Heart Failure with Normal Natriuretic Peptide Levels and Preserved Ejection Fraction: A Prospective Clinical and Cardiac MRI Study.

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.

Long-term outcomes prediction in diabetic heart failure with preserved ejection fraction by cardiac MRI.

OBJECTIVES: We aimed to explore imaging features including tissue characterization and myocardial deformation in diabetic heart failure with preserved ejection fraction (HFpEF) patients by magnetic resonance imaging (MRI) and investigate its prognostic value for adverse outcomes. MATERIALS AND METHODS: Patients with HFpEF who underwent cardiac MRI between January 2010 and December 2016 were enrolled. Feature-tracking (FT) analysis and myocardial fibrosis were assessed by cardiac MRI. Cox proportional regression analysis was performed to determine the association between MRI variables and primary outcomes. Primary outcomes were all-cause death or heart failure hospitalization during the follow-up period. RESULTS: Of the 335 enrolled patients with HFpEF, 191 had diabetes mellitus (DM) (mean age: 58.7 years ± 10.8; 137 men). During a median follow-up of 10.2 years, 91 diabetic HFpEF and 56 non-diabetic HFpEF patients experienced primary outcomes. DM was a significant predictor of worse prognosis in HFpEF. In diabetic HFpEF, the addition of conventional imaging variables (left ventricular ejection fraction, left atrial volume index, extent of late gadolinium enhancement (LGE)) and global longitudinal strain (GLS) resulted in a significant increase in the area under the receiver operating characteristic curve (from 0.693 to 0.760, p < 0.05). After adjustment for multiple clinical and imaging variables, each 1% worsening in GLS was associated with a 9.8% increased risk of adverse events (p = 0.004). CONCLUSIONS: Diabetic HFpEF is characterized by more severely impaired strains and myocardial fibrosis, which is identified as a high-risk HFpEF phenotype. In diabetic HFpEF, comprehensive cardiac MRI provides incremental value in predicting prognosis. Particularly, MRI-FT measurement of GLS is an independent predictor of adverse outcome in diabetic HFpEF. CLINICAL RELEVANCE STATEMENT: Our findings suggested that MRI-derived variables, especially global longitudinal strain, played a crucial role in risk stratification and predicting worse prognosis in diabetic heart failure with preserved ejection fraction, which could assist in identifying high-risk patients and guiding therapeutic decision-making. KEY POINTS: • Limited data are available on the cardiac MRI features of diabetic heart failure with preserved ejection fraction, including myocardial deformation and tissue characterization, as well as their incremental prognostic value. • Diabetic heart failure with preserved ejection fraction patients was characterized by more impaired strains and myocardial fibrosis. Comprehensive MRI, including tissue characterization and global longitudinal strain, provided incremental value for risk prediction. • MRI served as a valuable tool for identifying high-risk patients and guiding clinical management in diabetic heart failure with preserved ejection fraction.

Adenosine Triphosphate Stress Myocardial Strain in Ischemic Heart Disease: An Animal Study with Histological Validation.

RATIONALE AND OBJECTIVES: It is still challenging for cardiac magnetic resonance (CMR) to detect ischemic heart disease (IHD) without the use of gadolinium contrast. We aimed to evaluate the potential value of adenosine triphosphate (ATP) stress myocardial strain derived from feature tracking (FT) as a novel method for detecting IHD in a swine model. MATERIALS AND METHODS: CMR cines, myocardial perfusion imaging at rest and during ATP stress, and late gadolinium enhancement were obtained in both control and IHD swine. Normal, remote, ischemic, and infarcted myocardium were analyzed. The diagnostic accuracy of myocardial strain for infarction and ischemia was assessed using coronary angiography and pathology as reference. RESULTS: Eleven IHD swine and five healthy control swine were enrolled in this study. Strain parameters, even at rest, were associated with myocardial ischemia and infarction(all p < 0.05). The area under receiver operating characteristic curve (AUC) values of all strain parameters for detecting infarcted myocardium exceeded 0.900 (all p < 0.05). The AUC values for detecting ischemic myocardium were as follows: 0.906 and 0.847 for stress and rest radial strain, 0.763 and 0.716 for stress and rest circumferential strain, 0.758 and 0.663 for stress and rest longitudinal strain (all p < 0.001). Heat maps demonstrated that all strain parameters showed mild to moderate correlations with the stress myocardial blood flow and myocardial perfusion reserve (all p < 0.05). CONCLUSION: CMR-FT-derived ATP stress myocardial strain shows promise as a noninvasive method for detecting myocardial ischemia and infarction in an IHD swine model, with rest strain parameters offering potential as a needle-free diagnostic option.

Developing and evaluating a chronic ischemic cardiomyopathy in swine model by rest and stress CMR.

A large animal model of chronic coronary artery disease (CAD) is crucial for the understanding the underlying pathophysiological processes of chronic CAD and consequences for cardiac structure and function. The goal of this study was to develop a chronic model of CAD in a swine model and to evaluate the changes of myocardial structure, myocardial motility, and myocardial viability during coronary stenosis. A total of 30 swine (including 24 experimental animals and 6 controls) were enrolled. The chronic ischemia model was constructed by using Ameroid constrictor in experimental group. The 24 experimental animals were further divided into 4 groups (6 animals in each group) and were sacrificed at 1, 2, 3 and 4 weeks after operation for pathological examination, respectively. Cardiac magnetic resonance (CMR) was performed preoperatively and weekly postoperatively until sacrificed both in experimental and control group. CMR cine images, rest/adenosine triphosphate (ATP) stress myocardial contrast perfusion and LGE were performed and analyzed. The rest wall thickening (WT) score was calculated from rest cine images. The MPRI (myocardial perfusion reserve index) and MPR (myocardial perfusion reserve) were calculated based on rest and stress perfusion images. Pathology staining including triphenyltetrazolium chloride, HE and picrosirus red staining were performed after swine were sacrificed and collagen volume fraction (CVF) was calculated. The time to formation of ischemic, hibernating, and infarcted myocardium was recorded. In experimental group, from 1w to 4w after surgery, the rest WT score decreased gradually from 35.2 ± 2.0%, 32.0 ± 2.9% to 30.5 ± 3.0% and finally 29.06 ± 1.78%, p < 0.001. Left ventricular ejection fraction was gradually impaired after modeling (58.9 ± 12.6%, 56.3 ± 10.1%, 55.3 ± 9.0%, 53.8 ± 9.9%, respectively). And the MPR and MPRI also decreased stepwise with extent of surgery time (MPRI dropped from 2.1 ± 0.4, 2.0 ± 0.2 to 1.8 ± 0.3 and finally 1.7 ± 0.1, p = 0.004; MPR dropped from 2.3 ± 0.4, 2.1 ± 0.2 to 1.9 ± 0.4 and finally 1.8 ± 0.1, p < 0.001). Stronger associations between MPR, MPRI and CVF were paralleled lower wall thickening scores in fibrosis-affected areas. The ischemic myocardium was first appeared in the first week after surgery (involving ten segments), hibernated myocardium was first appeared in the second week after surgery (involving seventeen segments). LGE was first appeared in eight swine in the third weeks after surgery (16 segments). At 4w after surgery, average 9.6 g scar tissue was found among 6 swine. At the same time, histological analysis established the presence of fibrosis and ongoing apoptosis in the infarcted area. In conclusion, our study provided valuable insights into the pathophysiological processes of chronic CAD and its consequences for cardiac structure and function in a large animal model through combining myocardial motion and stress perfusion.

A novel cardiac magnetic resonance-based personalized risk stratification model in dilated cardiomyopathy: a prospective study.

OBJECTIVES: To explore individual weight of cardiac magnetic resonance (CMR) metrics to predict mid-term outcomes in patients with dilated cardiomyopathy (DCM), and develop a risk algorithm for mid-term outcome based on CMR biomarkers. MATERIALS AND METHODS: Patients with DCM who underwent CMR imaging were prospectively enrolled in this study. The primary endpoint was a composite of heart failure (HF) death, sudden cardiac death (SCD), aborted SCD, and heart transplantation. RESULTS: A total of 407 patients (age 48.1 ± 13.8 years, 331 men) were included in the final analysis. During a median follow-up of 21.7 months, 63 patients reached the primary endpoint. NYHA class III/IV (HR = 2.347 [1.073-5.133], p = 0.033), left ventricular ejection fraction (HR = 0.940 [0.909-0.973], p < 0.001), late gadolinium enhancement (LGE) > 0.9% and ≤ 6.6% (HR = 3.559 [1.020-12.412], p = 0.046), LGE > 6.6% (HR = 6.028 [1.814-20.038], p = 0.003), and mean extracellular volume (ECV) fraction ≥ 32.8% (HR = 5.922 [2.566-13.665], p < 0.001) had a significant prognostic association with the primary endpoints (C-statistic: 0.853 [0.810-0.896]). Competing risk regression analyses showed that patients with mean ECV fraction ≥ 32.8%, LGE ≥ 5.9%, global circumferential strain ≥ - 5.6%, or global longitudinal strain ≥ - 7.3% had significantly shorter event-free survival due to HF death and heart transplantation. Patients with mean ECV fraction ≥ 32.8% and LGE ≥ 5.9% had significantly shorter event-free survival due to SCD or aborted SCD. CONCLUSION: ECV fraction may be the best independently risk factor for the mid-term outcomes in patients with DCM, surpassing LVEF and LGE. LGE has a better prognostic value than other CMR metrics for SCD and aborted SCD. The risk stratification model we developed may be a promising non-invasive tool for decision-making and prognosis. CLINICAL RELEVANCE STATEMENT: "One-stop" assessment of cardiac function and myocardial characterization using cardiac magnetic resonance might improve risk stratification of patients with DCM. In this prospective study, we propose a novel risk algorithm in DCM including NYHA functional class, LVEF, LGE, and ECV. KEY POINTS: • The present study explores individual weight of CMR metrics for predicting mid-term outcomes in dilated cardiomyopathy. • We have developed a novel risk algorithm for dilated cardiomyopathy that includes cardiac functional class, ejection fraction, late gadolinium enhancement, and extracellular volume fraction. • Personalized risk model derived by CMR contributes to clinical assessment and individual decision-making.

Dynamic changes in cardiac morphology, function, and diffuse myocardial fibrosis duration of diabetes in type 1 and type 2 diabetic mice models using 7.0 T CMR and echocardiography.

Background: Diabetes mellitus (DM) is associated with an increased risk of cardiovascular disease (CVD). Hence, early detection of cardiac changes by imaging is crucial to reducing cardiovascular complications. Purpose: Early detection of cardiac changes is crucial to reducing cardiovascular complications. The study aimed to detect the dynamic change in cardiac morphology, function, and diffuse myocardial fibrosis(DMF) associated with T1DM and T2DM mice models. Materials and methods: 4-week-old C57Bl/6J male mice were randomly divided into control (n=30), T1DM (n=30), and T2DM (n=30) groups. A longitudinal study was conducted every 4 weeks using serial 7.0T CMR and echocardiography imaging. Left ventricular ejection fraction (LV EF), tissue tracking parameters, and DMF were measured by cine CMR and extracellular volume fraction (ECV). Global peak circumferential strain (GCPS), peak systolic strain rate (GCPSSR) values were acquired by CMR feature tracking. LV diastolic function parameter (E/E') was acquired by echocardiography. The correlations between the ECV and cardiac function parameters were assessed by Pearson's test. Results: A total of 6 mice were included every 4 weeks in control, T1DM, and T2DM groups for analysis. Compared to control group, an increase was detected in the LV mass and E/E' ratio, while the values of GCPS, GCPSSR decreased mildly in DM. Compared to T2DM group, GCPS and GCPSSR decreased earlier in T1DM(GCPS 12W,P=0.004; GCPSSR 12W,P=0.04). ECV values showed a significant correlation with GCPS and GCPSSR in DM groups. Moreover, ECV values showed a strong positive correlation with E/E'(T1DM,r=0.757,P<0.001;T2DM, r=0.811,P<0.001). Conclusion: The combination of ECV and cardiac mechanical parameters provide imaging biomakers for pathophysiology, early diagnosis of cardiac morphology, function and early intervention in diabetic cardiomyopathy in the future.

Detection of Myocardial Ischemia Using Cardiovascular MRI Stress T1 Mapping: A Miniature-Swine Validation Study.

Purpose: To assess the efficacy of cardiac MRI stress T1 mapping in detecting ischemic and infarcted myocardium in a miniature-swine model, using pathologic findings as the reference standard. Materials and Methods: Ten adult male Chinese miniature swine, with coronary artery stenosis induced by an ameroid constrictor, and two healthy control swine were studied. Cardiac 3-T MRI rest and adenosine triphosphate stress T1 mapping and perfusion images, along with resting and late gadolinium enhancement images, were acquired at baseline and weekly up to 4 weeks after surgery or until humanely killed. A receiver operating characteristic analysis was used to analyze the performance of T1 mapping in the detection of myocardial ischemia. Results: In the experimental group, both the infarcted myocardium (ΔT1 = 10 msec ± 2 [SD]; ΔT1 percentage = 0.7% ± 0.1) and ischemic myocardium (ΔT1 = 10 msec ± 2; ΔT1 percentage = 0.9% ± 0.2) exhibited reduced T1 reactivity compared with the remote myocardium (ΔT1 = 53 msec ± 7; ΔT1 percentage = 4.7% ± 0.6) and normal myocardium (ΔT1 = 56 msec ± 11; ΔT1 percentage = 4.9% ± 1.1). Receiver operating characteristic analysis demonstrated high diagnostic performance of ΔT1 in detecting ischemic myocardium, with an area under the curve (AUC) of 0.84 (P < .001). Rest T1 displayed high diagnostic performance in detecting infarcted myocardium (AUC = 0.95; P < .001). When rest T1 and ΔT1 were combined, the diagnostic performance for both ischemic and infarcted myocardium were improved (AUCs, 0.89 and 0.97, respectively; all P < .001). The collagen volume fraction correlated with ΔT1, ΔT1 percentage, and Δ extracellular volume percentage (r = -0.70, -0.70, and -0.50, respectively; P = .001, .001, and .03, respectively). Conclusion: Using histopathologic validation in a swine model, noninvasive cardiac MRI stress T1 mapping demonstrated high performance in detecting ischemic and infarcted myocardium without the need for contrast agents.Keywords: Coronary Artery Disease, MRI, Myocardial Ischemia, Rest T1 Mapping, Stress T1 Mapping, Swine Model Supplemental material is available for this article. © RSNA, 2023See also commentary by Burrage and Ferreira in this issue.

Ventricular-atrial coupling in subjects with normal, preserved, and reduced left ventricular ejection fraction: insights from cardiac magnetic resonance imaging.

OBJECTIVES: To assess the correlation between LA and LV strain measurements in different clinical scenarios and evaluate to what extent LA deformation contributes to the prognosis of patients. METHODS: A total of 297 consecutive participants including 75 healthy individuals, 75 hypertrophic cardiomyopathy (HCM) patients, 74 idiopathic dilated cardiomyopathy (DCM), and 73 chronic myocardial infarction (MI) patients were retrospectively enrolled in this study. The associations of LA-LV coupling with clinical status were statistically analyzed by correlation, multiple linear regression, and logistic regression. Survival estimates were calculated by receiver operating characteristic analyses and Cox regression analyses. RESULTS: Overall, moderate correlations were found between LA and LV strain in every phase of the cardiac cycle (r: -0.598 to -0.580, all p < 0.001). The slope of the regression line of the individual strain-strain curve had a significant difference among 4 groups (-1.4 ± 0.3 in controls, -1.1 ± 0.6 in HCM, -1.8 ± 0.8 in idiopathic DCM, -2.4 ± 1.1 in chronic MI, all p < 0.05). During a median follow-up of 4.7 years, the total LA emptying fraction was independently associated with primary (hazard ratio: 0.968, 95% CI: 0.951-0.985) and secondary endpoints (hazard ratio: 0.957, 95% CI: 0.930-0.985) with an area under the curve (AUC) of 0.720 respectively, 0.806, which was significantly higher than the AUC of LV parameters. CONCLUSIONS: The coupled correlations between the left atria and ventricle in every phase and the individual strain-strain curve vary with etiology. LA deformation in late diastole provides prior and incremental information on cardiac dysfunction based on LV metrics. The total LA emptying fraction was an independent indicator for clinical outcome superior to that of LV typical predictors. CLINICAL RELEVANCE STATEMENT: Left ventricular-atrial coupling is not only valuable for comprehending the pathophysiological mechanisms of cardiovascular diseases caused by different etiologies but also holds significant importance for the prevention of adverse cardiovascular events and targeted treatment. KEY POINTS: • In HCM patients with preserved LVEF, LA deformation is a sensitive indicator for cardiac dysfunction prior to LV parameters with a reduced LA/LV strain ratio. • In patients with reduced LVEF, LV deformation impairment is more consequential than that of the LA with an increased LA/LV strain ratio. Furthermore, impaired LA active strain indicates potential atrial myopathy. • Among LA and LV parameters, the total LA emptying fraction is the best predictor for guiding clinical management and follow-up in patients with different statuses of LVEF.

Multimodality Imaging in Noonan Syndrome: Case Series of Young Children.

Noonan syndrome (NS) is an autosomal dominant disorder characterized by distinctive facial anomalies, growth failure, and a wide spectrum of cardiac abnormalities. Here, the clinical presentation, multimodality imaging characteristics, and management in a case series of four patients with NS are presented. Multimodality imaging showed frequently biventricular hypertrophy accompanied by biventricular outflow tract obstruction and pulmonary stenosis, similar late gadolinium enhancement pattern, and elevation of native T1 and extracellular volume, which may serve as multimodality imaging features in NS to aid in patient diagnosis and treatment. Keywords: Pediatrics, Echocardiography, MR Imaging, Cardiac Supplemental material is available for this article. © RSNA, 2023.

Cardiac MRI Risk Stratification for Dilated Cardiomyopathy with Left Ventricular Ejection Fraction of 35% or Higher.

Background Studies over the past 15 years have demonstrated that a considerable number of patients with dilated cardiomyopathy (DCM) who died from sudden cardiac death (SCD) had a left ventricular (LV) ejection fraction (LVEF) of 35% or higher. Purpose To identify clinical and cardiac MRI risk factors for adverse events in patients with DCM and LVEF of 35% or higher. Materials and Methods In this retrospective study, consecutive patients with DCM and LVEF of 35% or higher who underwent cardiac MRI between January 2010 and December 2017 were included. The primary end point was a composite of SCD or aborted SCD. The secondary end point was a composite of all-cause mortality, heart transplant, or hospitalization for heart failure. The risk factors for the primary and secondary end points were identified with multivariable Cox analysis. Results A total of 466 patients with DCM and LVEF of 35% or higher (mean age, 44 years ± 14 [SD]; 358 men) were included. During a mean follow-up of 79 months ± 30 (SD) (range, 7-143 months), 40 patients reached the primary end point and 61 reached the secondary end point. In the adjusted analysis, age (hazard ratio [HR], 1.03 per year [95% CI: 1.00, 1.05]; P = .04), family history of SCD (HR, 3.4 [95% CI: 1.3, 8.8]; P = .01), New York Heart Association (NYHA) class III or IV (HR vs NYHA class I or II, 2.1 [95% CI: 1.1, 3.9]; P = .02), and myocardial scar at late gadolinium enhancement (LGE) MRI greater than or equal to 7.1% of the LV mass (HR, 4.4 [95% CI: 2.4, 8.3]; P < .001) were associated with SCD or aborted SCD. For the composite secondary end point, LGE greater than or equal to 7.1% of the LV mass (HR vs LGE <7.1%, 2.0 [95% CI: 1.2, 3.4]; P = .01), left atrial maximum volume index, and reduced global longitudinal strain were independent predictors. Conclusion For patients with dilated cardiomyopathy and left ventricular (LV) ejection fraction of 35% or higher, cardiac MRI-defined myocardial scar greater than or equal to 7.1% of the LV mass was associated with sudden cardiac death (SCD) or aborted SCD. © RSNA, 2022 Online supplemental material is available for this article.

Clinical features, myocardial strain and tissue characteristics of heart failure with preserved ejection fraction in patients with obesity: A prospective cohort study.

Background: The pathophysiology and subsequent myocardial dysfunction of heart failure with preserved ejection fraction (HFpEF) with comorbid obesity has not been extensively described. This study aimed to investigate the clinical features and cardiovascular magnetic resonance (CMR) derived myocardial strain and tissue characteristics in patients with HFpEF and comorbid obesity phenotype. Methods: In this prospective cohort study, we included consecutive patients admitted to Fuwai hospital in China who underwent CMR. Patients with HFpEF or obesity were diagnosed with demographic data, clinical presentation, laboratory test, and echocardiography or CMR imaging. The key exclusion criteria were cardiomyopathy, primary valvular heart disease, and significant coronary artery disease. Participant data were obtained from the electronic medical records database or inquiry. Comparisons of clinical features and CMR derived structural and functional parameters amongst different groups were made using one-way analysis of variance, or χ2 tests, and post hoc Bonferroni analysis where appropriate. Findings: Between January 1, 2019 and July 31, 2021, 280 participants (108 patients with HFpEF and obesity, 50 patients with HFpEF and normal weight, 72 patients with obesity, and 50 healthy controls) were enrolled. Compared with patients with HFpEF and normal weight, patients with HFpEF and obesity were younger males, and had higher plasma volume, uric acid and hemoglobin levels, yet less often atrial fibrillation, and lower NT-proBNP levels, and had higher left ventricular mass index, end-diastole/systole volume index, lower left atrial volume index, and worse myocardial strains (all p ≤ 0.05), but no remarkable difference in late gadolinium enhancement (LGE) presence and extracellular volume fraction (ECV). After adjusting for age, atrial fibrillation, and coronary artery disease, only global longitudinal strain (GLS, p = 0.031) and early-diastolic global longitudinal strain rate (eGLSR, p = 0.043) were considerably worse in patients with HFpEF and obesity versus patients with HFpEF and normal weight. Furthermore, early-diastolic strain rates showed no linear association with ECV in patients with HFpEF and obesity. Moreover, GLS demonstrated the highest diagnostic ability when compared with traditional CMR structural parameters and ECV to diagnose patients with HFpEF and obesity in the setting of obesity. Interpretation: Higher systemic inflammation, and worse GLS and eGLSR may be the distinct features of obesity-related HFpEF phenotype; strains and ECV may represent different mechanisms of HFpEF with obesity, deserving further study. Funding: The Construction Research Project of Key Laboratory (Cultivation) of Chinese Academy of Medical Sciences (2019PT310025); National Natural Science Foundation of China (81971588); Capital's Funds for Health Improvement and Research (CFH 2020-2-4034); Youth Key Program of High-level Hospital Clinical Research (2022-GSP-QZ-5).

Left ventricular strain derived from cardiac magnetic resonance can predict outcomes of pulmonary valve replacement in patients with repaired tetralogy of Fallot.

Purpose: Several adults with repaired tetralogy of Fallot (rToF) undergo pulmonary valve replacement (PVR) to reduce the right ventricular volume and retain right ventricular function. However, there is currently no consensus on the ideal time for PVR surgery in asymptomatic patients with rTOF with pulmonary regurgitation (PR). Clinical outcomes after PVR are also indeterminate. Recently, myocardial strain and strain rate derived from cardiac magnetic resonance (CMR) feature tracking were found to be more sensitive to right ventricular dysfunction than conventional parameters and therefore may add prognostic value in patients with rToF. We aimed to analyze whether pre-PVR left ventricular (LV) strain and strain rate detected by CMR feature tracking are associated with midterm outcomes after PVR in patients with rToF. Methods: Seventy-eight asymptomatic patients with rToF who required PVR due to moderate or severe PR were prospectively enrolled between January 2014 and June 2020. CMR cine sequences were obtained, and feature tracking parameters were measured preoperatively. Adverse events were documented during the follow-up. Receiver operating characteristic analysis was performed to determine the cutoff value. Kaplan-Meier curves were drawn with log-rank statistics; moreover, univariate and multivariate Cox proportional hazards regression analyses and Harrel C-indices were analyzed. Results: During 3.6 ± 1.8 years of follow-up, 25 adverse events were recorded. Kaplan-Meier survival curves and univariate Cox analysis verified that patients with significantly reduced radial strain (RS), circumferential strain (CS), longitudinal strain (LS), RS rate at systole and diastole (RSRs and RSRe), and circumferential and LS rates at diastole (CSRe and LSRe) had worse event-free survival. After multivariate correction, only LS and LSRe remained significantly associated with adverse outcomes (hazard ratio = 1.243 [1.083-1.428] and 0.067 [0.017-0.258], respectively, all p < 0.05). The cutoff values of LS and LSRe were -12.30 (%) and 1.07 (s-1), respectively. Conclusion: The LV strain and strain rate prior to PVR are important prognostic factors for adverse events after PVR in rToF.

Left atrial dysfunction may precede left atrial enlargement and abnormal left ventricular longitudinal function: a cardiac MR feature tracking study.

BACKGROUND: The role of the dysfunction of left atrium in the occurrence and development of cardiovascular disease has been gradually recognized. We aim to compare the impact on left atrial (LA) function between patients with hypertrophic cardiomyopathy (HCM) and hypertension (HTN) without LA enlargement using cardiovascular magnetic resonance feature tracking (CMR-FT), and if possible, explore the capability of LA function for providing clinical implication and predicting clinical adverse events in the early stage of cardiovascular disease. METHODS: Consecutive 60 HCM patients and 60 HTN patients with normal LA size among 1413 patients who underwent CMR were retrospectively analyzed as well as 60 controls. Left atrial and ventricular functions were quantified by volumetric and CMR-FT derived strain analysis from long and short left ventricular view cines. The primary endpoint was a composite of all-cause death, stroke, new-onset or worsening heart failure to hospitalization, and paroxysmal or persistent atrial fibrillation. RESULTS: Compared to the controls, both HTN and HCM participants had impaired LA reservoir function (εs) and conduit function (εe) with the different stage of LA booster pump dysfunction (εa). LA strain was more sensitive than LV longitudinal strain (GLS) for evaluate primary endpoint (εs: 33.9% ± 7.5 vs. 41.2% ± 14.3, p = 0.02; εe: 13.6% ± 6.2 vs. 17.4% ± 10.4, p = 0.03; εa: 20.2% ± 6.0 vs. 23.7% ± 8.8, p = 0.07; GLS: -19.4% ± 6.4 vs. -20.0% ± 6.8, p = 0.70, respectively). After a mean follow-up of 6.8 years, 23 patients reached primary endpoint. Cox regression analyses indicated impaired LA reservoir and booster pump strain were associated with clinical outcomes in patients at the early stage of HTN and HCM (p < 0.05). CONCLUSIONS: CMR-FT-derived strain is a potential and robust tool in demonstrating impaired LA mechanics, quantifying LA dynamics and underlining the impacts on LA-LV coupling in patients with HTN and HCM without LA enlargement. The corresponding LA dysfunction is a promising metric to assess clinical implication and predict prognosis at the early stage, superior to GLS.

T1 Mapping and Extracellular Volume Fraction in Dilated Cardiomyopathy: A Prognosis Study.

OBJECTIVES: The aim of this study is to examine the prognostic value of T1 mapping and the extracellular volume (ECV) fraction in patients with dilated cardiomyopathy (DCM). BACKGROUND: Patients with DCM with functional left ventricular remodeling have poorer prognoses. Noninvasive assessment of myocardial fibrosis using T1 mapping and the ECV fraction may improve risk stratification of patients with DCM; however, this has not yet been systematically evaluated. METHODS: A total of 659 consecutive patients with DCM (498 men; 45 ± 15 years) who underwent cardiac magnetic resonance with T1 mapping and late gadolinium enhancement (LGE) imaging with a 1.5-T magnetic resonance scanner were enrolled in this study. Primary endpoints were cardiac-related death and heart transplantation. Secondary endpoints were hospitalization for heart failure, ventricular arrhythmias, and implantable cardioverter-defibrillator or cardiac resynchronization therapy implantation. Survival estimates were calculated by Kaplan-Meier curves with the log-rank test. RESULTS: During a mean follow-up of 66.3 ± 20.9 months, 122 and 205 patients with DCM reached the primary and secondary endpoints, respectively. The presence of LGE had an association with both of the primary and secondary endpoints observed in the patients with DCM (both P < 0.001). The maximum native T1 (HR: 1.04; 95% CI: 1.02-1.09) and maximum ECV fraction (HR: 1.14; 95% CI: 1.08-1.21) had associations with the primary endpoints in the patients with positive LGE (both P < 0.001), whereas the mean native T1 (HR: 1.13; 95% CI: 1.10-1.36) and mean ECV fraction (HR: 1.32; 95% CI: 1.12-1.53) had the best associations in the patients with negative LGE (all P < 0.001). CONCLUSIONS: T1 mapping and the ECV fraction had prognostic value in patients with DCM and were particularly important in patients with DCM without LGE. Using a combination of T1 mapping, ECV fraction, and LGE provided optimal risk stratification for patients with DCM.

Multiparametric Cardiovascular Magnetic Resonance in Acute Myocarditis: Comparison of 2009 and 2018 Lake Louise Criteria With Endomyocardial Biopsy Confirmation.

Background: Cardiac magnetic resonance (CMR) has been shown to improve the diagnosis of myocarditis, but no systematic comparison of this technique is currently available. The purpose of this study was to compare the 2009 and 2018 Lake Louise Criteria (LLC) for the diagnosis of acute myocarditis using 3.0 T MRI with endomyocardial biopsy (EMB) as a reference and to provide the cutoff values for multiparametric CMR techniques. Methods: A total of 73 patients (32 ± 14 years, 71.2% men) with clinically suspected myocarditis undergoing EMB and CMR with 3.0 T were enrolled in the study. Patients were divided into two groups according to EMB results (EMB-positive and -negative groups). The CMR protocol consisted of cine-SSFP, T2 STIR, T2 mapping, early and late gadolinium enhancement (EGE, LGE), and pre- and post-contrast T1 mapping. Their potential diagnostic ability was assessed with receiver operating characteristic curves. Results: The myocardial T1 and T2 relaxation times were significantly higher in the EMB-positive group than in the EMB-negative group. Optimal cutoff values were 1,228 ms for T1 relaxation times and 58.5 ms for T2 relaxation times with sensitivities of 86.0 and 83.7% and specificities of 93.3 and 93.3%, respectively. The 2018 LLC had a better diagnostic performance than the 2009 LLC in terms of sensitivity, specificity, positive predictive value, and negative predictive value. T1 mapping + T2 mapping had the largest area under the curve (0.95) compared to other single or combined parameters (2018 LLC: 0.91; 2009 LLC: 0.76; T2 ratio: 0.71; EGEr: 0.67; LGE: 0.73; ). The diagnostic accuracy for the 2018 LLC was the highest (91.8%), followed by T1 mapping (89.0%) and T2 mapping (87.7%). Conclusion: Emerging technologies such as T1/ T2 mapping have significantly improved the diagnostic performance of CMR for the diagnosis of acute myocarditis. The 2018 LLC provided the overall best diagnostic performance in acute myocarditis compared to other single standard CMR parameters or combined parameters. There was no significant gain when 2018LLC is combined with the EGE sequence.

The role of 4D flow MRI for clinical applications in cardiovascular disease: current status and future perspectives.

Magnetic resonance imaging (MRI) four-dimensional (4D) flow is a type of phase-contrast (PC) MRI that uses blood flow encoded in 3 directions, which is resolved relative to 3 spatial and temporal dimensions of cardiac circulation. It can be used to simultaneously quantify and visualize hemodynamics or morphology disorders. 4D flow MRI is more comprehensive and accurate than two-dimensional (2D) PC MRI and echocardiography. 4D flow MRI provides numerous hemodynamic parameters that are not limited to the basic 2D parameters, including wall shear stress (WSS), pulse wave velocity (PWV), kinetic energy, turbulent kinetic energy (TKE), pressure gradient, and flow component analysis. 4D flow MRI is widely used to image many parts of the body, such as the neck, brain, and liver, and has a wide application spectrum to cardiac diseases and large vessels. This present review aims to summarize the hemodynamic parameters of 4D flow MRI technology and generalize their usefulness in clinical practice in relation to the cardiovascular system. In addition, we note the improvements that have been made to 4D flow MRI with the application of new technologies. The application of new technologies can improve the speed of 4D flow, which would benefit clinical applications.

Early Diastolic Longitudinal Strain Rate at MRI and Outcomes in Heart Failure with Preserved Ejection Fraction.

Background Assessment of subclinical myocardial dysfunction by using feature tracking has shown promise in prognosis evaluation of heart failure with preserved ejection fraction (HFpEF). Global early diastolic longitudinal strain rate (eGLSR) can identify earlier diastolic dysfunction; however, limited data are available on its prognostic value in HFpEF. Purpose To evaluate the association between left ventricular (LV) eGLSR and primary composite outcomes (all-cause death or heart failure hospitalization) in patients with HFpEF. Materials and Methods In this retrospective study, consecutive patients with HFpEF (included from January 2010 to March 2013) underwent cardiovascular MRI. The correlation between eGLSR and variables was assessed by using linear regression. The association between eGLSR (obtained with use of feature tracking) and outcomes was analyzed by using Cox proportional regression. Results A total of 186 patients with HFpEF (mean age ± standard deviation, 59 years ± 12; 77 women) were included. The eGLSR was weakly correlated with LV end-diastole volume index (Pearson correlation coefficient [r] = -0.35; P < .001), heart rate (r = 0.35; P < .001), and LV ejection fraction (r = 0.30; P < .001) and moderately correlated with LV end-systole volume index (r = -0.41; P < .001). At a median follow-up of 9.2 years (interquartile range, 8.7-10.0 years), 72 patients experienced primary composite outcomes. Impaired eGLSR, defined as an eGLSR of less than 0.57 per second, was associated with a greater rate of heart failure hospitalization or all-cause death (hazard ratio, 2.0 [95% CI: 1.1, 3.7]; P = .02) after adjusting for multiple clinical and imaging-based variables. Conclusion Left ventricular global early diastolic longitudinal strain rate obtained from cardiovascular MRI feature tracking was independently associated with adverse outcomes in patients with heart failure with preserved ejection fraction. © RSNA, 2021 Online supplemental material is available for this article. An earlier incorrect version appeared online. This article was corrected on October 22, 2021.

Patients who do not fulfill criteria for hypertrophic cardiomyopathy but have unexplained giant T-wave inversion: a cardiovascular magnetic resonance mid-term follow-up study.

BACKGROUND: Patients who have unexplained giant T-wave inversions but do not meet criteria for hypertrophic cardiomyopathy (HCM) (left ventricular (LV) wall thickness < 1.5 cm) demonstrate LV apical morphological features that differ from healthy subjects. Currently, it remains unknown how the abnormal LV apical morphology in this patient population changes over time. The purpose of this study was to investigate LV morphological and functional changes in these patients using a mid-term cardiovascular magnetic resonance (CMR) exam. METHODS: Seventy-one patients with unexplained giant T-wave inversion who did not fulfill HCM criteria were studied. The mean interval time of the follow-up CMR was 24.4 ± 8.3 months. The LV wall thickness was measured in each LV segment according to the American Heart Association 17-segmented model. The apical angle (ApA) was also measured. A receiver operating curve (ROC) was used to identify the predictive values of the CMR variables. RESULTS: Of 71 patients, 16 (22.5%) progressed to typical apical HCM, while 55 (77.5%) did not progress to HCM criteria. The mean apical wall thickness was significantly different between the two groups at both baseline and follow-up, with the apical HCM group having greater wall thickness at both time points (all p < 0.001). There was a significant difference between the two groups in the change of ApA (- 1.5 ± 2.7°/yr vs. - 0.7 ± 2.0°/yr, p < 0.001) over time. The combination of mean apical wall thickness and ApA proved to be the best predictor for fulfilling criteria for apical HCM with a threshold value of 8.1 mm and 90° (sensitivity 93.8%, specificity 85.5%). CONCLUSIONS: CMR metrics identify predictors for progression to HCM in patients with unexplained giant T-wave inversion.