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.

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.

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.

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.

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.

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.

Heart Failure With Preserved Ejection Fraction in Hypertension Patients: A Myocardial MR Strain Study.

BACKGROUND: Despite current recommendations for heart failure with preserved ejection fraction (HFpEF), few studies have demonstrated the ability of MRI to identify subtle functional differences between HFpEF with essential hypertension (HFpEF-HTN) patients and hypertension patients (HTN). PURPOSE: This study aimed to detect and evaluate HFpEF in patients with HTN using feature-tracking (FT) and to ascertain optimal strain cutoffs for the diagnosis of HFpEF-HTN. STUDY TYPE: Retrospective study. POPULATION: Three groups (84 with HFpEF-HTN; 72 with HTN; and 70 healthy controls). FIELD STRENGTH: 1.5T, steady-state free precession (SSFP), and half-Fourier single-shot turbo spin-echo (HASTE) sequences. ASSESSMENT: All patients underwent laboratory testing and imaging protocols (echocardiography and MRI). FT-derived left ventricular (LV) strain and strain rate (SR) were measured and compared among the three groups with adjustment for confounding factors. STATISTICAL TESTS: Kolmogorov-Smirnov's test, independent-sample t-tests, one-way analysis of variance (ANOVA), Pearson's correlation coefficient, area under the receiver-operator characteristic (ROC) curve (AUC), and logistic regression. RESULTS: Compared to 72 HTN patients and 70 healthy controls, HFpEF-HTN patients (84 patients) demonstrated significantly impaired LV strains (except for global peak systolic radial strain, GRS, P < 0.05 for all). Only LV global peak systolic longitudinal strain (GLS) was significantly impaired in HTN patients vs. controls (P < 0.05). The global peak systolic circumferential SR (sGCSR) showed the highest diagnostic value for the differentiation of HFpEF-HTN patients from HTN patients (AUC, 0.731; cutoff value, -1.11/s; sensitivity, 56.0%; specificity, 84.7%). Only global peak early diastolic longitudinal SR (eGLSR) remained independently associated with a diagnosis of HFpEF-HTN in multilogistic analysis. The major strain parameters significantly correlated with LV ejection fraction, end-systolic volume index, and N-terminal pro-brain natriuretic peptide (P < 0.05 for all) and also demonstrated differences between NYHA functional class. DATA CONCLUSION: HFpEF-HTN patients suffer from both systolic and diastolic cardiac dysfunction. FT-derived strain parameters have potential value for the diagnosis and risk stratification of HFpEF-HTN patients. Level of Evidence 3. Technical Efficacy Stage 2.

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.

MRI T1 Mapping in Hypertrophic Cardiomyopathy: Evaluation in Patients Without Late Gadolinium Enhancement and Hemodynamic Obstruction.

Background The value of native myocardial T1 mapping and extracellular volume (ECV) fraction in patients who have hypertrophic cardiomyopathy (HCM) but no late gadolinium enhancement (LGE) and no hemodynamic obstruction are currently unknown. Purpose To evaluate myocardial fibrosis in patients with nonobstructive HCM and no LGE by using native myocardial T1 mapping and ECV fraction and to study their relationships to left ventricular (LV) function and LV hypertrophy. Materials and Methods Patients with HCM who underwent cardiac MRI between 2012 and 2015 were retrospectively evaluated. Patients were included if they had no LGE at MRI, LV ejection fraction greater than or equal to 45%, and no LV outflow tract obstruction. Healthy participants had similar age and sex distribution. Native myocardial T1 and ECV were measured with MRI. Results A total of 258 patients with HCM (mean age ± standard deviation, 49 years ± 15; 74% men) and 122 healthy participants (mean age, 50 years ± 14; 76% men) were evaluated. Native myocardial T1 was longer and ECV fraction was higher in the patients with HCM relative to the healthy participants (mean native T1, 950 msec ± 48 vs 913 msec ± 46; mean ECV, 24.5% ± 2.8 vs 23.0% ± 2.7; both P < .001). Maximum T1 and ECV values correlated strongly with LV mass index for the entire patient cohort with HCM (both r = 0.86; P < .001) and for the subgroups (r = 0.86 and 0.85 for interventricular septal group and r = 0.88 and 0.86 for apical group; all P < .001). Conclusion Prolonged myocardial T1 and elevated extracellular volume in hypertrophic cardiomyopathy suggests diffuse myocardial fibrosis, even in the absence of regionally apparent late gadolinium enhancement and hemodynamic obstruction, and is associated with left ventricular hypertrophy. © RSNA, 2019 See also the editorial by Bluemke and Lima in this issue.

Age- and Sex-Specific Reference Values for Atrial and Ventricular Structures in the Validated Normal Chinese Population: A Comprehensive Measurement by Cardiac MRI.

BACKGROUND: Left and right cardiac structures have been shown to provide important prognostic information in patients with various cardiac disorders. They have always been important biomarkers in patients with heart failure and are crucial in the judgment of a variety of heart diseases. PURPOSE: To provide age- and sex-specific reference values of the normal cardiac structure of Chinese adults. STUDY TYPE: Prospective study. POPULATION: In all, 200 healthy adult volunteers with 20 men and 20 women in each of five age deciles from 20 to 70 years. FIELD STRENGTH: 3.0T, steady-state free precession (SSFP), turbo spin-echo (TSE) sequence. ASSESSMENT: The reference range of cardiac structure values was normalized to age, gender, and body surface area (BSA). The height, weight, blood pressure, and body mass index were measured as well. STATISTIC TESTS: Kolmogorov-Smirnov's, independent-sample t-tests, one-way analysis of variance (ANOVA), Pearson's coefficient, and linear regression. RESULTS: The normalized left atrial (LA) transverse diameter (two-chamber view) at end-systolic, and left ventricular outflow tract diameter (LVOT) were significantly larger in females compared to males (all P < 0.001), while LA volume at end-systole was found higher in males (males: 36.25 ± 10.03 mL vs. females: 32.78 ± 10.27 mL). With increasing age, there was a weak but significant decrease in normalized LA transverse diameter (two-chamber view) at end- systolic (r = -0.25, P < 0.001). The normalized RA volume at end-systole and RVOT diameter showed significant decrease with advancing age (r = -0.22, P = 0.002; r = -0.34, P < 0.001). The indexed left and right ventricular volumes were mostly smaller with advancing age. The LA longitudinal parameters correlated significantly with LA area measured in the two-chamber view at end-systole (r = 0.78, P < 0.001). DATA CONCLUSION: Reference values for the morphological parameters of the intracardiac structure by sex and age distribution are provided in a Chinese population. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 5 J. Magn. Reson. Imaging 2020;52:1031-1043.

Computed tomography angiography-derived fractional flow reserve (CT-FFR) for the detection of myocardial ischemia with invasive fractional flow reserve as reference: systematic review and meta-analysis.

OBJECTIVES: A method named computed tomography angiography-derived fractional flow reserve (FFRCT) is an alternative method for detecting hemodynamically significant coronary stenosis. We carried out a meta-analysis to derive reliable assessment of the diagnostic performances of FFRCT and compare the diagnostic accuracy with CCTA using FFR as reference. METHODS: We searched PubMed, EMBASE, The Cochrane Library, and Web of science for relevant articles published from January 2008 until May 2019 using the following search terms: FFRCT, noninvasive FFR, non-invasive FFR, noninvasive fractional flow reserve, non-invasive fractional flow reserve, and CCTA. Pooled estimates of sensitivity and specificity with the corresponding 95% confidence intervals (CIs) and the summary receiver operating characteristic curve (sROC) were determined. RESULTS: Sixteen studies published between 2011 and 2019 were included with a total of 1852 patients and 2731 vessels. The pooled sensitivity and specificity for FFRCT at the per-patient level was 89% (95% CI, 85-92%) and 71% (95% CI, 61-80%), respectively, while on the per-vessel basis was 85% (95% CI, 82-88%) and 82% (95% CI, 75-87%), respectively. No apparent difference in the sensitivity at per-patient and per-vessel level between FFRCT and CCTA was observed (0.89 versus 0.93 at per-patient; 0.85 versus 0.88 at per-vessel). However, the specificity of FFRCT was higher than CCTA (0.71 versus 0.32 at per-patient analysis; 0.82 versus 0.46 at per-vessel analysis). CONCLUSIONS: FFRCT obtained a high diagnostic performance and is a viable alternative to FFR for detecting coronary ischemic lesions. KEY POINTS: • Noninvasive FFRCThas higher specificity for anatomical and physiological assessment of coronary artery stenosis compared with CCTA. • Noninvasive FFRCTis a viable alternative to invasive FFR for the detection and exclusion of coronary lesions that cause ischemia.

Prognostic value of T1 mapping and extracellular volume fraction in cardiovascular disease: a systematic review and meta-analysis.

T1 mapping and extracellular volume (ECV) fraction are useful new magnetic resonance imaging (MRI) techniques to evaluate myocardial fibrosis; however, their prognostic value has not been well described. In this study, a systematic review and meta-analysis evaluating the prognostic value of these techniques is performed in patients with ischemic and non-ischemic cardiomyopathy. PubMed, Cochrane CENTRAL, and Meta-Register of Controlled Trials were searched for studies that utilized T1 mapping and ECV and that also had ≥ 12 months of follow-up data. The primary endpoints included were cardiovascular death and non-fatal cardiac events (heart failure, acute coronary syndrome). Six studies involving a total of 1524 patients and a mean follow-up of 26.3 months were included. Patients had a mean age of 57.6 years and 56.5% were male. Summary effect estimates were generated with fixed/random-effects modeling and hazard ratios were assessed. Patients with a higher ECV value had a significantly higher incidence of cardiovascular death (hazard ratio [HR] 1.79 [95% CI 1.24 to 2.58; P = 0.09) and combined cardiac events (HR 1.11 [95% CI 1.08-1.15]; P < 0.0001). Patients with higher native T1 values and (HR 1.06 [95% CI 0.96 to 1.17]; P = 0.27) and lower post contrast T1 value (HR 0.99 [95% CI 0.98-0.99], P < 0.001) overall had no increased risk for cardiovascular events. Comparing with other CMR parameters, ECV has excellent potential prognostic value and can help guide risk stratification of patients with ischemic or non-ischemic cardiomyopathy into high and low risk for adverse cardiovascular events.

Incremental prognostic value of cardiovascular magnetic resonance imaging in patients with severe LV dysfunction undergoing coronary artery bypass grafting.

BACKGROUND: Coronary artery disease (CAD) remains a significant global health issue, particularly when complicated by left ventricular ejection fraction (LVEF) < 35%. Although coronary artery bypass grafting (CABG) is recommended for such cases, the unclear prognosis necessitates further investigation. METHOD: This retrospective study aimed to determine whether cardiovascular magnetic resonance (CMR) imaging provides additional prognostic value in guiding effective clinical management. The study included patients with CAD and LVEF < 35% who underwent CABG surgery after enhanced CMR between March 2016 and March 2023. CMR was performed using a 3.0T scanner with steady-state free precession and phase-sensitive inversion recovery sequences. Prognostic analysis of clinical and CMR data was conducted, with the endpoint defined as cardiovascular death, revascularization, hospitalization for heart failure, or stroke. Statistical analysis included Student's t-test, chi-squared test, univariate and multivariate Cox regression analysis, receiver operating characteristic analysis, Harrell C statistical analysis, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) analysis. RESULT: The study included 152 patients (mean age 58.6 ± 9.7 years; 138 men). During a mean follow-up of 2.0 years, 8 patients experienced cardiovascular death, while 1 case had revascularization, 13 had hospitalization for heart failure, and 11 had a stroke. Left atrial diameter index (LADi) (hazard ratio [HR], 1.08 [95% confidence interval (CI): 1.02-1.15]; P = 0.04) and late gadolinium enhancement (LGE) mass (HR, 1.03 [95% CI: 1.01-1.06]; P < 0.001) were associated with the endpoint, even after adjusting for multiple clinical variables. Adding LADi and LGE mass improved risk prediction for adverse events, as indicated by the C-index (0.738, p < 0.01), IDI (0.36), and NRI (0.13). CONCLUSION: Left atrial diameter index (LADi) and scar burden are valuable prognostic indicators in patients with LVEF < 35% undergoing CABG. They offer enhanced risk stratification beyond traditional clinical factors, highlighting their importance in guiding clinical management.

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.

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.

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.

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.

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.