Background Non-dilated left ventricular cardiomyopathy (NDLVC), characterised by non-ischaemic scar/fatty replacement or isolated systolic dysfunction without dilatation, lacks validated risk stratification tools. We aimed to define cardiac magnetic resonance (CMR)-based phenotypes and evaluate their association with clinical outcomes. Methods In 515 patients with NDLVC (mean age 45 (16) years), three phenotypes were classified by CMR: late gadolinium enhancement (LGE+)/H- (LGE with preserved left ventricular ejection fraction (LVEF), n=130), LGE-/H+ (hypokinesia without LGE, n=226) and LGE+/H+ (LGE with reduced LVEF, n=159). The primary endpoint was all-cause death/heart transplantation; secondary endpoints included heart failure (HF) events and malignant ventricular arrhythmia (MVA). Results Over a mean follow-up of 6.5 (1.9) years, 29 patients (5.6%) reached the primary endpoint, while 81 (15.7%) and 19 (3.7%) experienced HF and MVA, respectively. The LGE+/H+ subgroup demonstrated the highest risk for composite clinical endpoints compared with other phenotypic groups (p<0.001). Multivariable analysis identified New York Heart Association class >II (HR 3.42, 95% CI 1.58 to 7.39, p=0.002), LVEF (HR 0.91 per 1% increase, 95% CI 0.88 to 0.95, p<0.001) and LGE extent (HR 1.14 per 3% increase, 95% CI 1.07 to 1.21, p<0.001) as independent predictors of the primary endpoint, with excellent discriminative power (C-statistic 0.862). In the adjusted model, LGE extent also independently predicted HF (HR 1.11 per 3%, 95% CI 1.06 to 1.17, p<0.001). The univariable Cox regression analysis indicated LGE extent was significantly associated with MVA (HR 1.12 per 3%, 95% CI 1.02 to 1.23, p=0.021). Conclusion CMR phenotyping enables risk stratification in NDLVC. LGE extent provides an objective marker to identify high-risk patients-even with preserved ejection fraction-supporting its integration into routine evaluation.

Purpose To evaluate the feasibility, efficiency, and diagnostic concordance of a full comprehensive free-breathing cardiac MRI protocol. Materials and Methods In this prospective study conducted between June 2024 and August 2024, free-breathing and breath-holding MRI acquisitions were compared across all sequences using a 3.0-T scanner. Outcomes included scanning time, image quality, left ventricular (LV) functional parameters, and tissue characterization. Paired comparisons between free-breathing and breath-holding acquisitions were performed using matched-pairs Wilcoxon tests or t tests as appropriate. Results In this analysis of 605 participants (mean age ± SD, 48 years ± 17; 422 male), the full free-breathing cardiac MRI protocol reduced scanning duration compared with breath-holding techniques (20.9 minutes ± 3.1 vs 34.4 minutes ± 7.5; P < .001); free-breathing cine, T1 mapping, and late gadolinium enhancement (LGE) acquisitions achieved 54%, 28%, and 33% time reductions, respectively. Free-breathing cardiac MRI consistently achieved diagnostic image quality: Cine had a slightly lower score (4 [IQR, 4-4] vs 5 [IQR, 4-5]; P < .001), whereas T1/T2 mapping and flow showed similar scores of 5 (P > .05). LGE scores were higher with free-breathing (5 [IQR, 5-5] vs 5 [IQR, 4-5]; P < .001). Interobserver agreement was strong (κ = 0.80-0.93). Compared with the breath-holding measurement, free-breathing LV end-diastolic volume and LV end-systolic volume were higher (189.94 mL ± 84.74 vs 192.92 mL ± 86.32, P < .001; 104.99 mL ± 83.14 vs 108.52 mL ± 84.45, P < .001, respectively), whereas LV ejection fraction was lower (50.01% ± 17.93 vs 48.92% ± 17.66, P < .001), with excellent agreement between methods (intraclass correlation coefficient, 0.98-0.99). Native T1 values and LGE mass were slightly higher with free-breathing (P ≤ .001) but remained in excellent agreement with breath-holding methods. Conclusion Full free-breathing cardiac MRI reduced scanning duration while maintaining diagnostic image quality and strong agreement with breath-holding techniques across all sequences. Keywords: Cardiac MRI, Free-breathing, Breath-holding, Cardiac Imaging Supplemental material is available for this article. © RSNA, 2026.

Background MRI-derived arrhythmogenic substrate, including late gadolinium enhancement (LGE) and extracellular volume fraction (ECV), is indicative of sudden cardiac death (SCD) risk in nonischemic dilated cardiomyopathy (DCM). The relative prognostic value of LGE and ECV remains unclear. Purpose To evaluate the performance of LGE and T1 mapping in predicting SCD in patients with DCM and to explore clinical implementation. Materials and Methods This study enrolled 1105 patients with DCM who underwent cardiac MRI at four centers. The data were analyzed in a development cohort (n = 837, single center) and an external validation cohort (n = 268, multicenter). The primary end point comprised SCD, appropriate implantable cardioverter-defibrillator shock, and resuscitated cardiac arrest. The secondary end point comprised heart failure-related death, heart transplant, and left ventricle (LV) assist device implantation. Risk algorithms and a clinical workflow for SCD risk assessment were developed based on validated MRI predictors. Results In the development cohort, 78 patients reached the primary end point and 120 reached the secondary end point over a median follow-up of 58.3 months. In the adjusted analysis, LGE of at least 7.2% of the LV mass (hazard ratio [HR], 4.75 [95% CI: 2.91, 7.74]; P < .001), an ECV of at least 31.8% (HR, 2.91 [95% CI: 1.63, 5.22]; P = .001), and a native T1 z score of at least 2.1 (HR, 1.69 [95% CI: 1.04, 2.74]; P = .04) were associated with SCD-related events. Patients with an ECV of at least 31.8% and no LGE were at a higher risk of SCD events compared with those with an ECV less than 31.8% and presence of LGE of less than 7.2% or midwall and/or focal LGE. Patients with an LV ejection fraction greater than 35%, LGE less than 7.2%, and an ECV less than 31.8% exhibited a low risk of SCD, with an annual event rate of 0.2%. Patients with LGE of at least 7.2% exhibited a high risk of SCD-related events (annual event rate, 4.65%) irrespective of ECV and native T1 value and LGE distribution and/or pattern. Conclusion In nonischemic DCM, LGE of at least 7.2% was strongly predictive of SCD risk irrespective of distribution and pattern. ECV significantly enhanced risk stratification, particularly in patients with negative or focal and/or midwall LGE. © RSNA, 2025 Supplemental material is available for this article. See also the editorial by Sakuma in this issue.

PurposeAlthough gated first-pass contrast-enhanced sequences are the clinical standard for cardiovascular MR perfusion, some patient conditions necessitate using ungated steady-state sequences. However, through-plane cardiac motion and blood flow into the left ventricle can disrupt the magnetization steady state of the tissue, and perfusion quantification based on a steady-state assumption will contain errors. The tissue magnetization steady-state disruption can be eliminated with a proposed sequence modification that simultaneously excites transition bands with no change in the sequence resolution or timing parameters.Theory and MethodsThe proposed sequence modification simultaneously excites two transition bands adjacent to the imaged region. The transition bands experience the same consistent excitation history as the imaged slices. Thus, any tissue that moves into an imaged slice location from a transition band location will not disrupt the magnetization steady state. Gradient dephasing and radiofrequency spoiling are used to null the transition band signal so that it does not contribute to the reconstructed images. Transition bands were added to a two-dimensional ungated steady-state radial FLASH (fast low-angle shot) sequence with simultaneous multiband imaging on a PRISMA 3T MRI scanner. Phantom, normal canine, and human subject data are presented.ResultsTransition bands reduce the amount of tissue magnetization disruption to the steady state without adding artifacts to the imaged slices. Myocardial blood flow maps from a selected normal canine study and a normal human subject show good uniformity and consistency to literature values for all slices. Perfusion estimates with the proposed method also demonstrate good consistency with saturation-recovery methods commonly used for myocardial perfusion imaging.ConclusionWe have demonstrated that the proposed transition bands can reduce quantification errors resulting from blood flow into the left ventricle and through-plane cardiac and respiratory motion. There is no loss of image-acquisition efficiency, and temporal resolution is unchanged with this technique.

Patients with diabetes mellitus (DM) have a significantly increased risk of developing heart failure (HF), which exacerbates adverse cardiovascular outcomes. Limited data are available on the prognostic value of cardiac MRI in DM. We aimed to evaluate the association between MRI-derived strain analysis and adverse outcomes in DM patients at different heart failure (HF) stages. In this prospective study, DM participants with preserved ejection fraction (EF) underwent MRI examination between January 2019 and December 2021 were evaluated. Feature tracking strain parameters were measured using cine MRI. The primary outcome was a composite outcome including HF hospitalization or cardiovascular death. Cox proportional regression was used to assess the association between risk factors and outcomes. A total of 581 DM participants (mean age, 56 years ± 13; 401 men) including 390 asymptomatic patients (stage A/B HF) and 191 heart failure with preserved EF were evaluated. After a median follow-up of 34.3 months, 74 DM patients reached the primary outcome; 13(2.2

BACKGROUND:Heart failure (HF) is a global health burden. Myocardial fibrosis is a crucial promotor in HF progression which can be characterized noninvasively by cardiac magnetic resonance T1 mapping. OBJECTIVES:This study aims to systemically evaluate the prognostic value of myocardial T1 mapping and extracellular volume fraction (ECV) covering the entire spectrum of HF through a meta-analysis. METHODS:We searched PubMed, Web of Science, and SCOPUS for studies examining the prognostic value of T1 mapping in HF with reduced and preserved ejection fraction. Baseline level, mean difference, and HRs were pooled for meta-analysis. Subgroup analyses were conducted according to HF subtypes and clinical characteristics. RESULTS:Nineteen studies with 5,384 patients (56.2% male) were included in the analysis. Patients with adverse outcomes (mortality, HF-related event, or composite outcome) had higher native T1 and ECV values than those without (weighted mean difference: 41.17 ms and 4.73%, respectively). Both native T1 and ECV were positively associated with endpoints for the entire HF group (HR of 1% increase in ECV: 1.20 [95% CI: 1.13-1.28]; HR of >1% increase: 1.56 [95% CI: 1.40-1.75]; HR binary: 2.62 [95% CI: 2.07-3.32]; HR of 1-ms increase in native T1: 1.02 [95% CI: 1.01-1.03]; HR of ≥10-ms increase: 1.08 [95% CI: 1.05-1.11]; HR binary: 2.93 [95% CI: 2.03-4.23], all P < 0.05). For subgroup cohorts, native T1 had no significant prognostic value in HF with preserved ejection fraction (P > 0.05). Younger patients with HF with severe cardiac insufficiency (NYHA functional class III-IV), persistently increasing ECV, or negative late enhancement who exhibited abnormal T1 mapping were at higher risk of adverse outcomes. CONCLUSIONS:ECV has consistent prognostic implications across HF spectrum, regardless of HF types, clinical characteristics, and various etiology. Native T1 is less predictive than ECV, particularly in HF with preserved ejection fraction.

BACKGROUND:Current guidelines recommend implantable cardioverter defibrillators for the primary prevention of sudden cardiac death (SCD) in patients with dilated cardiomyopathy with left ventricular ejection fraction (LVEF)≤35%. However, its effectiveness is hindered by the inability to reliably discriminate between the risk of SCD and competing death of heart failure deterioration, thereby limiting its clinical utility. We aimed to refine the SCD risk stratification model based on cardiac magnetic resonance imaging for patients with dilated cardiomyopathy with LVEF≤35%. METHODS:A total of 1272 patients with dilated cardiomyopathy with LVEF≤35% who underwent cardiac magnetic resonance imaging were consecutively enrolled in this study. The primary end point is a composite of SCD or aborted SCD and the second end point is a composite of heart failure death and heart transplantation. RESULTS:Over a median follow-up of 86.3 months, 101 patients reached the primary end point. In the adjusted analysis, age (hazard ratio [HR], 1.02 [95% CI, 1.01-1.04]; P=0.006) years, a family history of SCD (HR, 2.00 [95% CI, 1.01-3.98]; P=0.05), NT-proBNP (N-terminal pro-B-type natriuretic peptide) (HR, 2.02 [95% CI, 1.18-3.44]; P=0.01), LVEF (per 5% HR, 0.79 [95% CI, 0.66-0.95]; P=0.01), and late gadolinium enhancement≥7.5% (HR, 4.11[95% CI, 2.72-6.21]; P<0.001) were associated with SCD or aborted SCD. Left atrial volume index≥68.3 mL/m2 was an independent predictor of the secondary end point (adjusted HR, 1.65 [95% CI, 1.13-2.40]; P=0.009). Compared with late gadolinium enhancement<7.5%, patients with late gadolinium enhancement≥7.5% and LVEF≤20% had a 7.12-fold higher risk of experiencing SCD events in competing Cox analysis (annual event rate, 4.8%). CONCLUSIONS:Patients with dilated cardiomyopathy with late gadolinium enhancement≥7.5% were at heightened risk of SCD events, which can be used for risk assessment. Risk stratifications for SCD, combining clinical and cardiac magnetic resonance imaging may potentially guide decision-making for implantable cardioverter defibrillator therapy.

Right ventricular global longitudinal and circumferential strain derived from cardiac MRI were independently associated with adverse outcomes in a large cohort of patients with heart failure with preserved ejection fraction.

Background Considering that 30% to 40% of patients do not benefit from cardiac resynchronization therapy implantation, it is insufficient to evaluate patients with heart failure with reduced ejection fraction solely based on QRS duration and morphology for guiding cardiac resynchronization therapy decisions and prognosis. A crucial step in addressing this issue is conducting a comprehensive pathophysiological assessment to understand the mechanisms underlying dyssynchrony and inefficient cardiac contraction. This study aims to utilize cardiac magnetic resonance imaging to explore underlying pathophysiological impairments in patients with heart failure with reduced ejection fraction with different QRS morphologies, seeking to identify better indicators for clinical assessment. Methods A retrospective analysis was conducted on 887 consecutive patients with nonischemic heart failure with reduced ejection fraction and prolonged QRS duration who underwent cardiac magnetic resonance imaging, as well as 200 subjects with heart failure with reduced ejection fraction and normal QRS duration as the control group. Results Patients with left bundle‐branch block (LBBB) had a reduced left ventricular/right ventricular ejection fraction ratio compared with controls and patients with right bundle‐ branch block (RBBB) (LBBB versus RBBB versus controls: 0.6 [0.5, 0.8] versus 0.8 [0.6, 1.1] versus 0.8 [0.6, 1.1]). Late gadolinium enhancement percentage and extracellular volume fraction were significantly larger in patients with RBBB and nonspecific intraventricular conduction delay than in controls and patients with LBBB. Patients with LBBB or intraventricular conduction delay were associated with more impaired left ventricular torsion (LBBB versus intraventricular conduction delay versus RBBB: 0.3°/cm [−0.3, 0.5] versus 0.4°/cm [0.2, 0.7] versus 0.5°/cm [0.2, 0.8]) and strains than those with RBBB. Multivariable logistic regression revealed that the left ventricular/right ventricular ejection fraction ratio and torsion were independent determinants of LBBB. Conclusions A reduced left ventricular/right ventricular ejection fraction ratio and impaired left ventricular torsion may serve as valuable predictors of dyssynchrony, potentially identifying patients most likely to benefit from cardiac resynchronization therapy.

In patients with acute myocarditis, cardiac MRI−derived native T1 and extracellular volume fraction provided incremental prognostic value for predicting occurrence of major adverse cardiovascular events when combined in a model with conventional clinical and imaging parameters.

BACKGROUND:Patients aged ≥65 years account for a disproportionately large portion of cardiovascular (CV) events and pose a challenge for noninvasive detection of coronary artery disease. OBJECTIVES:This study sought to determine the prognostic value of stress cardiac magnetic resonance (CMR) in a Medicare-eligible group of patients in a multicenter setting in the United States. METHODS:From a multicenter U.S. registry, the study identified patients aged ≥65 years who were referred for stress CMR for evaluation of myocardial inducible ischemia. The primary outcome was defined as CV death or nonfatal myocardial infarction, whereas the secondary outcome was defined as any primary outcome, hospitalization for unstable angina, hospitalization for congestive heart failure, and unplanned late coronary artery bypass grafting. The associations of CMR findings with CV outcomes adjusted to clinical risk markers and health care cost spending were determined. RESULTS:Among 1,780 patients (aged 73 ± 5.7 years; 46% female), study investigators observed 144 primary events and 323 secondary events, over a median follow-up of 4.8 years. The presence of inducible ischemia and late gadolinium enhancement (LGE) was associated with incrementally higher event rates. Patients with neither inducible ischemia nor LGE experienced a <1% annualized rate of primary outcome. In a multivariable model adjusted for CV risk factors, inducible ischemia and LGE maintained an independent association with primary (HR: 2.80 [95% CI: 1.93-4.05]; P < 0.001; and HR: 1.85 [95% CI: 1.21-2.82]; P = 0.004, respectively) and secondary (HR: 2.46 [95% CI: 1.90-3.19]; P < 0.001; and HR: 1.72 [95% CI: 1.30-2.27]; P < 0.001, respectively) outcomes. Rates of revascularization, as well as downstream costs for patients without CMR-detected inducible ischemia, remained low throughout the follow-up period. CONCLUSIONS:In a multicenter cohort of Medicare-eligible older patients, stress CMR was effective in providing risk stratification. (Stress CMR Perfusion Imaging in the United States [SPINS] study; NCT03192891).

BACKGROUND:Cardiovascular magnetic resonance (CMR) is rapidly expanding in China, yet comprehensive national data on its clinical application and research status are limited. This study aims to evaluate the current landscape of CMR across the country. METHODS:An electronic survey was conducted targeting the following two groups: physicians trained at the Fuwai Fellowship Program and members of the Chinese Society of Radiology. The survey encompassed details on CMR equipment, clinical practices, and research activities. RESULTS:Of 248 hospitals responded to the survey, 98.0% (243/248) were tertiary centers. The number of scanners distributed unevenly across geographic regions, with Central South China leading with 5.9/center. Siemens, Philips and GE were top three scanner vendors. Most centers initiated CMR program post-2015. Coronary artery disease was the primary indication for CMR. The median annual volume was 120/center. High-volume centers unevenly concentrated most CMR cases. The weighted average waiting period was 14.2 days, while scan durations ranged from 40 to 60 min. Two thirds of hospitals used post-processing software to analyze imaging. Half of responding centers included T1 and T2 mapping in clinical routine, but stress perfusion was underutilized in both clinic and research. Approximately one-third of centers had published CMR-related research. The majority of physicians were confident about the development of CMR. Major barriers to CMR development included long scan times, high costs, insufficient equipment, and limited training. CONCLUSION:CMR is experiencing rapid growth in China but faces significant regional disparities in access to technology and expertise. Efforts to reduce costs, improve training, and expand access to advanced techniques are crucial for balanced development.

Myocardial perfusion imaging plays a central role in the management of patients with known or suspected coronary artery disease (CAD) and increasingly in patients with suspected ischemia with normal coronary arteries (INOCA) as well as anomalous origins of the coronary arteries and Kawasaki disease. Stress perfusion cardiovascular magnetic resonance (CMR) is recognized by international guidelines, with several Class 1 indications for the detection of abnormal myocardial blood flow in these clinical scenarios and offers excellent diagnostic accuracy and independent prognostic value. While visual interpretation of the perfusion data is the prevailing analysis method in clinical practice, quantitative perfusion CMR is at least as accurate for the detection of significant obstructive CAD and provides a more accurate estimation of the total ischemic burden in patients with CAD. Moreover, quantitative myocardial perfusion analysis provides unique insights into the pathophysiology of myocardial ischemia, including microvascular disease in INOCA. Quantitative perfusion CMR can be fully automated, is user-independent, and may facilitate more widespread use of the modality. The aim of this Society for Cardiovascular Magnetic Resonance (SCMR) expert consensus document is to provide recommendations for the acquisition and analysis of quantitative myocardial perfusion CMR to facilitate standardization of methodology. This paper also discusses research and development goals to address current limitations, to ensure data reliability and validity, to create the basis for future multi-vendor and multicenter research, and to broaden the clinical use of quantitative perfusion CMR.

BACKGROUND:Early invasive revascularization guided by moderate to severe ischemia did not improve outcomes over medical therapy alone, underlying the need to identify high-risk patients for a more effective invasive referral. CMR could determine the myocardial extent and matching locations of ischemia and infarction. OBJECTIVES:This study sought to investigate if CMR peri-infarct ischemia is associated with adverse events incremental to known risk markers. METHODS:Consecutive patients were included in an expanded cohort of the multicenter SPINS (Stress CMR Perfusion Imaging in the United States) study. Peri-infarct ischemia was defined by the presence of any ischemic segment neighboring an infarcted segment by late gadolinium enhancement imaging. Primary outcome events included acute myocardial infarction and cardiovascular death, whereas secondary events included any primary events, hospitalization for unstable angina, heart failure hospitalization, and late coronary artery bypass surgery. RESULTS:Among 3,915 patients (age: 61.0 ± 12.9 years; 54.7% male), ischemia, infarct, and peri-infarct ischemia were present in 752 (19.2%), 1,123 (28.8%), and 382 (9.8%) patients, respectively. At 5.3 years (Q1-Q3: 3.9-7.2 years) of median follow-up, primary and secondary events occurred in 406 (10.4%) and 745 (19.0%) patients, respectively. Peri-infarct ischemia was the strongest multivariable predictor for primary and secondary events (HRadjusted: 1.72 [95% CI: 1.23-2.41] and 1.71 [95% CI: 1.32-2.20], respectively; both P < 0.001), adjusted for clinical risk factors, left ventricular function, ischemia extent, and infarct size. The presence of peri-infarct ischemia portended to a >6-fold increased annualized primary event rate compared to those with no infarct and ischemia (6.5% vs 0.9%). CONCLUSIONS:Peri-infarct ischemia is a novel and robust prognostic marker of adverse cardiovascular events.

Clinical application of cardiac magnetic resonance (CMR) is expanding but CMR assessment of LV diastolic function is still being validated. The purpose of this study was to validate assessments of left ventricular (LV) diastolic dysfunction (DD) using CMR by comparing with transthoracic echocardiography (TTE) performed on the same day. Patients with suspected or diagnosed cardiomyopathy (n = 63) and healthy volunteers (n = 24) were prospectively recruited and included in the study. CMR diastolic parameters were measured on cine images and velocity-encoded phase contrast cine images and compared with corresponding parameters measured on TTE. A contextual correlation feature tracking method was developed to calculate the mitral annular velocity curve. LV DD was classified by CMR and TTE following 2016 guidelines. Overall DD classification was 78.1% concordant between CMR and TTE (p < 0.0001). The trans-mitral inflow parameters correlated well between the two modalities (E, r = 0.78; A, r = 0.90; E/A, r = 0.82; all p < 0.0001) while the remaining diastolic parameters showed moderate correlation (e’, r = 0.64; E/e’, r = 0.54; left atrial volume index (LAVi), r = 0.61; all p < 0.0001). Classification of LV diastolic function by CMR showed good concordance with standardized grades established for TTE. CMR-based LV diastolic function may be integrated in routine clinical practice. Name of the registry: Technical Development of Cardiovascular Magnetic Resonance Imaging. Trial registration number: NCT00027170. Date of registration: November 26, 2001. URL of trial registry record: https://clinicaltrials.gov/ct2/show/NCT00027170

Purpose To describe the clinical presentation, comprehensive cardiac MRI characteristics, and prognosis of individuals with predisposed heart failure with preserved ejection fraction (HFpEF). Materials and Methods This prospective cohort study (part of MISSION-HFpEF [Multimodality Imaging in the Screening, Diagnosis, and Risk Stratification of HFpEF]; NCT04603404) was conducted from January 1, 2019, to September 30, 2021, and included individuals with suspected HFpEF who underwent cardiac MRI. Participants who had primary cardiomyopathy and primary valvular heart disease were excluded. Participants were split into a predisposed HFpEF group, defined as HFpEF with normal natriuretic peptide levels based on an HFA-PEFF (Heart Failure Association Pretest Assessment, Echocardiography and Natriuretic Peptide, Functional Testing, and Final Etiology) score of 4 from the latest European Society of Cardiology guidelines, and an HFpEF group (HFA-PEFF score of ≥ 5). An asymptomatic control group without heart failure was also included. Clinical and cardiac MRI-based characteristics and outcomes were compared between groups. The primary end points were death, heart failure hospitalization, or stroke. Results A total of 213 participants with HFpEF, 151 participants with predisposed HFpEF, and 100 participants in the control group were analyzed. Compared with the control group, participants with predisposed HFpEF had worse left ventricular remodeling and function and higher systemic inflammation. Compared with participants with HFpEF, those with predisposed HFpEF, whether obese or not, were younger and had higher plasma volume, lower prevalence of atrial fibrillation, lower left atrial volume index, and less impaired left ventricular global longitudinal strain (-12.2% ± 2.8 vs -13.9% ± 3.1; P < .001) and early-diastolic global longitudinal strain rate (eGLSR, 0.52/sec ± 0.20 vs 0.57/sec ± 0.15; P = .03) but similar prognosis. Atrial fibrillation occurrence (hazard ratio [HR] = 3.90; P = .009), hemoglobin level (HR = 0.94; P = .001), and eGLSR (per 0.2-per-second increase, HR = 0.28; P = .002) were independently associated with occurrence of primary end points in participants with predisposed HFpEF. Conclusion Participants with predisposed HFpEF showed relatively unique clinical and cardiac MRI features, warranting greater clinical attention. eGLSR should be considered as a prognostic factor in participants with predisposed HFpEF. Keywords: Heart Failure with Preserved Ejection Fraction, Normal Natriuretic Peptide Levels, Cardiovascular Magnetic Resonance, Myocardial Strain, Prognosis Clinical trial registration no. NCT04603404 Supplemental material is available for this article. © RSNA, 2024

Abstract Background T1 mapping and T2 mapping have become essential components of the 2018 Lake Louise criteria and obtained excellent results in diagnosing myocarditis. However, their prognostic value in acute myocarditis has not yet been well recognized or established. Purpose Our study aims to investigate the prognostic value of T1 mapping, T2 mapping, and extracellular volume fraction (ECV) in a large cohort of patients with suspected acute myocarditis. Materials Patients meeting the recommended clinical criteria for suspected acute myocarditis were consecutively enrolled. The primary endpoint is the composite of cardiac death, heart failure hospitalization, heart transplantation, sustained ventricular arrhythmia, and recurrent myocarditis, defined as major adverse cardiovascular events (MACE). All patients underwent CMR at 3.0 T scanner using a standardized, routine imaging protocol, and the three short-axis view slices (basal, mid-ventricular, and apical) were divided into 16 segments according to the American Heart Association 17-segment model (apex excluded). We also averaged the native T1 values, ECV, and T2 values of all 16 segments to get global T1 and ECV fraction values, respectively. Statistically significant parameters from univariate Cox analyses were put into multivariate Cox analysis. Results A total of 235 patients (150 men; 32±13 years) were enrolled in this study. During a mean follow-up of 43.0±3.6 months, MACE occurred in 37 patients (15.7%) and was univariably associated with heart failure presentation, left ventricular ejection fraction, left ventricular end-systolic volume index, left ventricular end-diastolic volume index, native T1 and ECV. Patients with MACE showed higher global native T1, ECV, and T2 values (1348±59 vs 1266±51, p=<0.001; 40.0±8.7 vs 32.8±5.9, p<0.001; 63.4±12.1 vs. 55.5±9.1, p=0.011), and were more likely to have tissue changes in the interventricular septum and anterior wall (Figure 1). In a series of nesting multivariable Cox regression models, the addition of native T1 (per 10-ms increase: HR, 1.128; 95% CI: 1.043, 1.220; p = 0.003; Harrell’s C-index = 0.833) or ECV (per 5% increase: HR, 1.382; 95% CI: 1.060, 1.802; p = 0.017; Harrell’s C-index = 0.847) improved prognostication compared with the model based on clinical variables, left ventricular ejection fraction, and septal late gadolinium enhancement (Harrell’s C-index = 0.762) (Figure 2). T2 in multivariate Cox regression analysis didn’t show predictive value, but his inclusion increased the C-index of the model to 0.814. Conclusions Myocardial parametric mapping not only holds substantial diagnostic value but also plays a critical role in the prognostic assessment and risk prediction of myocarditis. Their utilization in these contexts enhances the accuracy and effectiveness of clinical evaluations and decision-making processes.