Myocardial Extracellular Volume Research Articles

Cardiac MRI for clinical dilated cardiomyopathy: Improved diagnostic power via combined T1, T2, and ECV

IntroductionEarly diagnosis of patients with dilated cardiomyopathy (DCM) remains challenging. Cardiac MR can correlate myocardial changes with their pathological basis. There have been some previous studies on the effect of T1 mapping in DCM, but there is limited data on the incremental value of T2 mapping for DCM in routine clinical practice. This study will examine whether the combination of MRI T1 and T2 mapping offers greater advantages in the diagnosis of DCM. MethodsThe study included 28 patients with DCM and 21 healthy controls. CMR evaluation included late gadolinium enhancement (LGE), T1 mapping, extracellular volume (ECV) fraction and T2 mapping. The DCM group was divided into LGE (+) and LGE (−) subgroups. The main modes of LGE are subendocardial, midwall, subepicardial, or transmural. T1 values, T2 values, and ECV in the 16 segments myocardial levels were measured by post-processing software. Student's t-tests or Mann–Whitney U test was used to compare between two groups, and one-way ANOVA or Kruskal–Wallis H test was used to compare between multiple groups, with p values corrected by Bonferroni. The difference was considered statistically significant at P < 0.05. ROC curve analysis was used to compare the area under the curve (AUC) of each index and its combined value, and the cut-off value, sensitivity and specificity were determined by Jordan's index. ResultsMean native myocardial T1, ECV and T2 were significantly higher in the DCM group compared to controls (p ≤ 0.001, respectively). The best cut-off values for T1, T2 and ECV to discriminate DCM from controls were 1184 ms, 40.9 ms and 29.2%, respectively. The AUC of T1, ECV and T2 were 0.87, 0.89, and 0.83, respectively. The combined AUC of the three values was 0.96. ConclusionNative T1 value and ECV overcome some of the limitations of LGE, and the T2 helps to understand the extent of myocardial damage. The combination of T1 and T2 mapping techniques can reveal fibrotic and oedematous changes in the early stages of DCM, providing a more comprehensive assessment of DCM and better guidance for individualised clinical management of patients. Implications for practiceWe suggest that the addition of T2 mapping to the routine CMR examination of patients with suspected DCM, and the combined assessment of T1mapping and T2 mapping can provide complementary information about the disease and improve the early diagnosis of DCM.

Myocardial extracellular volume derived from contrast-enhanced chest computed tomography in longitudinal evaluation of cardiac toxicity in patients treated with immune checkpoint inhibitors.

The immune-related adverse effects after immune checkpoint inhibitors (ICIs) treatment have always been a hot topic. Although the incidence of myocarditis is not high among the related adverse effects, the mortality rate is extremely high once it occurs. In the past, the risk of cancer therapy-related cardiac dysfunction (CTRCD) after drug treatment was evaluated based on imaging examinations, but this evaluation still had certain limitations. Currently, the extracellular volume (ECV) score measurement calculated using cardiac magnetic resonance T1 mapping has become a reliable method for evaluating myocardial toxicity and computed tomography (CT) examination may become an alternative. This study aimed to longitudinally evaluate the cardiac toxicity of patients treated with ICIs using myocardial ECV derived from contrast-enhanced chest CT. A total of 500 patients with III-IV lung cancer and esophageal cancer treated with ICIs were evaluated. Participants underwent baseline examination and at least 1 follow-up examination after treatment. Contrast-enhanced chest CT-ECV, left ventricular ejection fraction (LVEF), and measurement of cardiac troponin T (cTnT) were conducted before the first treatment, 3-6 months after the first treatment, and about 12 months after the first treatment, respectively. The ECV value of the middle part of the left ventricular septum was evaluated on CT venography and plain scan, the LVEF value was evaluated by color Doppler ultrasound, and the quantity of cTnT was detected by chemiluminescence. Cancer therapy-related cardiac dysfunction was recorded. The mean baseline LVEF value was 68.51%±4.81% (N0=500), and those of LVEF1, LVEF2, and LVEF3 were 68.77%±4.30%, 68.16%±3.59%, and 66.23%±4.20%, respectively (N1=500, N2=467, and N3=361, respectively). There was no significant difference between LVEF1, LVEF2, and LVEF0 (P1=0.095, P2=0.062), whereas LVEF3 was significantly lower than LVEF0 (P<0.001). The average baseline cTnT0 value was 7.42±3.95 (N0=500). The values of cTnT1, cTnT2, and cTnT3 were 10.05±11.40, 12.24±13.59, and 14.54±14.49, respectively (N1=500, N2=467, N3=361). The values of cTnT1, cTnT2, and cTnT3 were significantly higher than cTnT0 (P1<0.001, P2<0.001, P3<0.001). The average ECV0 was 47.14%±7.48% (N0=500). ECV1, ECV2, and ECV3 were 50.85%±6.79%, 53.44%±6.96% and 52.64%±7.58% respectively (N1=500, N2=467 and N3=361). ECV1, ECV2, and ECV3 were significantly higher than ECV0 (P1<0.001, P2<0.001, P3<0.001). CTRCD occurred in 49 patients. There were significant differences between the CTRCD (+) group and the CTRCD (-) group in cTnT1, cTnT2, and cTnT3 (P1<0.001, P2<0.001, and P3<0.001, respectively) and in ECV1, ECV2, and ECV3 (P1=0.039, P2=0.041, and P3=0.013, respectively). CT-ECV began to increase at the early stage after the treatment of ICIs. CT-ECV is a potential biomarker for dynamically monitoring the cardiac toxicity of tumor patients after receiving ICIs. ECV may be used to speculate the CTRCD caused by the treatment of ICIs.

Prognostic value of measurement of myocardial extracellular volume using dual-energy CT in heart failure with preserved ejection fraction

Diffuse myocardial fibrosis is associated with adverse outcomes in heart failure with preserved ejection fraction (HFpEF). Dual-energy CT (DECT) can noninvasively assess myocardial fibrosis by quantification of extracellular volume (ECV) fraction. This study evaluated the association between ECV measured by DECT and clinical outcomes in patients with HFpEF. 125 hospitalized HFpEF patients were enrolled in this retrospective cohort study. ECV was measured using DECT with late iodine enhancement. The composite endpoint was defined as HFpEF hospitalization and all-cause mortality during the follow-up. During the median follow-up of 10.4 months, 34 patients (27.20%) experienced the composite outcomes, including 5 deaths; and 29 HFpEF hospitalizations. The higher DECT-ECV group had higher rates of composite outcomes than the low ECV group (log-rank X2 = 6.818, P = 0.033). In multivariate Cox regression analysis, the ECV (HR 1.17, 95% CI 1.06–1.30, P = 0.001) and NT-pro BNP (HR 2.83, 95% CI 1.16–6.88, P = 0.022) were independent risk factors for the adverse outcomes. Myocardial ECV measured using DECT was an independent risk factor for adverse outcomes in patients with HFpEF.

Efficacy of Computed Tomography-Based Evaluation of Myocardial Extracellular Volume Combined With Red Flags for Early Screening of Concealed Cardiac Amyloidosis in Patients With Atrial Fibrillation.

The prevalence of transthyretin amyloid cardiomyopathy (ATTR-CM) in atrial fibrillation (AF) patients remains unclear. We explored the efficacy of computed tomography-based myocardial extracellular volume (CT-ECV) combined with red flags for the early screening of concealed ATTR-CM in AF patients undergoing catheter ablation.Methods and Results: Patients referred for AF ablation at Oita University Hospital were prescreened using the red-flag signs defined by echocardiographic or electrocardiographic findings, medical history, symptoms, and blood biochemical findings. Myocardial CT-ECV was quantified in red flag-positive patients using routine pre-AF ablation planning cardiac CT with the addition of delayed-phase cardiac CT scans. Patients with high (>35%) ECV were evaluated using technetium pyrophosphate (99 mTc-PYP) scintigraphy. A cardiac biopsy was performed during the planned AF ablation procedure if 99 mTc-PYP scintigraphy was positive. Between June 2022 and June 2023, 342 patients were referred for AF ablation. Sixty-seven (19.6%) patients had at least one of the red-flag signs. Myocardial CT-ECV was evaluated in 57 patients because of contraindications to contrast media, revealing that 16 patients had high CT-ECV. Of these, 6 patients showed a positive 99 mTc-PYP study, and 6 patients were subsequently diagnosed with wild-type ATTR-CM via cardiac biopsy and genetic testing. CT-ECV combined with red flags could contribute to the systematic early screening of concealed ATTR-CM in AF patients undergoing catheter ablation.

Cardiometabolic biomarker patterns associated with cardiac MRI defined fibrosis and microvascular dysfunction in patients with heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction (HFpEF) is a complex disease process influenced by metabolic disorders, systemic inflammation, myocardial fibrosis, and microvascular dysfunction. The goal of our study is to identify potential relationships between plasma biomarkers and cardiac magnetic resonance (CMR) imaging markers in patients with HFpEF. Nineteen subjects with HFpEF and 15 age-matched healthy controls were enrolled and underwent multiparametric CMR and plasma biomarker analysis using the Olink® Cardiometabolic Panel (Olink Proteomics, Uppsala, Sweden). Partial least squares discriminant analysis (PLS-DA) was used to characterize CMR and biomarker variables that differentiate the subject groups into two principal components. Orthogonal projection to latent structures by partial least squares (OPLS) analysis was used to identify biomarker patterns that correlate with myocardial perfusion reserve (MPR) and extracellular volume (ECV) mapping. A PLS-DA could differentiate between HFpEF and normal controls with two significant components explaining 79% (Q2 = 0.47) of the differences. For OPLS, there were 7 biomarkers that significantly correlated with ECV (R2 = 0.85, Q = 0.53) and 6 biomarkers that significantly correlated with MPR (R2 = 0.92, Q2 = 0.32). Only 1 biomarker significantly correlated with both ECV and MPR. Patients with HFpEF have unique imaging and biomarker patterns that suggest mechanisms associated with metabolic disease, inflammation, fibrosis and microvascular dysfunction.

Profile of serum microRNAs in heart failure with reduced and preserved ejection fraction: Correlation with myocardial remodeling

Background and aimsCardiomyocyte hypertrophy and interstitial fibrosis are key components of myocardial remodeling in Heart Failure (HF) with preserved (HFpEF) or reduced ejection fraction (HFrEF). MicroRNAs (miRNAs) are non-coding, evolutionarily conserved RNA molecules that may offer novel insights into myocardial remodeling. This study aimed to characterize miRNA expression in HFpEF (LVEF ≥ 45%) and HFrEF (LVEF < 45%) and its association with myocardial remodeling. MethodsProspectively enrolled symptomatic HF patients (HFpEF:n = 36; HFrEF:n = 31) and controls (n = 23) underwent cardiac magnetic resonance imaging with T1-mapping and circulating miRNA expression (OpenArray system). Results13 of 188 miRNAs were differentially expressed between HF groups (11 downregulated in HFpEF). Myocardial extracellular volume (ECV) was increased in both HF groups (HFpEF 30 ± 5%; HFrEF 30 ± 3%; controls 26 ± 2%, p < 0.001). miR-128a-3p, linked to cardiac hypertrophy, fibrosis, and dysfunction, correlated positively with ECV in HFpEF (r = 0.60, p = 0.01) and negatively in HFrEF (r = −0.51, p = 0.04). miR-423-5p overexpression, previously associated HF mortality, was inversely associated with LVEF (r = − 0.29, p = 0.04) and intracellular water lifetime (τic) (r = −0.45, p < 0.05) in both HF groups, and with NT-proBNP in HFpEF (r = −0.63, p < 0.01). ConclusionsmiRNA expression profiles differed between HF phenotypes. The differential expression and association of miR-128a-3p with ECV may reflect the distinct vascular, interstitial, and cellular etiologies of HF phenotypes.

Myocardial Strain for the Differentiation of Myocardial Involvement in the Post-Acute Sequelae of COVID-19-A Multiparametric Cardiac MRI Study.

Myocardial involvement was shown to be associated with an unfavorable prognosis in patients with COVID-19, which could lead to fatal outcomes as in myocardial injury-induced arrhythmias and sudden cardiac death. We hypothesized that magnetic resonance imaging (MRI) myocardial strain parameters are sensitive markers for identifying subclinical cardiac dysfunction associated with myocardial involvement in the post-acute sequelae of COVID-19 (PASC). This study evaluated 115 subjects, including 65 consecutive COVID-19 patients, using MRI for the assessment of either post-COVID-19 myocarditis or other cardiomyopathies. Subjects were categorized, based on the results of the MRI exams, as having either 'suspected' or 'excluded' myocarditis. A control group of 50 matched individuals was studied. Along with parameters of global cardiac function, the MRI images were analyzed for measurements of the myocardial T1, T2, extracellular volume (ECV), strain, and strain rate. Based on the MRI late gadolinium enhancement and T1/T2/ECV mappings, myocarditis was suspected in 7 out of 22 patients referred due to concern of myocarditis and in 9 out of 43 patients referred due to concern of cardiomyopathies. The myocardial global longitudinal, circumferential, and radial strains and strain rates in the suspected myocarditis group were significantly smaller than those in the excluded myocarditis group, which in turn were significantly smaller than those in the control group. The results showed significant correlations between the strain, strain rate, and global cardiac function parameters. In conclusion, this study emphasizes the value of multiparametric MRI for differentiating patients with myocardial involvement in the PASC based on changes in the myocardial contractility pattern and tissue structure.

Early signs of myocardial systolic dysfunction in patients with type 2 diabetes are strongly associated with myocardial microvascular dysfunction independent of myocardial fibrosis: a prospective cohort study

BackgroundPatients with diabetes demonstrate early left ventricular systolic dysfunction. Notably reduced global longitudinal strain (GLS) is related to poor outcomes, the underlying pathophysiology is however still not clearly understood. We hypothesized that pathophysiologic changes with microvascular dysfunction and interstitial fibrosis contribute to reduced strain.Methods211 patients with type 2 diabetes and 25 control subjects underwent comprehensive cardiovascular phenotyping by magnetic resonance imaging. Myocardial blood flow (MBF), perfusion reserve (MPR), extracellular volume (ECV), and 3D feature tracking GLS and global circumferential (GCS) and radial strain (GRS) were quantified.ResultsPatients (median age 57 [IQR 50, 67] years, 70% males) had a median diabetes duration of 12 [IQR 6, 18] years. Compared to control subjects GLS, GCS, and GRS were reduced in the total diabetes cohort, and GLS was also reduced in the sub-group of patients without diabetic complications compared to control subjects (controls − 13.9 ± 2.0%, total cohort − 11.6 ± 3.0%; subgroup − 12.3 ± 2.6%, all p < 0.05). Reduced GLS, but not GCS or GRS, was associated with classic diabetes complications of albuminuria (UACR ≥ 30 mg/g) [β (95% CI) 1.09 (0.22–1.96)] and autonomic neuropathy [β (95% CI) 1.43 (0.54–2.31)] but GLS was not associated with retinopathy or peripheral neuropathy. Independently of ECV, a 10% increase in MBF at stress and MPR was associated with higher GLS [multivariable regression adjusted for age, sex, hypertension, smoking, and ECV: MBF stress (β (95% CI) − 0.2 (− 0.3 to − 0.08), MPR (β (95% CI) − 0.5 (− 0.8 to − 0.3), p < 0.001 for both]. A 10% increase in ECV was associated with a decrease in GLS in univariable [β (95% CI) 0.6 (0.2 to 1.1)] and multivariable regression, but this was abolished when adjusted for MPR [multivariable regression adjusted for age, sex, hypertension, smoking, and MPR (β (95% CI) 0.1 (− 0.3 to 0.6)]. On the receiver operating characteristics curve, GLS showed a moderate ability to discriminate a significantly lowered stress MBF (AUC 0.72) and MPR (AUC 0.73).ConclusionsMyocardial microvascular dysfunction was independent of ECV, a biomarker of myocardial fibrosis, associated with GLS. Further, 3D GLS could be a potential screening tool for myocardial microvascular dysfunction. Future directions should focus on confirming these results in longitudinal and/or interventional studies.

Kiosk 2R-TC-05 - Left Ventricular Remodeling Based on Myocardial Extracellular Volume (ECV) in Children and Young Adults with Aortic Coarctation

Kiosk 2R-TC-05 - Left Ventricular Remodeling Based on Myocardial Extracellular Volume (ECV) in Children and Young Adults with Aortic Coarctation

The impact of water exchange on estimates of myocardial extracellular volume calculated using contrast enhanced T1 measurements: A preliminary analysis in patients with severe aortic stenosis.

Guidelines recommend measuring myocardial extracellular volume (ECV) using T1 -mapping before and 10-30 min after contrast agent administration. Data are then analyzed using a linear model (LM), which assumes fast water exchange (WX) between the ECV and cardiomyocytes. We investigated whether limited WX influences ECV measurements in patients with severe aortic stenosis (AS). Twenty-five patients with severe AS and 5 healthy controls were recruited. T1 measurements were made on a 3 T Siemens system using a multiparametric saturation-recovery single-shot acquisition (a) before contrast; (b) 4 min post 0.05 mmol/kg gadobutrol; and (c) 4 min, (d) 10 min, and (e) 30 min after an additional gadobutrol dose (0.1 mmol/kg). Three LM-based ECV estimates, made using paired T1 measurements (a and b), (a and d), and (a and e), were compared to ECV estimates made using all 5 T1 measurements and a two-site exchange model (2SXM) accounting for WX. Median (range) ECV estimated using the 2SXM model was 25% (21%-39%) for patients and 26% (22%-29%) for controls. ECV estimated in patients using the LM at 10 min following a cumulative contrast dose of 0.15 mmol/kg was 21% (17%-32%) and increased significantly to 22% (19%-35%) at 30 min (p = 0.0001). ECV estimated using the LM was highest following low dose gadobutrol, 25% (19%-38%). Current guidelines on contrast agent dose for ECV measurements may lead to underestimated ECV in patients with severe AS because of limited WX. Use of a lower contrast agent dose may mitigate this effect.

How Cardiac Fibrosis Assessed via T1 Mapping Is Associated with Liver Fibrosis in Patients with Non-Alcoholic Fatty Liver Disease

(1) Background: Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. Although cardiovascular and NAFLD risk factors overlap, an independent association between these conditions may exist. Hepatic and cardiac fibrosis are important markers of mortality, but the correlation between these markers in patients with NAFLD has not been well studied. Our main objective was to determine the degree of myocardial fibrosis in patients with NAFLD and its correlation with the severity of liver fibrosis. (2) Methods: In this cross-sectional study, patients with NAFLD were allocated to two groups according to the stage of liver fibrosis assessed using MRI: no or mild fibrosis (F0–F1) and significant fibrosis (F2–F4). Framingham risk scores were calculated to evaluate cardiovascular risk factors, and patients underwent multiparametric cardiac and abdominal MRIs. (3) Results: The sample comprised 44 patients (28 with no or mild liver fibrosis and 16 with significant liver fibrosis). The mean age was 57.9 ± 12 years, and 41% were men. Most patients had high cardiac risk factors and carotid disease. Relative to patients with no or mild liver fibrosis, those with significant fibrosis had a higher median calcium score (p = 0.05) and increased myocardial extracellular volume (ECV; p = 0.02). Liver fibrosis correlated with cardiac fibrosis, represented by the ECV (r = 0.49, p &lt; 0.001). The myocardial ECV differentiated patients with and without significant liver fibrosis (AUC = 0.78). (4) Conclusion: This study showed that diffuse myocardial fibrosis is associated with liver fibrosis in patients with NAFLD.

Myocardial Fibrosis Improves in Young Patients with Sickle Cell Disease after Hematopoietic Cell Transplantation

Introduction: Cardiovascular complications are a leading cause of early mortality in patients with sickle cell disease (SCD). Chronic anemia, iron overload and repeated microvascular ischemic insults with reperfusion injury often result in progressive myocardial injury and maladaptive remodeling in SCD patients. Patients with SCD develop diffuse myocardial fibrosis, which can be detected by quantifying the myocardial extracellular volume (ECV) using cardiovascular magnetic resonance (CMR) imaging. Our group and others have previously shown that diffuse myocardial fibrosis is highly prevalent in both children and young adults with SCD, including those who have normal ventricular size and function by echocardiography. Additionally, we have shown that the disease modifying therapies (DMT) such as hydroxyurea or chronic transfusions do not appear to be protective against development of diffuse myocardial fibrosis. In a retrospective study, we found no difference in the myocardial ECV in patients who began DMT early (less than 6 years of age) versus later in life (at least 6 years or after) (Morin CE and Sharma A et al. Blood 2023.). Hematopoietic cell transplantation (HCT) can cure SCD, but myocardial effects of the therapy are unknown. Our goal was to evaluate cardiovascular parameters of function and injury, especially the progression of diffuse myocardial fibrosis, by comparing serial CMR studies performed before and after HCT in patients with SCD. Methods: We performed prospective CMR evaluation of children and young adults with SCD who received a matched sibling donor (MSD) or haploidentical donor (HAPLO) HCT following a reduced toxicity conditioning on a clinical trial (NCT04362293). CMR was performed pre-HCT, and at 1 month, and 12 months post-HCT. CMR-derived ventricular and atrial volumes were calculated. ECV was measured from T1 maps with a modified Look-Locker inversion recovery (MOLLI) sequence in short-axis. T2 and T2* maps were obtained. Regions of interest in the mid-ventricular septum were identified for analysis. We report descriptive statistics for CMR measures along with paired t-tests comparing patient ECV levels at 1-month and 12-months post-HCT to their respective baseline ECV. Results: Our study cohort consisted of 14 patients with SCD who underwent HCT and had serial CMR evaluations available. Thirteen patients had HbSS genotype and one had HbSC genotype. All patients were receiving DMT, either with hydroxyurea or chronic transfusions prior to HCT. Participants were majority male (57%) with median age of 15.2 years (range 6.8-21.3) at the pre-HCT CMR. Six received an MSD HCT and 8 received a HAPLO HCT. Ten patients each had follow up CMR evaluations performed at 1 month, and 12 months post-HCT. At 1 and 12 months post-HCT ejection fraction was preserved while biventricular volume and cardiac index decreased (Table 1). Compared to pre-HCT, ECV decreased from median 29% [range 27-38] to 28% (range 21-35, P= 0.061) at 1 month and 27% (range 24-31, P= 0.043) at 12 months post-HCT. There was no difference in the cardiac chamber sizes or the ECV measurements of those who received a MSD versus HAPLO HCT. Conclusions: We observed an improvement in cardiac chamber sizes with preservation of cardiac function as early as one month after HCT in patients with SCD. We further noted a reduction in ECV indicating a decrease in diffuse myocardial fibrosis in these young patients with SCD. To our knowledge, this is the first study to show that diffuse myocardial fibrosis can improve in patients with SCD after HCT. In addition to further corroborating the organ function protective effects of HCT in patients with SCD, these data further demonstrate the use of CMR as an essential non-invasive tool to assess the effects of therapeutic interventions on SCD-cardiac injury.

Clinical Utility of Computed Tomography–Derived Myocardial Extracellular Volume Fraction: A Systematic Review and Meta-Analysis

BackgroundComputed tomography (CT)–derived extracellular volume fraction (ECV) is a noninvasive method to quantify myocardial fibrosis. Although studies suggest CT is a suitable measure of ECV, clinical use remains limited. ObjectivesA meta-analysis was performed to determine the clinical value of CT-derived ECV in cardiovascular diseases. MethodsElectronic database searches of PubMed, Web of Science Core Collection, Cochrane advanced search, and EMBASE were performed. The most pivotal analysis entailed the comparison of ECV ascertained through CT-ECV among the control, aortic stenosis, and cardiac amyloidosis cohorts. The diagnostic test accuracy for detecting cardiac amyloidosis was assessed using summary receiver-operating characteristics curve. ResultsPooled CT-derived ECV values were 28.5% (95% CI: 27.3%-29.7%) in the control, 31.9% (95% CI: 30.2%-33.8%) in the aortic stenosis, and 48.9% (95% CI: 44.5%-53.3%) in the cardiac amyloidosis group. ECV was significantly elevated in aortic stenosis (P = 0.002) (vs controls) but further elevated in cardiac amyloidosis (P < 0.001) (vs aortic stenosis). CT-derived ECV had a high diagnostic accuracy for cardiac amyloidosis, with sensitivity of 92.8% (95% CI: 86.7%-96.2%), specificity of 84.8% (95% CI: 68.6%-93.4%), and area under the summary receiver-operating characteristic curve of 0.94 (95% CI: 0.88-1.00). ConclusionsThis study is the first comprehensive systematic review and meta-analysis of CT-derived ECV evaluation in cardiac disease. The high diagnostic accuracy of CT-ECV suggests the usefulness of CT-ECV in the diagnosis of cardiac amyloidosis in preoperative CT planning for transcatheter aortic valve replacement.

Relationship between myocardial strain, coronary microvascular dysfunction, and myocardial extracellular volume in patients with type 2 diabetes: a cross-sectional CMR study

Abstract Background Patients with diabetes often develop heart failure with preserved ejection and often demonstrate early indications of myocardial dysfunction by decreased strain, notably the global longitudinal (GLS). The underlying myocardial phenotypical changes in patients with diabetes are coronary microvascular dysfunction and myocardial interstitial fibrosis. The relation of these to strain-indicators of early systolic dysfunction is not established. Purpose We hypothesized that coronary microvascular function and interstitial fibrosis contribute to the subclinical myocardial dysfunction seen in patients with diabetes. Method With gadolinium contrast and adenosine-stress magnetic resonance imaging, we determined myocardial blood flow (MBF) and perfusion ratio (MPR) and extracellular volume (ECV; an imaging biomarker of diffuse fibrosis) in 211 patients with type 2 diabetes without macrovascular coronary artery disease and 25 control subjects. Left ventricular (LV) function was determined from its ejection fraction and 3D feature tracking of GLS, circumferential (GCS), and radial strains (GRS). Results Without a significant age- or sex-differences to control subjects, patients (median age 57 years [IQR 50, 67], 70% males) had a median diabetes duration of 12 [IQR 6, 18] years. LV ejection fraction was normal and similar to controls. Compared to control subjects (GLS -13.9±2.0%), GLS, GCS and GRS were reduced in the total diabetes cohort, and GLS was reduced also in the subgroup of patients without any diabetes complications (total -11.6±3.0%; without-complications -12.3±2.6%). GLS, but not GCS or GRS or LVEF, was associated with albuminuria (b (95%CI) 1.09 (0.22-1.96)) and autonomic neuropathy (b (95%CI) 1.43 (0.54-2.31)). Independently of ECV, a 10% increase in MBF at adenosine-stress and MPR was associated with improved GLS in uni- and multivariable regression analyses. A 10% increase in ECV was associated with a decrease in GLS in univariable and multivariable regression analysis, but this was abolished when adjusted for MPR. GLS showed a moderate ability to discriminate a significantly lowered myocardial blood flow at stress defined as &amp;lt;1.49 mL/min/g (AUC 0.72, GLS threshold -11.5%; sensitivity 75% and specificity 53%) and myocardial perfusion ratio defined as as &amp;lt;2.1 (AUC 0.73, GLS threshold -10.8% resulted in a sensitivity of 71% and a specificity of 70%). GLS had a poor ability to predict increased extracellular volume defined as &amp;gt; 31% (AUC 0.60, GLS threshold -13.5 resulted in a sensitivity of 72% and a specificity of 34%). Conclusion Of the two important phenotypical changes seen with type 2 diabetes, microvascular dysfunction and fibrosis, coronary microvacular dysfunction demonstrates the more important relation to early systolic compromise as determined from the left ventricle global longitudinal strain.Associations of Systolic parametersROC curve

Abstract 15484: Heart Transplantation in a Light-Chain Amyloidosis Patient at Mayo Stage IIIa After Anti-Plasma Cell Chemotherapy With Complete Remission

A 42-year-old female patient was admitted for lower limb edema. Laboratory tests showed nephrotic proteinuria (2.76g/24h). Serum-free λ light chains were 84.9 mg/L, with a κ/λ ratio of 0.12. Bone marrow examination detected 6% immature clonal plasma cells. Amyloid deposition was identified in a renal biopsy. Cardiac magnetic resonance (CMR) revealed normal left ventricular ejection fraction (LVEF), left ventricular circumferential late gadolinium enhancement (LGE), and elevated myocardial T1 value (1459ms) and extracellular volume (47.4%). She was diagnosed with AL amyloidosis and classed as IIIa by the Mayo Stage 2004. A hematologic complete response (CR) was achieved and sustained after treatment with sequencing cyclophosphamide, bortezomib, dexamethasone (CyBorD) and daratumumab regimen. The follow-up CMRs were underwent at 6, 12, and 18 months after starting chemotherapy, which monitored cardiac changes in reponse to CR. Unfortunately, there was no alleviation of cardiac involvement. CMR re-examination (at 42 months) revealed severe cardiac function impairment (LVEF 28%), and dramatically increased extracellular volume (66.2%). Then, she underwent heart transplantation (HTx) evaluated by the heart transplantation multidisciplinary team. Three months later, she was doing well, CMR demonstrated stable cardiac allograft function. Repeated endomyocardial biopsies showed no amyloid deposits. This case illustrates that cardiac amyloid deposition might be a dynamic process in AL amyloidosis and highlights the value of CMR in long-term monitoring and identifying the patients reached CR who need HTx.

Abstract 12256: The High FIB-4 Index is Independently Associated With an Increased Myocardial Extracellular Volume Fraction Quantified by Contrast-Enhanced Cardiac Magnetic Resonance Imaging

Introduction: Liver fibrosis is associated with heart failure and left ventricular diastolic dysfunction. The fibrosis 4 (FIB-4) index is calculated from transaminases, age, and platelet count and can be used to screen patients with liver fibrosis. The myocardial extracellular volume fraction (ECVf) can be evaluated using contrast-enhanced cardiac magnetic resonance imaging (CMR). Hypothesis: ECVf is increased in patients with high FIB-4 index. AIMS: This study aimed to clarify the association between FIB-4 index and ECVf. Methods: A retrospective analysis was performed on patients aged ≥ 45 years with left ventricular ejection fraction (LVEF) &gt; 40 % who underwent CMR at two Japanese institutions. Patients were divided into 3 groups according to the FIB-4 index: Low: FIB-4 index &lt; 1.3; Intermediate: 1.3 ≤ FIB-4 index &lt; 2.67; High: 2.67 ≤ FIB-4 index. The association between the FIB-4 index and ECVf was evaluated using multiple regression analysis, with the FIB-4 index treated as a continuous and nominal variable. Results: A total of 244 patients were included in the analysis, 136 of whom underwent contrast-enhanced CMR and could be evaluated for ECVf. The ECVf of the high FIB-4 index group was significantly higher than that of the other two groups (High: 31.0 ± 4.3 %; Intermediate: 27.9 ± 3.4 %; Low: 27.6 ± 3.7 %. High vs. Intermediate, p = 0.014; High vs. Low, p = 0.008; Intermediate vs. Low, p = 0.65). Multivariate analysis showed that both the FIB-4 index (continuous variable) and high FIB-4 index (nominal variable) were associated with higher ECVf (continuous variable, p = 0.043; nominal variable, p = 0.016). Conclusions: The high FIB-4 index was independently associated with increased ECVf. In contrast, patients with the intermediate FIB-4 index did not have increased ECVf. These suggested the usefulness of FIB-4 index as a cardiac fibrotic parameter.

MRI-derived extracellular volume as a biomarker of cancer therapy cardiotoxicity: systematic review and meta-analysis

ObjectivesMRI-derived extracellular volume (ECV) allows characterization of myocardial changes before the onset of overt pathology, which may be caused by cancer therapy cardiotoxicity. Our purpose was to review studies exploring the role of MRI-derived ECV as an early cardiotoxicity biomarker to guide timely intervention.Materials and methodsIn April 2022, we performed a systematic search on EMBASE and PubMed for articles on MRI-derived ECV as a biomarker of cancer therapy cardiotoxicity. Two blinded researchers screened the retrieved articles, including those reporting ECV values at least 3 months from cardiotoxic treatment. Data extraction was performed for each article, including clinical and technical data, and ECV values. Pooled ECV was calculated using the random effects model and compared among different treatment regimens and among those who did or did not experience overt cardiac dysfunction. Meta-regression analyses were conducted to appraise which clinical or technical variables yielded a significant impact on ECV.ResultsOverall, 19 studies were included. Study populations ranged from 9 to 236 patients, for a total of 1123 individuals, with an average age ranging from 12.5 to 74 years. Most studies included patients with breast or esophageal cancer, treated with anthracyclines and chest radiotherapy. Pooled ECV was 28.44% (95% confidence interval, CI, 26.85−30.03%) among subjects who had undergone cardiotoxic cancer therapy, versus 25.23% (95%CI 23.31−27.14%) among those who had not (p = .003).ConclusionA higher ECV in patients who underwent cardiotoxic treatment could imply subclinical changes in the myocardium, present even before overt cardiac pathology is detectable.Clinical relevance statementThe ability to detect subclinical changes in the myocardium displayed by ECV suggests its use as an early biomarker of cancer therapy–related cardiotoxicity.Key Points• Cardiotoxicity is a common adverse effect of cancer therapy; therefore, its prompt detection could improve patient outcomes.• Pooled MRI-derived myocardial extracellular volume was higher in patients who underwent cardiotoxic cancer therapy than in those who did not (28.44% versus 25.23%, p = .003).• MRI-derived myocardial extracellular volume represents a potential early biomarker of cancer therapy cardiotoxicity.

Focal and diffuse myocardial fibrosis both contribute to regional hypoperfusion assessed by post-processing quantitative-perfusion MRI techniques.

Indications for stress-cardiovascular magnetic resonance imaging (CMR) to assess myocardial ischemia and viability are growing. First pass perfusion and late gadolinium enhancement (LGE) have limited value in balanced ischemia and diffuse fibrosis. Quantitative perfusion (QP) to assess absolute pixelwise myocardial blood flow (MBF) and extracellular volume (ECV) as a measure of diffuse fibrosis can overcome these limitations. We investigated the use of post-processing techniques for quantifying both pixelwise MBF and diffuse fibrosis in patients with clinically indicated CMR stress exams. We then assessed if focal and diffuse myocardial fibrosis and other features quantified during the CMR exam explain individual MBF findings. This prospective observational study enrolled 125 patients undergoing a clinically indicated stress-CMR scan. In addition to the clinical report, MBF during regadenoson-stress was quantified using a post-processing QP method and T1 maps were used to calculate ECV. Factors that were associated with poor MBF were investigated. Of the 109 patients included (66 ± 11 years, 32% female), global and regional perfusion was quantified by QP analysis in both the presence and absence of visual first pass perfusion deficits. Similarly, ECV analysis identified diffuse fibrosis in myocardium beyond segments with LGE. Multivariable analysis showed both LGE (β = -0.191, p = 0.001) and ECV (β = -0.011, p < 0.001) were independent predictors of reduced MBF. In patients without clinically defined first pass perfusion deficits, the microvascular risk-factors of age and wall thickness further contributed to poor MBF (p < 0.001). Quantitative analysis of MBF and diffuse fibrosis detected regional tissue abnormalities not identified by traditional visual assessment. Multi-parametric quantitative analysis may refine the work-up of the etiology of myocardial ischemia in patients referred for clinical CMR stress testing in the future and provide a deeper insight into ischemic heart disease.

Myocardial native T1 mapping and extracellular volume quantification in asymptomatic female carriers of Duchenne muscular dystrophy gene mutations

BackgroundFemale carriers of dystrophin gene mutations (DMD-FC) were previously considered non-manifesting, but in recent decades, cardiomyopathy associated with muscular dystrophy and myocardial fibrosis has been described. Our study aimed to assess prospectively myocardial fibrosis in asymptomatic DMD-FC compared to a sex-matched control group (CG) with similar age distribution using native T1 mapping and extracellular volume (ECV) quantification by cardiovascular magnetic resonance (CMR) imaging.Materials and methods38 DMD-FC with verified genetic mutation and 22 healthy volunteers were included. Using CMR, native T1 relaxation time and ECV quantification were determined in each group. Late gadolinium enhancement (LGE) was assessed in all cases.ResultsThere were 38 DMD-FC (mean age 39.1 ± 8.8 years) and 22 healthy volunteers (mean age 39.9 ± 12.6 years) imagined by CMR. The mean global native T1 relaxation time was similar for DMD-FC and CG (1005.1 ± 26.3 ms vs. 1003.5 ± 25.0 ms; p-value = 0.81). Likewise, the mean global ECV value was also similar between the groups (27.92 ± 2.02% vs. 27.10 ± 2.89%; p-value = 0.20). The segmental analysis of mean ECV values according to the American Heart Association classification did not show any differences between DMD-FC and CG. There was a non-significant trend towards higher mean ECV values of DMD-FC in the inferior and inferolateral segments of the myocardium (p-value = 0.075 and 0.070 respectively).ConclusionThere were no statistically significant differences in the mean global and segmental native T1 relaxation times and the mean global or segmental ECV values. There was a trend towards higher segmental mean ECV values of DMD-FC in the inferior and inferolateral walls of the myocardium.

Quantification of myocardial extracellular volume without blood sampling

Aims Cardiac magnetic resonance (CMR) T1 relaxation time mapping is an established technique primarily used to identify diffuse interstitial fibrosis and oedema. The myocardial extracellular volume (ECV) can be calculated from pre- and post-contrast T1 relaxation times and is a reproducible parametric index of the proportion of volume occupied by non-cardiomyocyte components in myocardial tissue. The conventional calculation of the ECV requires blood sampling to measure the haematocrit (HCT). Given the high variability of the HCT, the blood collection is recommended within 24 h of the CMR scan, limiting its applicability and posing a barrier to the clinical routine use of ECV measurements. In recent years, several research groups have proposed a method to determine the ECV by CMR without blood sampling. This is based on the inverse relationship between the T1 relaxation rate (R1) of blood and the HCT. Consequently, a ‘synthetic’ HCT could be estimated from the native blood R1, avoiding blood sampling. Methods and results We performed a review and meta-analysis of published studies on synthetic ECV, as well as a secondary analysis of previously published data to examine the effect of the chosen regression modell on bias. While, overall, a good correlation and little bias between synthetic and conventional ECV were found in these studies, questions regarding its accuracy remain. Conclusion Synthetic HCT and ECV can provide a ‘non-invasive’ quantitative measurement of the myocardium’s extracellular space when timely HCT measurements are not available and large alterations in ECV are expected, such as in cardiac amyloidosis. Due to the dependency of T1 relaxation times on the local setup, calculation of local formulas using linear regression is recommended, which can be easily performed using available data.