Myocardial tissue phase mapping reveals impaired myocardial tissue velocities in obesity

The dual prevalence of advanced degrees of obesity and heart failure: a study from the National Inpatient Sample database

BACKGROUND

National prevalence rates for obesity and heart failure (HF) have been steadily increasing, which predisposes patients to higher morbidity and mortality rates.

OBJECTIVES

The purpose of this study was to evaluate the prevalence of HF stages in hospitalized patients according to their body mass index (BMI).

SETTING

Academic institution.

METHODS

National Inpatient Sample data from 2016 to 2018 were examined to identify patients with obesity, HF (presence or absence of advanced HF [AHF]), and cardiogenic shock (CS). The proportion of hospital admissions was determined for each category on the basis of the presence of AHF with/without CS. A comparative analysis was performed between patients with and without AHF, and multivariate logistic regression analysis was performed for the event of AHF. The same analyses were performed for the event of CS.

RESULTS

A total of 3,354,970 hospital admissions were identified. The prevalence of hospital admissions with a diagnosis of AHF and class III obesity and a diagnosis of CS and class III obesity was 21% and .5%, respectively. The prevalence of AHF and other classes of BMI and CS and other classes of BMI was 17% and .5%, respectively. The univariate analysis showed that there were significant variations in 10 factors between hospital admissions with/without the diagnosis of both AHF and CS. Statistical analyses indicated the following findings: Hospitalized patients in higher obesity groups are more likely to have AHF, and they are less likely to have CS compared with those with a BMI of ≤29.9.

CONCLUSIONS

This study revealed that the prevalence of AHF was significantly higher in hospitalized patients with class III obesity. These findings have implications for clinical management, and it can be inferred that these patients are less likely to receive advanced cardiac replacement therapies and might benefit from innovative approaches to address severe dual morbidity.

Phenotyping heart failure by cardiac magnetic resonance imaging of cardiac macro- and microscopic structure: state of the art review

Heart failure demographics have evolved in past decades with the development of improved diagnostics, therapies, and prevention. Cardiac magnetic resonance (CMR) has developed in a similar timeframe to become the gold-standard non-invasive imaging modality for characterizing diseases causing heart failure. CMR techniques to assess cardiac morphology and function have progressed since their first use in the 1980s. Increasingly efficient acquisition protocols generate high spatial and temporal resolution images in less time. This has enabled new methods of characterizing cardiac systolic and diastolic function such as strain analysis, exercise real-time cine imaging and four-dimensional flow. A key strength of CMR is its ability to non-invasively interrogate the myocardial tissue composition. Gadolinium contrast agents revolutionized non-invasive cardiac imaging with the late gadolinium enhancement technique. Further advances enabled quantitative parametric mapping to increase sensitivity at detecting diffuse pathology. Novel methods such as diffusion tensor imaging and artificial intelligence-enhanced image generation are on the horizon. Magnetic resonance spectroscopy (MRS) provides a window into the molecular environment of the myocardium. Phosphorus (31P) spectroscopy can inform the status of cardiac energetics in health and disease. Proton (1H) spectroscopy complements this by measuring creatine and intramyocardial lipids. Hyperpolarized carbon (13C) spectroscopy is a novel method that could further our understanding of dynamic cardiac metabolism. CMR of other organs such as the lungs may add further depth into phenotypes of heart failure. The vast capabilities of CMR should be deployed and interpreted in context of current heart failure challenges.

Myocardial strain imaging in Duchenne muscular dystrophy

Cardiomyopathy (CM) is the leading cause of death for individuals with Duchenne muscular dystrophy (DMD). While DMD CM progresses rapidly and fatally for some in teenage years, others can live relatively symptom-free into their thirties or forties. Because CM progression is variable, there is a critical need for biomarkers to detect early onset and rapid progression. Despite recent advances in imaging and analysis, there are still no reliable methods to detect the onset or progression rate of DMD CM. Cardiac strain imaging is a promising technique that has proven valuable in DMD CM assessment, though much more work has been done in adult CM patients. In this review, we address the role of strain imaging in DMD, the mechanical and functional parameters used for clinical assessment, and discuss the gaps where emerging imaging techniques could help better characterize CM progression in DMD. Prominent among these emerging techniques are strain assessment from 3D imaging and development of deep learning algorithms for automated strain assessment. Improved techniques in tracking the progression of CM may help to bridge a crucial gap in optimizing clinical treatment for this devastating disease and pave the way for future research and innovation through the definition of robust imaging biomarkers and clinical trial endpoints.

Inflamed adipose tissue: A culprit underlying obesity and heart failure with preserved ejection fraction

The incidence of heart failure with preserved ejection fraction is increasing in patients with obesity, diabetes, hypertension, and in the aging population. However, there is a lack of adequate clinical treatment. Patients with obesity-related heart failure with preserved ejection fraction display unique pathophysiological and phenotypic characteristics, suggesting that obesity could be one of its specific phenotypes. There has been an increasing recognition that overnutrition in obesity causes adipose tissue expansion and local and systemic inflammation, which consequently exacerbates cardiac remodeling and leads to the development of obese heart failure with preserved ejection fraction. Furthermore, overnutrition leads to cellular metabolic reprogramming and activates inflammatory signaling cascades in various cardiac cells, thereby promoting maladaptive cardiac remodeling. Growing evidence indicates that the innate immune response pathway from the NLRP3 inflammasome, to interleukin-1 to interleukin-6, is involved in the generation of obesity-related systemic inflammation and heart failure with preserved ejection fraction. This review established the existence of obese heart failure with preserved ejection fraction based on structural and functional changes, elaborated the inflammation mechanisms of obese heart failure with preserved ejection fraction, proposed that NLRP3 inflammasome activation may play an important role in adiposity-induced inflammation, and summarized the potential therapeutic approaches.

Isolated obesity resistance condition or associated with aerobic exercise training does not promote cardiac impairment

Mechanisms involved in cardiac function and calcium (Ca²⁺) handling in obese-resistant (OR) rats are still poorly determined. We tested the hypothesis that unsaturated high-fat diet (HFD) promotes myocardial dysfunction in OR rats, which it is related to Ca²⁺ handling. In addition, we questioned whether exercise training (ET) becomes a therapeutic strategy. Male Wistar rats (n=80) were randomized to standard or HFD diets for 20 weeks. The rats were redistributed for the absence or presence of ET and OR: control (C; n=12), control + ET (CET; n=14), obese-resistant (OR; n=9), and obese-resistant + ET (ORET; n=10). Trained rats were subjected to aerobic training protocol with progressive intensity (55-70% of the maximum running speed) and duration (15 to 60 min/day) for 12 weeks. Nutritional, metabolic, and cardiovascular parameters were determined. Cardiac function and Ca²⁺ handling tests were performed in isolated left ventricle (LV) papillary muscle. OR rats showed cardiac atrophy with reduced collagen levels, but there was myocardial dysfunction. ET was efficient in improving most parameters of body composition. However, the mechanical properties and Ca²⁺ handling from isolated papillary muscle were similar among groups. Aerobic ET does not promote morphological and cardiac functional adaptation under the condition of OR.

Obesity cardiomyopathy: evidence, mechanisms, and therapeutic implications

The prevalence of heart failure is on the rise and imposes a major health threat, in part, due to the rapidly increased prevalence of overweight and obesity. To this point, epidemiological, clinical, and experimental evidence supports the existence of a unique disease entity termed “obesity cardiomyopathy,” which develops independent of hypertension, coronary heart disease, and other heart diseases. Our contemporary review evaluates the evidence for this pathological condition, examines putative responsible mechanisms, and discusses therapeutic options for this disorder. Clinical findings have consolidated the presence of left ventricular dysfunction in obesity. Experimental investigations have uncovered pathophysiological changes in myocardial structure and function in genetically predisposed and diet-induced obesity. Indeed, contemporary evidence consolidates a wide array of cellular and molecular mechanisms underlying the etiology of obesity cardiomyopathy including adipose tissue dysfunction, systemic inflammation, metabolic disturbances (insulin resistance, abnormal glucose transport, spillover of free fatty acids, lipotoxicity, and amino acid derangement), altered intracellular especially mitochondrial Ca²⁺ homeostasis, oxidative stress, autophagy/mitophagy defect, myocardial fibrosis, dampened coronary flow reserve, coronary microvascular disease (microangiopathy), and endothelial impairment. Given the important role of obesity in the increased risk of heart failure, especially that with preserved systolic function and the recent rises in COVID-19-associated cardiovascular mortality, this review should provide compelling evidence for the presence of obesity cardiomyopathy, independent of various comorbid conditions, underlying mechanisms, and offer new insights into potential therapeutic approaches (pharmacological and lifestyle modification) for the clinical management of obesity cardiomyopathy.

Regional myocardial motion in patients with mild cognitive impairment: a pilot study

Background

Cardiovascular disease (CVD) is a risk factor for cognitive impairment in the elderly. Manifestations of subclinical CVDs can be found in patients with cognitive impairment. The aim of the present study was to test the hypothesis that patients with mild cognitive impairment (MCI) have different magnetic resonance imaging (MRI)-derived regional myocardial motion indices compared with healthy controls.

Methods

Eleven MCI patients (age, 65.5 years ±5.9; range, 55–81 years old) and 11 sex−/age-matched healthy volunteers were enrolled. All of the participants underwent a head MRI and cardiac MRI. Global cortical atrophy (GCA) was graded on the head MRI. The left ventricular ejection fraction (LVEF) and regional strain, strain rate, displacement and velocity were measured on cine images. The GCA scores, global cardiac function and regional myocardial motion indices were compared between MCI patients and healthy controls using the t-test.

Results

MCI patients had a higher GCA score than healthy controls (p = 0.048). However, there was no significant difference in LVEF between MCI patients and controls. Compared to healthy controls, MCI patients had a lower peak radial strain (29.1% ± 24.1% vs. 46.4% ± 43.4%, p < 0.001), lower peak diastolic radial strain rate (3.2 ± 2.4 s^− 1 vs. 6.0 ± 3.0 s^− 1, p < 0.001), lower peak diastolic circumferential strain rate (2.5 ± 2.1 s^− 1 vs. 3.2 ± 2.1 s^− 1, p = 0.002), lower peak systolic radial displacement (4.2 ± 2.2 mm vs. 5.2 ± 3.3 mm, p = 0.002), lower peak diastolic radial velocity (31 ± 18 mm/s vs. 45 ± 33 mm/s, p < 0.001), and lower peak diastolic circumferential velocity (178 ± 124 degree/s vs. 217 ± 131 degree/s, p = 0.005).

Conclusion

MRI-derived regional myocardial strain, strain rate and velocity were found to be different between MCI patients and healthy controls. Regional myocardial motion indices have the potential to become novel quantitative imaging biomarkers for representing the risk of neurodegenerative disorders, such as Alzheimer’s disease (AD).

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0824-2) contains supplementary material, which is available to authorized users.

Effect of Weight Extremes on Ventricular Volumes and Myocardial Strain in Repaired Tetralogy of Fallot as Measured by CMR

Pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot (rTOF-TAP) is often based on cardiac MRI (CMR) right ventricular (RV) volumes indexed to body surface area (BSA). Weight extremes result in increased patient morbidity and affect indexed measurements. We hypothesized that patients with rTOF-TAP at extremes of weight have (1) over- or underestimated indexed volumes and (2) altered parameters of cardiac function. CMRs in patients with rTOF-TAP were retrospectively reviewed; analysis included right and left ventricular (LV) volumes and ejection fractions (EF) and peak global LV circumferential strain (ε _cc) from myocardial tagged images. Indexed volumes were recalculated using ideal BSA. Weight categories were assigned: underweight, appropriate weight, overweight, and obese. Linear regression models with weight category, spline of age, and gender were created to assess the association of weight and parameters of volume and function. When RV volumes were corrected for ideal BSA, 11 (31%) additional overweight and obese patients met published criteria for PVR and 3 (38%) underweight patients no longer met criteria. Obese and overweight patients had larger absolute LV and RV diastolic volumes, but no difference in volumes indexed to ideal BSA. Modeling demonstrated no difference in LVEF or RVEF by weight categories but significant differences in global LV ε _cc. Extremes of body weight may result in inappropriate timing of PVR. Extremes of weight lead to abnormalities in global LV ε _cc. Although clinical implications of abnormal ε _cc are unclear, these patients may be at higher risk for early ventricular dysfunction.

Magnetic resonance tissue phase mapping demonstrates altered left ventricular diastolic function in children with chronic kidney disease

BACKGROUND

Echocardiographic examinations have revealed functional cardiac abnormalities in children with chronic kidney disease.

OBJECTIVE

To assess the feasibility of MRI tissue phase mapping in children and to assess regional left ventricular wall movements in children with chronic kidney disease.

MATERIALS AND METHODS

Twenty pediatric patients with chronic kidney disease (before or after renal transplantation) and 12 healthy controls underwent tissue phase mapping (TPM) to quantify regional left ventricular function through myocardial long (Vz) and short-axis (Vr) velocities at all 3 levels of the left ventricle.

RESULTS

Patients and controls (age: 8 years-20 years) were matched for age, height, weight, gender and heart rate. Patients had higher systolic blood pressure. No patient had left ventricular hypertrophy on MRI or diastolic dysfunction on echocardiography. Fifteen patients underwent tissue Doppler echocardiography, with normal z-scores for mitral early diastolic (V_E), late diastolic (V_A) and peak systolic (V_S) velocities. Throughout all left ventricular levels, peak diastolic Vz and Vr (cm/s) were reduced in patients: Vz_base -10.6 ± 1.9 vs. -13.4 ± 2.0 (P < 0.0003), Vz_mid -7.8 ± 1.6 vs. -11 ± 1.5 (P < 0.0001), Vz_apex -3.8 ± 1.6 vs. -5.3 ± 1.6 (P = 0.01), Vr_base -4.2 ± 0.8 vs. -4.9 ± 0.7 (P = 0.01), Vr_mid -4.7 ± 0.7 vs. -5.4 ± 0.7 (P = 0.01), Vr_apex -4.7 ± 1.4 vs. -5.6 ± 1.1 (P = 0.05).

CONCLUSION

Tissue phase mapping is feasible in children and adolescents. Children with chronic kidney disease show significantly reduced peak diastolic long- and short-axis left ventricular wall velocities, reflecting impaired early diastolic filling. Thus, tissue phase mapping detects chronic kidney disease-related functional myocardial changes before overt left ventricular hypertrophy or echocardiographic diastolic dysfunction occurs.

Cardiac Imaging in Heart Failure with Comorbidities

Imaging modalities stand at the frontiers for progress in congestive heart failure (CHF) screening, risk stratification and monitoring. Advancements in echocardiography (ECHO) and Magnetic Resonance Imaging (MRI) have allowed for improved tissue characterizations, cardiac motion analysis, and cardiac performance analysis under stress. Common cardiac comorbidities such as hypertension, metabolic syndromes and chronic renal failure contribute to cardiac remodeling, sharing similar pathophysiological mechanisms starting with interstitial changes, structural changes and finally clinical CHF. These imaging techniques can potentially detect changes earlier. Such information could have clinical benefits for screening, planning preventive therapies and risk stratifying patients. Imaging reports have often focused on traditional measures without factoring these novel parameters. This review is aimed at providing a synopsis on how we can use this information to assess and monitor improvements for CHF with comorbidities.

The role of MRI in understanding the underlying mechanisms in obesity associated diseases

Obesity and its possible association with diseases including diabetes and cardiovascular diseases have been studied for decades for its impact on healthcare. Recent studies clearly indicate the need for developing accurate and reproducible methodologies for assessing body fat content and distribution. Body fat distribution plays a significant role in developing an insight in the underlying mechanisms in which adipose tissue is linked with various diseases. Among imaging technologies including computerized axial tomography (CAT or CT), magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS), MRI and MRS seem to be the best emerging techniques and together are being considered as the gold standard for body fat content and distribution. This paper reviews studies up to the present time involving different methodologies of these two emerging technologies and presents the basic concepts of MRI and MRS with required novel image analysis techniques in accurate, quantitative, and direct assessment of body fat content and distribution. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.

Heart deformation analysis: measuring regional myocardial velocity with MR imaging

The aim of the present study was to test the hypothesis that heart deformation analysis (HDA) may serve as an alternative for the quantification of regional myocardial velocity. Nineteen healthy volunteers (14 male and 5 female) without documented cardiovascular diseases were recruited following the approval of the institutional review board (IRB). For each participant, cine images (at base, mid and apex levels of the left ventricle [LV]) and tissue phase mapping (TPM, at same short-axis slices of the LV) were acquired within a single magnetic resonance (MR) scan. Regional myocardial velocities in radial and circumferential directions acquired with HDA (Vrr and Vcc) and TPM (Vr and VФ) were measured during the cardiac cycle. HDA required shorter processing time compared to TPM (2.3 ± 1.1 min/case vs. 9.5 ± 3.7 min/case, p < 0.001). Moderate to good correlations between velocity components measured with HDA and TPM could be found on multiple myocardial segments (r = 0.460-0.774) and slices (r = 0.409-0.814) with statistical significance (p < 0.05). However, significant biases of velocity measures at regional myocardial areas between HDA and TPM were also noticed. By providing comparable velocity measures as TPM does, HDA may serve as an alternative for measuring regional myocardial velocity with a faster image processing procedure.

The paradox of obesity cardiomyopathy and the potential for weight loss as a therapy

Obesity is an independent risk factor for developing heart failure and the combination of the two disease states will prove to be a significant health burden over the coming years. Obesity is likely to contribute to the development of heart failure through a variety of mechanisms, including structural and functional changes, lipotoxicity and steatosis and altered substrate selection. However, once heart failure has developed, it seems that obesity confers a beneficial influence on prognosis in what has been termed the 'obesity paradox'. This may be a statistical phenomenon, but it should be considered that there is truly a protective state in the physiology of obesity. There is little evidence regarding the impact of weight loss in obese heart failure and whether or not this is beneficial. There have been small studies regarding the cardiovascular effects of both dietary weight loss and bariatric surgery, but few in heart failure. This is an important and increasingly relevant clinical question which must be addressed.