Extracellular Fluid Research Articles

Comprehensive remote myocardium characterisation using T1 mapping in patients with ST-segment elevation myocardial infarction

Abstract Background Myocardial tissue injury due to acute myocardial infarction (AMI) does not only occur in the myocardium that is supplied by the culprit lesion, but can also extend to the remote, non-infarcted myocardium. The prognostic implications of remote myocardium changes assessed by cardiac magnetic resonance (CMR) are not fully understood. The aim was to investigate the prognostic relevance of remote myocardium alterations assessed by CMR T1 mapping (native T1 and extracellular volume (ECV)) in patients after ST-segment elevation myocardial infarction (STEMI). Methods This study analyzed 491 STEMI patients treated with primary percutaneous coronary intervention (PCI) that were included in the prospective MARINA-STEMI study (NCT04113356). CMR imaging was performed 4 (Interquartile range [IQR]: 3-5) days after PCI. CMR images were analyzed for left ventricular (LV) function, standard infarct characteristics as well as native remote T1 and remote ECV. The primary clinical endpoint was the composite of all-cause mortality, re-infarction and new congestive heart failure (Major adverse cardiovascular events, MACE). Results Remote native T1 (median: 1009 [IQR: 979-1044] ms) was associated with female sex, peak NT-pro-BNP levels, peak hs-cTnT elevations, TIMI-risk score, admission Killip class, anterior infarct location, post-interventional TIMI-flow, LV ejection fraction and microvascular injury. Remote ECV (median: 26.37 [IQR: 24.28-29.27] %) was associated with age, female sex, peak NT-pro-BNP levels, diabetes, TIMI-risk score, admission Killip class, anterior infarct location, LV ejection fraction and microvascular injury. Over a median follow-up of 12 months (IQR: 12-13) after STEMI, 42 MACE outcomes occurred. Higher native remote T1-times (1018.5 [IQR: 997.0-1064.0] ms vs. 1007.0 [IQR: 977.0-1041.5] ms, p=0.033) as well as a higher remote ECV-values (28.07 vs. 26.27 %, p=0.009) were observed in patients with MACE. Multivariable Cox regression analysis demonstrated that remote ECV (hazard ratio (HR): 1.53 [confidence interval (CI): 1.07-2.19], p=0.020) but not native remote T1 associated with MACE. Conclusions A comprehensive assessment of the remote myocardium with native T1 and ECV provides prognostic information in a contemporary cohort of low risk STEMI patients. Remote ECV, but not remote native T1, was found to be an independent predictor of MACE.

Protein quantitative trait loci identifies genetic biomarkers of proteins associated with measures of myocardial fibrosis in new-onset, treatment naive rheumatoid arthritis

Abstract Introduction The excess risk of cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA) compared to the general population is attributed to chronic inflammation. Identifying the underlying mechanisms and shared inflammatory pathways more precisely would enable tailored treatment. Purpose To identify genetic variants associated with the cardio-metabolic-inflammatory proteomic signature in patients with early, treatment-naïve RA and low CVD risk. Methods The Coronary Artery Disease Evaluation in RA (CADERA) study was a bolt-on to a RCT of patients with early, treatment-naïve RA and low CVD risk profile (maximum of 1 traditional CVD risk factor and no diabetes mellitus). Normalised expression of 334 proteins from 75 CADERA patients who underwent cardiovascular magnetic resonance imaging (CMR) was measured using the Olink Proximity Extension Immunoassay across Inflammation, Cardiovascular II, III and Cardiometabolic panels. Genome-wide single nucleotide polymorphism (SNP) data were generated using the Illumina Global Screening Array and was imputed and checked for data quality using standard approaches. Proteins associated with CMR parameters were identified using Bayesian mixed effects linear regression. Protein quantitative trait locus (pQTL) analysis was then performed using linear regression models adjusted for age, gender, and systolic blood pressure. Cis-pQTLs were defined as SNPs within 1Mb of the protein-encoding gene, and significance threshold was set at 1e-5. Due to sample size, trans-pQTLs were not considered in this analysis. Linkage disequilibrium (LD) clumping was performed using PLINK software to identify index SNPs defined as the most significant variant in LD (r2 <0.5) within a region of +/- 250Kb. Results Following quality control 318 proteins and 5,971,781 SNPs were available for analysis in 75 CADERA patients. The median age was 51 years [inter-quartile range (IQR) 40 - 61] with 52/75 (69%) females, 40/75 (53%) current/ex-smokers, and median body mass index (BMI) 26.4kg/m2 (IQR 23.3 - 28). Participants had a median RA symptom duration of 21.9 weeks (IQR 14.4 - 32.7). Only 8/75 (10%) reported a history of hypertension, hypercholesteroaemia or family history of CVD. 54 out of 318 proteins were associated with CMR measures of myocardial fibrosis and/or vascular stiffness. 460 cis-pQTLs were identified for 20 out of the 318 proteins. LD clumping revealed 40 cis-pQTLs independently associated with these 20 proteins. Of these, NOTCH3 (rs34763630) was positively associated with extracellular volume, and SELPLG (rs7980427) was negatively associated with late gadolinium enhancement as detected on CMR (table 1). No other proteins with genetic support were associated with CMR measures. Conclusion This study for the first time, implicates genetic markers associated with two proteins as putative candidate biomarkers of CMR-identified myocardial fibrosis in new-onset RA that now warrant validation in an independent cohort.

Serial quantitative stress perfusion cardiac magnetic resonance in patients undergoing coronary artery bypass grafting; prediction of symptomatic benefit

Abstract Background Serial multiparametric cardiovascular magnetic resonance (CMR) in patients undergoing coronary artery bypass grafting (CABG) may provide mechanistic insight into dynamic and persistent abnormalities of the myocardium in patients with stable coronary artery disease (CAD). Objectives To assess for dynamic CMR markers of myocardial hypoperfusion and cardiac remodelling in patients undergoing CABG. Methods Patients with CAD awaiting elective CABG were recruited into an observational cohort study. Baseline evaluation included bloods, Seattle Angina Questionnaire-7, and adenosine stress perfusion CMR. Automated fully quantitative stress and rest myocardial blood flow was calculated, alongside assessment of the visual ischaemic burden. Native and post-contrast septal T1 indices were also measured. Repeat evaluation at 6-12 months post CABG was performed. Results Of 43 patients who underwent serial evaluation with CMR (mean age 62.1±9.3, median LVEF 68% [IQR: 62-73%]), there was improvement in the median visual ischaemic burden (18% [IQR: 11-21] vs 42% [IQR: 27-51], P<0.001), mean global stress myocardial blood flow (1.5±0.5 ml/min/g vs 1.3±0.5 ml/min/g, P=0.002) and median global myocardial perfusion reserve (2.4 [IQR: 1.7-2.8] vs 1.7 [IQR: 1.4-2.2], P=0.002) following CABG. Greater improvement in the SAQ-7 summary score was associated with a larger visual ischaemic burden at baseline (ρ=0.44, P=0.004) and a greater decrease in the visual ischaemic burden following CABG (ρ=-0.38, P=0.02). Quantitative MBF metrics did not associate with baseline or change in SAQ-7 summary score. Mean LV extracellular matrix volume decreased following CABG (16.6±3.6ml/m2 vs 18.2±4.6ml/m2, P=0.009). Conclusion Multiparametric CMR identifies dynamic changes in markers of myocardial perfusion and interstitial fibrosis in patients following CABG. Visual assessment of inducible myocardial hypoperfusion may identify patients who will derive the most symptomatic benefit from CABG. The results, however, suggest an important degree of residual inducible ischaemia and an unclear clinical role for CMR-derived MBF calculations.Serial CMR perfusion dataAssociation of SAQ with perfusion

Coronary microvascular dysfunction as assessed by cardiac MRI and its association with aerobic exercise capacity in dilated cardiomyopathy

Abstract Background Dilated cardiomyopathy (DCM) has a poor prognosis. Aerobic exercise capacity (peak VO2) is an independent predictor of mortality but the central mechanisms contributing to exercise intolerance in DCM are unknown. Purpose To characterise myocardial perfusion reserve (MPR) and determine if cardiovascular magnetic resonance (CMR) measures of structure, function and microvascular function are associated with aerobic exercise capacity in DCM. Methods Single centre, prospective, case-control comparison of adults with DCM and matched controls. Adenosine-stress perfusion CMR to assess cardiac structure, function and quantitative perfusion, and cardiopulmonary exercise testing (CPET) to determine peak VO2, was performed. Controls were propensity matched based on age, sex, body mass index and diabetes status, and between group comparison was adjusted for other key clinical characteristics (CMR: ethnicity and systolic blood pressure; CPET: ethnicity, systolic blood pressure, smoking history and lung disease). Comparison of perfusion in segments with and without late gadolinium enhancement was performed using mixed effects linear regression taking into account individual patient segmental perfusion. Pre-specified multivariable linear regression, including key clinical and cardiac variables, was undertaken in patients with DCM to identify independent associations with percentage predicted peak VO2, which incorporates age, sex, height and weight. Results Sixty-six patients with DCM (median age 61 years, 71% male) were matched to 66 controls (median age 59 years, 71% male). The DCM group had greater left ventricular (LV) end-diastolic and end-systolic volumes, lower systolic and diastolic function, and had more focal and diffuse fibrosis compared to controls (Table 1). There was lower rest (0.58±0.14 versus 0.65±0.17 mL/min/g; P=0.033) and stress (1.53±0.49 versus 2.01±0.60 mL/g/min; P<0.001) myocardial blood flow, and lower MPR (2.69±0.84 versus 3.15±0.84 mL/g/min; P=0.002) in the DCM group. In DCM patients, mixed effects linear regression demonstrated lower rest (adjusted mean 0.54(95% CI 0.50-0.57) versus 0.58(0.55-0.62) mL/g/min; P<0.001) and stress MBF (1.38(1.25-1.51) versus 1.55(1.43-1.67) mL/g/min; P<0.001) in segments with LGE compared to segments without LGE, but there was no difference in MPR (2.71(2.47-2.96) versus 2.76(2.55-2.97) mL/g/min; P=0.496). DCM patients had markedly lower peak VO2 (19.8±5.5 versus 25.2±7.3 mL/kg/min; P<0.001). Multivariable linear regression demonstrated that LV ejection fraction, extracellular volume fraction and MPR, but not LV mass, were independently associated with percentage predicted peak VO2 in DCM (R squared=0.531, P<0.001; Table 2). Conclusions DCM patients have lower rest and stress myocardial blood flow and lower MPR compared to controls. In DCM, MPR, LV ejection fraction and fibrosis are independently associated with aerobic exercise capacity.

Postoperative assessment of interstitial myocardial fibrosis in aortic valve pathologies: insights from a cardiac magnetic resonance study

Abstract Background Data on the characteristics of diffuse myocardial fibrosis (DMF) among patient undergoing valve surgery for aortic regurgitation (AR), high-gradient aortic stenosis (HG-AS), and low-flow low-gradient aortic stenosis with low ejection fraction (LFLG-AS) are limited. Purpose To assess the postoperative characteristics of DMF and to compare post- and pre-operative cardiac magnetic resonance imaging (CMR) data. Methods Patients diagnosed with AR (38), HG-AS (62), and LFLG-AS (39), who met criteria for surgical intervention, were prospectively included. Pseudo-severe AS was excluded. Post-operative CMR was performed 6 to 8 months after surgery, and a comparison between post- and pre-operative data was made (delta=Δ). Quantitative analysis included assessment of extracellular volume fraction (ECV), indexed ECV (iECV), and myocardial mass (MM). Results There were differences in baseline characteristics among patients with AR, HG-AS, and LFLG-AS concerning age (54±14 vs 63±8 vs 67±8 years, respectively; p<0.01), male gender (75% vs 50% vs 82%, respectively; p<0.01), NYHA functional class III and IV (37.5% vs 55.2% vs 30.8%, respectively; p=0.03), EuroSCORE II (1.16±0.5 vs 1.26±0.46 vs 3.39±2.65%, respectively; p<0.01), and STS (0.74±0.29 vs 1.11±0.5 vs 3.21±2.11%, respectively; p<0.01). Global ECV was similar between groups (29.2±5.6 vs 27.0±3.6 vs 29.4±5.9%, respectively; p=0.01), MM was different between groups (215±76 vs 161±51 vs 203±51g, respectively; p<0.01), and iECV was different between groups and significantly higher in AS patients (50.1±31.0 vs 21±8 vs 34.2±10.2ml/m², respectively; p<0.01). All patients underwent valve surgery and there were differences regarding extracorporeal circulation time (94±25 vs 97±20 vs 75±41min, respectively; p<0.01), and 30-day mortality (0% vs 3% vs 15%, respectively; p<0.01). Post-surgery data from patients with AR (32), HG-AS (62), and LFLG-AS (21) demonstrated a comparable decrease across all groups concerning preoperative MM (ΔMM: -39.3±41.5 vs -33.4±30.9 vs -23.4±34.2g, respectively; p=0.36) (Figure 1). In contrast, iECV decreased post-surgery only in AR, remaining stable in HG-AS and LFLG-AS (ΔiECV: -19.1±22.5 vs -1.4±7.4 vs 0.9±12ml/m², respectively; p<0.01). Thus, postoperative ECV maintained commensurate values in AR, while increasing in HG-AS and LFLG-AS (ΔECV: -0.1±4.5 vs 1.5±5.1 vs 2.9±4.9%, respectively; p=0.09). Δ left ventricular ejection fraction (LVEF) was similar across groups (ΔLVEF: -1.5±10.6 vs 1.1±11.7 vs 2.6±16%, respectively; p=0.44). Conclusion In the postoperative period, a decrease in MM was observed in all groups of aortic valve pathologies. However, only patients with AR showed a simultaneous and proportional reduction in DMF mass, explaining the patterns of ECV variation. Thus, the reduction of DMF in the postoperative period appears to vary according to the phenotypes presented, and patients with AR exhibit early reverse remodeling despite having high levels of DMF.Delta iECV, LV mass and ECV measures

Computed tomography-derived myocardial extracellular volume: a diagnostic marker for cardiac amyloidosis in transcatheter aortic valve implantation patients with biopsy confirmation

Abstract Background Transthyretin cardiac amyloidosis (ATTR-CA) appears to be prevalent in aortic stenosis (AS). The coexistence of ATTR-CA and severe AS is associated with an increased risk of hospitalization for heart failure after transcatheter aortic valve implantation (TAVI). The identification of ATTR-CA is of great clinical importance. In this study, we investigated the diagnostic value of computed tomography-derived myocardial extracellular volume (CT-ECV) for the diagnosis of biopsy-proven ATTR-CA. Methods From December 2022 to January 2024, we enrolled patients who underwent both TAVI and myocardial biopsy. CT-ECV was measured as part of routine CT imaging before TAVI and myocardial biopsy for definitive diagnosis of CA. Results Of 131 TAVI patients, 101 patients underwent myocardial biopsy. Eight patients (7.9%) were diagnosed with ATTR-CA. There were no significant differences in electrocardiographic parameters. On echocardiography, left ventricular ejection fraction (64 ± 16% vs. 65 ± 14%, p = 0.84) was similar between the 2 groups, whereas intraventricular septum and left ventricular posterior wall in diastole were thicker in the ATTR-CA group (15 ± 3mm vs. 13 ± 2mm, p = 0.04 and 14 ± 3mm vs. 12 ± 2mm, p <0.01, respectively). Significantly higher CT-ECV values were found in the ATTR-CA group than in the non-ATTR-CA group (32.6 ± 3.7% vs. 28.1 ± 3.7%, p = 0.001). Conclusions Patients with biopsy-proven ATTR-CA had high CT-ECV values. Routine CT-ECV evaluation before TAVI may be useful for the diagnosis of ATTR-CA.

Histopathological myocardial changes in patients with severe aortic stenosis referred for surgical valve replacement: a CMR correlation study

Abstract Background Myocardial fibrosis (MF) takes part in left ventricular (LV) remodeling in patients with aortic stenosis (AS), driving the transition from hypertrophy to heart failure. The structural events that occur in this transition are not fully enlightened. Aim To describe histopathology changes at endomyocardial biopsy (EMB) in patients with severe AS referred to surgical aortic valve replacement (AVR); to correlate them with LV tissue characterization from pre-operative cardiac magnetic resonance (CMR). Methods One-hundred-fifty-eight patients (73[68-77]years, 50%women) referred for surgical AVR because of severe symptomatic AS, with pre-operative CMR (n=143) with late gadolinium enhancement (LGE), T1, T2 mapping and extracellular volume fraction (ECV) quantification. Intra-operative septal EMB was obtained in 129 patients. MF was assessed through Masson ́s Trichrome histochemistry. Immunohistochemistry was performed for both inflammatory cells and extracellular matrix (ECM) characterization (Type I Collagen, Fibronectin, Tenascin C). Results Non-ischemic LGE was present in 106 patients (67.1%) (median fraction: 5.0% [2.0-9.7]). Native T1 was above normal: 1053ms[1024-1071] and T2 within normal range (39.3ms[37.3-42.0]). Median MF was 11.9%[6.54-19.97], with predominant type I collagen perivascular distribution (95.3%). Subendocardial cardiomyocyte ischemic-like changes were identified in 45% of EMB. There was no inflammation, despite ECM remodeling expression. MF quantification at EMB was correlated with LGE mass and indexed ECV (p=0.008; p=0.017, respectively). Conclusion Patients with severe symptomatic AS referred for surgical AVR have unspecific histological myocardial changes, including signs of cardiomyocyte ischemic insult. ECM remodeling is ongoing, with MF heterogeneity. These features may be recognized by comprehensive CMR involving LGE, T1 mapping derived indexes and their combination with LV morphofunctional characterization.

The prognostic and incremental value of T1 mapping for predicting adverse events in hypertrophic cardiomyopathy

Abstract Background In patients with hypertrophic cardiomyopathy (HCM), the prognostic value of native T1 and extracellular volume fraction (ECV) for adverse cardiovascular events has not been well defined. Methods Consecutive 663 participants with HCM who underwent cardiovascular magnetic resonance (CMR) were recruited. The follow-up endpoints included heart failure (HF)-related death and sudden cardiac death (SCD) or aborted SCD. Results During the median follow-up time of 44 months (interquartile range [IQR]: 23 to 66.0 months), 56 (8.4%) participants reached composite endpoints including 38 (5.7%) with SCD or aborted SCD, 16 (2.4%) with HF-related death and 2 (0.3%) with heart transplantation. On multivariable Cox proportional hazards regression analyses, native T1 including late gadolinium enhancement (LGE) from three short axes were significantly associated with cardiac death (basal native T1: hazard ratio [HR], 1.06 per 10 ms increase; 95% confidence interval [CI], 1.02 to 1.09; middle native T1: HR, 1.05 per 10 ms increase; 95% CI, 1.01 to 1.09; apical native T1: HR, 1.04 per 10 ms increase; 95% CI, 1.02 to 1.07; all P < 0.05) after adjustment for non-sustained ventricular tachycardia, history of syncope, the extent of LGE, left atrial size, and NYHA class. Conversely, only basal ECV was associated with cardiac death (basal ECV including LGE area: HR, 1.08 per 1% increase, 95%CI, 1.03 to 1.13, P = 0.001; basal ECV excluding LGE: HR, 1.1 per 1% increase; 95%CI, 1.04 to 1.16; P < 0.001) In addition, participants with increased mean native T1 (≥1349.4 ms) or basal ECV(≥ 29.4%) were more likely to suffer from cardiac death in the entire study cohort or the subgroup with low LGE extent (<15%) or low ESC risk score (<6%) (all P < 0.05). Furthermore, the addition of mean LV native T1 (≥1349.4 ms) or basal ECV (≥ 29.4%) to current risk factors in the guidelines could further improve prediction for the composite endpoint (C-index increased to 0.719 from 0.521 for the AHA/ACC risk model, P < 0.001; C index increased to 0.709 from 0.514 for the ESC risk model; P < 0.001). Conclusions In this study of patients with HCM, mean native T1 of three short axes and basal ECV were independently associated with cardiac death and added incremental value to conventional clinical predictors for patients with HCM.Figure 1.Demonstrative images.Figure 2 Incremental Value of T1 mapping

CILP1 and NTproBNP in pulmonary hypertension and right ventricular pressure overload: a translational experimental study

Abstract Introduction Cartilage intermediate layer protein 1 (CILP1) has emerged as a novel marker of right ventricular (RV) dysfunction in pulmonary hypertension (PH), although there is still little evidence on its role in different scenarios of RV pressure overload. The aim of our study was to analyze CILP1 as a biomarker of RV remodeling and PH severity, and compare it with N-terminal pro-brain natriuretic peptide (NTproBNP), in different experimental models of RV pressure overload. Methods Three different experimental models of RV pressure overload compared to a sham procedure were evaluated in 24 Yucatan pigs: chronic postcapillary PH by pulmonary vein banding (M1, n=6); chronic PH by aorto-pulmonary shunting (M2, n=6); RV pressure overload by PA banding (thus without PH) (M3, n=6); and sham procedure (M0, n=6). Animals were evaluated at 8 months after surgery by right heart catheterization, cardiac magnetic resonance (CMR), and blood/histological sampling. Levels of CILP1 and NTproBNP at the RV myocardium and blood were determined with dedicated ELISA and compared among groups by Wilcoxon test with Bonferroni correction. Associations between biomarkers and RV performance indices and pulmonary arterial pressure (PAP) were assessed with Spearman correlation test. Results M1 animals developed chronic postcapillary PH with normal left ventricular (LV) performance and RV maladaptive hypertrophy (RV fibrosis and systolic dysfunction). M2 animals developed chronic precapillary PH associated with LV dilatation and RV maladaptive hypertrophy. On contrast, M3-animals developed severe RV pressure overload (without PH) and hypertrophy but maintained normal RV systolic function. CILP1 and NTproBNP levels were moderately correlated (R=0.56, p=0.002). CILP1 levels in RV myocardium and plasma were significantly higher in M1, whereas NTproBNP plasma levels were significantly higher in M2 (Figure 1). CILP1 in plasma and RV myocardium significantly correlated with PAP, while myocardial CILP1 levels also correlated with RV extracellular volume (RV-ECV) by CMR (Figure 2). NTproBNP myocardial levels correlated with RV ejection fraction and RV-ECV and plasmatic levels correlated with PAP (Figure 2). Conclusions CILP1 levels were increased in the presence of PH and isolated RV dysfunction, whereas NTproBNP levels were increased in the model of PH, RV dysfunction and LV remodeling. Myocardial levels of both peptides correlated with diffuse fibrosis, estimated by CMR, whereas plasmatic levels of both biomarkers correlated with PAP. This suggests that CILP1 may be a more specific marker of RV dysfunction in PH, being less dependent of LV parameters.CILP1 and NTproBNP levels among modelsCorrelation with PAP & RV remodeling

Myocardial parametric mapping in patients with suspected acute myocarditis: a prognosis study

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

Cardiac magnetic resonance T1 imaging for the diagnosis of cardiac amyloidosis among patients with symptomatic heart failure

Abstract Background Cardiac amyloidosis (CA) is a significant cause of heart failure in elderly patients. However, specific signs in cardiac imaging are lacking, hence bone scintigraphy in combination with screening for monoclonal protein, or myocardial biopsy is required for the diagnosis. Cardiac magnetic resonance (CMR) imaging with T1 mapping is a promising diagnostic tool, which may allow to differentiate causes of left ventricular (LV) hypertrophy, particularly CA. Purpose The aim of this study was to test the diagnostic accuracy of T1 mapping for the diagnosis of CA in elderly patients with symptomatic heart failure and red flags for CA. Methods We prospectively enrolled 120 patients aged above 60 years with symptomatic heart failure NYHA II-IV, LV ejection fraction ≥ 40%, increased LV wall thickness of ≥ 12 mm end-diastolic on echocardiography, and elevated cardiac biomarkers (N-terminal pro-B-type natriuretic peptide (NT-proBNP) ≥ 1,000 ng/L, high-sensitivity cardiac troponin T (hs-cTnT) ≥ 14 ng/L). All patients underwent standardized quantitative CMR with a 3.0T scanner. 99mTc-DPD bone scintigraphy, blood screening for monoclonal protein, and, where applicable, cardiac biopsy, were performed as reference methods in all patients. Primary endpoint was diagnostic accuracy of native T1 mapping for the diagnosis of CA. Results 112 patients were included in the final analysis. Median age was 81.0 years (interquartile range 74.0–85.0 years), and 45% were female. CA was diagnosed in 38 patients (34%), of which 32 suffered from a Transthyretin (ATTR) and 6 patients from light chain (AL) amyloidosis. The areas under the receiver operating characteristic curves for native T1 were 0.713, 0.772, 0.836 for global, septal short-axis (SAX), and septal 4-chamber (4Ch) view measurements. The corresponding value of extracellular volume fraction (ECV) was 0.904 (Figure 1). Based on these results, we developed a new diagnostic algorithm for the diagnosis of CA including T1 septal 4Ch and ECV, with a sensitivity and positive predictive value of both 92.9% and a specificity and negative predictive value of 95.8% (Figure 2). Thereby, contrast application can be avoided in 33% of patients. A definite diagnosis could be provided in 81%. Conclusion CMR with T1 imaging provides a high diagnostic accuracy to diagnose CA in patients with symptomatic heart failure at risk for CA. These data may help to identify underlying causes in heart failure which require specific treatment. An earlier diagnosis of CA may improve outcome of these patients.Figure 1Figure 2

Evaluating myocardial involvement in patients with multiple myeloma at different stages a cardiac MR T1 mapping study

Abstract Background At present, the International criteria for diagnosis multiple myeloma（MM） do not specifically highlight the use of cardiac magnetic resonance (CMR) to detect abnormal myocardial infiltration in patients at different clinical stages of MM. Extracellular volume fraction (ECV) based on CMR T1 mapping indicates expansion of the extracellular space or deposition of material in infiltrative heart diseases. Purpose To detect whether myocardial involvement in patients with MM at different clinical stages based on CMR T1 mapping. Methods A cohort consisting of 20 patients with diagnosed MM and 15 sex- and age-matched controls (Cs) were recruited for this study. All participants underwent CMR examination to obtain native T1 and ECV. The patients with MM were stratified into three groups based on the International Staging System (ISS): Stage I (n=5), Stage II (n=7), and Stage III (n=8). Cardiac amyloidosis (CA) is diagnosed based on the patient's clinical presentation and tissue biopsy. The baseline biochemical indices were collected before CMR examination. Result Among patients with MM, there were a total of 9 patients diagnosed with CA, comprising 3 patients in stage II and 6 patients in stage III. The ECV in stage III patients (45.13±11.89%) was significantly higher compared to that in stage I (26.65±4.22%), stage II (34.09±8.90%), and controls (25.40±2.52%) (p < 0.05). Furthermore, the ECV in stage II patients (34.09±8.90%) was higher compared to controls (25.40±2.52%), though not significantly different from stage I patients (26.65±4.22%). Correlation analysis revealed a positive correlation between brain natriuretic peptide (BNP) levels and ECV (r=0.606, p=0.013). Receiver operating characteristic (ROC) curve analysis demonstrated that ECV had good predictive value for CA, with an area under the curve (AUC) of 0.898 (p < 0.01), and the optimal cutoff value for ECV was determined to be 33.7%. Conclusions ECV derived from CRM T1 mapping holds promise for identifying amyloid accumulation, which deteriorates progressively with the advancement of disease stages in patients with MM. It is recommended that patients diagnosed with Stage II and Stage III MM should undergo CMR to facilitate the early detection of myocardial infiltrative damage.

Age-related decline in cardiac lymphatic vessels causes cardiac edema and macrophage accumulation

Abstract As life expectancy has significantly increased, age-related diseases, particularly cardiovascular diseases, have become a primary global cause of death. Aging has multiple effects on the heart and is one major risk factor for cardiovascular diseases. The microcirculation has been extensively studied in this context. However, the contribution of the lymphatic vasculature, which is responsible for draining excessive tissue fluid and immune cells, to age-related pathologies is currently unknown. To address the effect of aging on lymphatics, we examined lymphatic capillary density using LYVE1 and PDPN staining in old (>20 months) and young (3 months) mouse hearts. Aging induced a significant reduction in lymphatic vessel density in the sub-endocardial and –epicardial area of aged left ventricles, in both genders (0.28±0.08 fold and 0.68±0.03 fold; p<0.05), while the right ventricle showed no change. Notably, dilation of (pre-) collector lymphatics was observed in in old hearts, indicating, together with the lymphatic vessel reduction, a lymphatic drainage dysfunction. Indeed, cardiac aging was accompanied by increased numbers of CD68+ macrophages, accumulation of the plasma protein fibrinogen and amyloid into the interstitial space. Moreover, we observed a significant increase in tissue oedema in the aged hearts (p<0.05). The decline in lymphatic vessels was associated with a reduced expression of Vegfc (0.72±0.04 fold; p<0.005), a major lymphatic growth factor, in 20-month-old mouse hearts compared to their 3-month-old counterparts. To establish a causal link between lymphatic dysfunction and age-related cardiac changes, we examined hearts from 3-month-old Flt4;Prox1-CreERT2 mice, that have defective lymphatic vessels. Also these mice, despite their young age, displayed fibrinogen (1.32±0.08 fold; p<0.05) and CD68+ macrophage (1.58±0.08 fold; p<0.05) accumulation compared to wildtype littermates. Apart from these, other age-related changes, such as tendency to cardiac hypertrophy, were also observed; this is currently under further investigation. Likewise, blocking VEGFC signaling in young mice by overexpressing the soluble form of Flt4 impaired cardiac lymphatic capillary density (0.62±0.06 fold; p<0.01), leading to increased macrophage and fibrinogen accumulation (1.69±0.09 fold, 4.60±0.30 fold; p<0.001), suggesting that a decline of lymphatics induces some of the age-associated pathologies. Finally, we addressed whether restoring Vegfc expression in old mice can rescue age-related cardiac impairment. Overexpressing Vegfc via AAV9 in aged mice restored cardiac lymphatic density by 3-fold and reduced CD68+ macrophage density by 1.6-fold, without effect on fibrinogen accumulation. In conclusion, our study demonstrates an age-related reduction in left ventricular lymphatic density, cardiac edema and inflammation. Vegfc overexpression prevented the age-dependent decline of lymphatic vasculature and reduced cardiac inflammation.

Comparison of DNA extraction procedures for detection of Mycoplasma bovis directly from extended bovine semen straw samples using a commercial M. bovis PCR

BackgroundMycoplasma bovis is a global pathogen of cattle but was detected for the first time in New Zealand in 2017, triggering a response under their Biosecurity Act as an “unwanted organism”. Following a lengthy eradication campaign, the Ministry of Primary Industries (MPI) now requires all bovine semen destined for export to New Zealand to be screened with an M. bovis-specific real-time PCR (rtPCR) compliant with amended import health standard (IHS) test requirements aimed at preventing the accidental importation of M. bovis. The standard stipulates that semen samples cannot be centrifuged prior to DNA extraction. To comply with these strict requirements, one of the listed tests was validated together with different DNA preparation steps and compared with existing in-house procedures. DNA was extracted from semen straws using the current in-house semi-automated platform procedures for processing culture, tissue and body fluid sample submissions and was compared with the stipulated test requirements. DNA from centrifuged and unspun semen samples spiked with M. bovis was also compared.ResultsThe rtPCR had a sensitivity and specificity of 100% (95% confidence interval = 79–100% and 74–100%, respectively) when testing DNA from other Mycoplasma species or bovine semen spiked with the latter, with a high level of repeatability for within- and between- run replicates. The consistent limit of detection was 0.001 pg/µl M. bovis DNA and between 5.3 × 102 and 7.5 × 102 CFU/ml M. bovis when artificially spiked in semen. DNA extracted using the KingFisher Flex was detected with lower Cq values than the Maxwell 16, but the comparable improvements in sensitivity were mainly associated with non-centrifuged samples (p < 0.001). None of the procedures tested impeded the detection sensitivity of M. bovis in the presence of competitor organisms Acholeplasma laidlawii, Mycoplasma bovigenitalium and Ureaplasma diversum, confirming M. bovis specificity of the polC target.ConclusionsUnder the experimental conditions applied, this rtPCR test efficiently detected M. bovis in extended bovine semen straw samples from DNA extracted using both semi-automated extraction platforms, irrespective of prior centrifugation of extended semen.

Epidemiological Aspects, Clinicopathology, Hemato-biochemistry and Therapeutic Management of Viperine Snake Envenomation in Buffaloes (Bubalus bubalis)

Background: Poisonous snakebite is a neglected tropical disease, frequently reported in animals including buffaloes. Snakebites are responsible for considerable morbidity and mortality in animals causing economic losses to dairy farmers. Methods: To establish the baseline data of epidemiology, clinical syndrome, hemato-biochemistry and diagnosis of viper snakebites and to standardize the treatment of viper snakebite in buffaloes. Result: The highest incidence of viper envenomation was observed during the monsoon and post-monsoon season in female buffaloes above 4 years of age. The clinical signs such as tachycardia, increased respiration rate, ascending swelling of affected limbs, asymmetrical swelling with dyspnea in case of bite over face and bleeding at the site of bite were observed in envenomed buffaloes. Hemato-biochemical analysis revealed neutrophilic leukocytosis, thrombocytopenia, prolonged capillary blood clotting time, elevated values of blood urea nitrogen (BUN) and creatinine. Post-mortem examination showed hemorrhages and blood-stained serous fluid in subcutaneous tissue and skeletal muscles of the affected limbs. The histopathological changes such as extensive myonecrosis and hemorrhages with marked edema in skeletal muscles, widespread interstitial and intra-alveolar hemorrhages and fibrinous microthrombi in pulmonary vasculature, multifocal to coalescing areas of massive hemorrhages and coagulative necrosis within hepatic parenchyma and marked degeneration of renal tubular epithelium were evident. Therapeutic regimen consisting of polyvalent anti-snake venom, with antibiotics, diuretics, vitamin B complex, styptics, fluids and corticosteroids in non-pregnant while non-steroidal anti-inflammatory drugs in pregnant buffaloes was used. The present treatment strategy showed subsidence of clinical signs, restoration of platelet count, blood clotting time, urea nitrogen and creatinine values depicting clinical recovery with 88.15% survival rate in treated buffaloes.

The preoperative prediction of lymph node metastasis of resectable pancreatic ductal adenocarcinoma using dual-layer spectral computed tomography.

To investigate the value of dual-layer spectral computed tomography (DLCT) parameters derived from primary tumors in predicting lymph node metastasis (LNM) of resectable pancreatic ductal adenocarcinoma (PDAC). In this retrospective study, patients with resectable PDAC who underwent DLCT within 2-week intervals before surgery were enrolled and randomly divided into training and validation sets at a 7:3 ratio. The patients' clinical data, CT morphological features, and DLCT parameters were analyzed. Univariate and multivariate logistic analyses were used to identify the predictors and construct a predictive model, and receiver operator characteristic (ROC) curves were programmed to evaluate the predictive efficacy. We enrolled 107 patients (44 patients with LNM and 63 patients without LNM). Among all variables, iodine concentration in the venous phase, extracellular volume, and tumor size were identified as independent predictors of LNM. The nomogram model, incorporating the two DLCT parameters and the morphological feature, achieved an area under the curve (AUC) of 0.877 (95% confidence interval [CI]: 0.803-0.952) and 0.842 (95% CI: 0.707-0.977) for predicting LNM in the training and validation sets, respectively. Furthermore, the AUC of the nomogram model was greater than that of morphological features of lymph nodes in the training (AUC = 0.877 vs. 0.570) and validation (AUC = 0.842 vs. 0.583) sets. DLCT has the potential to predict LNM in patients with resectable PDAC and show a better predictive value than morphological features of lymph nodes. Question Morphological features of lymph nodes are of limited value in detecting metastatic lymph nodes in pancreatic ductal adenocarcinoma (PDAC). Findings Dual-layer spectral computed tomography (DLCT) parameters and morphological features derived from PDAC lesions show good preoperatively predictive efficacy for lymph node metastasis. Clinical relevance The proposed DLCT-based nomogram model may serve as an effective and convenient tool for preoperatively predicting lymph node metastasis of resectable PDAC.

Investigation on structurally reinforced synthetic bone grafts via tricalcium silicate

AbstractTricalcium silicate (C3S) is one of the main components of mineral trioxide aggregates, which is used in dental endodontic treatment. C3S provides workable viscosity itself and fast hydration when water is added, and it is known to be nontoxic, noncarcinogenic, nongenotoxic, biocompatible, and insoluble in tissue fluids. In this study, C3S is added to synthetic bone‐graft materials from 30% to 60% to deliver viscosity to increase workability in the early stage of implant surgical procedure and to attain some degree of compressive strength after the hydration. Additionally, the porosity is not overly reduced to maintain the ability for bone regeneration. The porosity of the samples was confirmed to be 40%–50% with the formation of the C3S matrices. Simultaneously, the maximum compressive strength was ensured at 14.9 MPa within 24 h of curing time. The radiopacity required for post‐procedural diagnosis was evaluated. The radiopacity of the samples with 50% and 60% C3S was 1.0 mm Al and 1.1 mm Al, respectively. When ZrO2 was added, the radiopacity was enhanced to 1.6 mm Al. Overall, the experimental results showed that the bone‐graft added C3S would be suitable for alveolar bone support and rigid matrix formation in implant surgery.

Comprehensive quantitative magnetic resonance imaging assessment of skeletal muscle pathophysiology in golden retriever muscular dystrophy: Insights from multicomponent water T2 and extracellular volume fraction.

Quantitative MRI and MRS have become important tools for the assessment and management of patients with neuromuscular disorders (NMDs). Despite significant progress, there is a need for new objective measures with improved specificity to the underlying pathophysiological alteration. This would enhance our ability to characterize disease evolution and improve therapeutic development. In this study, qMRI methods that are commonly used in clinical studies involving NMDs, like water T2 (T2H2O) and T1 and fat-fraction (FF) mapping, were employed to evaluate disease activity and progression in the skeletal muscle of golden retriever muscular dystrophy (GRMD) dogs. Additionally, extracellular volume (ECV) fraction and single-voxel bicomponent water T2 relaxometry were included as potential markers of specific histopathological changes within the tissue. Apart from FF, which was not significantly different between GRMD and control dogs and showed no trend with age, T2H2O, T1, ECV, and the relative fraction of the long-T2 component, A2, were significantly elevated in GRMD dogs across all age ranges. Moreover, longitudinal assessment starting at 2months of age revealed significant decreases in T2H2O, T1, ECV, A2, and the T2 of the shorter-T2 component, T21, in both control and GRMD dogs during their first year of life. Notably, insights from ECV and bicomponent water T2 indicate that (I) the elevated T2H2O and T1 values observed in dystrophic muscle are primarily driven by an expansion of the extracellular space, likely driven by the edematous component of inflammatory responses to tissue injury and (II) the significant decrease of T2H2O and T1 with age in control and GRMD dogs reflects primarily the progressive increase in fiber diameter and protein content during tissue development. Our study underscores the potential of multicomponent water T2 relaxometry and ECV to provide valuable insights into muscle pathology in NMDs.

Microvascular obstruction in cardiac amyloidosis.

Cardiac amyloidosis (CA) is characterized by deposition of amyloid fibrils within the extracellular space, causing disarray of the myocardial structure and capillary architecture. This study aims to characterize the prevalence of microvascular obstruction (MVO) in patients with CA and to assess the association between MVO and prognosis. The study population comprised 800 patients, of which 400 had light-chain CA (AL-CA) and 400 had transthyretin CA (ATTR-CA). MVO was present in 221 (27.6%) patients, and more common in ATTR-CA than AL-CA (124 [56.1%] vs. 97 [43.9%], p = 0.033). Patients with MVO had a more severe cardiac phenotype evidenced by higher N-terminal pro-brain natriuretic peptide (3516 ng/L [1944-6247] vs. 2508 ng/L [1203-5752], p < 0.001), worse global longitudinal strain (-10.5% [-12.6; -7.9] vs. -12.0% [-16.0; -8.9], p < 0.001), and higher extracellular volume (56% [51-61] vs. 50% [45-57], p < 0.001). Patients with AL-CA and MVO had a higher serum troponin (86 ng/L [47-148] vs. 59 ng/L [44-78], p < 0.001), and higher T2 (53 ms [50-56] vs. 50 ms [48-52], p < 0.001), but lower extracellular volume (55% [50-60] vs. 58% [53-61], p = 0.008) and lower indexed myocyte cell volume (48.6 g/m2 [41.1-59.8] vs. 55.7 g/m2 [47.5-68.4], p < 0.001) than patients with ATTR-CA and MVO. MVO was associated with an increased risk of mortality in the overall population (hazard ratio [HR] 1.28, 95% confidence interval [CI] 1.03-1.59, p = 0.025), and the subgroup with AL-CA (HR 1.59, 95% CI 1.17-2.17, p = 0.003) but not ATTR-CA (HR 1.04, 95% CI 0.77-1.40, p = 0.814). Microvascular obstruction is common in CA and is related to markers of amyloid infiltration. MVO is associated with an increased risk of mortality in AL-CA, but not in ATTR-CA. This reflects the intrinsic differences in disease biology between these two forms of CA, with MVO likely related to multiple myocardial processes, amyloid infiltration, oedema and myocyte death.

The curious case of the Dana platypus and what it can teach us about how lead shotgun pellets behave in fluid preserved museum specimens and may limit their scientific value.

Fluid preserved animal specimens in the collections of natural history museums constitute an invaluable archive of past and present animal diversity. Well-preserved specimens have a shelf-life spanning centuries and are widely used for e.g. anatomical, taxonomical and genetic studies. The way specimens were collected depended on the type of animal and the historical setting. As many small mammals and birds were historically collected by shooting, large quantities of heavy metal residues, primarily lead, may have been introduced into the sample in the form of lead shot pellets. Over time, these pellets may react with tissue fluids and/or the fixation and preservation agents and corrode into lead salts. As these chemicals are toxic, they could constitute a health issue to collection staff. Additionally, heavy element chemicals interfere with several imaging technologies increasingly used for non-invasive studies, and may confound anatomical and pathological investigations on affected specimens. Here we present a case-study based on platypus (Ornithorhynchus anatinus) and other small mammals containing lead pellets from the collection of The Natural History Museum of Denmark.