Combined Prognostic Impact of Low Muscle Mass and Hypoalbuminemia in Patients Hospitalized for Heart Failure: A Retrospective Cohort Study

BACKGROUND

Sarcopenia and hypoalbuminemia have been identified as independent predictors of increased adverse outcomes, including mortality and readmissions, in hospitalized older adults with acute decompensated heart failure (ADHF). However, the impact of coexisting sarcopenia and hypoalbuminemia on morbidity and death in adults with ADHF has not yet been investigated. We aimed to investigate the combined effects of lower muscle mass (LMM) as a surrogate for sarcopenia and hypoalbuminemia on in-hospital and postdischarge outcomes of patients hospitalized for ADHF.

METHODS AND RESULTS

A total of 385 patients admitted for ADHF between 2017 and 2020 at a single institution were retrospectively identified. Demographic and clinical data were collected, including serum albumin levels at admission and discharge. Skeletal muscle indices were derived from semi-automated segmentation software analysis on axial chest computed tomography at the twelfth vertebral level. Our analysis revealed that patients who had LMM with admission hypoalbuminemia experienced increased diagnoses of infection and delirium with longer hospital length of stay and more frequent discharge to a facility. Upon discharge, 27.9% of patients had higher muscle mass without discharge hypoalbuminemia (reference group), 9.7% had LMM without discharge hypoalbuminemia, 38.4% had higher muscle mass with discharge hypoalbuminemia, and 24.0% had LMM with discharge hypoalbuminemia; mortality rates were 37.6%, 51.4%, 48.9%, and 63.2%, respectively. 1- and 3-year mortality risks were highest in those with LMM and discharge hypoalbuminemia; this relationship remained significant over a median 23.6 (3.1-33.8) months follow-up time despite multivariable adjustments (hazard ratio, 2.03 [95% CI, 1.31-3.16]; P=0.002).

CONCLUSIONS

Hospitalization with ADHF, LMM, and hypoalbuminemia portend heightened mortality risk.

Diagnostic Approach for Suspected Acute Myocarditis: Considerations for Standardization and Broadening Clinical Spectrum

Myocarditis is most recognized in patients with moderate to severe, recent-onset heart failure. However, less typical presentations including myocardial infarction with normal coronary arteries and arrhythmias are important manifestations but less commonly recognized to be caused by myocarditis. Most cases of myocarditis can be self-limiting without specific treatment; however, appropriate identification of risk during the diagnostic process of myocarditis and once a diagnosis is established is of primordial importance to identify patients in need for more specific follow-up and management. We propose a flexible, multitiered approach to the diagnostic process, allowing for capturing of the spectrum of myocarditis at an early time-point, individualized use of diagnostic resources through disease severity phenotyping, and providing structured follow-up care once myocarditis is confirmed. Such diagnostic processes allow for identification of specific etiologies with potential therapeutic consequences or allows for the comprehension of disease chronicity by understanding genetic contributions or elements of persistent immune dysregulation and degree of cardiac damage. The article highlights the evolving field of immunophenotyping in myocarditis, generating a potential for the development of targeted therapeutic approaches. Currently long-term follow-up should be titrated to the refined risk assessments of patients with a diagnosis of myocarditis and includes arrhythmia monitoring and imaging when the results will likely impact management. Genetic testing should be considered in selected cases, and histologic diagnosis may be considered in nonresponders even at later stages.

Insulinotropic Effects of Neprilysin and/or Angiotensin Receptor Inhibition in Mice

Treatment of heart failure with the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan improved glycemic control in individuals with type 2 diabetes. The relative contribution of neprilysin inhibition versus angiotensin II receptor antagonism to this glycemic benefit remains unknown. Thus, we sought to determine the relative effects of the neprilysin inhibitor sacubitril versus the angiotensin II receptor blocker valsartan on beta-cell function and glucose homeostasis in a mouse model of reduced first-phase insulin secretion, and whether any beneficial effects are additive/synergistic when combined in sacubitril/valsartan. High fat-fed C57BL/6J mice treated with low-dose streptozotocin (or vehicle) were followed for eight weeks on high fat diet alone or supplemented with sacubitril, valsartan or sacubitril/valsartan. Body weight and fed glucose levels were assessed weekly. At the end of the treatment period, insulin release in response to intravenous glucose, insulin sensitivity, and beta-cell mass were determined. Sacubitril and valsartan, but not sacubitril/valsartan, lowered fasting and fed glucose levels and increased insulin release in diabetic mice. None of the drugs altered insulin sensitivity or beta-cell mass, but all reduced body weight gain. Effects of the drugs on insulin release were reproduced in angiotensin II-treated islets from lean C57BL/6J mice, suggesting the insulin response to each of the drugs is due to a direct effect on islets and mechanisms therein. In summary, sacubitril and valsartan each exert beneficial insulinotropic, glycemic and weight-reducing effects in obese and/or diabetic mice when administered alone; however, when combined, mechanisms within the islet contribute to their inability to enhance insulin release.