Gadolinium-enhanced Cardiac Magnetic Resonance Imaging Research Articles

Patient selection for LIVE therapy: From clinical indications to multimodality imaging individual case planning.

Less Invasive Ventricular Enhancement (LIVE) with Revivent TC is an innovative therapy for symptomatic ischemic heart failure (HF). It is designed to reconstruct a negatively remodeled left ventricle (LV) after an anterior myocardial infarction (MI) by plication of the scar tissue. Its indications are specific, and as with any other structural heart intervention, the success of the procedure starts with appropriate patient selection. We aim to present the indications of the technique, crucial aspects in patient selection, and individual case planning approach. After clinical evaluation, transthoracic echocardiography is the first imaging modality to be performed in a potential candidate for the therapy. However, definitive indication and detailed case planning rely on late gadolinium-enhanced cardiac magnetic resonance imaging or multiphasic contrast-enhanced cardiac computed tomography. These imaging modalities also assist with relative or absolute contra-indications for the procedure. Individual assessment is done to tailor the procedure to the specifics of the LV anatomy and location of the myocardial scar. LIVE procedure is a unique intervention to treat symptomatic HF and ischemic cardiomyopathy after anterior MI. It is a highly customizable intervention that allows a patient-tailored approach, based on multimodality imaging assessment and planification.

Well-Known and Novel Serum Biomarkers for Risk Stratification of Patients with Non-ischemic Dilated Cardiomyopathy.

Non-ischemic dilated cardiomyopathy encompasses a wide spectrum of myocardial disorders, characterized by left ventricular dilatation with systolic impairment and increased risk of sudden cardiac death. In spite of all the therapeutic progress that has been made in recent years, dilated cardiomyopathy continues to be an important cause of cardiac transplant, being associated with an enormous cost burden for health care systems worldwide. Predicting the prognosis of patients with dilated cardiomyopathy is essential to individualize treatment. Late gadolinium enhancement-cardiac magnetic resonance imaging, microvolt T-wave alternans, and genetic testing have emerged as powerful tools in predicting sudden cardiac death occurrence and maximizing patient’s selection. Despite all these new diagnostic modalities, additional tests to complement or replace current tools are required for better risk stratification. Therefore, biomarkers are an easy and important tool that can help to detect patients at risk of adverse cardiovascular events. Additionally, identifying potential biomarkers involved in dilated cardiomyopathy can provide us important information regarding the diagnostic, prognostic, risk stratification, and response to treatment for these patients. Many potential biomarkers have been studied in patients with dilated cardiomyopathy, but only a few have been adopted in current practice. Therefore, the aim of our review is to provide the clinicians with an update on the well-known and novel biomarkers that can be useful for risk stratification of patients with non-ischemic dilated cardiomyopathy.

Reversible Cause of Cardiac Arrest and Secondary Prevention Implantable Cardioverter Defibrillators in Patients With Coronary Artery Disease: Value of Complete Revascularization and LGE-CMR.

BackgroundIn survivors of sudden cardiac arrest with obstructive coronary artery disease, it remains challenging to distinguish ischemia as a reversible cause from irreversible scar‐related ventricular arrhythmias. We aimed to evaluate the value of implantable cardioverter‐defibrillator (ICD) implantation in sudden cardiac arrest survivors with presumably reversible ischemia and complete revascularization.Methods and ResultsThis multicenter retrospective cohort study included 276 patients (80% men, age 67±10 years) receiving ICD implantation for secondary prevention. Angiography was performed before ICD implantation. A subgroup of 166 (60%) patients underwent cardiac magnetic resonance imaging with late gadolinium enhancement before implantation. Patients were divided in 2 groups, (1) ICD‐per‐guideline, including 228 patients with incomplete revascularization or left ventricular ejection fraction ≤35%, and (2) ICD‐off‐label, including 48 patients with complete revascularization and left ventricular ejection fraction >35%. The primary outcome was time to appropriate device therapy (ADT). During 4.0 years (interquartile range, 3.5–4.6) of follow‐up, ADT developed in 15% of the ICD‐off‐label group versus 43% of the ICD‐per‐guideline group. Time to ADT was comparable in the ICD‐off‐label and ICD‐per‐guideline groups (hazard ratio (HR), 0.46; P=0.08). No difference in mortality was observed (HR, 0.95; P=0.93). Independent predictors of ADT included age (HR, 1.03; P=0.01), left ventricular end‐diastolic volume HR, (1.05 per 10 mL increase; P<0.01) and extent of transmural late gadolinium enhancement (HR, 1.12; P=0.04).ConclusionsThis study demonstrates that sudden cardiac arrest survivors with coronary artery disease remain at high risk of recurrent ventricular arrhythmia, even after complete revascularization and with preserved left ventricular function. Late gadolinium enhancement–cardiac magnetic resonance imaging derived left ventricular volumes and extent of myocardial scar were independently associated with.

Effect of intramyocardial haemorrhage on structural and functional echocardiographic parameters of myocardium after ST-segment elevation myocardial infarction with

Aim. To analyze the effect of intramyocardial haemorrhage (IMH) on the structural and functional echocardiographic parameters of myocardium in patients with primary ST-segment elevation myocardial infarction (STEMI).Material and methods. The study included 60 patients with primary STEMI reperfused within 12 hours after symptom onset. On the second day after the event, all subjects underwent gadolinium-enhanced cardiac magnetic resonance imaging (MRI). IMH was visualized as T2-weighted hypointense areas. Subsequently, all patients underwent the standard echocardiography on the 7th day after MI.Results. IMH was revealed in 31 patients (51,6%). In 22 patients (70,9%), IMH was accompanied by microvascular obstruction (MVO). In the remaining 9 patients (29%), an isolated IMH phenomenon was visualized. Lower values of left ventricular ejection fraction (LVEF) and LV volume parameters were associated with a combination of MVO and IMH. At the same time, the indices of volumetric characteristics and LVEF in isolated IMH were the same as in the group without IMH and MVO. It was demonstrated that the IMH occupies 1% (1-3%) of the LV myocardium. Correlation analysis showed a moderate inverse correlation between the IMH area and LV contractile function: the larger the area, the lower the LVEF (R=-0,35; p=0,007).Conclusions. The analysis of the influence of different IMH phenotypes on the structural and functional echocardiographic parameters of myocardium in the short-term period after STEMI has shown that the combination of IMH with MVO and isolated IMH have different effects on LV contractile function. The combination of IMH with MVO is a predictor of a decrease in LVEF and increase of end-systolic volume (ESV), while an isolated IMH does not affect these parameters. Correlations between the IMH area and a decrease in LVEF, as well as an increase in ESV, have been demonstrated.

High sensitivity C-reactive protein is associated with worse infarct healing after revascularized ST-elevation myocardial infarction

Background:The inflammatory response due to myocardial tissue injury in the setting of acute ST-elevation myocardial infarction (STEMI) is essential for proper local infarct healing. However, an excessive inflammatory response may aggravate myocardial damage and hampers infarct healing processes. The present study aimed to investigate the association of systemic inflammatory biomarkers with infarct size (IS) dynamics post-STEMI, using cardiac magnetic resonance (CMR) imaging. MethodsThis prospective observational study included 245 STEMI patients treated with primary percutaneous coronary intervention (pPCI). Peak values of high-sensitivity C-reactive protein (hs-CRP), white blood cell count (WBCc) and fibrinogen were determined serially until 96 h after pPCI. Infarct healing, defined as relative IS reduction from baseline to 4 months after STEMI, was assessed using late gadolinium enhanced CMR imaging. ResultsIS significantly decreased from 16% of left ventricular mass (LVM) (Interquartile range [IQR]:8–24) at baseline to 10% (IQR:5–17) at 4 months (p < 0.001). Relative IS reduction was 35% (IQR:8–50). Whereas peak WBCc (p = 0.926) and peak fibrinogen (p = 0.161) were not significantly associated with relative IS reduction, peak hs-CRP showed a significant association with IS reduction (p = 0.003). In multivariable logistic regression analysis, the association between peak hs-CRP and relative IS reduction remained significant after adjustment for baseline IS, hypertension, hs-cardiac troponin T and N-terminal pro B-type natriuretic peptide (odds ratio:0.35 [95% confidence interval:0.19–0.63]; p = 0.001). ConclusionsIn STEMI patients treated with pPCI, hs-CRP was independently associated with 4 months IS reduction as determined by CMR, suggesting a pathophysiological interplay between inflammation and adverse infarct healing in survivors of acute STEMI.

High sensitivity C-reactive protein is associated with worse infarct healing after revascularized ST-elevation myocardial infarction

Abstract Background The inflammatory response due to myocardial tissue injury in the setting of acute ST-elevation myocardial infarction (STEMI) is essential for proper local infarct healing. However, an excessive inflammatory response may aggravate myocardial damage and hampers infarct healing processes. The present study aimed to investigate the association of systemic inflammatory biomarkers with infarct size (IS) dynamics post-STEMI, using cardiac magnetic resonance (CMR) imaging. Methods This prospective observational study included 245 STEMI patients treated with primary percutaneous coronary intervention (pPCI). Peak values of high-sensitivity C-reactive protein (hs-CRP), white blood cell count (WBCc) and fibrinogen were determined serially until 96 hours after pPCI. Infarct healing, defined as relative IS reduction from baseline to 4 months after STEMI, was assessed using late gadolinium enhanced CMR imaging. Results IS significantly decreased from 16% of left ventricular mass (LVM) (Interquartile range [IQR]:8–24) at baseline to 10% (IQR:5–17) at 4 months (p&amp;lt;0.001). Relative IS reduction was 35% (IQR:8–50). Whereas peak WBCc (p=0.926) and peak fibrinogen (p=0.161) were not significantly associated with relative IS reduction, peak hs-CRP showed a significant association with IS reduction (p=0.003). In multivariable logistic regression analysis, the association between peak hs-CRP and relative IS reduction remained significant after adjustment for baseline IS, hypertension, hs-cardiac troponin T and N-terminal pro B-type natriuretic peptide (odds ratio:0.35 [95% confidence interval:0.19–0.63]; p=0.001). Conclusions In STEMI patients treated with pPCI, hs-CRP was independently associated with 4 months IS reduction as determined by CMR, suggesting a pathophysiological interplay between inflammation and adverse infarct healing in survivors of acute STEMI. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Austrian Society of Cardiology

A global benchmark of algorithms for segmenting the left atrium from late gadolinium-enhanced cardiac magnetic resonance imaging.

Segmentation of medical images, particularly late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) used for visualizing diseased atrial structures, is a crucial first step for ablation treatment of atrial fibrillation. However, direct segmentation of LGE-MRIs is challenging due to the varying intensities caused by contrast agents. Since most clinical studies have relied on manual, labor-intensive approaches, automatic methods are of high interest, particularly optimized machine learning approaches. To address this, we organized the 2018 Left Atrium Segmentation Challenge using 154 3D LGE-MRIs, currently the world's largest atrial LGE-MRI dataset, and associated labels of the left atrium segmented by three medical experts, ultimately attracting the participation of 27 international teams. In this paper, extensive analysis of the submitted algorithms using technical and biological metrics was performed by undergoing subgroup analysis and conducting hyper-parameter analysis, offering an overall picture of the major design choices of convolutional neural networks (CNNs) and practical considerations for achieving state-of-the-art left atrium segmentation. Results show that the top method achieved a Dice score of 93.2% and a mean surface to surface distance of 0.7 mm, significantly outperforming prior state-of-the-art. Particularly, our analysis demonstrated that double sequentially used CNNs, in which a first CNN is used for automatic region-of-interest localization and a subsequent CNN is used for refined regional segmentation, achieved superior results than traditional methods and machine learning approaches containing single CNNs. This large-scale benchmarking study makes a significant step towards much-improved segmentation methods for atrial LGE-MRIs, and will serve as an important benchmark for evaluating and comparing the future works in the field. Furthermore, the findings from this study can potentially be extended to other imaging datasets and modalities, having an impact on the wider medical imaging community.

Left ventricular pseudothrombus: Multimodality imaging rules out a “ghost image” of a thrombus seen on cardiac computed tomography

Cardiac computed tomography showed a hypodense area in the apex of the left ventricle in a 57-year-old man with a history of anterior myocardial infarction three years earlier. To confirm or rule out a suspected thrombus, he underwent gadolinium-enhanced cardiac magnetic resonance imaging, contrast-enhanced two-dimensional transthoracic echocardiography, and three-dimensional transthoracic echocardiography. Multimodality imaging ruled out the presence of a thrombus.

Myocardial tissue characterization by gadolinium-enhanced cardiac magnetic resonance imaging for risk stratification of adverse events in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a genetic cardiomyopathy with a wide spectrum of clinical manifestations. Patients can be asymptomatic or suffer major adverse events including sudden cardiac death, ventricular arrhythmias, and heart failure. Identification of individuals with HCM who are at risk for these complications remains challenging. While echocardiography remains the mainstay of diagnostic evaluation, cardiac magnetic resonance imaging (CMR) is an important adjunctive diagnostic modality with emerging applications for risk-stratification of adverse events in the HCM population. Although not included in current guidelines for HCM management, there is increasing evidence to support the use of CMR for routine prognostic assessment of HCM patients. In this review we discuss the use of CMR techniques, including late gadolinium enhancement, T1 mapping, and quantification of extracellular volume fraction, for the risk stratification of three major adverse events in HCM: sudden cardiac death, ventricular arrhythmias, and congestive heart failure.

Pseudotrombo en ventrículo izquierdo. “Imagen fantasma” en tomografía axial computarizada. Diagnóstico multimodalidad

Cardiac computed tomography showed a hypodense area in the apex of the left ventricle in a 57-year-old man with a history of anterior myocardial infarction three years earlier. To confirm or rule out a suspected thrombus, he underwent gadolinium-enhanced cardiac magnetic resonance imaging, contrast-enhanced two-dimensional transthoracic echocardiography, and three-dimensional transthoracic echocardiography. Multimodality imaging ruled out the presence of a thrombus.

P872 A case of transient atrioventricular block: the role of cardiac magnetic resonance imaging

Abstract A 42-year old man with no relevant past medical history presented to the emergency department for recurrent transient loss of consciousness in the last 12 hours. 3 weeks earlier he had flu-like symptoms which spontaneously resolved. Physical examination revealed altered mental state, heart rate 30 beats per minute, respiratory rate 30 cycles per minute, blood pressure 70/40mmHg and basal lung rales on pulmonary auscultation. Blood gas analysis revealed hyperlactacidemia with hypocapnia. Electrocardiogram showed third-degree atrioventricular block. Atropine was administrated (total dose 3mg) with no rate response. Transcutaneous pacing was initiated followed by a temporary transvenous pacemaker, removed after 72 hours. Transthoracic echocardiogram revealed compromised left ventricular systolic function (ejection fraction by Simpson’s method 45%) due to septal dyskinesia and reduced global longitudinal strain (-11%). Blood analysis revealed erythrocyte sedimentation rate 20mm/hr, C-reactive protein 2.43mg/dL and negative high-sensitivity troponin T (9.44ng/L). Rheumatologic screening was negative. Coronary computed tomography angiography revealed normal epicardial coronaries. Cardiac magnetic resonance imaging (CMRI) performed 7 days after admission revealed preserved left ventricular systolic function (ejection fraction 51%). Late gadolinium enhancement showed scared myocardium in the medium and basal segments of the interventricular septum, compatible with subacute myocarditis. Due to the history of recurrent syncope, a permanent pacemaker was inserted. The patient was discharged the day after. No further syncope occurred. In last pacemaker follow-up, 9 months after presentation, patient had 0% auricular and ventricular pacing and 100% sensing over the previous 6 months. Discussion Transient atrioventricular block is a well-known complication of myocarditis when there is involvement of the conduction system by the inflammatory reaction. However, in rare cases it can persist or recur. CMRI plays an important role in these cases. Gadolinium-enhanced CMRI can be used to access the extent of inflammation and cellular edema and delayed-enhanced CMRI can also be used to quantify scarring which has important prognostic value. CMRI can also play a crucial role in excluding infiltrative disorders with conduction system involvement. Also, in these patients, the transient aspect of atrioventricular block poses a challenge when deciding about permanent pacemaker insertion. Abstract P872 Figure. Magnetic Ressonance IVS

160 Echocardiographic assessment of CRT candidates. Does additional scar evaluation by MRI improve prediction of response?

Abstract Background Myocardial scar presence and extent, has a considerable influence on response to cardiac resynchronization therapy (CRT). Apical rocking (ApRock) and septal flash (SF) are associated with favourable outcome after CRT. Little is known however to which extent visual assessment of mechanical dyssynchrony by ApRock, SF and scar predicts CRT response. We therefore investigated, if additional scar assessment by cardiac magnetic resonance imaging (MRI) adds to the predictive value of the visual evaluation of echocardiographic images in CRT candidates. Methods A total of 201 unselected patients referred for CRT, who fulfil the contemporary guidelines for CRT implantation, were enrolled in this prospective multicentre study. Two experienced observers visually assessed echocardiographic images before CRT implantation, focussing on the presence of ApRock, SF and location and extent of scar segments of the left ventricle (LV), resulting in a CRT response prediction (i.e. Integrative Prediction). A third observer provided a consensus reading in case of disagreement. All observers were blinded to all patient information other than the ischaemic aetiology of heart failure. Independent from that, segmental myocardial scar burden was objectified by late gadolinium enhancement (LGE) cardiac MRI (LGE &amp;gt; 50%). CRT response was defined as ≥15% reduction in LV end-systolic volume on echocardiography, one year after device implantation. Results Overall, 69 (34%) patients had an ischaemic aetiology of heart failure. Before CRT, ApRock and SF were present in 129 (64%) and 136 (68%) patients, respectively. ApRock and SF alone predicted CRT response with an area under the curve (AUC) of 0.85 (95% CI: 0.79-0.91) and 0.84 (95% CI: 0.77-0.91) (Figure A), while the echocardiographic Integrative Prediction had an AUC of 0.90 (95% CI: 0.84-0.95), with a sensitivity of 93% and a specificity of 87% for the prediction of CRT response (Figure B) (p &amp;lt; 0.05 vs. ApRock and SF alone). When combining information on ApRock, SF and the number of scarred segments on MRI in a statistical model, the AUC was comparable to the echocardiographic Integrative Prediction [0.90 (95% CI: 0.84-0.96)] as was sensitivity and specificity (91% and 83%, respectively, p = N.S. vs. Integrative Prediction) (Figure C). Conclusions An integrative visual assessment of LV function has an excellent predictive value for CRT response. Our data show, that the echocardiographic estimation of scar burden is sufficiently accurate and cannot be further improved by an additional MRI scar assessment. Abstract 160 Figure.

Assessment of ventricular tachyarrhythmia in patients with hypertrophic cardiomyopathy with machine learning-based texture analysis of late gadolinium enhancement cardiac MRI

To assess the diagnostic value of machine learning-based texture feature analysis of late gadolinium enhancement images on cardiac magnetic resonance imaging (MRI) for assessing the presence of ventricular tachyarrhythmia (VT) in patients with hypertrophic cardiomyopathy. This retrospective study included 64 patients with hypertrophic cardiomyopathy who underwent cardiac MRI and 24-hour Holter monitoring within 1 year before cardiac MRI. There were 42 men and 22 women with a mean age of 48.13±13.06 (SD) years (range: 20-70 years). Quantitative textural features were extracted via manually placed regions of interest in areas with high and intermediate signal intensity on late gadolinium-chelate enhanced images. Feature selection and dimension reduction were performed. The diagnostic performances of machine learning classifiers including support vector machines, Naive Bayes, k-nearest-neighbors, and random forest for predicting the presence of VT were assessed using the results of 24-hour Holter monitoring as the reference test. All machine learning models were assessed with and without the application of the synthetic minority over-sampling technique (SMOTE). Of the 64 patients with hypertrophic cardiomyopathy, 21/64 (32.8%) had VT. Of eight machine learning models investigated, k-nearest-neighbors with SMOTE exhibited the best diagnostic accuracy for the presence or absence of VT. k-nearest-neighbors with SMOTE correctly identified 40/42 (95.2%) VT-positive patients and 40/43 (93.0%) VT-negative patients, yielding 95.2% sensitivity (95% CI: 82.5%-99.1%), 93.0% specificity (95% CI: 79.8%-98.1%) and 94.1% accuracy (95% CI: 88.8%-98%). Machine learning-based texture analysis of late gadolinium-chelate enhancement-positive areas is a promising tool for the classification of hypertrophic cardiomyopathy patients with and without VT.

Unmodified autologous stem cells at point of care for chronic myocardial infarction.

BACKGROUNDNumerous studies investigated cell-based therapies for myocardial infarction (MI). The conflicting results of these studies have established the need for developing innovative approaches for applying cell-based therapy for MI. Experimental studies on animal models demonstrated the potential of fresh, uncultured, unmodified, autologous adipose-derived regenerative cells (UA-ADRCs) for treating acute MI. In contrast, studies on the treatment of chronic MI (CMI; > 4 wk post-MI) with UA-ADRCs have not been published so far. Among several methods for delivering cells to the myocardium, retrograde delivery into a temporarily blocked coronary vein has recently been demonstrated as an effective option.AIMTo test the hypothesis that in experimentally-induced chronic myocardial infarction (CMI; > 4 wk post-MI) in pigs, retrograde delivery of fresh, uncultured, unmodified, autologous adipose-derived regenerative cells (UA-ADRCs) into a temporarily blocked coronary vein improves cardiac function and structure.METHODSThe left anterior descending (LAD) coronary artery of pigs was blocked for 180 min at time point T0. Then, either 18 × 106 UA-ADRCs prepared at “point of care” or saline as control were retrogradely delivered via an over-the-wire balloon catheter placed in the temporarily blocked LAD vein 4 wk after T0 (T1). Effects of cells or saline were assessed by cardiac magnetic resonance (CMR) imaging, late gadolinium enhancement CMR imaging, and post mortem histologic analysis 10 wk after T0 (T2).RESULTSUnlike the delivery of saline, delivery of UA-ADRCs demonstrated statistically significant improvements in cardiac function and structure at T2 compared to T1 (all values given as mean ± SE): Increased mean LVEF (UA-ADRCs group: 34.3% ± 2.9% at T1 vs 40.4 ± 2.6% at T2, P = 0.037; saline group: 37.8% ± 2.6% at T1 vs 36.2% ± 2.4% at T2, P > 0.999), increased mean cardiac output (UA-ADRCs group: 2.7 ± 0.2 L/min at T1 vs 3.8 ± 0.2 L/min at T2, P = 0.002; saline group: 3.4 ± 0.3 L/min at T1 vs 3.6 ± 0.3 L/min at T2, P = 0.798), increased mean mass of the left ventricle (UA-ADRCs group: 55.3 ± 5.0 g at T1 vs 71.3 ± 4.5 g at T2, P < 0.001; saline group: 63.2 ± 3.4 g at T1 vs 68.4 ± 4.0 g at T2, P = 0.321) and reduced mean relative amount of scar volume of the left ventricular wall (UA-ADRCs group: 20.9% ± 2.3% at T1 vs 16.6% ± 1.2% at T2, P = 0.042; saline group: 17.6% ± 1.4% at T1 vs 22.7% ± 1.8% at T2, P = 0.022).CONCLUSIONRetrograde cell delivery of UA-ADRCs in a porcine model for the study of CMI significantly improved myocardial function, increased myocardial mass and reduced the formation of scar tissue.

Association Between Unrecognized Myocardial Infarction and Cerebral Infarction on Magnetic Resonance Imaging

It is uncertain whether unrecognized myocardial infarction (MI) is a risk factor for cerebral infarction. To determine whether unrecognized MI detected by cardiac magnetic resonance imaging (MRI) is associated with cerebral infarction. This is a cross-sectional study of ICELAND MI, a cohort substudy of the Age, Gene/Environment Susceptibility-Reykjavik Study conducted in Iceland. Enrollment occurred from January 2004 to January 2007 from a community-dwelling cohort of older Icelandic individuals. Participants aged 67 to 93 years who underwent both brain MRI and late gadolinium enhancement cardiac MRI were included. Data analysis was performed from September 2018 to March 2019. Unrecognized MI identified by cardiac MRI. Unrecognized MI was defined as cardiac MRI evidence of MI without a history of clinically evident MI. Recognized MI was defined as cardiac MRI evidence of MI with a history of clinically evident MI. Cerebral infarctions on brain MRI were included regardless of associated symptoms. Multiple logistic regression was used to evaluate the association between MI status (no MI, unrecognized MI, or recognized MI) and cerebral infarction after adjustment for demographic factors and vascular risk factors. In addition, we evaluated the association between unrecognized MI and embolic infarcts of undetermined source. Five enrolled participants had nondiagnostic brain MRI studies and were excluded. Among 925 participants, 480 (51.9%) were women; the mean (SD) age was 75.9 (5.3) years. There were 221 participants (23.9%) with cardiac MRI evidence of MI, of whom 68 had recognized MI and 153 unrecognized MI. There were 308 participants (33.3%) with brain MRI evidence of cerebral infarction; 93 (10.0%) had embolic infarcts of undetermined source. After adjustment for demographic factors and vascular risk factors, the likelihood (odds ratio) of having cerebral infarction was 2.0 (95% CI, 1.2-3.4; P = .01) for recognized MI and 1.5 (95% CI, 1.02-2.2; P = .04) for unrecognized MI. After adjustment for demographics and vascular risk factors, unrecognized MI was also associated with embolic infarcts of undetermined source (odds ratio, 2.0 [95% CI, 1.1-3.5]; P = .02). In a population-based sample, we found an association between unrecognized MI and cerebral infarction. These findings suggest that unrecognized MI may be a novel risk factor for cardiac embolism and cerebral infarction.

Quantitative Analysis of a Whole Cardiac Mass Using Dual-Energy Computed Tomography: Comparison with Conventional Computed Tomography and Magnetic Resonance Imaging

It is critical to distinguish between cardiac tumors and thrombi because they require different treatment strategies. Although accurate differentiation of these cardiac masses can be challenging, computed tomography (CT) and magnetic resonance imaging (MRI) are promising tools to improve their diagnosis. This study aimed to assess the diagnostic value of a volume-based quantification strategy using dual-energy CT to differentiate between cardiac tumors and thrombi. We prospectively enrolled 41 patients who had a cardiac mass. All patients underwent electrocardiography gated dual-energy CT. Among them, 28 patients underwent late gadolinium enhancement cardiac MRI. For quantitative analysis, the following parameters of the entire cardiac masses were measured: CT attenuation values in Hounsfield units (HU), iodine concentration (mg/ml), and signal intensity (SI) ratio. A mixed effects model was used to evaluate the significance of differences in mean CT attenuation, mean iodine concentration, and SI ratios between the cardiac tumor and thrombus groups. Diagnostic performance of each parameter was evaluated by constructing a receiver operating characteristics curve. A total of 24 cardiac tumors and 19 cardiac thrombi were analyzed. The mean iodine concentration was significantly higher in tumors than in thrombi (tumors: 2.98 ± 0.23; thrombi: 1.79 ± 0.26, p = 0.002). The diagnostic performance of iodine concentration was better than that of post-contrast HU (area under the curve [AUC]: 0.77 vs. 0.51; p < 0.001), and worse than that of SI ratio (AUC: 0.89; p = 0.04) for differentiation of cardiac tumors and thrombi. Dual-energy CT using volume-based iodine measurements can differentiate between cardiac tumors and thrombi.

High-resolution three-dimensional late gadolinium-enhanced cardiac magnetic resonance imaging to identify the underlying substrate of ventricular arrhythmia.

AimsCardiac magnetic resonance (CMR) is recommended as a second-line method to diagnose ventricular arrhythmia (VA) substrate. We assessed the diagnostic yield of CMR including high-resolution late gadolinium-enhanced (LGE) imaging.Methods and resultsConsecutive patients with sustained ventricular tachycardia (VT), non-sustained VT (NSVT), or ventricular fibrillation/aborted sudden death (VF/SCD) underwent a non-CMR diagnostic workup according to current guidelines, and CMR including LGE imaging with both a conventional breath-held and a free-breathing method enabling higher spatial resolution (HR-LGE). The diagnostic yield of CMR was compared with the non-CMR workup, including the incremental value of HR-LGE. A total of 157 patients were enrolled [age 54 ± 17 years; 75% males; 88 (56%) sustained VT, 52 (33%) NSVT, 17 (11%) VF/SCD]. Of these, 112 (71%) patients had no history of structural heart disease (SHD). All patients underwent electrocardiography and echocardiography, 72% coronary angiography, and 51% exercise testing. Pre-CMR diagnoses were 84 (54%) no SHD, 39 (25%) ischaemic cardiomyopathy (ICM), 11 (7%) non-ischaemic cardiomyopathy (NICM), 3 (2%) arrhythmogenic right ventricular cardiomyopathy (ARVC), 2 (1%) hypertrophic cardiomyopathy (HCM), and 18 (11%) other. CMR modified these diagnoses in 48 patients (31% of all and 43% of those with no SHD history). New diagnoses were 9 ICM, 28 NICM, 8 ARVC, 1 HCM, and 2 other. CMR modified therapy in 19 (12%) patients. In patients with no SHD after non-CMR tests, SHD was found in 32 of 84 (38%) patients. Eighteen of these patients showed positive HR-LGE and negative conventional LGE. Thus, HR-LGE significantly increased the CMR detection of SHD (17–38%, P < 0.001).ConclusionCMR including HR-LGE imaging has high diagnostic value in patients with VAs. This has major prognostic and therapeutic implications, particularly in patients with negative pre-CMR workup.

Magnetic Resonance Imaging-Detected Myocardial Inflammation and Fibrosis in Rheumatoid Arthritis: Associations With Disease Characteristics and N-Terminal Pro-Brain Natriuretic Peptide Levels.

Myocardial dysfunction and heart failure (HF) are increased in rheumatoid arthritis (RA), yet there are few studies of the myocardium in RA. RA patients with no known heart disease or risk factors underwent gadolinium-enhanced cardiac magnetic resonance imaging (MRI). Images were assessed for left-ventricular (LV) structural and functional parameters and for myocardial late gadolinium enhancement (LGE; an indicator of myocardial fibrosis) and T2-weighted imaging (an indicator of active inflammation). We modeled the associations between RA characteristics and N-terminal pro-brain natriuretic protein (NT-proBNP) levels with LGE and T2-weighted imaging. We also assessed whether LGE and/or T2-weighted imaging were associated with abnormal LV structure or dysfunction. A total of 60 RA patients were studied. LGE was present in 19 (32%) and T2-weighted imaging in 7 (12%), 5 of whom also had LGE. After adjustment for relevant confounders, higher odds of LGE with each swollen joint (odds ratio [OR] 1.87, P = 0.008), each log unit higher C-reactive protein level (OR 3.36, P = 0.047), and each log unit higher NT-proBNP (OR 20.61, P = 0.009) were found. NT-proBNP was also significantly higher (135%) among those with T2-weighted imaging than in those without T2-weighted imaging or LGE. Higher LV mass index and LV mass:end diastolic volume ratio were observed in those with T2-weighted imaging than in those with no myocardial abnormalities and in those with LGE without T2-weighted imaging; however, ejection fraction was not reduced in those with either LGE or T2-weighted imaging. These data suggest that cardiac MRI findings indicating myocardial inflammation/fibrosis are correlated with RA disease activity and alterations in myocardial structure known to precede clinical HF.

Plasminogen Activator Inhibitor Type I Controls Cardiomyocyte Transforming Growth Factor-β and Cardiac Fibrosis.

Fibrosis is the pathological consequence of stress-induced tissue remodeling and matrix accumulation. Increased levels of plasminogen activator inhibitor type I (PAI-1) have been shown to promote fibrosis in multiple organ systems. Paradoxically, homozygous genetic deficiency of PAI-1 is associated with spontaneous age-dependent, cardiac-selective fibrosis in mice. We have identified a novel PAI-1-dependent mechanism that regulates cardiomyocyte-derived fibrogenic signals and cardiac transcriptional pathways during injury. Cardiac fibrosis in subjects with homozygous mutation in SERPINE-1 was evaluated with late gadolinium-enhanced cardiac magnetic resonance imaging. A murine cardiac injury model was performed by subcutaneous infusion of either saline or Angiotensin II by osmotic minipumps. We evaluated blood pressure, cardiac function (by echocardiography), fibrosis (with Masson Trichrome staining), and apoptosis (with TUNEL staining), and we performed transcriptome analysis (with RNA sequencing). We further evaluated fibrotic signaling in isolated murine primary ventricular myocytes. Cardiac fibrosis was detected in 2 otherwise healthy humans with complete PAI-1 deficiency because of a homozygous frameshift mutation in SERPINE-1. In addition to its suppressive role during spontaneous cardiac fibrosis in multiple species, we hypothesized that PAI-1 also regulates fibrosis during cardiac injury. Treatment of young PAI-1-/- mice with Angiotensin II induced extensive hypertrophy and fibrotic cardiomyopathy, with increased cardiac apoptosis and both reactive and replacement fibrosis. Although Angiotensin II-induced hypertension was blunted in PAI-1-/- mice, cardiac hypertrophy was accelerated. Furthermore, ventricular myocytes were found to be an important source of cardiac transforming growth factor-β (TGF-β) and PAI-1 regulated TGF-β synthesis by cardiomyocytes in vitro as well as in vivo during cardiac injury. Transcriptome analysis of ventricular RNA after Angiotensin II treatment confirmed that PAI-1 deficiency significantly enhanced multiple TGF-β signaling elements and transcriptional targets, including genes for extracellular matrix components, mediators of extracellular matrix remodeling, matricellular proteins, and cardiac integrins compared with wild-type mice. PAI-1 is an essential repressor of cardiac fibrosis in mammals. We define a novel cardiomyocyte-specific regulatory mechanism for TGF-β production by PAI-1, which explains the paradoxical effect of PAI-1 deficiency in promoting cardiac-selective fibrosis. Thus, PAI-1 is a molecular switch that controls the cardiac TGF-β axis and its early transcriptional effects that lead to myocardial fibrosis.

Right ventricular outflow tract high-density endocardial unipolar voltage mapping in patients with Brugada syndrome: evidence for electroanatomical abnormalities.

Epicardial structural abnormalities at the right ventricular outflow tract (RVOT) may provide the arrhythmia substrate in Brugada syndrome (BrS). Electroanatomical endocardial unipolar voltage mapping is an emerging tool that accurately identifies epicardial abnormalities in different clinical settings. This study investigated whether endocardial unipolar voltage mapping of the RVOT detects electroanatomical abnormalities in patients with BrS. Ten asymptomatic patients (8 males, 34.5 ± 11.2 years) with spontaneous type 1 ECG pattern of BrS and negative late gadolinium enhancement-cardiac magnetic resonance imaging (LGE-c-MRI) underwent high-density endocardial electroanatomical mapping (>800 points). Using a cut-off of 1 mV and 4 mV for normal bipolar and unipolar voltage, respectively, derived from 20 control patients without structural heart disease established by LGE-c-MRI, the extend of low-voltage areas within the RVOT was estimated using a specific calculation software. The mean RVOT area presenting low-voltage bipolar signals in BrS patients was 3.4 ± 1.7 cm2 (range 1.5-7 cm2). A significantly greater area of abnormal unipolar signals was identified (12.6 ± 4.6 cm2 [range 7-22 cm2], P: 0.001). Both bipolar and unipolar electroanatomical abnormalities were mainly located at the free wall of the RVOT. The mean RVOT activation time was significantly prolonged in BrS patients compared to control population (86.4 ± 16.5 vs. 63.4 ± 9.7 ms, P < 0.001). Isochronal mapping demonstrated lines of conduction slowing within the RVOT in 8/10 BrS patients. Wide areas of endocardial unipolar voltage abnormalities that possibly reflect epicardial structural abnormalities are identified at the RVOT of BrS patients.