus, the sinotubular junction, and the ascending aorta, with or without anatomical tracking. Flow quantification was compared with ventricular volumes, pulmonary flow using Pearson correlation test, bias and limits of agreement (LOA) using Bland Altman method, and with multiparametric transthoracic echocardiography quantification using weighted kappa test. ResultsEighty-eight patients (63 men, 25 women) with a mean age of 50.5 ± 14.8 (standard deviation) years (age range: 20.8–78.3) were included. Changes in flow with or without tracking were modest (< 5 mL). The best correlation was obtained at the aortic annulus for forward volume (r = 0.84; LOA [-28.4; 25.3] mL) and at the regurgitant jet and sinotubular junction for regurgitant volume (r = 0.68; LOA [-27.8; 33.8] and r = 0.69; LOA [-28.6; 24.2] mL). A combined approach for regurgitant fraction and net volume calculations using forward volume measured at ANN and regurgitant volume at sinotubular junction performed better than each level taken separately (r = 0.90; LOA [-20.7; 10.0] mL and r = 0.48, LOA [-33.8; 33.4] %). The agreement between transthoracic echocardiography and 4D flow cardiac MRI for aortic regurgitation grading was poor (kappa, 0.13 to 0.42). ConclusionIn patients with BAV, aortic flow quantification by 4D flow cardiac MRI is the most accurate at the annulus for the forward volume, and at the sinotubular junction or directly in the jet for the regurgitant volume.

Papillary Muscle Infarction by Cardiac MRI in Patients With Mitral Regurgitation.

Papillary muscle (PM) infarction (PMI) detected by cardiac magnetic resonance imaging (CMR) is associated with poor outcomes. Whether PM parameters provide more value for mitral regurgitation (MR) management currently remains unclear. Therefore, we examined the prognostic value of PMI using CMR in patients with MR. Between March 2018 and July 2023, we retrospectively enrolled 397 patients with MR undergoing CMR. CMR was used to detect PMI qualitatively and quantitively. We also collected baseline clinical, echocardiography, and follow-up data. Of the 397 patients with MR (52.4 ± 13.9 years), 117 (29.5%) were assigned to the PMI group, with 280 (70.5%) in the non-PMI group. PMI was demonstrated more in the posteromedial PM (PM-PM, 98/117) than in the anterolateral PM (AL-PM, 45/117). Compared with patients without PMI, patients with PMI had a decreased AL-PM (41.5 ± 5.4 vs. 45.6 ± 5.3)/PM-PM diastolic length (35.0 ± 5.2 vs. 37.9 ± 4.0), PM-longitudinal strain (LS, 20.4 ± 6.1 vs. 24.9 ± 4.6), AL-PM-LS (19.7 ± 6.8 vs. 24.7 ± 5.6)/PM-PM-LS (21.2 ± 7.9 vs. 25.2 ± 6.0), and increased inter-PM distance (25.7 ± 8.0 vs. 22.7 ± 6.2, all p < 0.001). Multiple logistic regression analyses identified male sex (odds ratio [OR] = 3.65, 95% confidence interval = 1.881-7.081, p < 0.001) diabetes mellitus (OR/95% CI/p = 2.534/1.13-5.68/0.024), AL-PM diastolic length (OR/95% CI/p = 0.841/0.77-0.92/< 0.001), PM-PM diastolic length (OR/95% CI/p = 0.873/0.79-0.964/0.007), inter-PM distance (OR/95% CI/p = 1.087/1.028-1.15/0.003), AL-PM-LS (OR/95% CI/p = 0.892/0.843-0.94/< 0.001), and PM-PM-LS (OR/95% CI/p = 0.95/0.9-0.992/0.021) as independently associated with PMI. Over a 769 ± 367-day follow-up, 100 (25.2%) patients had arrhythmia. Cox regression analyses indicated that PMI (hazard ratio [HR]/95% CI/p = 1.644/1.062-2.547/0.026), AL-PM-LS (HR/95% CI/p = 0.937/0.903-0.973/0.001), and PM-PM-LS (HR/95% CI/p = 0.933/0.902-0.965/< 0.001) remained independently associated with MR. The CMR-derived PMI and LS parameters improve the evaluation of PM dysfunction, indicating a high risk for arrhythmia, and provide additive risk stratification for patients with MR.

Dynamic Regularized Adaptive Cluster Optimization (DRACO) for Quantitative Cardiac Cine MRI in Complex Arrhythmias.

Irregular cardiac motion can render conventional segmented cine MRI nondiagnostic. Clustering has been proposed for cardiac motion binning and may be optimized for complex arrhythmias. To develop an adaptive cluster optimization method for irregular cardiac motion, and to generate the corresponding time-resolved cine images. Prospective. Thirteen with atrial fibrillation, four with premature ventricular contractions, and one patient in sinus rhythm. Free-running balanced steady state free precession (bSSFP) with sorted golden-step, reference real-time sequence. Each subject underwent both the sorted golden-step bSSFP and the reference Cartesian real-time imaging. Golden-step bSSFP images were reconstructed using the dynamic regularized adaptive cluster optimization (DRACO) method and k-means clustering. Image quality (4-point Likert scale), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), edge sharpness, and ventricular function were assessed. Paired t-tests, Friedman test, regression analysis, Fleiss' Kappa, Bland-Altman analysis. Significance level P < 0.05. The DRACO method had the highest percent of images with scores ≥3 (96% for diastolic frame, 93% for systolic frame, and 93% for multiphase cine) and the percentages were significantly higher compared with both the k-means and real-time methods. Image quality scores, SNR, and CNR were significantly different between DRACO vs. k-means and between DRACO vs. real-time. Cardiac function analysis showed no significant differences between DRACO vs. the reference real-time. DRACO with time-resolved reconstruction generated high quality images and has early promise for quantitative cine cardiac MRI in patients with complex arrhythmias including atrial fibrillation. Stage 2.

Quantitative metrics of the LV trabeculated layer by cardiac CT and cardiac MRI in patients with suspected noncompaction cardiomyopathy.

To compare cardiac computed tomography (CCT) and cardiac magnetic resonance (CMR) for the quantitative assessment of the left ventricular (LV) trabeculated layer in patients with suspected noncompaction cardiomyopathy (NCCM). Subjects with LV excessive trabeculation who underwent both CMR and CCT imaging as part of the prospective international multicenter NONCOMPACT clinical study were included. For each subject, short-axis CCT and CMR slices were matched. Four quantitative metrics were estimated: 1D noncompacted-to-compacted ratio (NCC), trabecular-to-myocardial area ratio (TMA), trabecular-to-endocardial cavity area ratio (TCA), and trabecular-to-myocardial volume ratio (TMV). In 20 subjects, end-diastolic and mid-diastolic CCT images were compared for the quantification of the trabeculated layer. Relationships between the metrics were investigated using linear regression models and Bland-Altman analyses. Forty-eight subjects (49.9 ± 12.8years; 28 female) were included in this study. NCC was moderately correlated (r = 0.62), TMA and TMV were strongly correlated (r = 0.78 and 0.78), and TCA had excellent correlation (r = 0.92) between CMR and CCT, with an underestimation bias from CCT of 0.3 units, and 5.1, 4.8, and 5.4 percent-points for the 4 metrics, respectively. TMA, TCA, and TMV had excellent correlations (r = 0.93, 0.96, 0.94) and low biases (- 3.8, 0.8, - 3.8 percent-points) between the end-diastolic and mid-diastolic CCT images. TMA, TCA, and TMV metrics of the LV trabeculated layer in patients with suspected NCCM demonstrated high concordance between CCT and CMR images. TMA and TCA were highly reproducible and demonstrated minimal differences between mid-diastolic and end-diastolic CCT images. The results indicate similarity of CCT to CMR for quantifying the LV trabeculated layer, and the small differences in quantification between end-diastole and mid-diastole demonstrate the potential for quantifying the LV trabeculated layer from clinically performed coronary CT angiograms. • Data on cardiac CT for quantifying the left ventricular trabeculated layer are limited. • Cardiac CT yielded highly reproducible metrics of the left ventricular trabeculated layer that correlated well with metrics defined by cardiac MR. • Cardiac CT appears to be equivalent to cardiac MR for the quantification of the left ventricular trabeculated layer.

Identification of Myocardial Scarring Using Contrast-Free Cardiac MRI in Patients With Autoimmune Rheumatic Diseases.

Late gadolinium enhancement (LGE) cardiac MRI is the method of choice in revealing the presence of myocardial scarring, but its availability remains limited in clinical practice. To assess myocardial scarring in patients with autoimmune rheumatic diseases (ARDs) using contrast-free cardiac MRI with a radiomics model. Retrospective. One hundred ninety-two patients (mean age, 41 years ± 15, 62 men) with or without ARDs, grouped into a training set of 153 patients and a testing set of 39 patients. 3.0 T/ cine imaging with a balanced steady-state free precession sequence, T1 mapping with a modified Look-Locker inversion recovery sequence, and LGE imaging with a phase-sensitive inversion recovery gradient echo sequence. LGE assessment was the reference standard for identifying myocardial scarring. Based on motion features extracted from cine images and tissue characterization features extracted from native T1 maps, a fully automated radiomics model with T1, cine MRI, or combined inputs was developed. Logistic regression model was used to detect myocardial scarring using contrast-free cardiac MRI parameters. Receiver operating characteristic curves were analyzed to assess the accuracy, sensitivity, and specificity in detecting myocardial scarring. Sensitivities of the models were further assessed in patients with various myocardial scarring proportions. Z-statistic and dice coefficient were assessed to compare the performance. P-values <0.05 were considered significant. The multivariable regression model exhibited an accuracy of 85.3%, a sensitivity of 93.5%, and a specificity of 50.0%. The radiomics model with T1 and cine MRI input exhibited an accuracy of 75.7%, a sensitivity of 60.9%, and a specificity of 85.5%. Moreover, the radiomics model showed a sensitivity of 90.9% among patients with >25% myocardial scarring. The proposed radiomics model allowed for the identification of myocardial scarring similar to LGE, but on contrast-free cardiac MRI in patients with ARDs. 3 TECHNICAL EFFICACY: Stage 1.

Coronary artery disease in cardiac amyloidosis

Abstract Background Cardiac amyloidosis is an important disease causing significant morbidity and mortality. Due to the ageing society as well as better diagnostic tools such as 3,3-diphosphono-1,2-propanodicarboxylic acid scintigraphy (DPD scan), cardiac amyloidosis has increased in prevalence, however, the coexistence, as well as the differences in presentation with coronary artery disease (CAD), has not yet been discovered. Purpose The purpose of the study is to evaluate the prevalence of CAD in patients with cardiac amyloidosis, to assess differences in late gadolinium enhancement (LGE) in cardiac MRI, and to assess differences in symptoms such as dyspnea. Materials and Methods We retrospectively assessed all patients with cardiac amyloidosis at our center and screened for an evaluation of coronary artery disease with coronary angiography, coronary CT, or myocardial scintigraphy. In all patients, who underwent cardiac MRI we assessed the pattern of LGE using the cardiac left ventricular segmentation model published by the AHA [1]. Results 295 patients (27% female, 74 ± 11 years) with cardiac amyloidosis (26% AL-amyloidosis, 74% ATTR-amyloidosis) were retrospectively assessed. Of those, 205 (69%) had a CAD evaluation. In 69 patients (34%), significant CAD was present, 10 patients (5%) had undergone CABG and 48 patients (23%) had received a PCI in the past. In patients with CAD, 3 patients (4%) suffered from NYHA IV and 51 patients (74%) were symptomatic with NYHA II or NYHA III. There were no significant differences to patients without CAD (p=0.252). In 153 patients (75%), cardiac MRI was performed. In 7% of the patients, no LGE was obvious, in 84%, a diffuse circular subendocardial to transmural LGE with basoapical gradient, typical for cardiac amyloidosis, could be observed. In 6% of the cases, a subendocardial pattern typical for post-ischemic changes could be observed; in 56% of the patients, a previous myocardial infarction was known. In the remaining 3%, LGE in the insertion points could be observed. Conclusion With 34%, CAD is highly prevalent in patients with cardiac amyloidosis. In 28%, a coronary intervention (surgical or interventional) was performed, making coronary interventions in patients with cardiac amyloidosis a feasible option. Cardiac MRI in patients with concomitant CAD and cardiac amyloidosis often shows the typical diffuse LGE, therefore, visualization of postischemic changes in these patients is difficult. Furthermore, symptoms do not differ between patients with CAD and no CAD.

Effects of empagliflozin on cardiac structure, function and biomarkers in patients with heart failure with preserved ejection fraction: study protocol for a randomised, placebo-controlled prospective trial

IntroductionHeart failure (HF) with preserved ejection fraction (HFpEF) has become the main type of HF worldwide. Although large randomised controlled studies have demonstrated the beneficial effects of sodium–glucose cotransporter 2...

Cardiac MRI safety assessment of patients with congenital heart disease and cardiac implantable electronic devices with abdominal pulse generators and epicardial leads

Abstract Funding Acknowledgements Type of funding sources: None. Background Reports about cardiac MRI safety and utility in pediatric and adult patients with non-MR-conditional cardiac implantable electronic devices with abdominal pulse generator and epicardial leads remain underreported. Purpose To retrospectively assess safety of cardiac MRI with non-MR-conditional abdominal pulse generators and epicardial leads in pediatric and adult patients with congenital heart disease. Methods Between 04/2020 and 01/2023 25 patients aged 2–32 years (mean 12.7±8.3 years) with abdominal pulse generators and up to three epicardial leads underwent cardiac MRI at 1,5T. SAR was limited to 2W/kg. 19/25 (76%) patients carried pacemakers, 1/25 (4%) ICD, 4/25 (16%) CRTs. 12/25 (48%) of the examinations were performed under general anesthesia. Patients were continuously monitored during cardiac MRI. Results of thresholds, sensing and impedances of the devices were assessed before and after MRI examination. Results In 24/25 (96%) the examination could be finished without significant changes in thresholds, sensing and impedances of the abdominally placed devices. One examination was terminated early because of a major adverse event of heating/abdominal discomfort. Three minor adverse events in three different patients were inability to program back to previous setting (patient 1), alert that the elective replacement indicator (ERI) was reached (patient 2), and significantly elevated impedance (patient 3). Patient 1 and 2 remained in MRI mode and had to be monitored after the MRI examination. Reconfiguration was possible in both patients after 24 hours. Patient 3 had normal results for impedances in the pacemaker query 24 hours after the cardiac MRI examination. Conclusion Our data suggest that cardiac MRI in patients with non-MR-conditional abdominal pulse generators and epicardial leads in pediatric and adult patients with congenital heart disease can be imaged safely in an experienced and multidisciplinary environment. The potential increased risks of MRI in these patients should be balanced against the value of the diagnostic information that can be obtained.

Cardiac MRI in patients with COVID-19 infection

ObjectiveCOVID-19 infection is a systemic disease with various cardiovascular symptoms and complications. Cardiac MRI with late gadolinium enhancement is the modality of choice for the assessment of myocardial involvement. T1 and T2 mapping can increase diagnostic accuracy and improve further management. Our study aimed to evaluate the different aspects of myocardial damage in cases of COVID-19 infection using cardiac MRI.MethodsThis descriptive retrospective study included 86 cases, with a history of COVID-19 infection confirmed by positive RT-PCR, who met the inclusion criteria. Patients had progressive chest pain or dyspnoea with a suspected underlying cardiac cause, either by an abnormal electrocardiogram or elevated troponin levels. Cardiac MRI was performed with late contrast-enhanced (LGE) imaging, followed by T1 and T2 mapping.ResultsTwenty-four patients have elevated hsTnT with a median hsTnT value of 133 ng/L (IQR: 102 to 159 ng/L); normal value < 14 ng/L. Other sixty-two patients showed elevated hsTnI with a median hsTnI value of 1637 ng/L (IQR: 1340 to 2540 ng/L); normal value < 40 ng/L. CMR showed 52 patients with acute myocarditis, 23 with Takotsubo cardiomyopathy, and 11 with myocardial infarction. Invasive coronary angiography was performed only in selected patients.ConclusionDifferent COVID-19-related cardiac injuries may cause similar clinical symptoms. Cardiac MRI is the modality of choice to differentiate between the different types of myocardial injury such as Takotsubo cardiomyopathy and infection-related cardiomyopathy or even acute coronary syndrome secondary to vasculitis or oxygen-demand mismatch.Key Points• It is essential to detect early COVID-related cardiac injury using different cardiac biomarkers and cardiac imaging, as it has a significant impact on patient management and outcome.• Cardiac MRI is the modality of choice to differentiate between the different aspects of COVID-related myocardial injury.

Myocardial Fibrosis at Cardiac MRI Helps Predict Adverse Clinical Outcome in Patients with Mitral Valve Prolapse.

Background Patients with mitral valve prolapse (MVP) may develop adverse outcomes even in the absence of mitral regurgitation or left ventricular (LV) dysfunction. Purpose To investigate the prognostic value of mitral annulus disjunction (MAD) and myocardial fibrosis at late gadolinium enhancement (LGE) cardiac MRI in patients with MVP without moderate-to-severe mitral regurgitation or LV dysfunction. Materials and Methods In this longitudinal retrospective study, 118 144 cardiac MRI studies were evaluated between October 2007 and June 2020 at 15 European tertiary medical centers. Follow-up was from the date of cardiac MRI examination to June 2020; the minimum and maximum follow-up intervals were 6 months and 156 months, respectively. Patients were excluded if at least one of the following conditions was present: cardiomyopathy, LV ejection fraction less than 40%, ischemic heart disease, congenital heart disease, inflammatory heart disease, moderate or worse mitral regurgitation, participation in competitive sport, or electrocardiogram suggestive of channelopathies. In the remainder, cardiac MRI studies were reanalyzed, and patients were included if they were aged 18 years or older, MVP was diagnosed at cardiac MRI, and clinical information and electrocardiogram monitoring were available within 3 months from cardiac MRI examination. The end point was a composite of adverse outcomes: sustained ventricular tachycardia (VT), sudden cardiac death (SCD), or unexplained syncope. Multivariable Cox regression analysis was performed. Results A total of 474 patients (mean age, 47 years ± 16 [SD]; 244 women) were included. Over a median follow-up of 3.3 years, 18 patients (4%) reached the study end point. LGE presence (hazard ratio, 4.2 [95% CI: 1.5, 11.9]; P = .006) and extent (hazard ratio, 1.2 per 1% increase [95% CI: 1.1, 1.4]; P = .006), but not MAD presence (P = .89), were associated with clinical outcome. LGE presence had incremental prognostic value over MVP severity and sustained VT and aborted SCD at baseline (area under the receiver operating characteristic curve, 0.70 vs 0.62; P = .03). Conclusion In contrast to mitral annulus disjunction, myocardial fibrosis determined according to late gadolinium enhancement at cardiac MRI was associated with adverse outcome in patients with mitral valve prolapse without moderate-to-severe mitral regurgitation or left ventricular dysfunction. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Gerber in this issue.

Correlation of serum ST2 levels with severity of diastolic dysfunction on echocardiography and findings on cardiac MRI in patients with heart failure with preserved ejection fraction

ObjectiveThe aim of the present study was to find a correlation of serum Suppression of tumorigenicity 2 (ST2) levels with severity of diastolic dysfunction on echocardiography and cardiac magnetic resonance imaging (CMRI) in heart failure with preserved ejection fraction (HFpEF) patients. MethodsFifty patients aged ≥18 years fulfilling diagnostic criteria for HFpEF were included. ST2 levels, 2D echocardiography and CMRI were performed. Left ventricular ejection fraction, E/A, Septal E/E’, left atrial volume index (LAVI), tricuspid regurgitation (TR), assessment of diastolic dysfunction, T1 mapping in milliseconds and late gadolinium enhancement (LGE) in percentage were noted. The primary outcome measure was to study correlation of ST2 levels with severity of diastolic dysfunction, whereas the secondary outcome measures were to study correlation of ST2 levels with native T1 mapping and LGE on CMRI. ResultsST2 levels showed statistically significant and positive correlation with E/E’ (r = 0.837), peak TR velocity (r = 0.373), LAVI (r = 0.74), E/A (r = 0.420), and T1 values in milliseconds (r = 0.619). There was no statistically significant correlation between ST2 level and LGE in % (r = 0.145). The median ST2 levels in patients with E/E’ > 14 and E/E’ ≤ 14 were 110.8 and 36.1 respectively (p-value < 0.05). The mean ST2 levels were significantly higher in patients who had diastolic dysfunction grade III (126.4) and New York Heart Association class IV (133.3). ConclusionsEvaluation of ST2 adds important information to support the diagnosis of left ventricular diastolic dysfunction in patients with HFpEF.

Detailed Assessment of Low-Voltage Zones Localization by Cardiac MRIinPatients With Implantable Devices.

The purpose of this study was to assess the performance and limitations of low-voltage zones (LVZ) localization by optimized late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) scar imaging in patients with cardiac implantable electronic devices (CIEDs). Scar evaluation by LGE-CMR can assist ventricular tachycardia (VT) ablation, but challenges with electroanatomical maps coregistration and presence of imaging artefacts from CIED limit accuracy. A total of 10 patients underwent VT ablation and preprocedural LGE-CMR using wideband imaging. Scar was segmented from CMR pixel signal intensity maps using commercial software (ADAS-VT, Galgo Medical) with bespoke tools and compared with detailed electroanatomical maps (CARTO). Coregistration of EP and imaging-derived scar was performed using the aorta as a fiducial marker, and the impact of coregistration was determined by assessing intraobserver/interobserver variability and using computer simulations. Spatial smoothing was applied to assess correlation at different spatial resolutions and to reduce noise. Pixel signal intensity maps localized low-voltage zones (V<1.5mV) with area under the receiver-operating characteristic curve: 0.82 (interquartile range [IQR]: 0.76-0.83), sensitivity 74% (IQR: 71%-77%), and specificity 78% (IQR: 73%-83%) and correlated with bipolar voltage (r =-0.57 [IQR: -0.68 to-0.42]) across patients. In simulations, small random shifts and rotations worsened LVZ localization in at least some cases. The use of the full aortic geometry ensured high reproducibility of LVZ localization (r >0.86 for area under the receiver-operating characteristic curve). Spatial smoothing improved localization of LVZ. Results for LVZ with V<0.5mV were similar. In patients with CIEDs, novel wideband CMR sequences and personalized coregistration strategies canlocalize LVZ with good accuracy and may assist VT ablation procedures.

Extent of Left Atrial Fibrosis Correlates with Descending Aorta Proximity at 3D Late Gadolinium Enhancement Cardiac MRI in Patients with Atrial Fibrillation.

To determine whether the distance between the descending aorta and left atrial (LA) wall correlates with the amount of fibrosis quantified in the posterior left inferior pulmonary vein (LIPV) area of the LA in patients with atrial fibrillation (AF). In this retrospective study, patients with AF underwent cardiac MRI in sinus rhythm prior to a pulmonary vein isolation procedure (July 2018 to February 2020). The mean distance (distancemean) and shortest distance (distanceshort) between the descending aorta and the LA wall were measured on three-dimensional (3D) contrast-enhanced MR angiograms; distancemean was defined as the average of five measurements at different levels between the descending aorta and the LA wall. The extent of LA fibrosis, both global fibrosis and regional fibrosis within the LIPV area, was derived from postprocessed, 3D, late gadolinium-enhanced images. Associations between the extent of fibrosis and the proximity of the descending aorta were analyzed by using correlative and multivariable analyses. A total of 47 (mean age, 60 years ± 8 [standard deviation]; 31 men) patients were included for analysis. The extent of fibrosis in the posterior LIPV area was correlated with the distancemean (r s = -0.48; P < .01) and distanceshort (r s = -0.49; P < .01). Patients with a short distance between the descending aorta and LA wall (defined as a distanceshort < 2 mm) had a higher percentage of fibrosis in the posterior LIPV area than patients with a distanceshort greater than 2 mm (38.7% ± 22.7 vs 21.2% ± 17.8; P < .01). The distance between the descending aorta and LA was correlated with the extent of quantified fibrosis within the posterior LIPV area.Keywords: MRI, Cardiac, Left Atrium Supplemental material is available for this article. © RSNA, 2022.

Incremental Value of Cardiac MRI in Patients Suspected to Have Myocarditis Following COVID-19 mRNA Vaccination

Myocarditis post MRNA based COVID-19 vaccination remains a community concern. This usually occurs in young males within 7 days post. We aimed to review local data for presentations of this including investigations and clinical outcomes. We performed a search of the cardiac MRI database for studies including the words “vaccine”, “Pfizer”, “Moderna” and “mRNA” alone and in combination. All cardiac MRIs were reviewed, and those with no evidence of myocardial or pericardial inflammation were excluded. The cases were then reviewed. Between February 2020 to February 2022, 14 cases were identified with MRI confirmed myocarditis post COVID-19 vaccination. 3 cases were deemed unlikely to be attributable to the vaccination. Of the remaining 11 patients, 7/11 (64%) were male, with a mean age of 20 years. Most had no significant medical history. 8/11 (73%) occurred after the second dose with a median onset of 3 days post vaccination. Chest pain (100%), dyspnoea (18%) and fevers (18%) were the most common presenting complaints. The mean peak troponin level was 7869 ng/L, mean CRP was 22.57 mg/L. 6/11 (54%) of had ECG abnormalities, widespread ST elevation was most common (37%). Transthoracic echocardiography was normal for most 9/11 (81.8%). Lateral wall subepicardial late gadolinium enhancement was the most common MRI finding. Mean LOS was 2.64 days. There were no readmissions. In keeping with international data, most cases were young, male, and after dose two. Most cases had normal TTE. Lateral wall LGE was the most common MRI finding. Most cases were clinically mild, with short LOS.

Cardiac MRI in Patients with Prolonged Cardiorespiratory Symptoms after Mild to Moderate COVID-19.

BackgroundMyocardial injury and inflammation at cardiac MRI in patients with COVID-19 have been described in recent publications. Concurrently, a chronic COVID-19 syndrome (CCS) after SARS-CoV-2 infection has been observed and manifests with symptoms such as fatigue and exertional dyspnea.PurposeTo explore the relationship between CCS and myocardial injury and inflammation as an underlying cause of the persistent complaints in previously healthy individuals.Materials and MethodsIn this prospective study from January 2021 to April 2021, study participants without known cardiac or pulmonary diseases prior to SARS-CoV-2 infection who had persistent CCS symptoms such as fatigue or exertional dyspnea after convalescence and healthy control participants underwent cardiac MRI. The cardiac MRI protocol included evaluating the T1 and T2 relaxation times, extracellular volume, T2 signal intensity ratio, and late gadolinium enhancement (LGE). Student t tests, Mann-Whitney U tests, and χ2 tests were used for statistical analysis.ResultsForty-one participants with CCS (mean age, 39 years ± 13 [standard deviation]; 18 men) and 42 control participants (mean age, 39 years ± 16; 26 men) were evaluated. The median time between the initial incidence of mild to moderate COVID-19 not requiring hospitalization and undergoing cardiac MRI was 103 days (interquartile range, 88–158 days). Troponin T levels were normal. Parameters indicating myocardial inflammation and edema were comparable between participants with CCS and control participants (T1 relaxation times: 978 msec ± 23 vs 971 msec ± 25 [P = .17]; T2 relaxation times: 53 msec ± 2 vs 52 msec ± 2 [P = .47]; T2 signal intensity ratios: 1.6 ± 0.2 vs 1.6 ± 0.3 [P = .10]). Visible myocardial edema was present in none of the participants. Three of 41 (7%) participants with CCS demonstrated nonischemic LGE, whereas no participants in the control group demonstrated nonischemic LGE (0 of 42 [0%]; P = .07). None of the participants fulfilled the 2018 Lake Louise criteria for the diagnosis of myocarditis.ConclusionIndividuals with chronic COVID-19 syndrome who did not undergo hospitalization for COVID-19 did not demonstrate signs of active myocardial injury or inflammation at cardiac MRI.© RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lima and Bluemke in this issue.

The Prognostic Value of Left Ventricular Mechanical Dyssynchrony Derived from Cardiac MRI in Patients with Idiopathic Dilated Cardiomyopathy.

To investigate the prognostic value of mechanical dyssynchrony evaluated by deformable registration algorithm (DRA) analysis of cardiac MRI (CMR) in patients with idiopathic dilated cardiomyopathy (DCM). This secondary analysis of a prospective study (clinical trial no. ChiCTR1800017058) enrolled 409 patients (mean age, 48 years ± 14:300 men) with idiopathic DCM who underwent CMR between June 2012 and September 2018. Mechanical dyssynchrony was measured as standard deviation of time-to-peak (sdTTP) and uniformity ratio estimate (URE) indexes by DRA strain analysis. The primary endpoint included all-cause mortality and heart transplantation. The secondary endpoint included primary endpoint, aborted sudden cardiac death, and heart failure readmission. Cox regression analyses and Kaplan-Meier survival analysis were performed to identify the association between variables and outcomes. During a median follow-up of 25.1 months, 57 and 132 patients reached primary and secondary endpoints, respectively. Most URE indexes were significantly lower in patients reaching primary endpoint. In multivariable analysis, circumferential URE (CURE) at apical level was independently associated with primary endpoints (hazard ratio, 0.307 [95% CI: 0.106, 0.883]; P = .03) and secondary endpoints (hazard ratio, 0.452 [95% CI: 0.209, 0.979]; P = .04), whereas most sdTTP measures were not. Furthermore, among patients with left ventricular ejection fraction of less than 35% or presence of late gadolinium enhancement, those with CURE at apical level of less than 0.917 had a significantly higher rate of adverse outcomes. URE indexes were more predictive of prognostic outcomes compared with sdTTP measurements; the CURE at apical level was an independent predictor of adverse cardiac events in patients with DCM.Keywords: Heart, Outcomes Analysis, MR-ImagingClinical trial registration no. ChiCTR1800017058 Supplemental material is available for this article. See also commentary by Rajiah and François in this issue.© RSNA, 2021.

Comparison of 68Ga-DOTANOC PET/CT with cardiac MRI in patients with clinical suspicion of cardiac sarcoidosis.

68Ga-DOTA-NaI-octreotide (DOTANOC) is a promising new alternative to 18F-fluorodeoxyglucose (FDG) for imaging inflammation in cardiac sarcoidosis. The aim of the study was to compare 68Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) with cardiac magnetic resonance imaging (CMR) in patients with clinical suspicion of cardiac sarcoidosis. Patients with extracardiac sarcoidosis and clinical suspicion of cardiac involvement underwent 68Ga-DOTANOC cardiac PET/CT, myocardial perfusion single photon emission computed tomography (MPS) and CMR (T2-weighted and delayed gadolinium-enhanced T1-weighted images). The patients were screened using revised criteria of Japanese circulation society. Presence of perfusion defects on MPS, abnormal myocardial uptake on 68Ga-DOTANOC PET/CT and characteristic pattern of late gadolinium enhancement (LGE) with or without T2 hyperintensity on CMR was considered positive. Seventeen patients (13 male and 4 female) were included in the study. Out of the 17 patients, both CMR and PET were positive in 11 and both were negative in 2. In the remaining 4 patients, CMR was positive but PET was normal. Thus, PET and CMR were concordant in 13 (76.5%) patients and discordant in 4 (23.5%). Intermodality agreement was fair (Cohen's kappa = 0.39). LGE on CMR is superior to 68Ga-DOTANOC PET/CT for detecting cardiac involvement in sarcoidosis and there is fair concordance between the two. However, since LGE does not specifically differentiate between inflammation and fibrosis, 68Ga-DOTANOC PET/CT may be better than CMR in identifying patients with active inflammation, since it directly targets inflammatory cells and can have a complementary role to CMR.

Patterns of Left Ventricular Hypertrophy and Late Gadolinium Enhancement on Cardiac MRI in Patients with Hypertrophic Cardiomyopathy and their Prognostic Significance - An Experience from a South Asian Country.

Objectives:Cardiac magnetic resonance (CMR) imaging is very pertinent in the diagnosis and risk stratification of patients with hypertrophic cardiomyopathy (HCM). We aimed to assess the patterns of left ventricular (LV) hypertrophy, late gadolinium enhancement (LGE), and their prognostic significance in HCM patients in Pakistani population, as no such data are available from Pakistan.Material and Methods:This was a retrospective, single center study. All patients who had confirmed diagnosis of HCM on CMR at Aga Khan University Hospital during the period of 2011–2019 were identified and included in the study.Results:A total of 74 patients were included with the mean age of 45.6 ± 15 years and the majority 71.6 % (n = 53) being male. Maximal LV wall thickness was 21.1 ± 5 mm, asymmetrical septal hypertrophy being the most common pattern (62.2%, n = 46). LGE was present in 75.7% (n = 56) with most common site being septum plus LV free wall (24.3%, n =18). Mean ejection fraction% was found to be lower in patients with LGE (P < 0.001). Major adverse cardiac events (MACE) were observed in 40.5% (n = 30). Presence of LGE and right ventricular involvement was found to have a statistically significant association with MACE (P value 0.018 and 0.046, respectively). In multivariable analysis, only LGE was significantly associated with MACE (odd ratio: 4.65; 95% CI: 1.21–17.88).Conclusion:Asymmetrical septal hypertrophy was the most common pattern of hypertrophy. LGE was present in three fourth of the study population and it was significantly associated with MACE.

Regional Amyloid Burden Differences Evaluated Using Quantitative Cardiac MRI in Patients with Cardiac Amyloidosis.

ObjectiveThis study aimed to investigate the regional amyloid burden and myocardial deformation using T1 mapping and strain values in patients with cardiac amyloidosis (CA) according to late gadolinium enhancement (LGE) patterns.Materials and MethodsForty patients with CA were divided into 2 groups per LGE pattern, and 15 healthy subjects were enrolled. Global and regional native T1 and T2 mapping, extracellular volume (ECV), and cardiac magnetic resonance (CMR)-feature tracking strain values were compared in an intergroup and interregional manner.ResultsOf the patients with CA, 32 had diffuse global LGE (group 2), and 8 had focal patchy or no LGE (group 1). Global native T1, T2, and ECV were significantly higher in groups 1 and 2 than in the control group (native T1: 1384.4 ms vs. 1466.8 ms vs. 1230.5 ms; T2: 53.8 ms vs. 54.2 ms vs. 48.9 ms; and ECV: 36.9% vs. 51.4% vs. 26.0%, respectively; all, p < 0.001). Basal ECV (53.7%) was significantly higher than the mid and apical ECVs (50.1% and 50.0%, respectively; p < 0.001) in group 2. Basal and mid peak radial strains (PRSs) and peak circumferential strains (PCSs) were significantly lower than the apical PRS and PCS, respectively (PRS, 15.6% vs. 16.7% vs. 26.9%; and PCS, −9.7% vs. −10.9% vs. −15.0%; all, p < 0.001). Basal ECV and basal strain (2-dimensional PRS) in group 2 showed a significant negative correlation (r = −0.623, p < 0.001). Group 1 showed no regional ECV differences (basal, 37.0%; mid, 35.9%; and apical, 38.3%; p = 0.184).ConclusionQuantitative T1 mapping parameters such as native T1 and ECV may help diagnose early CA. ECV, in particular, can reflect regional differences in the amyloid deposition in patients with advanced CA, and increased basal ECV is related to decreased basal strain. Therefore, quantitative CMR parameters may help diagnose CA and determine its severity in patients with or without LGE.