Dynamic changes in lung water density and volume following supine body positioning

PURPOSE

Measure the changes in relative lung water density (rLWD), lung volume, and total lung water content as a function of time after supine body positioning.

METHODS

An efficient ultrashort-TE pulse sequence with a yarnball k-space trajectory was used to measure water density-weighted lung images for 25 min following supine body positioning (free breathing, 74-s acquisitions, 3D images at functional residual capacity, 18 time points) in 9 healthy volunteers. Global and regional (10 chest-to-back positions) rLWD, lung volume, and total lung water volume were measured in all subjects at all time points. Volume changes were validated with a nitrogen washout study in 3 participants.

RESULTS

Global rLWD increased significantly (p = 0.001) from 31.8 ± 5.5% to 34.8 ± 6.8%, while lung volumes decreased significantly (p < 0.001) from 2390 ± 620 mL to 2130 ± 630 mL over the same 25-min interval. Total lung water volume decreased slightly from 730 ± 125 mL to 706 ± 126 mL (p = 0.028). There was a significant chest-to-back gradient in rLWD (20.7 ± 4.6% to 39.9 ± 6.1%) at all time points with absolute increases of 1.8 ± 1.2% at the chest and 5.4 ± 1.9% at the back. Nitrogen washout studies yielded a similar reduction in lung volume (12.5 ± 0.9%) and time course following supine positioning.

CONCLUSION

Lung volumes during tidal breathing decrease significantly over tens of minutes following supine body positioning, with corresponding increases in lung water density (9.2 ± 4.4% relative increase). The total volume of lung water is slightly reduced over this interval (3.3 ± 4.0% relative change). Evaluation of rLWD should take time after supine positioning, and more generally, all sources of lung volume changes should be taken into consideration to avoid significant bias.

Analysis of left ventricle regional myocardial motion for cardiac radioablation: Left ventricular motion analysis

PURPOSE

Left ventricle (LV) regional myocardial displacement due to cardiac motion was assessed using cardiovascular magnetic resonance (CMR) cine images to establish region-specific margins for cardiac radioablation treatments.

METHODS

CMR breath-hold cine images and LV myocardial tissue contour points were analyzed for 200 subjects, including controls (n = 50) and heart failure (HF) patients with preserved ejection fraction (HFpEF, n = 50), mid-range ejection fraction (HFmrEF, n = 50), and reduced ejection fraction (HFrEF, n = 50). Contour points were divided into segments according to the 17-segment model. For each patient, contour point displacements were determined for the long-axis (all 17 segments) and short-axis (segments 1-12) directions. Mean overall, tangential (longitudinal or circumferential), and normal (radial) displacements were calculated for the 17 segments and for each segment level.

RESULTS

The greatest overall motion was observed in the control group-long axis: 4.5 ± 1.2 mm (segment 13 [apical anterior] epicardium) to 13.8 ± 3.0 mm (segment 6 [basal anterolateral] endocardium), short axis: 4.3 ± 0.8 mm (segment 9 [mid inferoseptal] epicardium) to 11.5 ± 2.3 mm (segment 1 [basal anterior] endocardium). HF patients exhibited lesser motion, with the smallest overall displacements observed in the HFrEF group-long axis: 4.3 ± 1.7 mm (segment 13 [apical anterior] epicardium) to 10.6 ± 3.4 mm (segment 6 [basal anterolateral] endocardium), short axis: 3.9 ± 1.3 mm (segment 8 [mid anteroseptal] epicardium) to 7.4 ± 2.8 mm (segment 1 [basal anterior] endocardium).

CONCLUSIONS

This analysis provides an estimate of epicardial and endocardial displacement for the 17 segments of the LV for patients with normal and impaired LV function. This reference data can be used to establish treatment planning margin guidelines for cardiac radioablation. Smaller margins may be used for patients with higher degree of impaired heart function, depending on the LV segment.

Cardiac MRI evaluation of aortic biophysical properties in paediatric Turner syndrome

BACKGROUND

Aortopathy in Turner syndrome is associated with aortic dilation, and the risk of dissection is increased when the aortic size index is ≥ 2-2.5 cm/m2. We evaluated the aortic biophysical properties in paediatric Turner syndrome using cardiac MRI to determine their relationship to aortic size index.

METHODS

Turner syndrome patients underwent cardiac MRI to evaluate ventricular function, aortic dimensions, and biophysical properties (aortic stiffness index, compliance, distensibility, pulse wave velocity, and aortic and left ventricular elastance). Spearman correlation examined correlations between these properties and aortic size index. Data was compared to 10 controls.

RESULTS

Of 25 Turner syndrome patients, median age 14.7 years (interquartile range: 11.0-16.8), height z score -2.7 (interquartile range: -2.92 - -1.54), 24% had a bicuspid aortic valve. Turner syndrome had increased diastolic blood pressure (p < 0.001) and decreased left ventricular end-diastolic (p < 0.001) and end-systolic (p = 0.002) volumes compared to controls. Median aortic size index was 1.81 cm/m2 (interquartile range: 1.45-2.1) and 7 had an aortic size index > 2 cm/m2. Aortic and left ventricular elastance were greater in Turner syndrome compared to controls (both p < 0.001). Increased aortic size index correlated with increased aortic elastance (r = 0.5, p = 0.01) and left ventricular elastance (r = 0.59, p = 0.002) but not aortic compliance. Higher ascending aortic areas were associated with increased aortic compliance (r = 0.44, p = 0.03) and left ventricular elastance (r = 0.49, p = 0.01).

CONCLUSION

Paediatric Turner syndrome with similar aortic size index to controls showed MRI evidence of abnormal aortic biophysical properties. These findings point to an underlying aortopathy and provide additional parameters that may aid in determining risk factors for aortic dissection.

Effect of lower body negative pressure on cardiac and cerebral function in postural orthostatic tachycardia syndrome: A pilot MRI assessment

Postural orthostatic tachycardia syndrome (POTS) is characterized by an excessive heart rate (HR) response upon standing and symptoms indicative of inadequate cerebral perfusion. We tested the hypothesis that during lower body negative pressure (LBNP), individuals with POTS would have larger decreases in cardiac and cerebrovascular function measured using magnetic resonance (MR) imaging. Eleven patients with POTS and 10 healthy controls were studied at rest and during 20 min of -25 mmHg LBNP. Biventricular volumes, stroke volume (SV), cardiac output (Qc), and HR were determined by cardiac MR. Cerebral oxygen uptake (VO2 ) in the superior sagittal sinus was calculated from cerebral blood flow (CBF; MR phase contrast), venous O2 saturation (SvO2 ; susceptometry-based oximetry), and arterial O2 saturation (pulse oximeter). Regional cerebral perfusion was determined using arterial spin labelling. HR increased in response to LBNP (p < 0.001) with no group differences (HC: +9 ± 8 bpm; POTS: +13 ± 11 bpm; p = 0.35). Biventricular volumes, SV, and Qc decreased during LBNP (p < 0.001). CBF and SvO2 decreased with LBNP (p = 0.01 and 0.03, respectively) but not cerebral VO2 (effect of LBNP: p = 0.28; HC: -0.2 ± 3.7 mL/min; POTS: +1.1 ± 2.0 mL/min; p = 0.33 between groups). Regional cerebral perfusion decreased during LBNP (p < 0.001) but was not different between groups. These data suggest patients with POTS have preserved cardiac and cerebrovascular function.

Bruch's Membrane Calcification in Pseudoxanthoma Elasticum: Comparing Histopathology and Clinical Imaging

Purpose

To investigate the histology of Bruch's membrane (BM) calcification in pseudoxanthoma elasticum (PXE) and correlate this to clinical retinal imaging.

Design

Experimental study with clinicopathological correlation.

Subjects and Controls

Six postmortem eyes from 4 PXE patients and 1 comparison eye from an anonymous donor without PXE. One of the eyes had a multimodal clinical image set for comparison.

Methods

Calcification was labeled with OsteSense 680RD, a fluorescent dye specific for hydroxyapatite, and visualized with confocal microscopy. Scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (SEM-EDX) and time-of-flight secondary ion mass spectrometry (TOF-SIMs) were used to analyze the elemental and ionic composition of different anatomical locations. Findings on cadaver tissues were compared with clinical imaging of 1 PXE patient.

Main Outcome Measures

The characteristics and topographical distribution of hydroxyapatite in BM in eyes with PXE were compared with the clinical manifestations of the disease.

Results

Analyses of whole-mount and sectioned PXE eyes revealed an extensive, confluent OsteoSense labeling in the central and midperipheral BM, transitioning to a speckled labeling in the midperiphery. These areas corresponded to hyperreflective and isoreflective zones on clinical imaging. Scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy and TOF-SIMs analyses identified these calcifications as hydroxyapatite in BM of PXE eyes. The confluent fluorescent appearance originates from heavily calcified fibrous structures of both the collagen and the elastic layers of BM. Calcification was also detected in an aged comparison eye, but this was markedly different from PXE eyes and presented as small snowflake-like deposits in the posterior pole.

Conclusions

Pseudoxanthoma elasticum eyes show extensive hydroxyapatite deposition in the inner and outer collagenous and elastic BM layers in the macula with a gradual change toward the midperiphery, which seems to correlate with the clinical phenotype. The snowflake-like calcification in BM of an aged comparison eye differed markedly from the extensive calcification in PXE.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Left ventricle segment-specific motion assessment for cardiac-gated radiosurgery

Purpose.Cardiac radiosurgery is a non-invasive treatment modality for ventricular tachycardia, where a linear accelerator is used to irradiate the arrhythmogenic region within the heart. In this work, cardiac magnetic resonance (CMR) cine images were used to quantify left ventricle (LV) segment-specific motion during the cardiac cycle and to assess potential advantages of cardiac-gated radiosurgery.Methods.CMR breath-hold cine images and LV contour points were analyzed for 50 controls and 50 heart failure patients with reduced ejection fraction (HFrEF, EF < 40%). Contour points were divided into anatomic segments according to the 17-segment model, and each segment was treated as a hypothetical treatment target. The optimum treatment window (one fifth of the cardiac cycle) was determined where segment centroid motion was minimal, then the maximum centroid displacement and treatment area were determined for the full cardiac cycle and for the treatment window. Mean centroid displacement and treatment area reductions with cardiac gating were determined for each of the 17 segments.Results.Full motion segment centroid displacements ranged between 6-14 mm (controls) and 4-11 mm (HFrEF). Full motion treatment areas ranged between 129-715 mm2(controls) and 149-766 mm2(HFrEF). With gating, centroid displacements were reduced to 1 mm (controls and HFrEF), while treatment areas were reduced to 62-349 mm2(controls) and 83-393 mm2(HFrEF). Relative treatment area reduction ranged between 38%-53% (controls) and 26%-48% (HFrEF).Conclusion.This data demonstrates that cardiac cycle motion is an important component of overall target motion and varies depending on the anatomic cardiac segment. Accounting for cardiac cycle motion, through cardiac gating, has the potential to significantly reduce treatment volumes for cardiac radiosurgery.

Reference Values for Water-Specific T1 of the Liver at 3 T: T2*-Compensation and the Confounding Effects of Fat

BACKGROUND

T1 mapping of the liver is confounded by the presence of fat. Multiparametric T1 mapping combines fat-water separation with T1-weighting to enable imaging of water-specific T1 (T1Water ), proton density fat fraction (PDFF), and T2* values. However, normative T1Water values in the liver and its dependence on age/sex is unknown.

PURPOSE

Determine normative values for T1Water in the liver with comparison to MOLLI and evaluate a T2*-compensation approach to reduce T1 variability.

STUDY TYPE

Prospective observational; phantoms.

POPULATIONS

One hundred twenty-four controls (56 male, 18-75 years), 50 patients at-risk for liver disease (18 male, 30-76 years).

FIELD STRENGTH/SEQUENCE

2.89 T; Saturation-recovery chemical-shift encoded T1 Mapping (SR-CSE); MOLLI.

ASSESSMENT

SR-CSE provided T1Water measurements, PDFF and T2* values in the liver across three slices in 6 seconds. These were compared with MOLLI T1 values. A new T2*-compensation approach to reduce T1 variability was evaluated test/re-test reproducibility.

STATISTICAL TESTS

Linear regression, ANCOVA, t-test, Bland and Altman, intraclass correlation coefficient (ICC). P < 0.05 was considered statistically significant.

RESULTS

Liver T1 values were significantly higher in healthy females (F) than males (M) for both SR-CSE (F-973 ± 78 msec, M-930 ± 72 msec) and MOLLI (F-802 ± 55 msec, M-759 ± 69 msec). T1 values were negatively correlated with age, with similar sex- and age-dependencies observed in T2*. The T2*-compensation model reduced the variability of T1 values by half and removed sex- and age-differences (SR-CSE: F-946 ± 36 msec, M-941 ± 43 msec; MOLLI: F-775 ± 35 msec, M-770 ± 35 msec). At-risk participants had elevated PDFF and T1 values, which became more distinct from the healthy cohort after T2*-compensation. MOLLI systematically underestimated liver T1 values by ~170 msec with an additional positive T1-bias from fat content (~11 msec/1% in PDFF). Reproducibility ICC values were ≥0.96 for all parameters.

DATA CONCLUSION

Liver T1Water values were lower in males and decreased with age, as observed for SR-CSE and MOLLI acquisitions. MOLLI underestimated liver T1 with an additional large positive fat-modulated T1 bias. T2*-compensation removed sex- and age-dependence in liver T1, reduced the range of healthy values and increased T1 group differences between healthy and at-risk groups.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 1.

Determinants of Impaired Peak Oxygen Uptake in Breast Cancer Survivors: JACC: CardioOncology Primer

•Exercise intolerance is common among breast cancer survivors.•Exercise intolerance in breast cancer survivors is related to cardiac, vascular, and skeletal muscle impairments.•Holistic rehabilitation or pharmacological therapies are needed to address these impairments.

Sex-based Differences in the Phenotypic Expression and Prognosis of Idiopathic Non-ischemic Cardiomyopathy: A Cardiovascular Magnetic Resonance Study

AIMS

We sought to characterize sex-related differences in CMR-based cardiovascular phenotypes and prognosis in patients with idiopathic non-ischemic cardiomyopathy (NICM).

METHODS AND RESULTS

Patients with NICM enrolled in the Cardiovascular Imaging Registry of Calgary (CIROC) between 2015 and 2021 were identified. Z-score values for chamber volumes and function were calculated as standard deviation from mean values of 157 sex-matched healthy volunteers, ensuring reported differences were independent of known sex-dependencies. Patients were followed for the composite outcome of all-cause mortality, heart failure admission, or ventricular arrhythmia.A total of 747 patients were studied, 531 (71%) males. By Z-score values, females showed significantly higher left ventricular (LV) ejection fraction (EF; median difference 1 SD) and right ventricular (RV) EF (difference 0.6 SD) with greater LV mass (difference 2.1 SD; p-value<0.01 for all) versus males despite similar chamber volumes. Females had a significantly lower prevalence of mid-wall striae (MWS) fibrosis (23% versus 36%; p-value<0.001). Over a median follow-up of 4.7 years, 173 patients (23%) developed the composite outcome, with equal distribution in males and females. LV EF and MWS were significant independent predictors of the outcome (respective HR [95% CI] 0.97 [0.95-0.99] and 1.6 [1.2-2.3]; p-value=0.003 and 0.005). There was no association of sex with the outcome.

CONCLUSIONS

In a large contemporary cohort, NICM was uniquely expressed in females versus males. Despite similar chamber dilation, females demonstrated greater concentric remodelling, lower reductions in bi-ventricular function, and a lower burden of replacement fibrosis. Overall, their prognosis remained similar to male patients with NICM.

A Review on the Role of Exercise Training to Prevent a Decline in Cardiorespiratory Fitness and Cardiac Function in Breast Cancer Survivors

PURPOSE

Improvements in diagnosis and treatment mean that the long-term health of breast cancer survivors (BCS) is increasingly dictated by cardiovascular comorbidities. This is partly a consequence of exposure to cardiotoxic therapies, which result in cardiac dysfunction and decreased cardiorespiratory fitness (CRF). Exercise training (ExT) is a key therapeutic strategy for secondary prevention and increasing CRF in adults with established cardiovascular disease. Exercise-based cardio-oncology rehabilitation (CORE) has been proposed as an emerging strategy to address CRF and cardiac impairment in BCS. This review aims to (1) provide an overview of the impact of breast cancer therapy on CRF; (2) provide an up-to-date summary of the effects of ExT on CRF and cardiac function in BCS undergoing cardiotoxic therapy; and (3) discuss how traditional ExT approaches can be adapted for BCS undergoing therapy.

REVIEW METHODS

A literature review was performed based on an intensive literature search for systematic reviews and meta-analyses, randomized and non-randomized controlled trials and single-arm trials investigating the impact of exercise training or cardiac rehabilitation on CRF and/or cardiac function in BCS who are undergoing or have completed cardiotoxic cancer therapy.

SUMMARY

Overall, current evidence suggests that ExT induces clinically meaningful benefits for CRF in BCS during and after therapy. There is also emerging evidence that ExT can improve peak exercise measures of cardiac function; however, there is a need for further research to understand how to adapt these effective ExT approaches into clinical CORE-based settings.

Cardio-oncology and Cancer Rehabilitation: Is an Integrated Approach Possible?

With significant improvements in the understanding of cancer biology, improved detection, and the use of novel adjuvant therapies, each year more Canadians are surviving a cancer diagnosis. Despite their effectiveness these therapies often result in short- and long-term deleterious effects to major organ systems, particularly cardiovascular. Cardio-oncology is an emerging field of study with the aim to improve cardiovascular health across the oncology disease spectrum. International guidelines distinguish "cardio-oncology" rehabilitation from "cancer" rehabilitation, but how this is navigated is currently unknown. How such care should be assessed and integrated acutely or in the longer term remains unknown. Accordingly, the aim of this article is to consider the cancer patient's needs beyond the scope of cardio-oncology rehabilitation to holistically integrate cancer rehabilitation across the disease trajectory.

Integration of longitudinal and circumferential strain predicts volumetric change across the cardiac cycle and differentiates patients along the heart failure continuum

BACKGROUND

Left ventricular (LV) circumferential and longitudinal strain provide important insight into LV mechanics and function, each contributing to volumetric changes throughout the cardiac cycle. We sought to explore this strain-volume relationship in more detail, by mathematically integrating circumferential and longitudinal strain and strain rate to predict LV volume and volumetric rates of change.

METHODS

Cardiac magnetic resonance (CMR) imaging from 229 participants from the Alberta HEART Study (46 healthy controls, 77 individuals at risk for developing heart failure [HF], 70 patients with diagnosed HF with preserved ejection fraction [HFpEF], and 36 patients with diagnosed HF with reduced ejection fraction [HFrEF]) were evaluated. LV volume was assessed by the method of disks and strain/strain rate were assessed by CMR feature tracking.

RESULTS

Integrating endocardial circumferential and longitudinal strain provided a close approximation of LV ejection fraction (EFStrain), when compared to gold-standard volumetric assessment (EFVolume: r = 0.94, P < 0.0001). Likewise, integrating circumferential and longitudinal strain rate provided a close approximation of peak ejection and peak filling rates (PERStrain and PFRStrain, respectively) compared to their gold-standard volume-time equivalents (PERVolume, r = 0.73, P < 0.0001 and PFRVolume, r = 0.78, P < 0.0001, respectively). Moreover, each integrated strain measure differentiated patients across the HF continuum (all P < 0.01), with the HFrEF group having worse EFStrain, PERStrain, and PFRStrain compared to all other groups, and HFpEF having less favorable EFStrain and PFRStrain compared to both at-risk and control groups.

CONCLUSIONS

The data herein establish the theoretical framework for integrating discrete strain components into volumetric measurements across the cardiac cycle, and highlight the potential benefit of this approach for differentiating patients along the heart failure continuum.

Rationale and design of IMPACT-women: a randomised controlled trial of the effect of time-restricted eating, healthy eating and reduced sedentary behaviour on metabolic health during chemotherapy for early-stage breast cancer

Metabolic dysfunction and excess accumulation of adipose tissue are detrimental side effects from breast cancer treatment. Diet and physical activity are important treatments for metabolic abnormalities, yet patient compliance can be challenging during chemotherapy treatment. Time-restricted eating (TRE) is a feasible dietary pattern where eating is restricted to 8 h/d with water-only fasting for the remaining 16 h. The purpose of this study is to evaluate the effect of a multimodal intervention consisting of TRE, healthy eating, and reduced sedentary time during chemotherapy treatment for early-stage (I-III) breast cancer on accumulation of visceral fat (primary outcome), other fat deposition locations, metabolic syndrome and cardiovascular disease risk (secondary outcomes) compared with usual care. The study will be a two-site, two-arm, parallel-group superiority randomised control trial enrolling 130 women scheduled for chemotherapy for early-stage breast cancer. The intervention will be delivered by telephone, including 30-60-minute calls with a registered dietitian who will provide instructions on TRE, education and counselling on healthy eating, and goal setting for reducing sedentary time. The comparison group will receive usual cancer and supportive care including a single group-based nutrition class and healthy eating and physical activity guidelines. MRI, blood draws and assessment of blood pressure will be performed at baseline, after chemotherapy (primary end point), and 2-year follow-up. If our intervention is successful in attenuating the effect of chemotherapy on visceral fat accumulation and cardiometabolic dysfunction, it has the potential to reduce risk of cardiometabolic disease and related mortality among breast cancer survivors.

Magnetic Resonance Imaging of Aerosol Deposition

Nuclear magnetic resonance imaging (MRI) uses non-ionizing radiation and offers a host of contrast mechanisms with the potential to quantify aerosol deposition. This chapter introduces the physics of MRI, its use in lung imaging, and more specifically, the methods that are used for the detection of regional distributions of inhaled particles. The most common implementation of MRI is based on imaging of hydrogen atoms (1H) in water. The regional deposition of aerosol particles can be measured by the perturbation of the acquired 1H signals via labeling of the aerosol with contrast agents. Existing in vitro human and in vivo animal model measurements of regional aerosol deposition in the respiratory tract are described, demonstrating the capability of MRI to assess aerosol deposition in the lung.

Two-Photon Excited Fluorescence Lifetime Imaging of Tetracycline-Labeled Retinal Calcification

Deposition of calcium-containing minerals such as hydroxyapatite and whitlockite in the subretinal pigment epithelial (sub-RPE) space of the retina is linked to the development of and progression to the end-stage of age-related macular degeneration (AMD). AMD is the most common eye disease causing blindness amongst the elderly in developed countries; early diagnosis is desirable, particularly to begin treatment where available. Calcification in the sub-RPE space is also directly linked to other diseases such as Pseudoxanthoma elasticum (PXE). We found that these mineral deposits could be imaged by fluorescence using tetracycline antibiotics as specific stains. Binding of tetracyclines to the minerals was accompanied by increases in fluorescence intensity and fluorescence lifetime. The lifetimes for tetracyclines differed substantially from the known background lifetime of the existing natural retinal fluorophores, suggesting that calcification could be visualized by lifetime imaging. However, the excitation wavelengths used to excite these lifetime changes were generally shorter than those approved for retinal imaging. Here, we show that tetracycline-stained drusen in post mortem human retinas may be imaged by fluorescence lifetime contrast using multiphoton (infrared) excitation. For this pilot study, ten eyes from six anonymous deceased donors (3 female, 3 male, mean age 83.7 years, range 79-97 years) were obtained with informed consent from the Maryland State Anatomy Board with ethical oversight and approval by the Institutional Review Board.

Safety and efficacy of a kaolin-impregnated hemostatic gauze in cardiac surgery: A randomized trial

Objective

A kaolin-based nonresorbable hemostatic gauze, QuikClot Control+, has demonstrated effective hemostasis and safety when used for severe/life-threatening (grade 3/4) internal organ space bleeding. We evaluated the efficacy and safety of this gauze for mild to moderate (grade 1-2) bleeding in cardiac surgery compared with control gauze.

Methods

This was a randomized, controlled, single-blinded study of patients who underwent cardiac surgery between June 2020 and September 2021 across 7 sites with 231 subjects randomized 2:1 to QuikClot Control+ or control. The primary efficacy end point was hemostasis rate (ie, subjects achieving grade 0 bleed) through up to 10 minutes of bleeding site application, assessed using a semiquantitative validated bleeding severity scale tool. The secondary efficacy end point was the proportion of subjects achieving hemostasis at 5 and 10 minutes. Adverse events, assessed up to 30 days postsurgery, were compared between arms.

Results

The predominant procedure was coronary artery bypass grafting, and 69.7% and 29.4% were sternal edge and surgical site (suture line)/other bleeds, respectively. Of the QuikClot Control+ subjects, 121 of 153 (79.1%) achieved hemostasis within 5 minutes, compared with 45 of 78 (58.4%) controls (P < .001). At 10 minutes, 137 of 153 patients (89.8%) achieved hemostasis compared with 52 of 78 controls (68.4%) (P < .001). At 5 and 10 minutes, hemostasis was achieved in 20.7% and 21.4% more QuikClot Control+ subjects, respectively, compared with controls (P < .001). There were no significant differences in safety or adverse events between treatment arms.

Conclusions

QuikClot Control+ demonstrated superior performance in achieving hemostasis for mild to moderate cardiac surgery bleeding compared with control gauze. The proportion of subjects achieving hemostasis was more than 20% higher in QuikClot Control+ subjects at both timepoints compared with controls, with no significant difference in safety outcomes.

Fluorescence Lifetime Imaging of Human Sub-RPE Calcification In Vitro Following Chlortetracycline Infusion

We have shown that all sub-retinal pigment epithelial (sub-RPE) deposits examined contain calcium phosphate minerals: hydroxyapatite (HAP), whitlockite (Wht), or both. These typically take the form of ca. 1 μm diameter spherules or >10 μm nodules and appear to be involved in the development and progression of age-related macular degeneration (AMD). Thus, these minerals may serve as useful biomarkers the for early detection and monitoring of sub-RPE changes in AMD. We demonstrated that HAP deposits could be imaged in vitro by fluorescence lifetime imaging microscopy (FLIM) in flat-mounted retinas using legacy tetracycline antibiotics as selective sensors for HAP. As the contrast on a FLIM image is based on the difference in fluorescence lifetime and not intensity of the tetracycline-stained HAP, distinguishing tissue autofluorescence from the background is significantly improved. The focus of the present pilot study was to assess whether vascular perfusion of the well tolerated and characterized chlortetracycline (widely used as an orally bioavailable antibiotic) can fluorescently label retinal HAP using human cadavers. We found that the tetracycline delivered through the peripheral circulation can indeed selectively label sub-RPE deposits opening the possibility for its use for ophthalmic monitoring of a range of diseases in which deposit formation is reported, such as AMD and Alzheimer disease (AD).

Integrating Cardiac MRI Imaging and Multidisciplinary Clinical Care is Associated With Improved Outcomes in Patients With Fabry Disease

Given the inherent complexities of Fabry disease (FD) and evolving landscape of cardiovascular clinical management, there is no established ideal clinical care model for these patients. We identified clinical factors predictive of increased risk of major adverse cardiac events (MACE) in patients with FD targeted to improve clinical outcomes. Ninety-five patients studied over a median follow-up time of 6.3 years, and 26 patients reached the composite endpoint with a high prevalence of heart failure and cerebrovascular events and no cardiac-related mortality. Patients with MACE had worse health-related quality of life scores. Hypertrophy and presence of myocardial fibrosis increase risk of MACE by 4-5 times, and dyslipidemia increases risk of MACE by 3 times. Early Fabry-specific treatment and close monitoring of comorbidities reduce cardiac complications and mortality. These findings highlight the importance of comprehensive multidisciplinary management to help improve outcomes in FD patients.

Implementation of weekday time-restricted eating to improve metabolic health in breast cancer survivors with overweight/obesity

OBJECTIVE

This study aimed to evaluate the implementation of telephone-based delivery of weekday-only time-restricted eating (TRE), its preliminary efficacy for metabolic outcomes, and concurrent lifestyle changes.

METHODS

Twenty-two breast cancer survivors aged 60+ years with overweight/obesity completed an 8-week feasibility study of 12 to 8 p.m. weekday-only ad libitum TRE. The intervention was delivered by one registered dietitian call, twice-daily automated text messages asking about eating start and stop times, and three support phone calls. Magnetic resonance imaging, venipuncture, and 3 days of diet records and accelerometry were performed at baseline and after intervention.

RESULTS

Participants had a mean age of 66 (SD 5) years with BMI of 31.8 (4.8) kg/m² . Intervention implementation was successful, including excellent adherence (98%), participant acceptability, and a low symptom profile and cost ($63/participant). There were no significant changes in individual components of metabolic syndrome, lipid profile, or hemoglobin A_1c , despite clinically relevant changes occurring within individual participants. Magnetic resonance imaging-derived hepatic steatosis and thigh myosteatosis did not change. Dietary intake changes included reduced energy (-22%) and protein (-0.2 g/kg). Physical activity and sleep did not change.

CONCLUSIONS

Eight weeks of telephone-delivered weekday TRE is a feasible, acceptable, low-symptom, and low-cost intervention. Future studies may consider a longer intervention length for more consistent metabolic improvements and counseling to enhance protein intake.

A 2,7-dichlorofluorescein derivative to monitor microcalcifications

Herein, we report the crystal structure of 2,7-dichlorofluorescein methyl ester (DCF-ME) and its fluorescence response to hydroxyapatite binding. The reported fluorophore is very selective for staining the bone matrix and provides turn-on fluorescence upon hydroxyapatite binding. The reported fluorophore can readily pass the cell membrane of the C2C12 cell line, and it is non-toxic for the cell line. The reported fluorophore DCF-ME may find applications in monitoring bone remodeling and microcalcification as an early diagnosis tool for breast cancer and age-related macular degeneration.

Remission of type 2 diabetes and improved diastolic function by combining structured exercise with meal replacement and food reintroduction among young adults: the RESET for REMISSION randomised controlled trial protocol

INTRODUCTION

Type 2 diabetes mellitus (T2DM) onset before 40 years of age has a magnified lifetime risk of cardiovascular disease. Diastolic dysfunction is its earliest cardiac manifestation. Low energy diets incorporating meal replacement products can induce diabetes remission, but do not lead to improved diastolic function, unlike supervised exercise interventions. We are examining the impact of a combined low energy diet and supervised exercise intervention on T2DM remission, with peak early diastolic strain rate, a sensitive MRI-based measure, as a key secondary outcome.

METHODS AND ANALYSIS

This prospective, randomised, two-arm, open-label, blinded-endpoint efficacy trial is being conducted in Montreal, Edmonton and Leicester. We are enrolling 100 persons 18-45 years of age within 6 years' T2DM diagnosis, not on insulin therapy, and with obesity. During the intensive phase (12 weeks), active intervention participants adopt an 800-900 kcal/day low energy diet combining meal replacement products with some food, and receive supervised exercise training (aerobic and resistance), three times weekly. The maintenance phase (12 weeks) focuses on sustaining any weight loss and exercise practices achieved during the intensive phase; products and exercise supervision are tapered but reinstituted, as applicable, with weight regain and/or exercise reduction. The control arm receives standard care. The primary outcome is T2DM remission, (haemoglobin A1c of less than 6.5% at 24 weeks, without use of glucose-lowering medications during maintenance). Analysis of remission will be by intention to treat with stratified Fisher's exact test statistics.

ETHICS AND DISSEMINATION

The trial is approved in Leicester (East Midlands - Nottingham Research Ethics Committee (21/EM/0026)), Montreal (McGill University Health Centre Research Ethics Board (RESET for remission/2021-7148)) and Edmonton (University of Alberta Health Research Ethics Board (Pro00101088). Findings will be shared widely (publications, presentations, press releases, social media platforms) and will inform an effectiveness trial.

TRIAL REGISTRATION NUMBER

ISRCTN15487120.

Clinical Phenotypes of Heart Failure across the spectrum of Ejection Fraction: A Cluster Analysis

INTRODUCTION

Heart failure (HF), and especially HF with preserved ejection fraction (HFpEF), remains a challenging condition to define. The heterogenous nature of this population may be related to a variety of underlying etiologies interacting myocardial dysfunction.

METHOD

Alberta HEART study was a prospective, observational cohort that enrolled participants along the spectrum of heart failure including: healthy controls, people at risk of HF, and patients with HF and preserved (HFpEF) or reduced ejection fraction (HFrEF). We aimed to explore phenotypes of patients with HF and at-risk of developing HF. Utilising 27 detailed clinical, echocardiographic and biomarker variables, latent class analysis with and without multiple imputation was undertaken to identify distinct clinical phenotypes.

RESULTS

Of 621 participants, 191 (30.8%) and 169 (27.2%) were adjudicated by cardiologists to have HFpEF and HFrEF respectively. In the overall cohort, latent class analysis identified four distinct phenotypes. Phenotype A (n=152, 24.5%) was a healthy and low risk group. Phenotype B (n=129, 20.8%) demonstrated increased left ventricular mass and end-diastolic volumes, with elevated natriuretic peptides and clinical features of congestion. Phenotype C (n=128, 20.6%) was primarily characterised by obesity (80%) and normal indexed cardiac chamber sizes, low natriuretic peptide levels and minimal features of congestion. Phenotype D (n=212, 34.1%) consisted of elderly patients with clinical features of congestions. Phenotypes B and D demonstrated the highest risk of mortality and hospitalization over a median follow-up of 3.7 years.

CONCLUSION

Phenotypes with congestive features demonstrated increased risk profiles. Heart failure is a heterogenous classification which requires further work to appropriately categorise patients based on the underlying etiology or mechanism of impairment.

Quantification of changes in myocardial T1 * values with exercise cardiac MRI using a free-breathing non-electrocardiograph radial imaging

PURPOSE

To develop and evaluate a free breathing non-electrocardiograph (ECG) myocardial T₁ * mapping sequence using radial imaging to quantify the changes in myocardial T₁ * between rest and exercise (T₁ *_reactivity ) in exercise cardiac MRI (Ex-CMR).

METHODS

A free-running T₁ * sequence was developed using a saturation pulse followed by three Look-Locker inversion-recovery experiments. Each Look-Locker continuously acquired data as radial trajectory using a low flip-angle spoiled gradient-echo readout. Self-navigation was performed with a temporal resolution of ∼100 ms for retrospectively extracting respiratory motion. The mid-diastole phase for every cardiac cycle was retrospectively detected on the recorded electrocardiogram signal using an empirical model. Multiple measurements were performed to obtain mean value to reduce effects from the free-breathing acquisition. Finally, data acquired at both mid-diastole and end-expiration are picked and reconstructed by a low-rank plus sparsity constraint algorithm. The performance of this sequence was evaluated by simulations, phantoms, and in vivo studies at rest and after physiological exercise.

RESULTS

Numerical simulation demonstrated that changes in T₁ * are related to the changes in T₁ ; however, other factors such as breathing motion could influence T₁ * measurements. Phantom T₁ * values measured using free-running T₁ * mapping sequence had good correlation with spin-echo T₁ values and was insensitive to heart rate. In the Ex-CMR study, the measured T₁ * reactivity was 10% immediately after exercise and declined over time.

CONCLUSION

The free-running T₁ * mapping sequence allows free-breathing non-ECG quantification of changes in myocardial T₁ * with physiological exercise. Although, absolute myocardial T₁ * value is sensitive to various confounders such as B₁ and B₀ inhomogeneity, quantification of its change may be useful in revealing myocardial tissue properties with exercise.

Decongestive progressive resistance exercise with an adjustable compression wrap for breast cancer-related lymphoedema (DREAM): protocol for a randomised controlled trial

INTRODUCTION

Breast cancer-related lymphoedema (BCRL) is a chronic swelling in the arm on the side of the breast cancer surgery, affecting one in five women. Recent studies in BCRL have demonstrated that resistance exercise can improve symptoms and quality of life without worsening lymphoedema. No studies have explored whether combining the principles of progressive resistance exercise training with therapeutic strategies of compression therapy and the decongestive lymphatic exercise sequence are beneficial in reducing arm lymphoedema volume. The aim of this three-arm, provincial randomised controlled trial is to determine the efficacy of a 12-week decongestive progressive resistance exercise (DRE) programme in combination with the one of two types of compression garments compared with standard care.

METHODS AND ANALYSIS

Sixty women with BCRL will be recruited and randomly assigned to one of the following three groups: (1) Standard care, (2) DRE with use of a daytime compression garment during exercise and (3) DRE with use of an adjustable compression wrap during exercise. The primary outcome is the percentage reduction in arm lymphoedema volume. Secondary outcomes include bioimpedance analysis, muscular strength, shoulder range of motion, physical activity level and health-related quality of life. Exploratory outcomes include evaluating changes in arm tissue composition using MRI and examining outcomes between the two DRE experimental groups. The primary analysis will compare changes between the groups from baseline to week 12 reflecting the end of the randomised control trial period.

ETHICS AND DISSEMINATION

The trial has received ethics approval from the Health Research Ethics Board of Alberta: Cancer Committee. The study results will be disseminated through scientific peer-reviewed publications, and presented at national and international conferences, and other media portals. The programme protocol will be shared with healthcare professionals and patient groups through clinical workshops and webinars.

TRIAL REGISTRATION NUMBER

NCT05022823.

PROTOCOL VERSION

12 November 2021.

ISSUE DATE

26 April 2021.

Improved accuracy and precision with three-parameter simultaneous myocardial T1 and T2 mapping using multiparametric SASHA

PURPOSE

To develop and validate a three-parameter model for improved precision multiparametric SAturation-recovery single-SHot Acquisition (mSASHA) cardiac T₁ and T₂ mapping with high accuracy in a single breath-hold.

METHODS

The mSASHA acquisition consists of nine images of variable saturation recovery and T₂ preparation in 11 heartbeats with T₁ and T₂ values calculated using a three-parameter model. It was validated in simulations and phantoms at 3 T with comparison to a four-parameter joint T₁ -T₂ technique. The mSASHA acquisition was compared with MOLLI, SASHA, and T₂ -prepared balanced SSFP in 10 volunteers.

RESULTS

The mSASHA technique had high accuracy in phantoms compared to spin echo, with -0.2 ± 0.3% T₁ error and -2.4 ± 1.3% T₂ error. The mSASHA coefficient of variation in phantoms for T₁ was similar to MOLLI (0.7 ± 0.2% for both) and T₂ -prepared balanced SSFP for T₂ (1.3 ± 0.7% vs 1.4 ± 0.3%, adjusted p > .05 for both). In simulations, three-parameter mSASHA had higher precision than four-parameter joint T₁ -T₂ for both T₁ and T₂ (46% and 11% reductions in T₁ and T₂ interquartile range for native myocardium). In vivo myocardial mSASHA T₁ was similar to SASHA (1523 ± 18 ms vs 1520 ± 18 ms) with similar coefficient of variation to both MOLLI and SASHA (3.3 ± 0.6% vs 3.1 ± 0.6% and 3.3 ± 0.5% respectively, adjusted p > .05 for all). Myocardial mSASHA T₂ was 37.1 ± 1.1 ms with similar precision to T₂ -prepared balanced SSFP (6.7 ± 1.7% vs 6.0 ± 1.6%, adjusted p > .05).

CONCLUSION

Three-parameter mSASHA provides high-accuracy cardiac T₁ and T₂ quantification in a single breath-hold with similar precision to MOLLI and T₂ -prepared balanced SSFP. Further study is required to both establish normative values and demonstrate clinical utility in patient populations.

Radiographic presentation of artifactual dyed hair on lateral cephalograms, chemical processing, and forensic application: Novel case report

Forensic assessment employs an array of methods to identify human remains. Radiologic examinations with panoramic radiographs, computed tomography scans, Waters view, and nuclear magnetic resonance imaging may offer evidentiary clues in challenging cases, such as mass disasters. In these cases, alternative forensic tools are used to narrow lists of target victims using their biological features. This study aims to I) report on the unusual radiographic aspect of chemicals used for hair dyeing, and II) discuss the potential forensic application of this finding for human identification. The case depicts an asymptomatic 14-years-old female who presented for orthodontic therapy. During radiographic examination on a lateral cephalogram, numerous thin radiopaque streaks were visible, extending to the posterior neck between the occipital region of the skull base and vertebra C6. Clinical investigations revealed that these were artifactual hair images (possibly documented for the first time in the scientific literature). Inductively coupled plasma mass spectrometry (ICP-MS) analysis of the patient's scalp hair was performed for 10 heavy metals, including zinc, copper, iron, chromium, nickel, cadmium, tin, lead, antimony, and bismuth. Eight of these metals were detected at normal levels, ranging from 160 parts per million (ppm) for zinc to less than 1 ppm for nickel, cadmium, tin, lead, and antimony. Conversely, slightly elevated levels of chromium at 0.41 ppm and bismuth at 0.025 ppm were found in the hair sample. The distinctive radiographic presentation of artifactual hair images combined with the chemical properties of hair exposed to dye products may provide useful traces for human identification, especially in mass disasters.

A Contemporary Review of the Effects of Exercise Training on Cardiac Structure and Function and Cardiovascular Risk Profile: Insights From Imaging

Exercise is a commonly prescribed therapy for patients with established cardiovascular disease or those at high risk for de novo disease. Exercise-based, multidisciplinary programs have been associated with improved clinical outcomes post myocardial infarction and is now recommended for patients with cancer at elevated risk for cardiovascular complications. Imaging studies have documented numerous beneficial effects of exercise on cardiac structure and function, vascular function and more recently on the cardiovascular risk profile. In this contemporary review, we will discuss the effects of exercise training on imaging-derived cardiovascular outcomes. For cardiac imaging via echocardiography or magnetic resonance, we will review the effects of exercise on left ventricular function and remodeling in patients with established or at risk for cardiac disease (myocardial infarction, heart failure, cancer survivors), and the potential utility of exercise stress to assess cardiac reserve. Exercise training also has salient effects on vascular function and health including the attenuation of age-associated arterial stiffness and thickening as assessed by Doppler ultrasound. Finally, we will review recent data on the relationship between exercise training and regional adipose tissue deposition, an emerging marker of cardiovascular risk. Imaging provides comprehensive and accurate quantification of cardiac, vascular and cardiometabolic health, and may allow refinement of risk stratification in select patient populations. Future studies are needed to evaluate the clinical utility of novel imaging metrics following exercise training.

Rationale and design of the Diet Restriction and Exercise-induced Adaptations in Metastatic breast cancer (DREAM) study: a 2-arm, parallel-group, phase II, randomized control trial of a short-term, calorie-restricted, and ketogenic diet plus exercise during intravenous chemotherapy versus usual care

BACKGROUND

An underlying cause of solid tumor resistance to chemotherapy treatment is diminished tumor blood supply, which leads to a hypoxic microenvironment, dependence on anaerobic energy metabolism, and impaired delivery of intravenous treatments. Preclinical data suggest that dietary strategies of caloric restriction and low-carbohydrate intake can inhibit glycolysis, while acute exercise can transiently enhance blood flow to the tumor and reduce hypoxia. The Diet Restriction and Exercise-induced Adaptations in Metastatic Breast Cancer (DREAM) study will compare the effects of a short-term, 50% calorie-restricted and ketogenic diet combined with aerobic exercise performed during intravenous chemotherapy treatment to usual care on changes in tumor burden, treatment side effects, and quality of life.

METHODS

Fifty patients with measurable metastases and primary breast cancer starting a new line of intravenous chemotherapy will be randomly assigned to usual care or the combined diet and exercise intervention. Participants assigned to the intervention group will be provided with food consisting of 50% of measured calorie needs with 80% of calories from fat and ≤ 10% from carbohydrates for 48-72 h prior to each chemotherapy treatment and will perform 30-60 min of moderate-intensity cycle ergometer exercise during each chemotherapy infusion, for up to six treatment cycles. The diet and exercise durations will be adapted for each chemotherapy protocol. Tumor burden will be assessed by change in target lesion size using axial computed tomography (primary outcome) and magnetic resonance imaging (MRI)-derived apparent diffusion coefficient (secondary outcome) after up to six treatments. Tertiary outcomes will include quantitative MRI markers of treatment toxicity to the heart, thigh skeletal muscle, and liver, and patient-reported symptoms and quality of life. Exploratory outcome measures include progression-free and overall survival.

DISCUSSION

The DREAM study will test a novel, short-term diet and exercise intervention that is targeted to mechanisms of tumor resistance to chemotherapy. A reduction in lesion size is likely to translate to improved cancer outcomes including disease progression and overall survival. Furthermore, a lifestyle intervention may empower patients with metastatic breast cancer by actively engaging them to play a key role in their treatment.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03795493 , registered 7 January, 2019.

Cardiac remodelling predicts outcome in patients with chronic heart failure

Aims

Surveillance imaging is often used to detect remodelling, a change in cardiac geometry, and/or function; however, there are limited data in patients with chronic heart failure (HF). We sought to characterize cardiac remodelling in patients with chronic HF and evaluate its association with outcome.

Methods and results

A prospective cohort of patients at risk for HF or with chronic HF underwent cardiac magnetic resonance (CMR) at baseline and 1 year. Ventricular function, volumes, mass, left atrial volume, global longitudinal strain, and myocardial scar were measured. The primary outcome was a composite of death or cardiovascular hospitalization up to 5 years from the 1 year scan. Cox regression was used to identify 1 year CMR predictors of outcome after adjusting for baseline risk. A total of 262 patients (median age 68 years, 57% males) including 96 at risk for HF, 97 with HF and preserved ejection fraction, and 69 with HF and reduced ejection fraction were included. In the patients with HF, 55 events were identified during follow‐up. After adjustment for baseline clinical risk, Cox proportion hazard regressions only identified 1 year change in left ventricular (LV) mass index as a CMR predictor of outcome, adjusted hazard ratio 1.21 (1.02, 1.44) per 10% increase, P = 0.031. Cardiac remodelling defined as a 1 year change in LV mass index ≥15% was observed in 35% of patients with HF. Patients with adverse remodelling of LV mass index had more events on Kaplan–Meier analyses compared to those with no remodelling, log‐rank P = 0.004 for overall cohort, P = 0.035 for heart failure with preserved ejection fraction and P = 0.035 for heart failure and reduced ejection fraction.

Conclusions

Cardiac remodelling is common during serial CMR assessment of patients with chronic HF. Change in LV mass predicted long‐term outcomes whereas change in left ventricular ejection fraction did not.

Characterization of Calcium Phosphate Spherical Particles in the Subretinal Pigment Epithelium-Basal Lamina Space in Aged Human Eyes

Purpose

Micrometer-sized spherules formed of hydroxyapatite or whitlockite were identified within extracellular deposits that accumulate in the space between the basal lamina (BL) of retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane (sub-RPE-BL space). This investigation aimed to characterize the morphologic features, structure, and distribution of these spherules in aged human eyes with and without clinical indications of age-related macular degeneration (AMD).

Design

Experimental study.

Participants

Five human eyes with varying degrees of sub-RPE-BL deposits were obtained from the University College London Institute of Ophthalmology and Moorfield's Eye Hospital Tissue Repository or the Advancing Sight Network. Two eyes were reported as having clinical indications of AMD (age, 76-87 years), whereas 3 were considered healthy (age, 69-91 years).

Methods

Cadaveric eyes with sub-RPE-BL deposits were embedded in paraffin wax and sectioned to a thickness of 4-10 μm. Spherules were identified and characterized using high-resolution scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy, and time-of-flight secondary ion mass spectroscopy.

Main Outcome Measures

High-resolution scanning electron micrographs of spherules, the size-frequency distribution of spherules including average diameter, and the distribution of particles across the central-peripheral axis. Elemental maps and time-of-flight secondary ion mass spectra also were obtained.

Results

The precipitation of spherules is ubiquitous across the central, mid-peripheral, and far-peripheral axis in aged human eyes. No significant difference was found in the frequency of spherules along this axis. However, statistical analysis indicated that spherules exhibited significantly different sizes in these regions. In-depth analysis revealed that spherules in the sub-RPE-BL space of eyes with clinical signs of AMD were significantly larger (median diameter, 1.64 μm) than those in healthy aged eyes (median diameter, 1.16 μm). Finally, spherules showed great variation in surface topography and internal structure.

Conclusions

The precipitation of spherules in the sub-RPE-BL space is ubiquitous across the central-peripheral axis in aged human eyes. However, a marked difference exists in the size and frequency of spherules in eyes with clinical signs of AMD compared to those without, suggesting that the size and frequency of spherules may be associated with AMD.

Left atrial remodelling, mid-regional pro-atrial natriuretic peptide, and prognosis across a range of ejection fractions in heart failure

AIMS

Measures of structural and functional remodelling of the left atrium (LA) are emerging as useful biomarkers in heart failure (HF). We hypothesized that LA volume and its contribution to stroke volume (SV) would predict a composite endpoint of HF hospitalization or death in patients with HF.

METHODS AND RESULTS

We recruited 57 controls and 86 patients with HF, including preserved and reduced left ventricular ejection fraction (LVEF). Cardiac magnetic resonance imaging was used to evaluate LA volumes and contribution to LV SV. Plasma mid-region pro-atrial natriuretic peptide (MR-proANP) was evaluated. LA volume was negatively correlated with LVEF (P = 0.001) and positively correlated with LV mass in HFrEF (P < 0.001) but not in HFpEF. LA volume at end-diastole was associated with the composite endpoint in HFrEF (hazard ratio 1.26, 95% confidence interval 1.01-1.54; P = 0.044), but not HFpEF (1.06, 0.85-1.30; P = 0.612), per 10 mL/m increase. Active contribution to SV was negatively associated with the composite endpoint in HFpEF (0.32, 0.14-0.66; P = 0.001), but not HFrEF (0.91, 0.38-2.1; P = 0.828) per 10% increase. MR-proANP was associated with the composite endpoint in HFpEF (1.46, 1.03-1.94; P = 0.034), but not in HFrEF (1.14, 0.88-1.37; P = 0.278), per 100 pM increase.

CONCLUSION

We found different relationships between LA remodelling and biomarkers in HFrEF and HFpEF. Our results support the hypothesis that the pathophysiologic underpinnings of HFpEF and HFrEF are different, and atrial remodelling encompasses distinct components for each HF subtype.

Tricuspid Valve Tethering Is Associated with Residual Regurgitation after Valve Repair in Hypoplastic Left Heart Syndrome: A Three-Dimensional Echocardiographic Study

BACKGROUND

Tricuspid valve regurgitation (TR) is a risk factor for morbidity and mortality in children with hypoplastic left heart syndrome (HLHS). Surgical tricuspid valve (TV) repair is common, but durable repair remains challenging. The aim of this study was to examine mechanisms of TR requiring surgery, features associated with unsuccessful repair, and TV changes after surgical repair.

METHODS

Thirty-six patients with HLHS requiring TV repair (TVR) and 36 matched control subjects with HLHS were assessed using two-dimensional and three-dimensional echocardiography. Using three-dimensional echocardiography, TV coordinates from the annulus, leaflet, and ventricle were used to measure annular, leaflet, prolapse, and tethering values and anterior papillary muscle angle. TR grade and ventricular size, function, and shape were assessed using two-dimensional echocardiography.

RESULTS

Patients requiring TVR had greater total leaflet prolapse, larger TV annular and leaflet areas, and flatter annuli, with no difference in tethering, coaptation index, or anterior papillary muscle angle. In patients with HLHS, successful TVR at follow-up (58%) was associated with preoperative total leaflet prolapse (especially posterior). Unsuccessful repair was associated with preoperative tethering of the septal leaflet. TVR in patients with HLHS caused a reduction of total annular and leaflet size and reduced prolapse and tethering of the posterior leaflet but did not affect anterior leaflet prolapse or septal leaflet tethering.

CONCLUSIONS

Features associated with TVR include a flattened and dilated TV annulus with leaflet prolapse. The additional presence of a tethered septal leaflet before TVR is associated with significant postoperative TR. Current surgical techniques, predominantly posterior annuloplasty and commissuroplasty, adequately address annular size and posterior leaflet pathology, but not septal leaflet tethering. Individualized and innovative surgical techniques are vital to improve surgical repair success.

Quantification of lung water density with UTE Yarnball MRI

PURPOSE

An efficient Yarnball ultrashort-TE k-space trajectory, in combination with an optimized pulse sequence design and automated image-processing approach, is proposed for fast and quantitative imaging of water density in the lung parenchyma.

METHODS

Three-dimensional Yarnball k-space trajectories (TE = 0.07 ms) were designed at 3 T for breath-hold and free-breathing navigator acquisitions targeting the lung parenchyma (full torso spatial coverage) with minimal T₁ and T 2 ∗ weighting. A composite of all solid tissues surrounding the lungs (muscle, liver, heart, blood pool) was used for user-independent lung water density signal referencing and B₁ -inhomogeneity correction needed for the calculation of relative lung water density images. Sponge phantom experiments were used to validate absolute water density quantification, and relative lung water density was evaluated in 10 healthy volunteers.

RESULTS

Phantom experiments showed excellent agreement between sponge wet weight and imaging-derived water density. Breath-hold (13 seconds) and free-breathing (~2 minutes) Yarnball acquisitions in volunteers (2.5-mm isotropic resolution) had negligible artifacts and good lung parenchyma SNR (>10). Whole-lung average relative lung water density values with fully automated analysis were 28.2 ± 1.9% and 28.6 ± 1.8% for breath-hold and free-breathing acquisitions, respectively, with good test-retest reproducibility (intraclass correlation coefficient = 0.86 and 0.95, respectively).

CONCLUSIONS

Quantitative lung water density imaging with an optimized Yarnball k-space acquisition approach is possible in a breath-hold or short free-breathing study with automated signal referencing and segmentation.

Cardiac and Cardiometabolic Phenotyping of Trastuzumab-Mediated Cardiotoxicity: a Secondary Analysis of the MANTICORE trial

AIMS

An improved understanding of the pathophysiology of trastuzumab-mediated cardiotoxicity is required to improve outcomes of patients with HER2-positive breast cancer. We aimed to characterize the cardiac and cardiometabolic phenotype of trastuzumab-mediated toxicity and potential interactions with cardiac pharmacotherapy.

METHODS AND RESULTS

This study was an analysis of serial magnetic resonance imaging (MRI) and circulating biomarker data acquired from patients with HER2-positive early stage breast cancer participating in a randomized-controlled clinical trial for the pharmaco-prevention of trastuzumab-associated cardiotoxicity. Circulating biomarkers (B-type natriuretic peptide, troponin I, MMP-2 and -9, GDF-15, neuregulin-1 and IGF-1) and MRI of cardiac structure and function and abdominal fat distribution were acquired prior to trastuzumab, post-cycle 4 and post-cycle 17. Ninety-four participants (51±8 years) completed the study with 30 on placebo, 33 on perindopril, and 31 on bisoprolol. Post-cycle 4, global longitudinal strain (GLS) deteriorated from baseline in both placebo (+2.0±2.7%, p = 0.002) and perindopril (+0.9±2.5%, p = 0.04), but not with bisoprolol (-0.2±2.1%, p = 0.55). In all groups combined, extracellular volume fraction and GDF-15 increased post-cycle 4 (+1.3±4.4%, p = 0.004; +130±150%, p ≤ 0.001, respectively). However, no significant change in troponin I was detected throughout trastuzumab. In all groups combined, visceral and intermuscular fat volume increased post-cycle 4 (+7±17%, p = 0.02, +8±23%, p = 0.02, respectively), while muscle volume and IGF-1 decreased from post-cycle 4 to 17 (-2±10%, p = 0.008, -18±28%, p < 0.001, respectively).

CONCLUSION

Trastuzumab results in impaired cardiac function and early myocardial inflammation. Trastuzumab is also associated with deleterious changes to the cardiometabolic phenotype which may contribute to the increased cardiovascular risk in this population.

Reliability and reproducibility of cardiac MRI quantification of peak exercise function with long-axis views

The conventional approach to cardiac magnetic resonance (CMR) involving breath holds, electrocardiography-gating, and acquisition of a short-axis (SAX) image stack, introduces technical and logistical challenges for assessing exercise left ventricular (LV) function. Real-time, free-breathing CMR acquisition of long-axis (LAX) images overcomes these issues and also enables assessment of global longitudinal strain (GLS). We evaluated the reliability of a free-breathing LAX approach compared to the standard SAX approach and the reproducibility of free-breathing LAX. LV SAX (contiguous stack) and LAX (two-chamber and four-chamber) 3T CMR cine images were acquired four times within one scan in 32 women with cardiovascular risk factors (56±10 years, 28±4 kg/m2) as follows: 1) resting, gated-segmented, end-expiration breath-hold; 2) resting, real-time, free-breathing; 3) test-retest set of resting, real-time, free-breathing; 4) peak exercise (incremental-to-maximum, in-magnet, stepper test), real-time, free-breathing. A second scan was performed within one week in a subset (n = 5) to determine reproducibility of peak exercise measures. Reliability and agreement of the free-breathing LAX approach with the conventional SAX approach were assessed by intraclass correlation coefficient (ICC) and Bland-Altman plots, respectively. Normal control GLS reserve was also acquired in a separate set of 12 young, healthy control women (25±4 years, 22±2 kg/m2) for comparison. Comparisons of LV volumes and function among all techniques at rest had good-to-excellent reliability (ICC = 0.80-0.96), and excellent reliability between peak exercise free-breathing LAX and SAX evaluations (ICC = 0.92-0.96). Higher resting heart rates with free-breathing acquisitions compared to breath-hold (mean difference, limits of agreement: 5, 1-12 beats per minute) reduced reliability for cardiac output (ICC = 0.67-0.79). Reproducibility of the free-breathing LAX approach was good-to-excellent at rest and peak exercise (ICC = 0.74-0.99). GLS exercise reserve was impaired in older women at cardiovascular risk compared to young healthy women (-4.7±2.3% vs -7.4±2.1%, p = 0.001). Real-time, free-breathing CMR with LAX evaluation provides a reliable and reproducible method to assess rest and peak exercise cardiac function, including GLS.

Aerobic Fitness Is Related to Myocardial Fibrosis Post-Anthracycline Therapy

PURPOSE

We evaluated the impact of anthracyclines on left ventricular function and myocardial tissue characteristics using cardiovascular magnetic resonance (CMR) imaging to determine their relationship with V˙O2peak.

METHODS

Women with breast cancer who had not yet received treatment (No-AT, n = 16) and had received anthracycline treatment ~1 yr earlier (Post-AT, n = 16) and controls without cancer (CON, n = 16) performed a maximal exercise test and a comprehensive 3T CMR examination, including native myocardial T1 mapping, where elevated T1 times are indicative of myocardial fibrosis. ANOVA and linear regression were used to compare CMR variables between groups and to determine associations with V˙O2peak. Subgroup analysis was performed by categorizing participants as "fit" or "unfit" based on whether their V˙O2peak value was greater or less than 100% of reference value for age, respectively.

RESULTS

Left ventricular end-diastolic volume, ejection fraction, and mass were similar between groups. Post-AT, T1 times were elevated (1534 ± 32 vs 1503 ± 28 ms, P < 0.01), and V˙O2peak was reduced (23.1 ± 7.5 vs 29.5 ± 7.7 mL·kg-1⋅min-1, P = 0.02) compared with CON. In No-AT, T1 times and V˙O2peak were similar to CON. In the Post-AT group, T1 time was associated with V˙O2peak (R2 = 64%), whereas in the absence of anthracyclines (i.e., No-AT and CON groups), T1 time was not associated with V˙O2peak. Regardless of group, all fit women had similar T1 times, whereas unfit women Post-AT had higher T1 than unfit CON (1546 ± 22 vs 1500 ± 33 ms, P < 0.01).

CONCLUSIONS

After anthracycline chemotherapy, an elevated T1 time suggesting greater extent of myocardial fibrosis, was associated with lower V˙O2peak. However, those who were fit did not have evidence of myocardial fibrosis after anthracycline treatment.

Layer-specific strain in patients with heart failure using cardiovascular magnetic resonance: not all layers are the same

BACKGROUND

Global longitudinal strain (GLS), most commonly measured at the endocardium, has been shown to be superior to left ventricular (LV) ejection fraction (LVEF) for the identification of systolic dysfunction and prediction of outcomes in heart failure (HF). We hypothesized that strains measured at different myocardial layers (endocardium = ENDO, epicardium = EPI, average = AVE) will have distinct diagnostic and predictive performance for patients with HF.

METHODS

Layer-specific GLS, layer-specific global circumferential strain (GCS) and global radial strain (GRS) were evaluated by cardiovascular magnetic resonance imaging (CMR) feature tracking in the Alberta HEART study. A total of 453 subjects consisted of healthy controls (controls, n = 77), at-risk for HF (at-risk, n = 143), HF with preserved ejection fraction (HFpEF, n = 87), HF with mid-range ejection fraction (HFmrEF, n = 88) and HF with reduced ejection fraction (HFrEF, n = 58). For outcomes analysis, CMR-derived imaging parameters were adjusted with a base model that included age and N-terminal prohormone of b-type natriuretic peptide (NT-proBNP) to test their independent association with 5-year all-cause mortality.

RESULTS

GLS_EPI distinguished all groups with preserved LVEF (controls - 16.5 ± 2.4% vs. at-risk - 15.5 ± 2.7% vs. HFpEF - 14.1 ± 3.0%, p < 0.001) while GLS_ENDO and all GCS (all layers) were similar among these groups. GRS was reduced in HFpEF (41.1 ± 13.8% versus 48.9 ± 10.7% in controls, p < 0.001) and the difference between GLS_EPI and GLS_ENDO were significantly larger in HFpEF as compared to controls. Within the preserved LVEF groups, reduced GRS and GLS_EPI were significantly associated with increased LV mass (LVM) and LVM/LV end-diastolic volume EDV (concentricity). In multivariable analysis, only GLS_AVE and GRS predicted 5-year all-cause mortality (all ps < 0.05), with the strongest association with 5-year all-cause mortality by Akaike Information Criterion analysis and significant incremental value for outcomes prediction beyond LVEF or GLS_ENDO by the likelihood ratio test.

CONCLUSION

Global strains measured on endocardium, epicardium or averaged across the wall thickness are not equivalent for the identification of systolic dysfunction or outcomes prediction in HF. The endocardium-specific strains were shown to have poorest all-around performance. GLS_AVE and GRS were the only CMR parameters to be significantly associated with 5-year all-cause mortality in multivariable analysis. GLS_EPI and GRS, as well as the difference in endocardial and epicardial strains, were sensitive to systolic dysfunction among HF patients with normal LVEF (> 55%), in whom lower strains were associated with increased concentricity.

Free-breathing simultaneous myocardial T1 and T2 mapping with whole left ventricle coverage

PURPOSE

To develop a free-breathing sequence, that is, Multislice Joint T₁ -T₂ , for simultaneous measurement of myocardial T₁ and T₂ for multiple slices to achieve whole left-ventricular coverage.

METHODS

Multislice Joint T₁ -T₂ adopts slice-interleaved acquisition to collect 10 single-shot electrocardiogram-triggered images for each slice prepared by saturation and T₂ preparation to simultaneously estimate myocardial T₁ and T₂ and achieve whole left-ventricular coverage. Prospective slice-tracking using a respiratory navigator and retrospective image registration are used to reduce through-plane and in-plane motion, respectively. Multislice Joint T₁ -T₂ was validated through numerical simulations and phantom and in vivo experiments, and compared with saturation-recovery single-shot acquisition and T₂ -prepared balanced Steady-State Free Precession (T₂ -prep SSFP) sequences.

RESULTS

Phantom T₁ and T₂ from Multislice Joint T₁ -T₂ had good accuracy and precision, and were insensitive to heart rate. Multislice Joint T₁ -T₂ yielded T₁ and T₂ maps of nine left-ventricular slices in 1.4 minutes. The mean left-ventricular T₁ difference between saturation-recovery single-shot acquisition and Multislice Joint T₁ -T₂ across healthy subjects and patients was 191 ms (1564 ± 60 ms versus 1373 ± 50 ms; P < .05) and 111 ms (1535 ± 49 ms vs 1423 ± 49 ms; P < .05), respectively. The mean difference in left-ventricular T₂ between T₂ -prep SSFP and Multislice Joint T₁ -T₂ across healthy subjects and patients was -6.3 ms (42.4 ± 1.4 ms vs 48.7 ± 2.5; P < .05) and -5.7 ms (41.6 ± 2.5 ms vs 47.3 ± 2.7; P < .05), respectively.

CONCLUSION

Multislice Joint T₁ -T₂ enables quantification of whole left-ventricular T₁ and T₂ during free breathing within a clinically feasible scan time of less than 2 minutes.

Fluorescent Arylphosphonic Acids: Synergic Interactions between Bone and the Fluorescent Core

Herein, we report the third generation of fluorescent probes (arylphosphonic acids) to target calcifications, particularly hydroxyapatite (HAP). In this study, we use highly conjugated porphyrin-based arylphosphonic acids and their diesters, namely 5,10,15,20-tetrakis[m-(diethoxyphosphoryl)phenyl]porphyrin (m-H8 TPPA-OEt8 ) and 5,10,15,20-tetrakis [m-phenylphosphonic acid]porphyrin (m-H8 TPPA), in comparison with their positional isomers 5,10,15,20-tetrakis[p-(diisopropoxyphosphoryl)phenyl]porphyrin (p-H8 TPPA-iPr8 ) and 5,10,15,20-tetrakis [p-phenylphosphonic acid]porphyrin (p-H8 TPPA), which have phosphonic acid units bonded to sp2 carbon atoms of the fluorescent core. The conjugation of the fluorescent core is thus extended to the (HAP) through sp2 -bonded -PO3 H2 units, which generates increased fluorescence upon HAP binding. The resulting fluorescent probes are highly sensitive towards the HAP in rat bone sections. The designed probes are readily taken up by cells. Due to the lower reported toxicity of (p-H8 TPPA), these probes could find applications in monitoring bone resorption or adsorption, or imaging vascular or soft tissue calcifications for breast cancer diagnosis etc.

Simultaneous proton density fat-fraction and R 2 ∗ imaging with water-specific T1 mapping (PROFIT1 ): application in liver

PURPOSE

To describe and validate a simultaneous proton density fat-fraction (PDFF) imaging and water-specific T₁ mapping (T_1(Water) ) approach for the liver (PROFIT₁ ) with R 2 ∗ mapping and low sensitivity to B 1 + calibration or inhomogeneity.

METHODS

A multiecho gradient-echo sequence, with and without saturation preparation, was designed for simultaneous imaging of liver PDFF, R 2 ∗ , and T_1(Water) (three slices in ~13 seconds). Chemical-shift-encoded MRI processing yielded fat-water separated images and R 2 ∗ maps. T_1(Water)  calculation utilized saturation and nonsaturation-recovery water-separated images. Several variable flip angle schemes across k-space (increasing flip angles in sequential RF pulses) were evaluated for minimization of T₁ weighting, to reduce the B 1 + dependence of T_1(Water)  and PDFF (reduced flip angle dependence). T_1(Water)  accuracy was validated in mixed fat-water phantoms, with various PDFF and T₁ values (3T). In vivo application was illustrated in five volunteers and five patients with nonalcoholic fatty liver disease (PDFF, T_1(Water) , R 2 ∗ ).

RESULTS

A sin³ (θ) flip angle pattern (0 < θ < π/2 over k-space) yielded the largest PROFIT₁ signal yield with negligible B 1 + dependence for both T_1(Water) and PDFF. Mixed fat-water phantom experiments illustrated excellent agreement between PROFIT₁ and gold-standard spectroscopic evaluation of PDFF and T_1(Water)  (<1% T₁ error). In vivo PDFF, T_1(Water) , and R 2 ∗ maps illustrated independence of the PROFIT₁ values from B 1 + inhomogeneity and significant differences between volunteers and patients with nonalcoholic fatty liver disease for T_1(Water) (927 ± 56 ms vs. 1033 ± 23 ms; P < .05) and PDFF (2.0% ± 0.8% vs. 13.4% ± 5.0%, P < .05).  R 2 ∗ was similar between groups.

CONCLUSION

The PROFIT₁ pulse sequence provides fast simultaneous quantification of PDFF, T_1(Water) , and R 2 ∗ with minimal sensitivity to B 1 + miscalibration or inhomogeneity.

Circulating troponin and further left ventricular ejection fraction improvement in patients with previously recovered left ventricular ejection fraction

AIMS

The aim of this study is to determine factors associated with long-term recovery of left ventricular ejection fraction (LVEF) in patients with heart failure with reduced EF (HFrEF) and if further recovery also occurs in this group.

METHODS AND RESULTS

Among 621 participants enrolled in the Alberta Heart Failure Etiology and Analysis Team (HEART) Study, 316 with Stage C HF underwent comprehensive imaging and biomarker testing at enrolment and at 1-year follow up. Using pre-enrolment data, HF with recovered EF (HFrecEF) was defined as an absolute improvement ≥5% in LVEF from the prior lowest LVEF value, with a final LVEF value > 35% at or prior to study baseline. Participants with all LVEF > 40% were included for comparison. Hospitalization-free survival to 5 years was performed. The median cohort age was 66 years, and time from diagnosis was 4 years; 82% were male patients. Of the 316 patients, 95 (30%) patients had HFrecEF and 56 (18%) patients pHFrEF. On multivariate analysis, only shorter duration of HF was predictive of HFrecEF status. Over 1 year, LVEF increased in the HFrecEF group 4.0% (0.15-7.90, P = 0.042) as compared with persistent HFrEF, who in turn demonstrated higher baseline serum high sensitivity Troponin-T with further increase at follow up 0.55(0.33-0.86, P = 0.011). No change in any parameter in the HFpEF/HFmrEF group at follow up was observed.

CONCLUSIONS

Patients with HFrecEF demonstrate evidence of additional late improvement in LVEF and unchanged troponin levels, in contrast to those with persistent HFrEF, where LVEF does not improve and serum troponin rises over time. These data help to inform mechanisms relating to late LV remodelling.

Imaging hydroxyapatite in sub-retinal pigment epithelial deposits by fluorescence lifetime imaging microscopy with tetracycline staining

SIGNIFICANCE

Recent evidence suggests that hydroxyapatite (HAP) in sub-retinal pigment epithelial (sub-RPE) deposits in aged human eyes may act to nucleate and contribute to their growth to clinically detectable size. Sub-RPE deposits such as drusen are clinical hallmarks of age-related macular degeneration (AMD), therefore enhanced and earlier detection is a clinical need. We found that tetracycline-family antibiotics, long known to stain HAP in teeth and bones, can also label the HAP in sub-RPE deposits. However, HAP-bound tetracycline fluorescence excitation and emission spectra overlap with the well-known autofluorescence of outer retinal tissues, making them difficult to resolve.

AIM

In this initial study, we sought to determine if the HAP-bound tetracyclines also exhibit enhanced fluorescence lifetimes, providing a useful difference in lifetime compared with the short lifetimes observed in vivo in the human retina by the pioneering work of Schweitzer, Zinkernagel, Hammer, and their colleagues, and thus a large enough effect size to resolve the HAP from background by fluorescence lifetime imaging.

APPROACH

We stained authentic HAP with tetracyclines and measured the lifetime(s) by phase fluorometry, and stained aged, fixed human cadaver retinas with drusen with selected tetracyclines and imaged them by fluorescence lifetime imaging microscopy (FLIM).

RESULTS

We found that chlortetracycline and doxycycline exhibited substantial increase in fluorescence lifetime compared to the free antibiotics and the retinal background, and the drusen were easily resolvable from the retinal background in these specimens by FLIM.

CONCLUSIONS

These findings suggest that FLIM imaging of tetracycline (and potentially other molecules) binding to HAP could become a diagnostic tool for the development and progression of AMD.

Exercise Intolerance in Anthracycline-Treated Breast Cancer Survivors: The Role of Skeletal Muscle Bioenergetics, Oxygenation, and Composition

BACKGROUND

Peak oxygen consumption (VO₂ ) is reduced in women with a history of breast cancer (BC). We measured leg blood flow, oxygenation, bioenergetics, and muscle composition in women with BC treated with anthracycline chemotherapy (n = 16, mean age: 56 years) and age- and body mass index-matched controls (n = 16).

MATERIALS AND METHODS

Whole-body peak VO₂ was measured during cycle exercise. ³¹ Phosphorus magnetic resonance (MR) spectroscopy was used to measure muscle bioenergetics during and after incremental to maximal plantar flexion exercise (PFE). MR imaging was used to measure lower leg blood flow, venous oxygen saturation (S_v O₂ ), and VO₂ during submaximal PFE, and abdominal, thigh, and lower leg intermuscular fat (IMF) and skeletal muscle (SM).

RESULTS

Whole-body peak VO₂ was significantly lower in BC survivors versus controls (23.1 ± 7.5 vs. 29.5 ± 7.7 mL/kg/minute). Muscle bioenergetics and mitochondrial oxidative capacity were not different between groups. No group differences were found during submaximal PFE for lower leg blood flow, S_v O₂ , or VO₂ . The IMF-to-SM ratio was higher in the thigh and lower leg in BC survivors (0.36 ± 0.19 vs. 0.22 ± 0.07, p = .01; 0.10 ± 0.06 vs. 0.06 ± 0.02, p = .03, respectively) and were inversely related to whole-body peak VO₂ (r = -0.71, p = .002; r = -0.68, p = .003, respectively)_. In the lower leg, IMF-to-SM ratio was inversely related to VO₂ and O₂ extraction during PFE.

CONCLUSION

SM bioenergetics and oxidative capacity in response to PFE are not impaired following anthracycline treatment. Abnormal SM composition (increased thigh and lower leg IMF-to-SM ratio) may be an important contributor to reduced peak VO₂ during whole-body exercise among anthracycline-treated BC survivors.

IMPLICATIONS FOR PRACTICE

Peak oxygen consumption (peak VO₂ ) is reduced in breast cancer (BC) survivors and is prognostic of increased risk of cardiovascular disease-related and all-cause mortality. Results of this study demonstrated that in the presence of deficits in peak VO₂ 1 year after anthracycline therapy, skeletal muscle bioenergetics and oxygenation are not impaired. Rather, body composition deterioration (e.g., increased ratio of intermuscular fat to skeletal muscle) may contribute to reduced exercise tolerance in anthracycline BC survivors. This finding points to the importance of lifestyle interventions including caloric restriction and exercise training to restore body composition and cardiovascular health in the BC survivorship setting.

Quantification of lung water in heart failure using cardiovascular magnetic resonance imaging

BACKGROUND

Pulmonary edema is a cardinal feature of heart failure but no quantitative tests are available in clinical practice. The goals of this study were to develop a simple cardiovascular magnetic resonance (CMR) approach for lung water quantification, to correlate CMR derived lung water with intra-cardiac pressures and to determine its prognostic significance.

METHODS

Lung water density (LWD, %) was measured using a widely available single-shot fast spin-echo acquisition in two study cohorts. Validation Cohort: LWD was compared to left ventricular end-diastolic pressure or pulmonary capillary wedge pressure in 19 patients with heart failure undergoing cardiac catheterization. Prospective Cohort: LWD was measured in 256 subjects, including 121 with heart failure, 82 at-risk for heart failure and 53 healthy controls. Clinical outcomes were evaluated up to 1 year.

RESULTS

Within the validation cohort, CMR LWD correlated to invasively measured left-sided filling pressures (R = 0.8, p < 0.05). In the prospective cohort, mean LWD was 16.6 ± 2.1% in controls, 17.9 ± 3.0% in patients at-risk and 19.3 ± 5.4% in patients with heart failure, p < 0.001. In patients with or at-risk for heart failure, LWD >  20.8% (mean + 2 standard deviations of healthy controls) was an independent predictor of death, hospitalization or emergency department visit within 1 year, hazard ratio 2.4 (1.1-5.1, p = 0.03).

CONCLUSIONS

In patients with heart failure, increased CMR-derived lung water is associated with increased intra-cardiac filling pressures, and predicts 1 year outcomes. LWD could be incorporated in standard CMR scans.