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.

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.

Clinical Presentation and Outcome in a Contemporary Cohort of Patients With Acute Myocarditis: Multicenter Lombardy Registry.

BACKGROUND: There is controversy about the outcome of patients with acute myocarditis (AM), and data are lacking on how patients admitted with suspected AM are managed. We report characteristics, in-hospital management, and long-term outcome of patients with AM based on a retrospective multicenter registry from 19 Italian hospitals. METHODS: A total of 684 patients with suspected AM and recent onset of symptoms (<30 days) were screened between May 2001 and February 2017. Patients >70 years of age and those >50 years of age without coronary angiography were excluded. The final study population comprised 443 patients (median age, 34 years; 19.4% female) with AM diagnosed by either endomyocardial biopsy or increased troponin plus edema and late gadolinium enhancement at cardiac magnetic resonance. RESULTS: At presentation, 118 patients (26.6%) had left ventricular ejection fraction <50%, sustained ventricular arrhythmias, or a low cardiac output syndrome, whereas 325 (73.4%) had no such complications. Endomyocardial biopsy was performed in 56 of 443 (12.6%), and a baseline cardiac magnetic resonance was performed in 415 of 443 (93.7%). Cardiac mortality plus heart transplantation rates at 1 and 5 years were 3.0% and 4.1%. Cardiac mortality plus heart transplantation rates were 11.3% and 14.7% in patients with complicated presentation and 0% in uncomplicated cases (log-rank P<0.0001). Major AM-related cardiac events after the acute phase (postdischarge death and heart transplantation, sustained ventricular arrhythmias treated with electric shock or ablation, symptomatic heart failure needing device implantation) occurred in 2.8% at the 5-year follow-up, with a higher incidence in patients with complicated forms (10.8% versus 0% in uncomplicated AM; log-rank P<0.0001). ß-Adrenoceptor blockers were the most frequently used medications both in complicated (61.9%) and in uncomplicated forms (53.8%; P=0.18). After a median time of 196 days, 200 patients had follow-up cardiac magnetic resonance, and 8 of 55 (14.5%) with complications at presentation had left ventricular ejection fraction <50% compared with 1 of 145 (0.7%) of those with uncomplicated presentation. CONCLUSIONS: In this contemporary study, overall serious adverse events after AM were lower than previously reported. However, patients with left ventricular ejection fraction <50%, ventricular arrhythmias, or low cardiac output syndrome at presentation were at higher risk compared with uncomplicated cases that had a benign prognosis and low risk of subsequent left ventricular systolic dysfunction.

Cardiac magnetic resonance for prophylactic implantable-cardioverter defibrillator therapy international study: prognostic value of cardiac magnetic resonance-derived right ventricular parameters substudy.

AIMS: Right ventricular systolic dysfunction (RVSD) is an important determinant of outcomes in heart failure (HF) cohorts. While the quantitative assessment of RV function is challenging using 2D-echocardiography, cardiac magnetic resonance (CMR) is the gold standard with its high spatial resolution and precise anatomical definition. We sought to investigate the prognostic value of CMR-derived RV systolic function in a large cohort of HF with reduced ejection fraction (HFrEF). METHODS AND RESULTS: Study cohort comprised of patients enrolled in the CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DefibrillAtor ThErapy registry who had HFrEF and had simultaneous baseline CMR and echocardiography (n = 2449). RVSD was defined as RV ejection fraction (RVEF) <45%. Kaplan-Meier curves and cox regression were used to investigate the association between RVSD and all-cause mortality (ACM). Mean age was 59.8 ± 14.0 years, 42.0% were female, and mean left ventricular ejection fraction (LVEF) was 34.0 ± 10.8. Median follow-up was 959 days (interquartile range: 560-1590). RVSD was present in 936 (38.2%) and was an independent predictor of ACM (adjusted hazard ratio = 1.44; 95% CI [1.09-1.91]; P = 0.01). On subgroup analyses, the prognostic value of RVSD was more pronounced in NYHA I/II than in NYHA III/IV, in LVEF <35% than in LVEF ≥35%, and in patients with renal dysfunction when compared to those with normal renal function. CONCLUSION: RV systolic dysfunction is an independent predictor of ACM in HFrEF, with a more pronounced prognostic value in select subgroups, likely reflecting the importance of RVSD in the early stages of HF progression.

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.

Prognostic Value of Repeating Cardiac Magnetic Resonance in Patients With Acute Myocarditis.

BACKGROUND: Cardiac magnetic resonance (CMR) is widely used to confirm the diagnosis of acute myocarditis (AM) in the acute setting. CMR is often repeated after 6 months to assess the evolution of myocardial involvement. However, the clinical and prognostic role of 6-month CMR is unknown. OBJECTIVES: This multicenter study aimed to evaluate the clinical and prognostic role of 6-month repetition of CMR in patients with AM. METHODS: In a subgroup of 187 patients from the ITAMY (ITAlian study in MYocarditis) registry, CMR was performed within the first week after symptom onset (CMR-I) and repeated after 6 months (CMR-II). RESULTS: Myocardial edema was detected in all the patients at CMR-I and persisted in 31 (16%) at CMR-II. LGE was detected in 182 (96%) patients at CMR-I and in 164 (86%) at CMR-II. At CMR-II, 20 (11%) patients presented a complete recovery from edema and LGE, 30 (16%) patients had edema with LGE, and 137 (73%) presented LGE without edema. LGE disappeared completely in 18 (10%) patients, the number of LGE segments decreased in 87 (46%), unchanged in 58 (31%), and increased in 26 (14%). During a median clinical follow-up of 7 years (25th to 75th percentile: 6 to 8 years) cardiac events occurred in 22 patients. At Kaplan-Meier curves, patients with LGE and without edema had worse prognosis than others (p < 0.0001). Patients with increased extent of LGE (p = 0.02) had a worse prognosis than those with decreased/unchanged LGE. At multivariate Cox regression analysis, the midwall septal pattern of LGE and the presence of LGE without edema at CMR-II were independent predictors of a cardiac event. CONCLUSIONS: In the acute setting, LGE does not mean definite fibrosis, and it may disappear at 6 months. The presence of LGE without edema at 6-month CMR is associated with worse prognosis, particularly when distributed with a midwall septal pattern. LGE without edema could represent definite fibrosis whereas the presence of edema suggests a residual chance of recovery.

Role of right ventricular involvement in acute myocarditis, assessed by cardiac magnetic resonance.

OBJECTIVES: Right ventricular (RV) myocarditis (MY) is unrecognized, and its prevalence is unknown. We evaluated the prevalence of RV involvement in acute MY and its association with cardiac events (cardiac death, cardiac arrest, ventricular assist device, transplantation, and appropriate ICD intervention). METHODS: We enrolled 151 patients who underwent cardiac magnetic resonance for clinical suspicion of acute MY. The CMR protocol included T2-STIR images for edema detection, post-contrast cine-SSFP for hyperemia detection and late gadolinium enhancement (LGE) images. RESULTS: Signs of RV MY were found in 27 patients (17.8%): RV edema at T2-STIR in all of these 27 patients; RV LGE was detected in 11 patients (7.3%). The median RV myocardial segment involved was 2 (1-3). In 13 patients, RV edema was in direct continuity with LV edema of septum and inferior wall or with anterior septum and anterior wall. In 2 patients RV myocarditis was found without any signs of LV involvement. Patients with RV MY had higher RV end-diastolic volume index (p = 0.04) and RV mass index (p = 0.03), and lower RV ejection fraction (p < 0.001) than others. At Kaplan-Meier survival curve patients with RV MY had more cardiac events than those without RV involvement (p = 0.015). RV involvement, anteroseptal LGE and RV LGE were associated with cardiac events. CONCLUSION: RV involvement in acute MY is more frequent than previously hypothesized. RV MY was associated with cardiac events.

Left and right ventricular morphology, function and late gadolinium enhancement extent and localization change with different clinical presentation of acute myocarditis Data from the ITAlian multicenter study on MYocarditis (ITAMY).

AIMS: Poor data exist about cardiac magnetic resonance (CMR) findings in a large sample of acute myocarditis with different clinical presentations (heart failure, arrhythmias, and infarct-like presentation). METHODS: Five hundred and forty-three in-patients with a clinical suspected of acute myocarditis confirmed by CMR were enrolled. The clinical indications to perform CMR were chest pain and/or dyspnea and/or palpitations, or effort intolerance/malaise in the last month; elevated troponin and/or new ventricular dysfunction, and/or new ECG abnormalities; and suspected inflammatory cause. CMR examination has permitted to identify epicardial and mid-layer distribution of late gadolinium enhancement (LGE) and to quantify left ventricular (LV) and right ventricular (RV) volumes, and ejection fraction. RESULTS: According to the main clinical pattern of presentation, three groups were categorized: heart failure (heart failure group; 35 patients, 6.4%), arrhythmias (arrhythmias group; 24 patients, 4.4%), and infarct-like (infarct-like group, 484 patients, 89.2%).Heart failure group and arrhythmias group had significantly higher LV volumes and number of LGE segments and lower LV and RV ejection fraction than the infarct-like group.Epicardial LGE in the LV inferolateral wall was the most frequent LGE location in each group. Mid-layer LV septal LGE showed a greater prevalence in the heart failure (52%) and arrhythmias (47%) groups than in the infarct-like group (27%, P < 0.0001). CONCLUSION: In patients with CMR-detected acute myocarditis, heart failure, and arrhythmias have both a higher prevalence of LV and RV dysfunction, segments with LGE, and septal LGE with respect to the infarct-like group.

Cardiac MR With Late Gadolinium Enhancement in Acute Myocarditis With Preserved Systolic Function: ITAMY Study.

BACKGROUND: The prognostic role of cardiac magnetic resonance (CMR) and late gadolinium enhancement (LGE) has not been clarified in acute myocarditis (AM) with preserved left ventricular (LV) ejection fraction (EF). OBJECTIVES: This study sought to evaluate the role of CMR and LGE in the prognosis of AM with preserved LVEF. METHODS: This study analyzed data from ITAMY (ITalian multicenter study on Acute MYocarditis) and evaluated CMR results from 386 patients (299 male; mean age 35 ± 15 years) with AM and preserved LVEF. Clinical follow-up was performed for a median of 1,572 days. A clinical combined endpoint of cardiac death, appropriate implantable cardioverter-defibrillator firing, resuscitated cardiac arrest, and hospitalization for heart failure was used. RESULTS: Among the 374 patients with suitable images, LGE involved the subepicardial layer inferior and lateral wall in 154 patients (41%; IL group), the midwall layer of the anteroseptal wall in 135 patients (36%; AS [anteroseptal] group), and other segments in 59 patients (16%; other-LGE group), and it was absent in 26 patients (no-LGE group). The AS group had a greater extent of LGE and a higher LV end-diastolic volume index than other groups, but levels of inflammatory markers were lower than in the other groups. Kaplan-Meier curve analysis indicated that the AS group had a worse prognosis than the other groups (p < 0.0001). Finally, in multivariable analysis, AS LGE was the best independent CMR predictor of the combined endpoint (odds ratio: 2.73; 95% confidence interval: 1.2 to 5.9; p = 0.01). CONCLUSIONS: In patients with AM and preserved LVEF, LGE in the midwall layer of the AS myocardial segment is associated with a worse prognosis than other patterns of presentation.