Impact of Obesity on Volume Status in Patients With Ambulatory Chronic Heart Failure

Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial

Patients with obesity-related heart failure with preserved ejection fraction (HFpEF) display circulatory volume expansion and pressure overload contributing to cardiovascular-kidney end-organ damage. In the SUMMIT trial, patients with HFpEF and obesity were randomized to the long-acting glucose-dependent insulinotropic polypeptide receptor and glucagon-like peptide-1 receptor agonist tirzepatide (n = 364, 200 women) or placebo (n = 367, 193 women). As reported separately, tirzepatide decreased cardiovascular death or worsening heart failure. Here, in this mechanistic secondary analysis of the SUMMIT trial, tirzepatide treatment at 52 weeks, as compared with placebo, reduced systolic blood pressure (estimated treatment difference (ETD) -5 mmHg, 95% confidence interval (CI) -7 to -3; P < 0.001), decreased estimated blood volume (ETD -0.58 l, 95% CI -0.63 to -0.52; P < 0.001) and reduced C-reactive protein levels (ETD -37.2%, 95% CI -45.7 to -27.3; P < 0.001). These changes were coupled with an increase in estimated glomerular filtration rate (ETD 2.90 ml min-1 1.73 m-2 yr-1, 95% CI 0.94 to 4.86; P = 0.004), a decrease in urine albumin-creatinine ratio (ETD 24 weeks, -25.0%, 95% CI -36 to -13%; P < 0.001; 52 weeks, -15%, 95% CI -28 to 0.1; P = 0.051), a reduction in N-terminal prohormone B-type natriuretic peptide levels (ETD 52 weeks -10.5%, 95% CI -20.7 to 1.0%; P = 0.07) and a reduction in troponin T levels (ETD 52 weeks -10.4%, 95% CI -16.7 to -3.6; P = 0.003). In post hoc exploratory analyses, decreased estimated blood volume with tirzepatide treatment was significantly correlated with decreased blood pressure, reduced microalbuminuria, improved Kansas City Cardiomyopathy Questionnaire Clinical Summary Score and increased 6-min walk distance. Moreover, decreased C-reactive protein levels were correlated with reduced troponin T levels and improved 6-min walk distance. In conclusion, tirzepatide reduced circulatory volume-pressure overload and systemic inflammation and mitigated cardiovascular-kidney end-organ injury in patients with HFpEF and obesity, providing new insights into the mechanisms of benefit from tirzepatide. ClinicalTrials.gov registration: NCT04847557 .

Diastolic dysfunction in hypertension: a comprehensive review of pathophysiology, diagnosis, and treatment

Diastolic dysfunction refers to impaired relaxation or filling of the ventricles during the diastolic phase of the cardiac cycle. Left ventricular diastolic dysfunction (LVDD) is common in hypertensive individuals and is associated with increased morbidity and mortality. LVDD serves as a critical precursor to heart failure, particularly heart failure with preserved ejection fraction. The pathophysiology of LVDD in hypertension is complex, involving alterations in cardiac structure and function, neurohormonal activation, and vascular stiffness. While the diagnosis of LVDD relies primarily on echocardiography, management remains challenging due to a lack of specific treatment guidelines for LVDD. This review offers an overview of the pathophysiological mechanisms underlying LVDD in hypertension, diagnostic methods, clinical manifestations, strategies for managing LVDD, and prospects for future research.

Heart failure with preserved ejection fraction epidemiology, pathophysiology, diagnosis and treatment strategies

The prevalence of HF with preserved ejection raction (HFpEF, with EF ≥50%) is increasing across all populations with high rates of hospitalization and mortality, reaching up to 80% and 50%, respectively, within a 5-year timeframe. Comorbidity-driven systemic inflammation is thought to cause coronary microvascular dysfunction and increased epicardial adipose tissue, leading to downstream friborsis and molecular changes in the cardiomyocyte, leading to increased stiffness and diastolic dynsfunction. HFpEF poses unique challenges in terms of diagnosis due to its complex and diverse nature. The diagnosis of HFpEF relies on a combination of clinical assessment, imaging studies, and biomarkers. An additional important step in diagnosing HFpEF involves excluding certain cardiac diagnoses that may be specific underlying causes of HFpEF or may be masquerading as HFpEF and require specific alternative treatment approaches. In addition to administering sodium-glucose cotransporter 2 inhibitors to all patients, the most effective approach to enhance clinical outcomes may involve tailored therapy based on each patient's unique clinical profile. Exercise should be recommended for all patients to improve the quality of life. Glucagon-like peptide-1 1 agonists are a promising treatment option in obese HFpEF patients. Novel approaches targeting inflammation are also in early phase trials.

Long-term myocardial effects of noninvasive ventilation in patients with obesity hypoventilation syndrome

INTRODUCTION

Chronic effects of noninvasive ventilation on myocardial function in patients with obesity hypoventilation syndrome (OHS) are scarcely understood. The aim of the present study was to evaluate the long-term effects of volume-targeted bilevel positive airway pressure ventilation (BiPAP) on cardiac parameters and myocardial biomarkers in patients with OHS.

METHODS

Clinically stable patients with OHS referred to the tertiary center for the initiation of long-term BiPAP therapy were consecutively enrolled. At baseline, all participants underwent overnight cardiorespiratory polygraphy. BiPAP therapy using volume-targeted spontaneous/timed mode delivered via an oro-nasal mask was initiated. Beat-to-beat noninvasive monitoring by impedance cardiography was used to assess heart function at baseline and after 3 and 12 months of BiPAP use. Serum troponin 1, N-Terminal Pro-B-Type Natriuretic Peptide (NT-ProBNP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) were monitored.

RESULTS

Thirteen patients (10 men; mean age, 55.8 ± 9.8 years; mean body mass index of 47.8 ± 5.9 kg/m2) were recruited. From baseline to 3, and to 12 months of BiPAP use, left ventricular stroke volume (SV), ejection time (LVET), and ejection time index significantly increased (P = 0.030; P < 0.001; P = 0.003, respectively), while heart rate and systolic time ratio significantly decreased (P = 0.004; P = 0.034, respectively). Reductions in serum NT-proBNP, IL-6 and TNF-α were observed (P = 0.045; P = 0.018; P = 0.003, respectively). No significant changes in serum troponin were detected throughout the study.

CONCLUSIONS

The present findings of increased SV, in association with lengthening of LVET, reductions of NT-proBNP and reductions in circulatory inflammatory markers in patients with stable OHS and chronic moderate-to-severe daytime hypercapnia treated with BiPAP over 1 year support the role of this therapeutic mode in such patients.

Genetic associations of childhood and adult BMI on chronic heart failure and ischemic stroke: A Mendelian randomization

Background

Obesity has been confirmed to be associated with cardiovascular disease, but previous studies have focused on adults, and whether childhood obesity is associated with cardiovascular disease in adulthood needs further research.

Objective

This Mendelian randomization (MR) study aimed to investigate the associations of childhood and adult body mass index (BMI) with the risk of chronic heart failure (CHF) and ischemic stroke (IS).

Methods

Independent genetic instruments, demonstrating a strong association with exposure at the genome-wide significance level (P < 5 × 10-8), were carefully selected from comprehensive genome-wide association studies conducted within relevant European populations. Summary-level data for CHF and IS were obtained from the EBI database and large consortia of European population. To enhance robustness and generalizability, the analysis was replicated in an East Asian population cohort.

Results

According to a MR analysis based on a European population, a higher adult BMI was associated with an increased risk of CHF [(odds ratio (OR) 1.594, 95% confidence interval (CI) 1.483-1.713)] and IS (OR 1.163, 95%CI 1.096-1.233). In addition, higher childhood BMI level was associated with a higher risk of CHF (OR 1.323, 95%CI 1.153-1.524).and the effect was mainly driven by adult BMI. Replication analyses of adult BMI in East Asian populations showed consistent findings that adult BMI was associated with the risk of CHF (OR 2.167, 95%CI 1.786-2.630) and IS (OR 1.259, 95%CI 1.128-1.406).

Conclusions

Our study findings provide compelling evidence for the significant influence of adult BMI on the occurrence of CHF and IS. Furthermore, our observations suggest that the positive association between childhood BMI and the risk of CHF in adulthood can largely be attributed to individuals who maintain obesity into later life.

Semaglutide versus placebo in people with obesity-related heart failure with preserved ejection fraction: a pooled analysis of the STEP-HFpEF and STEP-HFpEF DM randomised trials

BACKGROUND

In the STEP-HFpEF (NCT04788511) and STEP-HFpEF DM (NCT04916470) trials, the GLP-1 receptor agonist semaglutide improved symptoms, physical limitations, bodyweight, and exercise function in people with obesity-related heart failure with preserved ejection fraction. In this prespecified pooled analysis of the STEP-HFpEF and STEP-HFpEF DM trials, we aimed to provide a more definitive assessment of the effects of semaglutide across a range of outcomes and to test whether these effects were consistent across key patient subgroups.

METHODS

We conducted a prespecified pooled analysis of individual patient data from STEP-HFpEF and STEP-HFpEF DM, randomised, double-blind, placebo-controlled trials at 129 clinical research sites in 18 countries. In both trials, eligible participants were aged 18 years or older, had heart failure with a left ventricular ejection fraction of at least 45%, a BMI of at least 30 kg/m2, New York Heart Association class II-IV symptoms, and a Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS; a measure of heart failure-related symptoms and physical limitations) of less than 90 points. In STEP-HFpEF, people with diabetes or glycated haemoglobin A1c concentrations of at least 6·5% were excluded, whereas for inclusion in STEP-HFpEF DM participants had to have been diagnosed with type 2 diabetes at least 90 days before screening and to have an HbA1c of 10% or lower. In both trials, participants were randomly assigned to either 2·4 mg semaglutide once weekly or matched placebo for 52 weeks. The dual primary endpoints were change from baseline to week 52 in KCCQ-CSS and bodyweight in all randomly assigned participants. Confirmatory secondary endpoints included change from baseline to week 52 in 6-min walk distance, a hierarchical composite endpoint (all-cause death, heart failure events, and differences in changes in KCCQ-CSS and 6-min walk distance); and C-reactive protein (CRP) concentrations. Heterogeneity in treatment effects was assessed across subgroups of interest. We assessed safety in all participants who received at least one dose of study drug.

FINDINGS

Between March 19, 2021 and March 9, 2022, 529 people were randomly assigned in STEP-HFpEF, and between June 27, 2021 and Sept 2, 2022, 616 were randomly assigned in STEP-HFpEF DM. Overall, 1145 were included in our pooled analysis, 573 in the semaglutide group and 572 in the placebo group. Improvements in KCCQ-CSS and reductions in bodyweight between baseline and week 52 were significantly greater in the semaglutide group than in the placebo group (mean between-group difference for the change from baseline to week 52 in KCCQ-CSS 7·5 points [95% CI 5·3 to 9·8]; p<0·0001; mean between-group difference in bodyweight at week 52 -8·4% [-9·2 to -7·5]; p<0·0001). For the confirmatory secondary endpoints, 6-min walk distance (mean between-group difference at week 52 17·1 metres [9·2 to 25·0]) and the hierarchical composite endpoint (win ratio 1·65 [1·42 to 1·91]) were significantly improved, and CRP concentrations (treatment ratio 0·64 [0·56 to 0·72]) were significantly reduced, in the semaglutide group compared with the placebo group (p<0·0001 for all comparisons). For the dual primary endpoints, the efficacy of semaglutide was largely consistent across multiple subgroups, including those defined by age, race, sex, BMI, systolic blood pressure, baseline CRP, and left ventricular ejection fraction. 161 serious adverse events were reported in the semaglutide group compared with 301 in the placebo group.

INTERPRETATION

In this prespecified pooled analysis of the STEP-HFpEF and STEP-HFpEF DM trials, semaglutide was superior to placebo in improving heart failure-related symptoms and physical limitations, and reducing bodyweight in participants with obesity-related heart failure with preserved ejection fraction. These effects were largely consistent across patient demographic and clinical characteristics. Semaglutide was well tolerated.

FUNDING

Novo Nordisk.

Evaluation of Right-Side Filling Pressure in Patients With Obesity With Heart Failure Using Handheld Ultrasound Score

The goal of this investigation is to evaluate the accuracy of handheld ultrasound score in assessing right atrial (RA) pressure in patients with obesity with heart failure. We prospectively studied 123 patients with heart failure referred for right-sided cardiac catheterization. Handheld ultrasound was performed before catheterization to evaluate volume status by estimating RA pressure using end-expiratory inferior vena cava (IVC) dimension, IVC respiratory collapsibility, and right internal jugular (RIJ) vein respiratory collapsibility. A 3-point simple score was created using multiple logistic regression. The patients were divided into 2 groups based on body mass index. The performance of this score was assessed using the receiver operating characteristics curve in each subgroup and was compared with the performance of the 2-point score (expiratory IVC dimension, IVC respiratory collapsibility). Median age was 58 years (interquartile range 48 to 65), and 37% were women. The 3-point score including RIJ performed better than did the 2-point score in patients with obesity (area under the curve 0.84 [0.74 to 0.95] vs 0.69 [0.58 to 0.81], p = 0.001). The performance of the scores did not differ in patients without obesity (area under the curve 0.85 [0.74 to 0.95] vs 0.82 [0.71 to 0.93], p = 0.49). In patients with obesity, the 3-point score had a specificity of 100% and sensitivity of 21% (11% to 31%) for elevated RA pressure ≥10 mm Hg. In conclusion, a 3-point score including both RIJ and IVC assessment performed better in patients with obesity with heart failure and highlights the importance of comprehensive evaluation in patients with obesity to achieve an accurate, noninvasive assessment of volume status.

Decoupling of Hemodynamics and Congestive Symptoms in Obese Patients With Heart Failure

BACKGROUND

Prior studies indicate significant physiological differences between obese and nonobese patients with heart failure (HF), but none have evaluated differences in hemodynamic patterns in these patient populations during treatment for acute decompensated HF (ADHF).

OBJECTIVES

In this study, we assessed differences in hemodynamic trends between obese and nonobese patients during treatment for ADHF.

METHODS

Obese (body mass index (BMI) >30, n = 63) and nonobese (BMI < 25, n = 69) patients with ADHF in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) study who had pulmonary artery catheterization data available through the duration of treatment were evaluated. Hemodynamics were analyzed at baseline and optimal day. Changes in BNP levels, weight, creatinine, BUN, 6MWT, orthopnea and dyspnea scores were assessed.

RESULTS

Despite similar baseline hemodynamics, obese patients had significantly less absolute and relative pulmonary arterial wedge pressure (PAWP) reduction (-16 ± 28 vs -32 ± 29%; P = 0.03) during treatment. Obese patients also had higher PAWPs (19.9 + 8 vs 15.5 + 6.8 mmHg; P = 0.01) and PA pressures at optimization compared with nonobese patients. Obese and nonobese patients had similar relative improvements in weight, BNP, 6-minute walk test distance, dyspnea and orthopnea scores, and similar changes in creatinine and BUN levels.

CONCLUSIONS

Obese patients treated for ADHF display less reduction in invasively measured left heart filling pressures, despite similar improvements in symptoms, weight loss, and noninvasive surrogates of congestion. Our findings suggest a degree of decoupling between left heart filling pressures and congestive symptoms in obese patients undergoing treatment for ADHF.

Heart Failure With Preserved Ejection Fraction: JACC Scientific Statement

The incidence and prevalence of heart failure with preserved ejection fraction (HFpEF) continue to rise in tandem with the increasing age and burdens of obesity, sedentariness, and cardiometabolic disorders. Despite recent advances in the understanding of its pathophysiological effects on the heart, lungs, and extracardiac tissues, and introduction of new, easily implemented approaches to diagnosis, HFpEF remains under-recognized in everyday practice. This under-recognition presents an even greater concern given the recent identification of highly effective pharmacologic-based and lifestyle-based treatments that can improve clinical status and reduce morbidity and mortality. HFpEF is a heterogenous syndrome and recent studies have suggested an important role for careful, pathophysiological-based phenotyping to improve patient characterization and to better individualize treatment. In this JACC Scientific Statement, we provide an in-depth and updated examination of the epidemiology, pathophysiology, diagnosis, and treatment of HFpEF.

How to Manage Heart Failure With Preserved Ejection Fraction: Practical Guidance for Clinicians

Although patients with heart failure with preserved ejection fraction (HFpEF) (left ventricular ejection fraction ≥50%) comprise nearly half of those with chronic heart failure, evidence-based treatment options for this population have historically been limited. Recently, however, emerging data from prospective, randomized trials enrolling patients with HFpEF have greatly altered the range of pharmacologic options to modify disease progression in selected patients with HFpEF. In the context of this evolving landscape, clinicians are increasingly in need of practical guidance regarding the best approach to management of this growing population. In this review, we build on the recently published heart failure guidelines by integrating contemporary data from recent randomized trials to provide a contemporary framework for diagnosis and evidence-based treatment of patients with HFpEF. Where gaps in knowledge persist, we provide "best available" data from post hoc analyses of clinical trials or data from observational studies to guide management until more definitive studies are available.

Obesity and heart failure with preserved ejection fraction: new insights and pathophysiological targets

Obesity and heart failure with preserved ejection fraction (HFpEF) represent two intermingling epidemics driving perhaps the greatest unmet health problem in cardiovascular medicine in the 21st century. Many patients with HFpEF are either overweight or obese, and recent data have shown that increased body fat and its attendant metabolic sequelae have widespread, protean effects systemically and on the cardiovascular system leading to symptomatic HFpEF. The paucity of effective therapies in HFpEF underscores the importance of understanding the distinct pathophysiological mechanisms of obese HFpEF to develop novel therapies. In this review, we summarize the current understanding of the cardiovascular and non-cardiovascular features of the obese phenotype of HFpEF, how increased adiposity might pathophysiologically contribute to the phenotype, and how these processes might be targeted therapeutically.

Intermittent Hypoxia and Weight Loss: Insights into the Etiology of the Sleep Apnea Phenotype

Sleep apnea (SA) is a major respiratory disorder with increased risk for hypertension and obesity; however, our understanding of the origins of this complex disorder remains limited. Because apneas lead to recurrent drops in O₂ during sleep, intermittent hypoxia (IH) is the main animal model to explore the pathophysiology of SA. Here, we assessed the impacts of IH on metabolic function and related signals. Adult male rats were exposed to 1 week of moderate IH (FiO₂ = 0.10-30 s, ten cycles/hour, 8 h/day). Using whole-body plethysmography, we measured respiratory variability and apnea index during sleep. Blood pressure and heart rate were measured by the tail-cuff method; blood samples were taken for multiplex assay. At rest, IH augmented arterial blood pressure, respiratory instability, but not apnea index. IH induced weight, fat, and fluid loss. IH also reduced food intake and plasma leptin, adrenocorticotropic hormone (ACTH), and testosterone levels but increased inflammatory cytokines. We conclude that IH does not replicate the metabolic clinical features of SA patient, thus raising our awareness of the limitations of the IH model. The fact that the risk for hypertension occurs before the appearance of apneas provides new insights into the progression of the disease.

Dapagliflozin for heart failure according to body mass index: the DELIVER trial

AIMS

Obesity is common and associated with unique phenotypic features in heart failure with preserved ejection fraction (HFpEF). Therefore, understanding the efficacy and safety of new therapies in HFpEF patients with obesity is important. The effects of dapagliflozin were examined according to body mass index (BMI) among patients in the Dapagliflozin Evaluation to Improve the LIVEs of Patients With PReserved Ejection Fraction Heart Failure trial.

METHODS AND RESULTS

Body mass index was analysed by World Health Organization (WHO) categories and as a continuous variable using restricted cubic splines. Body mass index ranged from 15.2 to 50 kg/m2 with a mean value of 29.8 (standard deviation ± 6.1) kg/m2. The proportions, by WHO category, were: normal weight 1343 (21.5%); overweight 2073 (33.1%); Class I obesity 1574 (25.2%); Class II obesity 798 (12.8%); and Class III obesity 415 (6.6%). Compared with placebo, dapagliflozin reduced the risk of the primary outcome to a similar extent across these categories: hazard ratio (95% confidence interval): 0.89 (0.69-1.15), 0.87 (0.70-1.08), 0.74 (0.58-0.93), 0.78 (0.57-1.08), and 0.72 (0.47-1.08), respectively (P-interaction = 0.82). The placebo-corrected change in Kansas City Cardiomyopathy Questionnaire total symptom score with dapagliflozin at 8 months was: 0.9 (-1.1, 2.8), 2.5 (0.8, 4.1), 1.9 (-0.1, 3.8), 2.7 (-0.5, 5.8), and 8.6 (4.0, 13.2) points, respectively (P-interaction = 0.03). The placebo-corrected change in weight at 12 months was: -0.88 (-1.28, -0.47), -0.65 (-1.04, -0.26), -1.42 (-1.89, -0.94), -1.17 (-1.94, -0.40), and -2.50 (-4.4, -0.64) kg (P-interaction = 0.002).

CONCLUSIONS

Obesity is common in patients with HFpEF and is associated with higher rates of heart failure hospitalization and worse health status. Treatment with dapagliflozin improves cardiovascular outcomes across the spectrum of BMI, leads to greater symptom improvement in patients with obesity, compared with those without, and has the additional benefit of causing modest weight loss.

Chloride in Heart Failure Syndrome: Its Pathophysiologic Role and Therapeutic Implication

Until recently, most studies of heart failure (HF) focused on body fluid dynamics through control of the sodium and water balance in the body. Chloride has remained largely ignored in the medical literature, and in clinical practice, chloride is generally considered as an afterthought to the better-known electrolytes of sodium and potassium. In recent years, however, the important role of chloride in the distribution of body fluid has emerged in the field of HF pathophysiology. Investigation of HF pathophysiology according to the dynamics of serum chloride is rational considering that chloride is an established key electrolyte for tubulo-glomerular feedback in the kidney and a possible regulatory electrolyte for body fluid distribution. The present review provides a historical overview of HF pathophysiology, followed by descriptions of the recent attention to the electrolyte chloride in the cardiovascular field, the known role of chloride in the human body, and recent new findings regarding the role of chloride leading to the proposed ‘chloride theory’ hypothesis in HF pathophysiology. Next, vascular and organ congestion in HF is discussed, and finally, a new classification and potential therapeutic strategy are proposed according to the ‘chloride theory’.

Comparison of fluid resuscitation weight-based dosing strategies in obese patients with severe sepsis

OBJECTIVE

This study aims to compare the composite outcome of progression to septic shock between 30 mL/kg/ideal body weight (IBW) versus 30 mL/kg/non-IBW fluid resuscitation dosing strategies in obese patients with severe sepsis.

METHODS

We retrospectively evaluated obese patients admitted to an academic tertiary care center for the management of severe sepsis. Patients were included if they had a fluid bolus order placed using the sepsis order set between Oct 2018 and Sept 2019. The primary objective was the composite of progression to septic shock, defined as either persistent hypotension within 3 h after the conclusion of the 30 mL/kg fluid bolus administration or the initiation of vasopressor(s) within 6 h of the bolus administration.

RESULTS

Of 72 included patients, 49 (68%) were resuscitated using an IBW-based and 23 (32%) using a non-IBW-based dosing strategy. There were similar rates of progression to septic shock in the IBW and non-IBW groups (18% vs. 26%; p = 0.54). Median ICU and hospital LOS in the IBW group versus non-IBW group were (0 [IQR 0] vs. 0 [IQR 0 to 4] days; p = 0.13) and (6 [IQR 3 to 10] vs. 8 [IQR 5 to 12] days; p = 0.07), respectively. In-hospital mortality rates were similar between the groups.

CONCLUSIONS

Our study results suggest that in obese septic patients, fluid administration using an IBW-dosing strategy did not affect the progression to septic shock.

Clinical Phenogroups in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for more than one-half of patients with heart failure. Effective treatment of HFpEF has not been established, largely because of the complexities and heterogeneity in the phenotypes of HFpEF. Categorizing patients based on clinical and pathophysiologic phenotype may provide more targeted and efficacious therapies. Despite this clinical need, there is no consensus on how to categorize patients with HFpEF into phenogroups. Possible metrics include the presence or absence of specific comorbidities that influence pathophysiology, imaging, hemodynamics, or other biomarkers. This article describes currently recognized phenotypes of HFpEF and potential treatment strategies.

Obesity, venous capacitance, and venous compliance in heart failure with preserved ejection fraction

AIMS

Circulating blood volume is functionally divided between the unstressed volume, which fills the vascular space, and stressed blood volume (SBV), which generates vascular wall tension and intravascular pressure. With decreases in venous capacitance, blood functionally shifts to the SBV, increasing central venous pressure and pulmonary venous pressures. Obesity is associated with both elevated venous pressure and heart failure with preserved ejection fraction (HFpEF). To explore the mechanisms underlying this association, we evaluated relationships between blood volume distribution, venous compliance, and body mass in patients with and without HFpEF.

METHODS AND RESULTS

Subjects with HFpEF (n = 62) and non-cardiac dyspnoea (NCD) (n = 79) underwent invasive haemodynamic exercise testing with echocardiography. SBV was estimated (eSBV) from measured haemodynamic variables fit to a comprehensive cardiovascular model. Compared to NCD, patients with HFpEF displayed a leftward-shifted central venous pressure-dimension relationship, indicating reduced venous compliance. eSBV was 81% higher at rest and 69% higher during exercise in HFpEF than NCD (both P < 0.0001), indicating reduced venous capacitance. Despite greater augmented eSBV with exercise, the increase in cardiac output was reduced in HFpEF, suggesting operation on the plateau of the Starling curve. Exercise eSBV was directly correlated with higher body mass index (r = 0.77, P < 0.0001) and inversely correlated with right ventricular-pulmonary arterial coupling (r = -0.57, all P < 0.0001).

CONCLUSIONS

Patients with HFpEF display reductions in systemic venous compliance and increased eSBV related to reduced venous capacitance, abnormalities in right ventricular-pulmonary artery interaction, and increased body fat. These data provide new evidence supporting an important role of venous dysfunction in obesity-related HFpEF and suggest that therapies that improve venous function may hold promise to improve clinical status in this cohort.

Pathophysiologic importance of visceral adipose tissue in women with heart failure and preserved ejection fraction

AIMS

Central obesity is a major risk factor for heart failure with preserved ejection fraction (HFpEF), particularly in women, but the mechanisms remain unclear. We hypothesized that sex-specific differences in visceral adipose tissue (VAT) content would differentially relate to haemodynamic severity of HFpEF in women and men.

METHODS AND RESULTS

Abdominal computed tomography (CT) and invasive haemodynamic exercise testing were performed in 105 subjects with HFpEF (63 women) and 105 age-, sex-, and body mass index-matched controls. Visceral adipose tissue area was quantified by CT. As compared with control women, VAT area was 34% higher in women with HFpEF (186 ± 112 vs. 139 ± 72 cm2, P = 0.006), while VAT area was not significantly different in men with or without HFpEF (294 ± 158 vs. 252 ± 92 cm2, P = 0.1). During exercise, pulmonary capillary wedge pressure (PCWP) increased markedly and to similar extent in both men and women with HFpEF. Women with increased VAT area displayed 33% higher PCWP during exercise compared with women with normal VAT area (28 ± 10 vs. 21 ± 10 mmHg, P = 0.001), whereas exercise PCWP was similar in men with or without excess VAT (24 ± 9 vs. 25 ± 6, P = 0.89). In women, each 100 cm2 increase in VAT area was associated with a 4.0 mmHg higher PCWP (95% CI 2.1, 6.0 mmHg; P < 0.0001), but there was no such relationship in men (interaction P = 0.009).

CONCLUSIONS

These data suggest that accumulation of excess VAT plays a distinct and important role in the pathophysiology of HFpEF preferentially in women. Further research is needed to better understand the mechanisms and treatment implications for visceral fat in HFpEF.

Sustained Improvement in Diastolic Reserve Following Percutaneous Pericardiotomy in a Porcine Model of Heart Failure With Preserved Ejection Fraction

BACKGROUND

Heart failure with preserved ejection fraction is increasing in prevalence, but few effective treatments are available. Elevated left ventricular (LV) diastolic filling pressures represent a key therapeutic target. Pericardial restraint contributes to elevated LV end-diastolic pressure, and acute studies have shown that pericardiotomy attenuates the rise in LV end-diastolic pressure with volume loading. However, whether these acute effects are sustained chronically remains unknown.

METHODS

Minimally invasive pericardiotomy was performed percutaneously using a novel device in a porcine model of heart failure with preserved ejection fraction. Hemodynamics were assessed at baseline and following volume loading with pericardium intact, acutely following pericardiotomy, and then again chronically after 4 weeks. Cardiac structure was assessed by magnetic resonance imaging.

RESULTS

The increase in LV end-diastolic pressure with volume loading was mitigated by 41% (95% CI, 27%-45%, P<0.0001; ΔLV end-diastolic pressure reduced from +9±3 mm Hg to +5±3 mm Hg, P=0.0003, 95% CI, -2.2 to -5.5). The effect was sustained at 4 weeks (+5±2 mm Hg, P=0.28 versus acute). There was no statistically significant effect of pericardiotomy on ventricular remodeling compared with age-matched controls. None of the animals developed hemodynamic or pathological indicators of pericardial constriction or frank systolic dysfunction.

CONCLUSIONS

The acute hemodynamic benefits of pericardiotomy are sustained for at least 4 weeks in a swine model of heart failure with preserved ejection fraction, without excessive chamber remodeling, pericarditis, or clinically significant systolic dysfunction. These data support trials evaluating minimally invasive pericardiotomy as a novel treatment for heart failure with preserved ejection fraction in humans.

Implications of peripheral oedema in heart failure with preserved ejection fraction: a heart failure network analysis

AIMS

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous condition, and tissue congestion manifested by oedema is not present in all patients. We compared clinical characteristics, exercise capacity, and outcomes in patients with HFpEF with and without oedema.

METHODS AND RESULTS

This study was a post hoc analysis of pooled data of patients with left ventricular ejection fraction of ≥50% enrolled in the DOSE, CARRESS-HF, RELAX, ATHENA, ROSE, INDIE, and NEAT trials. Patients were dichotomized by the severity of oedema. Cox proportional hazard regression and generalized linear regression models were used to assess associations between oedema, symptoms, and clinical outcomes. The ambulatory cohort included 393 patients (228 with and 165 without oedema), and the hospitalized cohort included 338 patients (249 with ≥moderate oedema and 89 with mild or none). Among ambulatory patients, patients with oedema had a higher body mass index (35.2 kg/m² [inter-quartile range, IQR 30.5, 41.6] vs. 31.6 kg/m² [IQR 27.9, 36.3], P < 0.001), greater burden of co-morbidities, higher intravascular pressures estimated on physical examination (elevated jugular venous pressure: 50% vs. 24.7%, P < 0.001), poorer renal function (creatinine: 1.2 mg/dL [IQR 0.9, 1.5] vs. 1 mg/dL [IQR 0.8, 1.3], P = 0.003), and lower peak VO₂ (adjusted mean difference -1.04 mL/kg/min, 95% confidence interval [-1.71, -0.37], P < 0.003). Among hospitalized patients, despite greater in-hospital fluid/weight loss in the ≥moderate oedema group, there was no difference in the improvement in dyspnoea by the visual analogue scale or well-being visual analogue scale from baseline to 3-4 days and no statistically significant difference in the rate of 60 day rehospitalization/death (adjusted hazard ratio 1.44, 95% confidence interval [0.87, 2.39], P = 0.156).

CONCLUSIONS

Patients with HFpEF and oedema display higher body mass, greater burden of co-morbidities, and more severe exercise intolerance, but clinical responses to treatment appear similar. Further research is required to better understand the nature of volume distribution in different HFpEF phenotypes.

Proposal for New Classification and Practical Use of Diuretics According to Their Effects on the Serum Chloride Concentration: Rationale Based on the "Chloride Theory"

Currently, diuretic therapy for heart failure (HF) pathophysiology is primarily focused on the sodium and water balance. Over the last several years, however, chloride (Cl) has been recognized to have an important role in HF pathophysiology, as both a prognostic marker and a possible central factor regulating the body fluid status. I recently proposed a unifying hypothesis for HF pathophysiology, called the "chloride theory", during HF worsening and recovery, as follows. Chloride is the key electrolyte for regulating both reabsorption of tubular electrolytes and water in the kidney through the renin-angiotensin-aldosterone system and distributing body fluid in each compartment of the body. As changes between the serum Cl concentration and plasma volume are intimately associated with worsening HF and its recovery after decongestive therapy, modulation of the serum Cl concentration by careful selection and combination of various diuretics and their doses could become an attractive therapeutic option for HF. In this review, I will propose a new classification and practical use of diuretics according to their effects on the serum Cl concentration. Diuretic use according to this classification is expected to be a useful strategy for the treatment of patients with HF.

Regional adiposity and heart failure with preserved ejection fraction

The role of obesity in the pathogenesis of heart failure (HF), and in particular HF with preserved ejection fraction (HFpEF), has drawn significant attention in recent years. The prevalence of both obesity and HFpEF has increased worldwide over the past decades and when present concomitantly suggests an obese-HFpEF phenotype. Anthropometrics, including body mass index, waist circumference, and waist-to-hip ratio, are associated with incident HFpEF. However, the cardiovascular effects of obesity may actually be driven by the distribution of fat, which can accumulate in the epicardial, visceral, and subcutaneous compartments. Regional fat can be quantified using non-invasive imaging techniques, including computed tomography, magnetic resonance imaging, and dual-energy X-ray absorptiometry. Regional variations in fat accumulation are associated with different HFpEF risk profiles, whereby higher epicardial and visceral fat have a much stronger association with HFpEF risk compared with elevated subcutaneous fat. Thus, regional adiposity may serve a pivotal role in the pathophysiology of HFpEF contributing to decreased cardiopulmonary fitness, impaired left ventricular compliance, upregulation of local and systemic inflammation, promotion of neurohormonal dysregulation, and increased intra-abdominal pressure and vascular congestion. Strategies to reduce total and regional adiposity have shown promise, including intensive exercise, dieting, and bariatric surgery programmes, but few studies have focused on HFpEF-related outcomes among obese. Further understanding the role these variable fat depots play in the progression of HFpEF and HFpEF-related hospitalizations may provide therapeutic targets in treating the obese-HFpEF phenotype.

Plasma volume variation across the menstrual cycle among healthy women of reproductive age: A prospective cohort study

Increases in reproductive hormones like estrogen, play an important role in the remarkable increases in plasma volume observed in pregnancy. Accurate estimates of plasma volume expansion during pregnancy depend on correctly timing and measuring plasma volume in nonpregnant women. However, to date, there is no consensus on the pattern of plasma volume across the menstrual cycle. We prospectively measured plasma volume in 45 women across a single menstrual cycle. A urine-based fertility monitor was used to time three clinic visits to distinct points in the menstrual cycle: the early follicular phase (~day 2), periovulation (~day 12), and the mid-point of the luteal phase (~day 21)-based on a 28-day cycle length. Healthy women aged 18-41 years with regular menstrual cycles and a healthy body weight were enrolled in the study. At each visit, blood samples were collected before and after injection of 0.25 mg/kg body weight of indocyanine green dye (ICG). Pre- and post-ICG injection plasma samples were used to measure plasma volume. Preinjection samples were used to measure ovarian hormones and plasma osmolality. Mean plasma volume was highest during the early follicular phase (2,276 ± 478 ml); it declined to 2,232 ± 509 ml by the late follicular phase and to 2,228 ± 502 ml by the midluteal phase. This study found that overall variations in plasma volume are small across the menstrual cycle. Therefore, in clinical practice and research, the menstrual cycle phase may not be an important consideration when evaluating plasma volume among women of reproductive age.