Obesity and the response to intensified diuretic treatment in decompensated heart failure: a DOSE trial substudy

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.

Advanced Hemodynamic Monitoring Allows Recognition of Early Response Patterns to Diuresis in Congestive Heart Failure Patients

There are no clear guidelines for diuretic administration in heart failure (HF), and reliable markers are needed to tailor treatment. Continuous monitoring of multiple advanced physiological parameters during diuresis may allow better differentiation of patients into subgroups according to their responses. In this study, 29 HF patients were monitored during outpatient intravenous diuresis, using a noninvasive wearable multi-parameter monitor. Analysis of changes in these parameters during the course of diuresis aimed to recognize subgroups with different response patterns. Parameters did not change significantly, however, subgroup analysis of the last quartile of treatment showed significant differences in cardiac output, cardiac index, stroke volume, pulse rate, and systemic vascular resistance according to gender, and in systolic blood pressure according to habitus. Changes in the last quartile could be differentiated using k-means, a technique of unsupervised machine learning. Moreover, patients' responses could be best clustered into four groups. Analysis of baseline parameters showed that two of the clusters differed by baseline parameters, body mass index, and diabetes status. To conclude, we show that physiological changes during diuresis in HF patients can be categorized into subgroups sharing similar response trends, making noninvasive monitoring a potential key to personalized treatment in HF.

Diabetes Mellitus and Heart Failure With Preserved Ejection Fraction: Role of Obesity

Heart failure with preserved ejection fraction is a growing epidemic and accounts for half of all patients with heart failure. Increasing prevalence, morbidity, and clinical inertia have spurred a rethinking of the pathophysiology of heart failure with preserved ejection fraction. Unlike heart failure with reduced ejection fraction, heart failure with preserved ejection fraction has distinct clinical phenotypes. The obese-diabetic phenotype is the most often encountered phenotype in clinical practice and shares the greatest burden of morbidity and mortality. Left ventricular remodeling plays a major role in its pathophysiology. Understanding the interplay of obesity, diabetes mellitus, and inflammation in the pathophysiology of left ventricular remodeling may help in the discovery of new therapeutic targets to improve clinical outcomes in heart failure with preserved ejection fraction. Anti-diabetic agents like glucagon-like-peptide 1 analogs and sodium-glucose co-transporter 2 are promising therapeutic modalities for the obese-diabetic phenotype of heart failure with preserved ejection fraction and aggressive weight loss via lifestyle or bariatric surgery is still key to reverse adverse left ventricular remodeling. This review focuses on the obese-diabetic phenotype of heart failure with preserved ejection fraction highlighting the interaction between obesity, diabetes, and coronary microvascular dysfunction in the development and progression of left ventricular remodeling. Recent therapeutic advances are reviewed.

Pulmonary Artery Pressure Monitoring Effectively Guides Management to Reduce Heart Failure Hospitalizations in Obesity

OBJECTIVES

This study sought to determine the impact of therapy guided by pulmonary artery (PA) pressure monitoring in patients with heart failure (HF) and obesity.

BACKGROUND

Obesity is prevalent in HF and associated with volume retention, but it complicates clinical assessment of congestion.

METHODS

The CardioMEMS Post Approval Study was a prospective, multicenter, open-label trial in 1,200 patients with New York Heart Association functional class III HF and prior HF hospitalization (HFH) within 12 months. Patients with a body mass index (BMI) >35 kg/m² were required to have a chest circumference <65 inches. Therapy was guided by PA pressure monitoring at sites, and HFHs were adjudicated 1 year before implantation and throughout follow-up. This analysis stratified patients according to ejection fraction (EF) <40% or ≥40% and by BMI <35 kg/m² or ≥35 kg/m².

RESULTS

Baseline PA diastolic pressure was higher in patients with BMI ≥35 kg/m² regardless of EF, but all PA pressures were reduced at 12 months in each cohort (P < 0.0001). HFH rate was reduced by >50% in both cohorts for EF <40% (BMI <35 kg/m² [HR: 0.48; 95% CI: 0.41-0.55] and ≥35 kg/m² [HR: 0.40; 95% CI: 0.31-0.53]) and EF ≥40% (BMI <35 kg/m² [HR: 0.42; 95% CI: 0.35-0.52] and ≥35 kg/m² [HR: 0.34; 95% CI: 0.25-0.45]; P < 0.0001). There was a nonsignificant trend toward greater reduction with more obesity. The all-cause hospitalization rate was also significantly reduced during monitoring (P < 0.01).

CONCLUSIONS

Management guided by PA pressure monitoring effectively reduced pressures, HFH, and all-cause hospitalization in patients with obesity regardless of EF. (CardioMEMS HF System Post Approval Study; NCT02279888).

Ultrasound indices of congestion in patients with acute heart failure according to body mass index

BACKGROUND

The inverse relationship between body mass index (BMI) and natriuretic peptide levels complicates the diagnosis of heart failure (HF) in obese patients. Assessment of congestion with ultrasound could facilitate HF diagnosis but it is unclear if any relationship exists amongst BMI, inferior vena cava (IVC) diameter and the number of B-lines.

METHODS

We performed a comprehensive echocardiographic evaluation within 24 h from hospital admission in patients with HF, including lung B-lines and IVC diameter, and studied their relationship with BMI and outcome.

RESULTS

216 patients (median age 81 (77-86) years) were enrolled. Median number of B-lines was 31 (IQR 26-38), median IVC diameter was 23 (22-25) mm and median BNP 991 (727-1601) pg/mL. BMI was inversely correlated with B-lines (r = - 0.50, p < 0.001), but not with IVC diameter (r = - 0.04, p = 0.58). Compared to overweight patients (BMI 25-29.9 kg/m2; n = 100) or with a normal BMI (BMI < 25 kg/m2; n = 59), obese patients (BMI ≥ 30 kg/m2; n = 57) had lower B-lines [28 (24-33) vs 30 (26-35), and vs 38 (32-42), respectively; p < 0.001] but similar IVC diameter. During the first 60 days of follow-up, there were 53 primary events: 29 patients died and 24 had a HF-related hospitalisation. B-lines and IVC diameter were independently associated with an increased risk. However, B-lines were less likely to predict outcome in the subgroup of patients with a BMI ≥ 30 kg/m².

CONCLUSIONS

Assessment of IVC diameter or B-lines in patients admitted with AHF identifies those at greater risk of death or HF readmission. However, assessment of B-lines might be influenced by BMI.

Obesity-Associated Heart Failure as a Theoretical Target for Treatment With Mineralocorticoid Receptor Antagonists

Importance

Despite their clinical benefits, mineralocorticoid receptor antagonists are greatly underprescribed by most practitioners who treat patients with chronic heart failure. A novel approach to encouraging the use of these drugs is to enhance awareness about the intimate link between aldosterone and obesity.

Observations

There is a strong association between abdominal obesity and circulating levels of aldosterone, and markers of abdominal obesity identify patients most likely to benefit from mineralocorticoid receptor antagonism. In a trial of patients with heart failure and a reduced ejection fraction, patients with an increased waist circumference exhibited an approximately 50% reduction in the risk of a primary end point. The magnitude of benefit was more than twice as great in patients with abdominal obesity than in those with a normal waist circumference, and patients with abdominal obesity tolerated treatment better than nonobese patients. Similarly, in a trial of patients with heart failure and a preserved ejection fraction, those who were most likely to have abdominal obesity (identified by their level of natriuretic peptides) were most likely to demonstrate a benefit of treatment with spironolactone, exhibiting an approximately 80% reduction in the risk of a primary end point (based on a small number of events).

Conclusions and Relevance

Although these analyses are post hoc, their concordance and strong biological foundation suggests that abdominal obesity may identify patients who respond most favorably to mineralocorticoid receptor antagonism. Given the easy availability of its measurement, targeting patients with an increased waist circumference could enhance the adoption of these important drugs for the treatment of chronic heart failure in clinical practice.

Obesity-Related Heart Failure With a Preserved Ejection Fraction: The Mechanistic Rationale for Combining Inhibitors of Aldosterone, Neprilysin, and Sodium-Glucose Cotransporter-2

Obesity-related heart failure with a preserved ejection fraction (HFpEF) is an important phenotype prevalent in the community, especially in people with metabolic disorders (e.g., dyslipidemia, diabetes). These individuals exhibit a marked expansion of plasma volume, but ventricular distensibility is limited, most likely as a result of cardiac microvascular rarefaction acting in concert with myocardial and pericardial fibrosis. Consequently, the increase in plasma volume causes a disproportionate increase in cardiac filling pressures, leading to heart failure, even though systolic ejection is not impaired. The features of this syndrome appear to be related (in part) to the overproduction of adipocyte-derived cell-signaling molecules, including aldosterone and neprilysin. The resulting sodium retention and plasma volume expansion is exacerbated by their mutual actions to promote cardiac and systemic inflammation and fibrosis. Inhibitors of aldosterone, neprilysin, and the sodium-glucose transporter-2 (SGLT2) can ameliorate the plasma volume expansion and pro-inflammatory and profibrotic pathways, potentially opposing the action of diverse adipocytokines. All 3 classes of drugs can reduce the quantity of visceral adipose tissue and ameliorate its abnormal biological properties. This mechanistic framework is supported by the results of large-scale randomized trials with mineralocorticoid receptor antagonists and SGLT2 inhibitors and is being further tested in an ongoing large-scale trial of neprilysin inhibition. The promise of using mineralocorticoid receptor antagonists, neprilysin inhibitors, and SGLT2 inhibitors (alone or in combination) in the management of obesity-related HFpEF suggests that physicians might finally have a phenotype of HFpEF that they can understand and treat.

Effect of bariatric surgery on heart failure

INTRODUCTION

Obesity increases the risk of heart failure (HF), which continues to be a significant proportion of all cardiovascular diseases and affects increasingly younger populations. The cross-talk between adipose and the heart involves insulin resistance, adipokine signaling and inflammation, with the capacity of adipose tissue to mediate hemodynamic signals, promoting progressive cardiomyopathy. Areas covered: From a therapeutic perspective, there is not yet a single obesity-related pathway that when addressed, can ameliorate cardiomyopathy in obese patients and this is a matter of ongoing research. There is poor evidence of the beneficial long-term effect of small nonsurgical intentional weight loss on HF outcomes, in contrast to the field of HF accompanying severe obesity where observational studies have shown that bariatric surgery is associated with improved cardiac structure/function in severely obese patients with HF and preserved ejection fraction (HFpEF) as well as with improved cardiac structure/function in those with HF and reduced ejection fraction (HFrEF). Few studies report positive outcomes in subjects with obesity and HF, both severe, who underwent bariatric surgery as a rescue treatment, including bridge to heart transplantation. Expert commentary: The fast growing prevalence of obesity will continue to require the development of appropriate interventions directed at controlling or slowing pathways of cardiac damage in these patients, but at present, bariatric surgery should be considered an option to try to decrease morbidity associated with HF in severely obese adults.