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.

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 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. 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.

Aims: Accurate risk stratification for patients with non-dilated left ventricular cardiomyopathy (NDLVC) remains challenging due to lack of dedicated clinical trials. This post hoc analysis aims to delineate the arrhythmic risk and assess the incremental value of cardiac magnetic resonance (CMR) imaging in the CarDiac magnEtic Resonance for prophylactic Implantable-cardioVerter defibrillAtor ThErapy (DERIVATE) study cohort meeting the NDLVC diagnostic criteria. Methods and results: Patients with NDLVC from the DERIVATE registry were identified in the absence of left ventricular (LV) dilatation and in the presence of non-ischaemic LV scarring (‘fibrotic NDLVC’) or isolated LV systolic dysfunction (LV ejection fraction < 50%) without fibrosis (‘hypokinetic NDLVC’). The primary endpoint was all-cause mortality. Major adverse arrhythmic cardiac events (MAACE) were the secondary endpoint and included sudden cardiac death (SCD) and aborted SCD. One hundred and ninety-seven NDLVC patients were identified from the cohort of the DERIVATE study (mean age: 59 ± 14 years; male: 135). Over a median follow-up of 2.7 years, 15 (8%) patients died and 8 (4%) experienced MAACE. Patients with ‘hypokinetic’ NDLVC had significantly lower rates of MAACE than non-ischaemic dilated cardiomyopathy (NIDCM) (P = 0.001), while patients with ‘fibrotic’ NDLVC had same rate of both primary (P = 0.48) and secondary endpoints (P = 0.616) compared with NIDCM patients. Multivariable analysis identified late gadolinium enhancement (LGE) with midwall distribution as an independent predictor of MAACE in NDLVC patients (hazard ratio 6.7, 95% confidence interval: 1.33–33.67; P = 0.021). Conclusion: NDLVC patients exhibit a heterogeneous risk profile for arrhythmic events. The presence of midwall LGE, similarly to NIDCM, is a significant predictor of MAACE, highlighting the importance of CMR imaging for risk stratification.

Immune checkpoint inhibitors (ICIs) are a family of anticancer drugs in which the immune response elicited against the tumor may involve other organs, including the heart. Cardiac magnetic resonance (CMR) imaging is increasingly used in the diagnostic work-up of myocardial inflammation; recently, several studies investigated the use of CMR in patients with ICI-myocarditis (ICI-M). The aim of the present systematic review is to summarize the available evidence on CMR findings in ICI-M. We searched electronic databases for relevant publications; after screening, six studies were selected, including 166 patients from five cohorts, and further 86 patients from a sub-analysis that were targeted for a tissue mapping assessment. CMR revealed mostly preserved left ventricular ejection fraction; edema prevalence ranged from 9% to 60%; late gadolinium enhancement (LGE) prevalence ranged from 23% to 83%. T1 and T2 mapping assessment were performed in 108 and 104 patients, respectively. When available, the comparison of CMR with endomyocardial biopsy revealed partial agreement between techniques and was higher for native T1 mapping amongst imaging biomarkers. The prognostic assessment was inconsistently assessed; CMR variables independently associated with the outcome included decreasing LVEF and increasing native T1. In conclusion, CMR findings in ICI-M include myocardial dysfunction, edema and fibrosis, though less evident than in more classic forms of myocarditis; native T1 mapping retained the higher concordance with EMB and significant prognostic value.

Uremic cardiomyopathy (UC), the peculiar cardiac remodeling secondary to the systemic effects of renal dysfunction, is characterized by left ventricular (LV) diffuse fibrosis with hypertrophy (LVH) and stiffness and the development of heart failure and increased rates of cardiovascular mortality. Several imaging modalities can be used to obtain a non-invasive assessment of UC by different imaging biomarkers, which is the focus of the present review. Echocardiography has been largely employed in recent decades, especially for the determination of LVH by 2-dimensional imaging and diastolic dysfunction by pulsed-wave and tissue Doppler, where it retains a robust prognostic value; more recent techniques include parametric assessment of cardiac deformation by speckle tracking echocardiography and the use of 3D-imaging. Cardiac magnetic resonance (CMR) imaging allows a more accurate assessment of cardiac dimensions, including the right heart, and deformation by feature-tracking imaging; however, the most evident added value of CMR remains tissue characterization. T1 mapping demonstrated diffuse fibrosis in CKD patients, increasing with the worsening of renal disease and evident even in early stages of the disease, with few, but emerging, prognostic data. Some studies using T2 mapping highlighted the presence of subtle, diffuse myocardial edema. Finally, computed tomography, though rarely used to specifically assess UC, might provide incidental findings carrying prognostic relevance, including information on cardiac and vascular calcification. In summary, non-invasive cardiovascular imaging provides a wealth of imaging biomarkers for the characterization and risk-stratification of UC; integrating results from different imaging techniques can aid a better understanding of the physiopathology of UC and improve the clinical management of patients with CKD.