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Myocardial Infarct Size (IS) determined soon after ST-segment elevation myocardial infarction (STEMI) has prognostic significance, and can be assessed by cardiac biomarker levels, electrocardiographic (ECG) parameters, and imaging modalities (including echocardiography and cardiac magnetic resonance imaging [CMRI]). We evaluated methods of IS assessment, 12-lead ECG Selvester QRS scores and high-sensitivity Troponin T (hsTnT) levels measured ≥48hr (plateau phase of hsTnT elevation), compared to paired CMRIs and echocardiograms, in a prospective cohort of patients with STEMI undergoing percutaneous coronary intervention (PCI) during the index hospitalisation. Associations were determined between IS, as assessed by these methods, and 24-month major adverse cardiac events (MACE), a hierarchical composite of: death, stroke and hospitalization for heart failure. Of 233 patients undergoing early CMRI after STEMI, 211 patients (86% male; 54% anterior MI) had first STEMIs, median age 56 years [interquartile range 50-64], of whom 165 (78%) underwent primary PCI and 46 (22%) pharmaco-invasive PCI. Ejection fraction improved from 48% [42-54] acutely to 52% [44-60] at 2 months (p< 0.05). Plateau phase hsTnT levels, QRS scoring and CMRI-determined IS post-STEMI correlated for anterior MIs (all comparisons r>0.4, p<0.01); highest tertiles of these 3 parameters predicted 24 month MACE (log-rank <0.01). Multi-variable binary logistic regression analysis showed 72h hsTnT levels predicted 24-month MACE (p<0.01). Post-PCI treatment of STEMI, hsTnT levels measured ≥48h and Selvester QRS scoring correlated with CMRI-determined IS. These parameters predicted MACE at 24 months and should be routinely assessed for post-STEMI risk stratification.

Background T1 mapping is a robust and highly reproducible application to quantify myocardial relaxation of longitudinal magnetisation. Available T1 mapping methods are presently site and vendor specific, with variable accuracy and precision of T1 values between the systems and sequences. We assessed the transferability of a T1 mapping method and determined the reference values of healthy human myocardium in a multicenter setting. Methods Healthy subjects (n = 102; mean age 41 years (range 17–83), male, n = 53 (52%)), with no previous medical history, and normotensive low risk subjects (n=113) referred for clinical cardiovascular magnetic resonance (CMR) were examined. Further inclusion criteria for all were absence of regular medication and subsequently normal findings of routine CMR. All subjects underwent T1 mapping using a uniform imaging set-up (modified Look- Locker inversion recovery, MOLLI, using scheme 3(3)3(3)5)) on 1.5 Tesla (T) and 3 T Philips scanners. Native T1-maps were acquired in a single midventricular short axis slice and repeated 20 minutes following gadobutrol. Reference values were obtained for native T1 and gadolinium-based partition coefficients, λ and extracellular volume fraction (ECV) in a core lab using standardized postprocessing. Results In healthy controls, mean native T1 values were 950 ± 21 msec at 1.5 T and 1052 ± 23 at 3 T. λ and ECV values were 0.44 ± 0.06 and 0.25 ± 0.04 at 1.5 T, and 0.44 ± 0.07 and 0.26 ± 0.04 at 3 T, respectively. There were no significant differences between healthy controls and low risk subjects in routine CMR parameters and T1 values. The entire cohort showed no correlation between age, gender and native T1. Cross-center comparisons of mean values showed no significant difference for any of the T1 indices at any field strength. There were considerable regional differences in segmental T1 values. λ and ECV were found to be dose dependent. There was excellent inter- and intraobserver reproducibility for measurement of native septal T1. Conclusion We show transferability for a unifying T1 mapping methodology in a multicenter setting. We provide reference ranges for T1 values in healthy human myocardium, which can be applied across participating sites.

Body surface area (BSA) is the most commonly used metric for body size indexation of echocardiographic measures, but its use in patients who are underweight or obese is questioned (body mass index (BMI) < 18.5 kg/m 2 or ≥ 30 kg/m 2 , respectively). We aim to use survival analysis to identify an optimal body size indexation metric for echocardiographic measures that would be a better predictor of survival than BSA regardless of BMI. Adult patients with no prior valve replacement were selected from the National Echocardiography Database Australia. Survival analysis was performed for echocardiographic measures both unindexed and indexed to different body size metrics, with 5-year cardiovascular mortality as the primary endpoint. Indexation of echocardiographic measures (left ventricular end-diastolic diameter [n = 230,109] and mass [n = 224,244], left atrial volume [n = 150,540], aortic sinus diameter [n = 90,805], right atrial area [n = 59,516]) by BSA had better prognostic performance vs unindexed measures (underweight: C-statistic 0.655 vs 0.647; normal weight/overweight: average C-statistic 0.666 vs 0.625; obese: C-statistic 0.627 vs 0.613). Indexation by other body size metrics (lean body mass, height, and/or weight raised to different powers) did not improve prognostic performance versus BSA by a clinically relevant magnitude (average C-statistic increase ≤ 0.02), with smaller differences in other BMI subgroups. Indexing measures of cardiac and aortic size by BSA improves prognostic performance regardless of BMI, and no other body size metric has a clinically meaningful better performance.

Background Cardiac magnetic resonance feature tracking (CMR-FT) and speckle tracking echocardiography (STE) are well-established strain imaging modalities. Multilayer strain measurement permits independent assessment of endocardial and epicardial strain. This novel and layer specific approach to evaluating myocardial deformation parameters may provide greater insight into cardiac contractility when compared to whole-layer strain analysis. The aim of this study is to validate CMR-FT as a tool for multilayer strain analysis by providing a direct comparison between multilayer global longitudinal strain (GLS) values between CMR-FT and STE. Methods We studied 100 patients who had an acute myocardial infarction (AMI), who underwent CMR imaging and echocardiogram at baseline and follow-up (48 ± 13 days). Dedicated tissue tracking software was used to analyse single- and multi-layer GLS values for CMR-FT and STE. Results Correlation coefficients for CMR-FT and STE were 0.685, 0.687, and 0.660 for endocardial, epicardial, and whole-layer GLS respectively (all p < 0.001). Bland Altman analysis showed good inter-modality agreement with minimal bias. The absolute limits of agreement in our study were 6.4, 5.9, and 5.5 for endocardial, whole-layer, and epicardial GLS respectively. Absolute biases were 1.79, 0.80, and 0.98 respectively. Intraclass correlation coefficient (ICC) values showed moderate agreement with values of 0.626, 0.632, and 0.671 respectively (all p < 0.001). Conclusion There is good inter-modality agreement between CMR-FT and STE for whole-layer, endocardial, and epicardial GLS, and although values should not be used interchangeably our study demonstrates that CMR-FT is a viable imaging modality for multilayer strain

Decreased hydraulic forces during diastole contribute to reduced left ventricular (LV) filling and heart failure with preserved ejection fraction. However, their association with diastolic function and patient outcomes are unknown. The aim of this retrospective, cross-sectional study was to determine the mechanistic association between diastolic hydraulic forces, estimated by echocardiography as the atrioventricular area difference (AVAD), and both diastolic function and survival. Patients (n = 5176, median [interquartile range] 5.5 [5.0–6.1] years follow-up, 1213 events) were selected from the National Echo Database Australia (NEDA) based on the presence of relevant transthoracic echocardiographic measures, LV ejection fraction (LVEF) ≥ 50%, heart rate 50–100 beats/minute, the absence of moderate or severe valvular disease, and no prior prosthetic valve surgery. NEDA contains echocardiographic and linked national death index mortality outcome data from 1985 to 2019. AVAD was calculated as the cross-sectional area difference between the LV and left atrium. LV diastolic dysfunction was graded according to 2016 guidelines. AVAD was weakly associated with E/e’, left atrial volume index, and LVEF (multivariable global R 2  = 0.15, p  < 0.001), and not associated with e’ and peak tricuspid regurgitation velocity. Decreased AVAD was independently associated with poorer survival, and demonstrated improved model discrimination after adjustment for diastolic function grading (C-statistic [95% confidence interval] 0.644 [0.629–0.660] vs 0.606 [0.592–0.621], p  < 0.001) and E/e’ (0.649 [0.635–0.664] vs 0.634 [0.618–0.649], p  < 0.001), respectively. Therefore, decreased hydraulic forces, estimated by AVAD, are weakly associated with diastolic dysfunction and demonstrate an incremental prognostic association with survival beyond conventional measures used to grade diastolic dysfunction.

Late gadolinium enhancement cardiac magnetic resonance imaging (CMRI) is the current standard for evaluation of myocardial infarct scar size and characteristics. Because post–ST-segment elevation myocardial infarction (STEMI) troponin levels correlate with clinical outcomes, we sought to determine the sampling period for high-sensitivity troponin T (hs-TnT) that would best predict CMRI-measured infarct scar characteristics and left ventricular (LV) function. Among 201 patients with first presentation with STEMI who were prospectively recruited, we measured serial hs-TnT levels at admission, peak, 24 hours, 48 hours, and 72 hours after STEMI. Indexed LV volumes, LV ejection fraction (LVEF) and infarct scar characteristics (scar size, scar heterogeneity, myocardial salvage index, and microvascular obstruction) were evaluated by CMRI at a median of 4 days post-STEMI. Peak and serial hs-TnT levels correlated positively with early indexed LV volumes and infarct scar characteristics, and negatively correlated with myocardial salvage index and LVEF. Both 48- and 72-hour hs-TnT levels similarly predicted “large” total infarct scar size (odds ratios [ORs] 3.08 and 3.53, both P < .001), myocardial salvage index (ORs 1.68 and 2.30, both P < .001), and LVEF <40% (ORs 2.16 and 2.17, both P < .001) on univariate analyses. On multivariate analyses, 48- and 72-hour hs-TnT levels independently predicted large infarct scar size (ORs 2.05 and 2.31, both P < .001), reduced myocardial salvage index (OR 1.39 [P = .031] and OR 1.55 [P = .009]), and LVEF <40% (OR 1.47 [P = .018] and OR 1.43 [P = .026]). All measured hs-TnT levels had a modest association and similar capacity to predict microvascular obstruction. Levels of hs-TnT at 48 and 72 hours, measured during the “plateau phase” post-STEMI, predicted infarct scar size, poor myocardial salvage, and LVEF. These levels also correlated with scar heterogeneity and microvascular obstruction post-STEMI. Since ascertaining peak levels after STEMI is challenging in routine practice, based on the biphasic kinetics of hs-TnT, a measurement at 48 to 72 hours (during the plateau phase) provides a useful and simple method for early evaluation of LV function and infarct scar characteristics.

We sought to determine the relationship of adverse diastolic remodeling (ie, worsening diastolic or persistent restrictive filling) with infarct scar characteristics, and to evaluate its prognostic value after ST-segment elevation myocardial infarction (STEMI). Severe diastolic dysfunction (restrictive filling) has known prognostic value post STEMI. However, ongoing left ventricular (LV) remodeling post STEMI may alter diastolic function even if less severe. There were 218 prospectively recruited STEMI patients with serial echocardiograms (transthoracic echocardiography) and cardiac magnetic resonance imaging (CMR) performed, at a median of 4 days (early) and 55 days (follow-up). LV ejection fraction and infarct characteristics were assessed by CMR, and comprehensive diastolic function assessment including a diastolic grade was evaluated on transthoracic echocardiography. ‘Adverse diastolic remodeling’ occurred if diastolic function grade either worsened (≥1 grade) between early and follow-up imaging, or remained as persistent restrictive filling at follow-up. Follow-up infarct scar size (IS) predicted adverse diastolic remodeling (area under the curve 0.86) and persistent restrictive filling (area under the curve 0.89). The primary endpoint of major adverse cardiovascular events (MACE) occurred in 48 patients during follow-up (mean, 710±79 days). Kaplan-Meier analysis showed that adverse diastolic remodeling (n=50) and persistent restrictive filling alone (n=33) were significant predictors of MACE (both P<.001). Multivariate Cox analysis, when adjusted for TIMI risk score and CMR IS, microvascular obstruction, and LV ejection fraction, showed adverse diastolic remodeling (HR 3.79, P<.001) was an independent predictor of MACE, as was persistent restrictive filling alone (HR 2.61, P=.019). Larger IS is associated with adverse diastolic remodeling. Following STEMI, adverse diastolic remodeling is a powerful prognostic marker, and identifies a larger group of ‘at-risk’ patients, than does persistent restrictive filling alone.

. Chemical data from soil and weathered waste material samples collected from five uranium mines north of the Grand Canyon (three reclaimed, one mined but not reclaimed, and one never mined) were used in a screening-level risk analysis for the Arizona chisel-toothed kangaroo rat ( Dipodomys microps leucotis ); risks from radiation exposure were not evaluated. Dietary toxicity reference values were used to estimate soil-screening thresholds presenting risk to kangaroo rats. Sensitivity analyses indicated that body weight critically affected outcomes of exposed-dose calculations; juvenile kangaroo rats were more sensitive to the inorganic constituent toxicities than adult kangaroo rats. Species-specific soil-screening thresholds were derived for arsenic (137 mg/kg), cadmium (16 mg/kg), copper (1,461 mg/kg), lead (1,143 mg/kg), nickel (771 mg/kg), thallium (1.3 mg/kg), uranium (1,513 mg/kg), and zinc (731 mg/kg) using toxicity reference values that incorporate expected chronic field exposures. Inorganic contaminants in soils within and near the mine areas generally posed minimal risk to kangaroo rats. Most exceedances of soil thresholds were for arsenic and thallium and were associated with weathered mine wastes.

Background Aggressive dose reduction strategies for cardiac CT require the prospective selection of limited cardiac phases. At lower heart rates, the period of mid-diastole is typically selected for image acquisition. We aimed to identify the effect of heart rate on the optimal CT acquisition phase within the period of mid-diastole. Methods We utilized high temporal resolution tissue Doppler to precisely measure coronary motion within diastole. Tissue-Doppler waveforms of the myocardium corresponding to the location of the circumflex artery (100 patients) and mid-right coronary arteries (50 patients) and the duration and timing of coronary motion were measured. Using regression analysis an equation was derived for the timing of the period of minimal coronary motion within the RR interval. In a validation set of 50 clinical cardiac CT examinations, we assessed coronary motion artifact and the effect of using a mid-diastolic imaging target that was adjusted according to heart rate vs a fixed 75% phase target. Results Tissue Doppler analysis shows the period of minimal cardiac motion suitable for CT imaging decreases almost linearly as the RR interval decreases, becoming extinguished at an average heart rate of 91 bpm for the circumflex (LCX) and 78 bpm for the right coronary artery (RCA). The optimal imaging phase has a strong linear relationship with RR duration (R 2  = 0.92 LCX, 0.89 RCA). The optimal phase predicted by regression analysis of the tissue-Doppler waveforms increases from 74% at a heart rate of 55 bpm to 77% at 75 bpm. In the clinical CT validation set, the optimal CT acquisition phase similarly occurred later with increasing heart rate. When the selected cardiac phase was adjusted according to heart rate the result was closer to the optimal phase than using a fixed 75% phase. While this effect was statistically significant (p < 0.01 RCA/LCx), the mean effect of heart-rate adjustment was minor relative to typical beat-to-beat variability and available precision of clinical phase selection. Conclusion High temporal resolution imaging of coronary motion can be used to predict the optimal acquisition phase in cardiac CT. The optimal phase for cardiac CT imaging within mid-diastole increases with increasing heart rate although the magnitude of change is small.

Purpose of the Review This review aims to provide a profound overview on most recent studies on the clinical significance of Cardiovascular Computed Tomography (CCT) in diagnostic and therapeutic pathways. Herby, this review helps to pave the way for a more extended but yet purposefully use in modern day cardiovascular medicine. Recent Findings In recent years, new clinical applications of CCT have emerged. Major applications include the assessment of coronary artery disease and structural heart disease, with corresponding recommendations by major guidelines of international societies. While CCT already allows for a rapid and non-invasive diagnosis, technical improvements enable further in-depth assessments using novel imaging parameters with high temporal and spatial resolution. Those developments facilitate diagnostic and therapeutic decision-making as well as improved prognostication. Summary This review determined that recent advancements in both hardware and software components of CCT allow for highly advanced examinations with little radiation exposure. This particularly strengthens its role in preventive care and coronary artery disease. The addition of functional analyses within and beyond coronary artery disease offers solutions in wide-ranging patient populations. Many techniques still require improvement and validation, however, CCT possesses potential to become a “one-stop-shop” examination.