AI Cardiac MRI Scar Analysis Aids Prediction of Major Arrhythmic Events in the Multicenter DERIVATE Registry.

Background Scar burden with late gadolinium enhancement (LGE) cardiac MRI (CMR) predicts arrhythmic events in patients with postinfarction in single-center studies. However, LGE analysis requires experienced human observers, is time consuming, and introduces variability. Purpose To test whether postinfarct scar with LGE CMR can be quantified fully automatically by machines and to compare the ability of LGE CMR scar analyzed by humans and machines to predict arrhythmic events. Materials and Methods This study is a retrospective analysis of the multicenter, multivendor CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DebrillAtor ThErapy (DERIVATE) registry. Patients with chronic heart failure, echocardiographic left ventricular ejection fraction (LVEF) of less than 50%, and LGE CMR were recruited (from January 2015 through December 2020). In the current study, only patients with ischemic cardiomyopathy were included. Quantification of total, dense, and nondense scars was carried out by two experienced readers or a Ternaus network, trained and tested with LGE images of 515 and 246 patients, respectively. Univariable and multivariable Cox analyses were used to assess patient and cardiac characteristics associated with a major adverse cardiac event (MACE). Area under the receiver operating characteristic curve (AUC) was used to compare model performances. Results In 761 patients (mean age, 65 years ± 11, 671 men), 83 MACEs occurred. With use of the testing group, univariable Cox-analysis found New York Heart Association class, left ventricle volume and/or function parameters (by echocardiography or CMR), guideline criterion (LVEF of ≤35% and New York Heart Association class II or III), and LGE scar analyzed by humans or the machine-learning algorithm as predictors of MACE. Machine-based dense or total scar conferred incremental value over the guideline criterion for the association with MACE (AUC: 0.68 vs 0.63, P = .02 and AUC: 0.67 vs 0.63, P = .01, respectively). Modeling with competing risks yielded for dense and total scar (AUC: 0.67 vs 0.61, P = .01 and AUC: 0.66 vs 0.61, P = .005, respectively). Conclusion In this analysis of the multicenter CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DebrillAtor ThErapy (DERIVATE) registry, fully automatic machine learning-based late gadolinium enhancement analysis reliably quantifies myocardial scar mass and improves the current prediction model that uses guideline-based risk criteria for implantable cardioverter defibrillator implantation. ClinicalTrials.gov registration no.: NCT03352648 Published under a CC BY 4.0 license. Supplemental material is available for this article.

Semiquantitative Chest CT Severity Score Predicts Failure of Noninvasive Positive-Pressure Ventilation in Patients Hospitalized for COVID-19 Pneumonia.

OBJECTIVE: Noninvasive positive-pressure ventilation (NPPV) emerged as an efficient tool for treatment of COVID-19 pneumonia. The factors influencing NPPV failure still are elusive. The aim of the study was to investigate the relationships between semiquantitative chest computed tomography (CT) scoring and NPPV failure and mortality in patients with COVID-19. DESIGN: Observational study. SETTING: Nonintensive care setting. PARTICIPANTS: A total of 112 patients consecutively admitted for COVID-19 pneumonia. INTERVENTIONS: Usual care including various degrees of respiratory support. MEASUREMENTS AND MAIN RESULTS: The semiquantitative CT score was calculated at hospital admission. Subgroups were identified according to the ventilation strategy used (oxygen delivered by Venturi mask n = 53; NPPV-responder n = 38; NPPV-failure n = 21). The study's primary endpoint was the use of NPPV. The secondary endpoints were NPPV failure and in-hospital death, respectively. CT score progressively increased among groups (six v nine v 14, p < 0.05 among all). CT score was an independent predictor of all study endpoints (primary endpoint: 1.25 [95% confidence interval {CI} 1.1-1.4], p = 0.001; NPPV failure: 1.41 [95% CI 1.18-1.69], p < 0.001; in-hospital mortality: 1.21 [95% CI 1.07-1.38], p = 0.003). According to receiver operator characteristics curve analysis, CT score was the most accurate variable for prediction of NPPV failure (area under the curve 0.862 with p < 0.001; p < 0.05 v other variables). CONCLUSIONS: The authors reported the common and effective use of NPPV in patients with COVID-19 pneumonia. In the authors' population, a semiquantitative chest CT analysis at hospital admission accurately identified those patients responding poorly to NPPV.

CarDiac magnEtic Resonance for prophylactic Implantable-cardioVerter defibrillAtor ThErapy in Non-Ischaemic dilated CardioMyopathy: an international Registry.

AIMS: The aim of this registry was to evaluate the additional prognostic value of a composite cardiac magnetic resonance (CMR)-based risk score over standard-of-care (SOC) evaluation in a large cohort of consecutive unselected non-ischaemic cardiomyopathy (NICM) patients. METHODS AND RESULTS: In the DERIVATE registry (www.clinicaltrials.gov/registration: RCT#NCT03352648), 1000 (derivation cohort) and 508 (validation cohort) NICM patients with chronic heart failure (HF) and left ventricular ejection fraction <50% were included. All-cause mortality and major adverse arrhythmic cardiac events (MAACE) were the primary and secondary endpoints, respectively. During a median follow-up of 959 days, all-cause mortality and MAACE occurred in 72 (7%) and 93 (9%) patients, respectively. Age and >3 segments with midwall fibrosis on late gadolinium enhancement (LGE) were the only independent predictors of all-cause mortality (HR: 1.036, 95% CI: 1.0117-1.056, P < 0.001 and HR: 2.077, 95% CI: 1.211-3.562, P = 0.008, respectively). For MAACE, the independent predictors were male gender, left ventricular end-diastolic volume index by CMR (CMR-LVEDVi), and >3 segments with midwall fibrosis on LGE (HR: 2.131, 95% CI: 1.231-3.690, P = 0.007; HR: 3.161, 95% CI: 1.750-5.709, P < 0.001; and HR: 1.693, 95% CI: 1.084-2.644, P = 0.021, respectively). A composite clinical and CMR-based risk score provided a net reclassification improvement of 63.7% (P < 0.001) for MAACE occurrence when added to the model based on SOC evaluation. These findings were confirmed in the validation cohort. CONCLUSION: In a large multicentre, multivendor cohort registry reflecting daily clinical practice in NICM work-up, a composite clinical and CMR-based risk score provides incremental prognostic value beyond SOC evaluation, which may have impact on the indication of implantable cardioverter-defibrillator implantation.

Patterns of late gadolinium enhancement in Duchenne muscular dystrophy carriers.

BACKGROUND: This study was designed to assess whether cardiovascular magnetic resonance imaging (CMR) in Duchenne muscular dystrophy carriers (DMDc) may index any cell milieu elements of LV dysfunction and whether this cardiac phenotype may be related to genotype. The null hypothesis was that myocardial fibrosis, assessed by late gadolinium enhancement (LGE), might be similarly accounted for in DMDc and gender and age-matched controls. METHODS: Thirty DMDc patients had CMR and genotyping with 37 gender and age-matched controls. Systolic and diastolic LV function was assessed by 2D-echocardiography. RESULTS: Absolute and percent LGE were higher in muscular symptomatic (sym) than asymptomatic (asy) DMDc (1.77 ± 0.27 vs 0.76 ± 0.17 ml; F = 19.6, p < 0.0001 and 1.86 ± 0.26% vs 0.68 ± 0.17%, F = 22.1, p < 0.0001, respectively). There was no correlation between LGE and age. LGE was seen most frequently in segments 5 and 6; segment 5 was involved in all asy-DMDc. Subepicardial LGE predominated, compared to the mid-myocardial one (11 out of 14 DMDc). LGE was absent in the subendocardium. No correlations were seen between genotyping (type of mutation, gene region and protein domain), confined to the exon's study, and cardiac phenotype. CONCLUSIONS: A typical myocardial LGE-pattern location (LV segments 5 and 6) was a common finding in DMDc. LGE was more frequently subepicardial plus midmyocardial in sym-DMDc, with normal LV systolic and diastolic function. No genotype-phenothype correlation was found.

Myocardial oedema contributes to interstitial expansion and associates with mechanical and electrocardiographic changes in takotsubo syndrome: a CMR T1 and T2 mapping study.

AIMS: myocardial oedema is largely represented in takotsubo syndrome (TTS) and may contribute to alter the myocardium morphology and function. The aim of the study is to describe relationships between oedema, mechanical, and electrical abnormalities in TTS. METHODS AND RESULTS: the study included n = 32 hospitalized TTS patients and n = 23 controls. Cardiac magnetic resonance (CMR) with tissue mapping and feature tracking was performed with concomitant 12-lead electrocardiogram (ECG) recording. Mean age of TTS was 72 ± 12 years old, 94% women. Compared with controls, patients had higher left ventricular (LV) mass, worse systolic function, higher septal native T1 (1116 ± 73 msec vs. 970 ± 23 msec, P < 0.001), T2 (56 ± 5 msec vs. 46 ± 2 msec, P < 0.001), and extracellular volume (ECV) fraction (32 ± 5% vs. 24 ± 1%, P < 0.001). TTS patients had higher apicobasal gradient of T2 values (12 ± 6 msec vs. 2 ± 6 msec, P < 0.001); basal LV wall displayed higher native T1, T2, and ECV (all P < 0.002) but similar circumferential strain against controls (-23 ± 3% vs. -24 ± 4%, P = 0.351). In the TTS cohort, septal T2 values showed significant correlations with native T1 (r = 0.609, P < 0.001), ECV (r = 0.689, P < 0.001), left ventricular ejection fraction (r = -0.459, P = 0.008) and aVR voltage (r = -0.478, P = 0.009). Negative T-wave voltage and QTc length correlated with apicobasal T2 mapping gradient (r = 0.499, P = 0.007 and r = 0.372, P = 0.047, respectively) but not with other tissue mapping measurements. CONCLUSIONS: CMR T1 and T2 mapping demonstrated increased myocardial water content conditioning interstitial expansion in acute TTS, detected even outside areas of abnormal wall motion. Oedema burden and distribution associated with mechanical and electrocardiographic changes, making it a potential prognostic marker and therapeutic target in TTS.

Cardiac Magnetic Resonance for Prophylactic Implantable-Cardioverter Defibrillator Therapy in Ischemic Cardiomyopathy: The DERIVATE-ICM International Registry.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) therapy is the most effective prophylactic strategy against sudden cardiac death (SCD) in patients with ischemic cardiomyopathy (ICM) and left ventricle ejection fraction (LVEF) ≤35% as detected by transthoracic echocardiograpgy (TTE). This approach has been recently questioned because of the low rate of ICD interventions in patients who received implantation and the not-negligible percentage of patients who experienced SCD despite not fulfilling criteria for implantation. OBJECTIVES: The DERIVATE-ICM registry (CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DebrillAtor ThErapy; NCT03352648) is an international, multicenter, and multivendor study to assess the net reclassification improvement (NRI) for the indication of ICD implantation by the use of cardiac magnetic resonance (CMR) as compared to TTE in patients with ICM. METHODS: A total of 861 patients with ICM (mean age 65 ± 11 years, 86% male) with chronic heart failure and TTE-LVEF <50% participated. Major adverse arrhythmic cardiac events (MAACE) were the primary endpoints. RESULTS: During a median follow-up of 1,054 days, MAACE occurred in 88 (10.2%). Left ventricular end-diastolic volume index (HR: 1.007 [95% CI: 1.000-1.011]; P = 0.05), CMR-LVEF (HR: 0.972 [95% CI: 0.945-0.999]; P = 0.045) and late gadolinium enhancement (LGE) mass (HR: 1.010 [95% CI: 1.002-1.018]; P = 0.015) were independent predictors of MAACE. A multiparametric CMR weighted predictive derived score identifies subjects at high risk for MAACE compared with TTE-LVEF cutoff of 35% with a NRI of 31.7% (P = 0.007). CONCLUSIONS: The DERIVATE-ICM registry is a large multicenter registry showing the additional value of CMR to stratify the risk for MAACE in a large cohort of patients with ICM compared with standard of care.

Characterization of COVID-19-Related Lung Involvement in Patients Undergoing Magnetic Resonance T1 and T2 Mapping Imaging: A Pilot Study.

Tissue characterization by mapping techniques is a recent magnetic resonance imaging (MRI) tool that could aid the tissue characterization of lung parenchyma in coronavirus disease-2019 (COVID-19). The aim of the present study was to compare lung MRI findings, including T1 and T2 mapping, in a group of n = 11 patients with COVID-19 pneumonia who underwent a scheduled cardiac MRI, and a cohort of healthy controls. MRI scout images were used to identify affected and remote lung regions within the patients' cohort and appropriate regions of interest (ROIs) were drawn accordingly. Both lung native T1 and T2 values were significantly higher in the affected areas of patients with COVID-19 as compared to the controls (1375 ms vs. 1201 ms, p = 0.016 and 70 ms vs. 30 ms, p < 0.001, respectively), whereas no significant differences were detected between the remote lung parenchyma of the COVID-19 patients and the controls (both p > 0.05). When a larger ROI was identified, comprising the whole lung parenchyma within the image irrespective of the affected and remote areas, the COVID-19 patients still retained higher native T1 (1278 ms vs. 1149 ms, p = 0.003) and T2 values (38 ms vs. 34 ms, p = 0.04). According to the receiver operator characteristics curves, the T2 value of the affected region retained the higher accuracy for the differentiation of the COVID-19 patients against the controls (area under the curve 0.934, 95% confidence interval 0.826−0.999). These findings, possibly driven by the ability of MRI tissue mapping to detect ongoing inflammation in the lungs of patients with COVID-19, suggest that T1 and T2 mapping of the lung is a feasible approach in this clinical scenario.

Lung Ultrasound in COVID-19: Clinical Correlates and Comparison with Chest Computed Tomography.

Lung ultrasound (LUS) and chest computed tomography (chest CT) are largely employed to evaluate coronavirus disease 2019 (COVID-19) pneumonia. We investigated semi-quantitative LUS and CT scoring in hospitalized COVID-19 patients. LUS and chest CT were performed within 24 h upon admission. Both were analyzed according to semi-quantitative scoring systems. Subgroups were identified according to median LUS score. Patients within higher LUS score group were older (79 vs 60 years, p<0.001), had higher C-reactive protein (CRP) (7.2 mg/dl vs 1.3 mg/dl, p<0.001) and chest CT score (10 vs 4, p=0.027) as well as lower PaO2/FiO2 (286 vs 356, p=0.029) as compared to patients within lower scores. We found a significant correlation between scores (r=0.390, p=0.023). Both LUS and CT scores correlated directly with patients age (r=0.586, p<0.001 and r=0.399, p=0.021 respectively) and CRP (r=0.472, p=0.002 and r=0.518, p=0.002 respectively), inversely with PaO2/FiO2 (r=-0.485, p=0.003 and r=-0.440, p=0.017 respectively). LUS score only showed significant correlation with hs-troponin T, NT-pro-BNP, and creatinine (r=0.433, p=0.019; r=0.411, p=0.027, and r=0.497, p=0.001, respectively). Semi-quantitative bedside LUS is related to the severity of COVID-19 pneumonia similarly to chest CT. Correlation of LUS score with markers of cardiac and renal injury suggests that LUS might contribute to a more comprehensive evaluation of this heterogeneous population.

Cardiac magnetic resonance in patients with acute cardiac injury and unobstructed coronary arteries.

AIM: To define the role of cardiac magnetic resonance (CMR) by analyzing a particular group of patients with suspected acute coronary syndrome (ACS) and normal coronary angiogram. METHODS: From January 2009 to December 2015, we examined 220 patients with clinical suspicion of ACS, Troponin elevation [the threshold used to define a positive Troponin T test (TnT) was 0.1 ng/mL] and no significant coronary disease at angiography (the patients were considered to have significant angiographic disease only a 50% stenosis was detected in any of their coronary arteries). The role of CMR with the late gadolinium enhancement was evaluated. RESULTS: CMR was performed to 190 patients (86%) of this group which reveals: Myocarditis in 90 patients (47%); apical ballooning (Tako-Tsubo syndrome) in 32 patients (17%); myocardial infarction (MI) in 40 patients (21%) and no clear diagnosis identified by CMR in 28 patients (15%). A comparison with previous studies was also made. Clinical and echocardiographic follow-ups were performed at 12 ± 2 mo and no major adverse cardiac events were revealed. CONCLUSION: There is a group of patients with clinical suspicion of ACS displaying normal coronary angiograms. CMR was demonstrated to be a valuable tool in the differential diagnosis evaluation of myocarditis, apical ballooning and MI.

Italian registry of cardiac magnetic resonance.

OBJECTIVES: Forty sites were involved in this multicenter and multivendor registry, which sought to evaluate indications, spectrum of protocols, impact on clinical decision making and safety profile of cardiac magnetic resonance (CMR). MATERIALS AND METHODS: Data were prospectively collected on a 6-month period and included 3376 patients (47.2 ± 19 years; range 1-92 years). Recruited centers were asked to complete a preliminary general report followed by a single form/patient. Referral physicians were not required to exhibit any specific certificate of competency in CMR imaging. RESULTS: Exams were performed with 1.5T scanners in 96% of cases followed by 3T (3%) and 1T (1%) magnets and contrast was administered in 84% of cases. The majority of cases were performed for the workup of inflammatory heart disease/cardiomyopathies representing overall 55.7% of exams followed by the assessment of myocardial viability and acute infarction (respectively 6.9% and 5.9% of patients). In 49% of cases the final diagnosis provided was considered relevant and with impact on patient's clinical/therapeutic management. Safety evaluation revealed 30 (0.88%) clinical events, most of which due to patient's preexisting conditions. Radiological reporting was recorded in 73% of exams. CONCLUSIONS: CMR is performed in a large number of centers in Italy with relevant impact on clinical decision making and high safety profile.

Late enhancement detected by cardiac magnetic resonance imaging in acute myocarditis mimicking acute myocardial infarction: location patterns and lack of correlation with systolic function.

OBJECTIVE: Clinical recognition of acute myocarditis is difficult. Late enhancement (LE) detected by magnetic resonance imaging appears to be a valuable tool for evaluating and monitoring inflammatory myocardial diseases. However, patterns of myocardial enhancement and its correlation with systolic function are not yet well defined. The aim of this study was to assess the extent and location of LE during the acute phase of active myocarditis mimicking acute myocardial infarction and at follow-up, in order to correlate LE with systolic function and to monitor disease progression. METHODS: Magnetic resonance imaging was performed in 13 patients with clinical symptoms and signs of acute myocarditis. RESULTS: All patients showed LE, which was located in the lateral free wall in 11 (85%) patients, at the basal level in eight (61%), at the mid level in nine (69%), and at the distal level in 10 (77%). Moreover, six (46%) patients showed LE in the posterior and inferior wall (P = 0.099 versus lateral wall), four (31%) patients in the septum and inferior wall (P = 0.017 versus lateral wall) and three (23%) patients in the anterior wall (P = 0.006 versus lateral wall). Left ventricular ejection fraction was 0.50 +/- 10 and it was severely reduced only in one patient (0.20). Conversely, in the remaining patients, left ventricular ejection fraction was preserved (> or =0.45) (P < 0.001). Multifocal LE was detected in eight (61%) patients, whereas pericardial effusion was observed only in two (15%) patients (P = 0.002). Twelve patients showed ST-segment elevation and chest pain, as it occurs in acute myocardial infarction, whereas one patient showed non-ST-segment elevation with dyspnoea, as it occurs in non-ST-elevation myocardial infarction. The mean follow-up duration was 4 +/- 12 months, and follow-up was complete for all but one patient who died. LE extent decreased in 11 (92%) patients, whereas new areas of LE were detected in one (8%) patient (P < 0.001). CONCLUSIONS: Contrast enhancement is a frequent finding in the clinical setting of suspected myocarditis and is associated with active and/or persistent myocardial inflammation. Myocarditis detected by magnetic resonance imaging predominantly occurs in the lateral free wall and very rarely affects systolic function.