Association of low body temperature and poor outcomes in patients admitted with worsening heart failure: a substudy of the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan (EVEREST) trial

The difference in core-surface temperature indicates the prognosis of heart failure patients

Aim: To evaluate the difference between core temperature and surface temperature (ΔT) as an index for the prognosis of heart failure (HF). Patients & methods: Core temperature and surface temperature were measured in 253 patients with HF. The association of ΔT with prognostic indicators of HF was analyzed. Results: Patients with ΔT ≥2°C were more likely to have lower left ventricular ejection fraction and lower estimated glomerular filtration rate, higher levels of troponin T, brain natriuretic peptide and procalcitonin, and high blood urea nitrogen/creatinine ratio. The risk of death increased by 32% for a 1°C increase in ΔT and was 4.36-times higher in the ΔT ≥2°C group than in the ΔT <2°C group. Conclusion: ΔT may be used to predict the prognosis of patients with HF.

Low body temperature and mortality in critically ill patients with coronary heart disease: a retrospective analysis from MIMIC-IV database

BACKGROUND

This study was aimed to investigate the correlation between low body temperature and outcomes in critically ill patients with coronary heart disease (CHD).

METHODS

Participants from the Medical Information Mart for Intensive Care (MIMIC)-IV were divided into three groups (≤ 36.5 ℃, 36.6-37.4 ℃, ≥ 37.5 ℃) in accordance with body temperature measured orally in ICU. In-hospital, 28-day and 90-day mortality were the major outcomes. Multivariable Cox regression, decision curve analysis (DCA), restricted cubic splines (RCS), Kaplan-Meier curves (with or without propensity score matching), and subgroup analyses were used to investigate the association between body temperature and outcomes.

RESULTS

A total of 8577 patients (65% men) were included. The in-hospital, 28-day, 90-day, and 1-year overall mortality rate were 10.9%, 16.7%, 21.5%, and 30.4%, respectively. Multivariable Cox proportional hazards regression analyses indicated that patients with hypothermia compared to the patients with normothermia were at higher risk of in-hospital [adjusted hazard ratios (HR) 1.23, 95% confidence interval (CI) 1.01-1.49], 28-day (1.38, 1.19-1.61), and 90-day (1.36, 1.19-1.56) overall mortality. For every 1 ℃ decrease in body temperature, adjusted survival rates were likely to eliminate 14.6% during the 1-year follow-up. The DCA suggested the applicability of the model 3 in clinical practice and the RCS revealed a consistent higher mortality in hypothermia group.

CONCLUSIONS

Low body temperature was associated with increased mortality in critically ill patients with coronary heart disease.

Association Between Body Temperature and In-Hospital Mortality Among Congestive Heart Failure Patients with Diabetes in Intensive Care Unit: A Retrospective Cohort Study

Body temperature (BT) has been utilized to assess patient outcomes across various diseases. However, the impact of BT on mortality in the intensive care unit (ICU) among patients with congestive heart failure (CHF) and diabetes mellitus (DM) remains unclear. We conducted a retrospective cohort study using data from the Medical Information Mart for Intensive Care (MIMIC)-IV data set. The primary outcome assessed was in-hospital mortality rates. BT was treated as a categorical variable in the analyses. The association between BT on ICU admission and in-hospital mortality was examined using multivariable logistic regression models, restricted cubic spline, and subgroup analysis. The cohort comprised 7063 patients with both DM and CHF (3135 females and 3928 males), with an average age of 71.5 ± 12.2 years. Comparative analysis of the reference group (Q4) revealed increased in-hospital mortality in Q6 and Q1 temperature groups, with fully adjusted odds ratios of 2.08 (95% confidence interval [CI]: 1.45-2.96) and 1.95 (95% CI: 1.35-2.79), respectively. Restricted cubic spline analysis demonstrated a U-shaped relationship between temperature on admission and mortality risk (p nonlinearity <0.001), with the nadir of risk observed at 36.8°C. The effect sizes and corresponding CIs below and above the threshold were 0.581 (95% CI: 0.434-0.777) and 1.674 (95% CI: 1.204-2.328), respectively. Stratified analyses further validated the robustness of this correlation. Our study establishes a nonlinear association between BT and in-hospital mortality in patients with both CHF and DM, with optimal suitable BT at 36.8°C. Further research is necessary to confirm this relationship.

Association between first 24-h mean body temperature and mortality in patients with diastolic heart failure in intensive care unit: A retrospective cohort study

Background

Body temperature (BT) has been used to evaluate the outcomes of patients with various diseases. In this study, patients with diastolic heart failure (DHF) in the intensive care unit (ICU) were examined for a correlation between BT and mortality.

Methods

This was a retrospective cohort study of the Medical Information Mart for Intensive Care (MIMIC)-IV dataset. A total of 4,153 patients with DHF were included. The primary outcomes were 28-day ICU and higher in-hospital mortality rates. BT was used in the analyses both as a continuous variable and as a categorical variable. According to the distribution of BT, the patients were categorized into three groups (hypothermia BT <36.5°C, normal 36.5°C ≤ BT <37.5°C, and hyperthermia BT ≥37.5°C). Multivariate logistic regression analysis was performed to explore the association between BT and patient outcomes.

Results

The proportions of the groups were 23.6, 69.2, and 7.2%, respectively. As a continuous variable, every 1°C increase in BT was associated with a 21% decrease in 28-day ICU mortality (OR: 0.79, 95% CI: 0.66-0.96, and p = 0.019) and a 23% decrease in in-hospital mortality (OR: 0.77, 95% CI: 0.66-0.91; and p = 0.002). When BT was used as a categorical variable, hypothermia was significantly associated with both 28-day ICU mortality (OR: 1.3, 95% CI: 1.03-1.65; and p = 0.026) and in-hospital mortality (OR: 1.31, 95% CI: 1.07-1.59; and p = 0.008). No statistical differences were observed between 28-day ICU mortality and in-hospital mortality with hyperthermia after adjustment.

Conclusion

The first 24-h mean BT after ICU admission was associated with 28-day ICU and in-hospital mortality in patients with DHF. Hypothermia significantly increased mortality, whereas hyperthermia did not.

Low body temperature and mortality in older patients with frailty in the emergency department

Purpose

The aim of this study was to assess the association between low body temperature and mortality in frail older adults in the emergency department (ED).

Methods

Inclusion criteria were: ≥ 75 years of age, Clinical Frailty Scale (CFS) score of 4–8, and temperature documented at ED admission. Patients were allocated to three groups by body temperature: low ≤ 36.0 °C, normal 36.1–38.0 and high ≥ 38.1. Odds ratios (OR) for 30-day and 90-day mortality were analysed.

Results

1577 patients, 61.2% female, were included. Overall mortalities were 85/1577 (5.4%) and 144/1557 (9.2%) in the 30-day and 90-day follow-ups, respectively. The ORs for low body temperature were 3.03 (1.72–5.35; P < 0.001) and 2.71 (1.68–4.38; P < 0.001) for 30-day and 90-day mortality, respectively. This association remained when adjusted for age, CFS score and gender. Mortality of the high-temperature group did not differ significantly when compared to the normal-temperature group.

Conclusions

Low body temperature in frail older ED patients was associated with significantly higher 30- and 90-day mortality.

Treatment with atrial natriuretic peptide induces adipose tissue browning and exerts thermogenic actions in vivo

Increasing evidence suggests natriuretic peptides (NPs) coordinate inter-organ metabolic crosstalk with adipose tissues and play a critical role in energy metabolism. We recently reported A-type NP (ANP) raises intracellular temperature in cultured adipocytes in a low-temperature-sensitive manner. We herein investigated whether exogenous ANP-treatment exerts a significant impact on adipose tissues in vivo. Mice fed a high-fat-diet (HFD) or normal-fat-diet (NFD) for 13 weeks were treated with or without ANP infusion subcutaneously for another 3 weeks. ANP-treatment significantly ameliorated HFD-induced insulin resistance. HFD increased brown adipose tissue (BAT) cell size with the accumulation of lipid droplets (whitening), which was suppressed by ANP-treatment (re-browning). Furthermore, HFD induced enlarged lipid droplets in inguinal white adipose tissue (iWAT), crown-like structures in epididymal WAT, and hepatic steatosis, all of which were substantially attenuated by ANP-treatment. Likewise, ANP-treatment markedly increased UCP1 expression, a specific marker of BAT, in iWAT (browning). ANP also further increased UCP1 expression in BAT with NFD. Accordingly, cold tolerance test demonstrated ANP-treated mice were tolerant to cold exposure. In summary, exogenous ANP administration ameliorates HFD-induced insulin resistance by attenuating hepatic steatosis and by inducing adipose tissue browning (activation of the adipose tissue thermogenic program), leading to in vivo thermogenesis during cold exposure.

Possible Association Between Body Temperature and B-Type Natriuretic Peptide in Patients With Cardiovascular Diseases

BACKGROUND

In addition to various biological effects of natriuretic peptides (NP) on cardiovascular systems, we recently reported that NP raises intracellular temperature in cultured adipocytes. We herein examined the possible thermogenic action of NP in consideration of hemodynamic parameters and inflammatory reaction by proposing structural equation models.

METHODS AND RESULTS

The study population consisted of 1985 consecutive patients who underwent cardiac catheterization. Covariance structure analyses were performed to clarify the direct contribution of plasma B-type NP (BNP) to body temperature (BT) by excluding other confounding factors. A hierarchical path model showed increase in BNP, increase in C-reactive protein and decrease in left ventricular ejection fraction were mutually associated. As expected, C-reactive protein was positively correlated with BT. Importantly, despite a negative correlation between BNP and left ventricular ejection fraction, a decrease in the left ventricular ejection fraction was associated with BT decrease, whereas elevation in BNP level was associated with BT increase independently of C-reactive protein level (P = .007).

CONCLUSIONS

Patients with LV dysfunction tend to manifest a decrease in BT, whereas BNP elevation is associated with an increase in BT independently of inflammatory response. These findings suggest the adaptive heat-retaining property of NP (and/or NP-associated factors) when BT falls owing to unfavorable hemodynamic conditions in a state of impaired cardiac function.

Abnormalities of Skeletal Muscle, Adipocyte Tissue, and Lipid Metabolism in Heart Failure: Practical Therapeutic Targets

Chronic diseases, including heart failure (HF), are often accompanied with skeletal muscle abnormalities in both quality and quantity, which are the major cause of impairment of the activities of daily living and quality of life. We have shown that skeletal muscle abnormalities are a hallmark of HF, in which metabolic pathways involving phosphocreatine and fatty acids are largely affected. Not only in HF, but the dysfunction of fatty acid metabolism may also occur in many chronic diseases, such as arteriosclerosis, as well as through insufficient physical exercise. Decreased fatty acid catabolism affects adenosine triphosphate (ATP) production in mitochondria, via decreased activity of the tricarboxylic acid cycle; and may cause abnormal accumulation of adipose tissue accompanied with hyperoxidation and ectopic lipid deposition. Such impairments of lipid metabolism are in turn detrimental to skeletal muscle, which is hence a chicken-and-egg problem between skeletal muscle and HF. In this review, we first discuss skeletal muscle abnormalities in HF, including sarcopenia; particularly their association with lipid metabolism and adipose tissue. On the other hand, the precise mechanisms involved in metabolic reprogramming and dysfunction are beginning to be understood, and an imbalance of daily nutritional intake of individuals has been found to be a causative factor for the development and worsening of HF. Physical exercise has long been known to be beneficial for the prevention and even treatment of HF. Again, the molecular mechanisms by which exercise promotes skeletal muscle as well as cardiac muscle functions are being clarified by recent studies. We propose that it is now the time to develop more “natural” methods to prevent and treat HF, rather than merely relying on drugs and medical interventions. Further analysis of the basic design of and molecular mechanisms involved in the human body, particularly the inextricable association between physical exercise and the integrity and functional plasticity of skeletal and cardiac muscles is required.

Admission Body Temperature in Critically Ill Patients as an Independent Risk Predictor for Overall Outcome

INTRODUCTION

Body temperature (BT) abnormalities are frequently observed in critically ill patients. We aimed to assess admission BT in a heterogeneous critically ill patient population admitted to an intensive care unit (ICU) as a prognostic parameter for intra-ICU and long-term mortality.

METHODS

A total of 6,514 medical patients (64 ± 15 years) admitted to a German ICU between 2004 and 2009 were included. A follow-up of patients was performed retrospectively. The association of admission BT with both intra-ICU and long-term mortality was investigated by logistic regression.

RESULTS

Patients with hypothermia (<36°C BT) were clinically worse and had more pronounced signs of multi-organ failure. Admission BT was associated with adverse overall outcome, with a 2-fold increase for hyperthermia (mortality 12%; odds ratio [OR] 1.80, 95% confidence interval [CI] 1.43-2.26; p < 0.001), and a 4-fold increase for the risk of hypothermia (mortality 24%; OR 4.05, 95% CI 3.38-4.85; p < 0.001) with respect to intra-ICU and long-term mortality. Moreover, hypothermia was even more harmful than hyperthermia, and both were strongly associated with intra-ICU mortality, especially in patients admitted with acute coronary syndrome (hypothermia: hazard ratio 6.12, 95% CI 4.12-9.11; p < 0.001; hyperthermia: OR 2.70, 95% CI 1.52-4.79; p< 0.001).

CONCLUSION

Admission BT is an independent risk predictor for both overall intra-ICU and long-term mortality in critically ill patients admitted to an ICU. Therefore, BT at admission might not only serve as a parameter for individual risk stratification but can also influence individual therapeutic decision-making.

Characterization of and factors associated with causes of pleural effusion in cats

OBJECTIVE To characterize and investigate potential associations between causes of pleural effusion and various clinical factors in a large cohort of affected cats. DESIGN Retrospective case series with nested cross-sectional study. ANIMALS 380 client-owned cats with a diagnosis of pleural effusion from January 1, 2009, through July 14, 2014, for which the cause of pleural effusion had been fully investigated. PROCEDURES Electronic medical records were reviewed and data collected regarding cat characteristics, clinical signs, cause of pleural effusion, treatment, and survival status at discharge from the hospital. Variables were examined for associations with causes of pleural effusion. RESULTS 87 (22.9%) cats died or were euthanized before discharge from the hospital. Congestive heart failure (CHF) was the most common cause (155 [40.8%]) of pleural effusion, followed by neoplasia (98 [25.8%]). Other causes included pyothorax, idiopathic chylothorax, trauma, feline infectious peritonitis, and nontraumatic diaphragmatic hernia. Cats with trauma or feline infectious peritonitis were significantly younger than those with CHF or neoplasia. Cats with lymphoma were significantly younger than those with carcinoma. Cats with CHF had a significantly lower rectal temperature at hospital admission (mean ± SD, 36.9 ± 1.2°C [98.4 ± 2.2°F]) than did cats with pleural effusion from other causes (37.9 ± 1.2°C [100.2 ± 2.2°F]). CONCLUSIONS AND CLINICAL RELEVANCE Cats with pleural effusion in this study had a poor prognosis; CHF and neoplasia were common causes. Age and hypothermia may be helpful to raise the index of suspicion for certain underlying causes of pleural effusion in cats.

Comparable effect of tolvaptan in heart failure patients with preserved or reduced ejection fraction

Background: It is unclear that the difference in efficacy of tolvaptan (TLV) on the length of hospital stay for both heart failure (HF) preserved ejection fraction (EF) (HFpEF) and reduced EF (HFrEF) patients.Methods: We investigated 369 patients who were hospitalized with HF from February 2011 to June 2016 and initiated TLV. Patients who died in hospital, transferred hospital or clinical scenario 4 or 5 were excluded. Finally, we analyzed 108 patients with HFpEF and 96 patients with HFrEF. We evaluated the relationship between the length of hospital stay and the date of TLV initiation. Moreover, we compared the early use (within the median) and delayed use (the median or later) of TLV.Results: The date of TLV initiation was statistically associated with the length of hospital stay in both HFpEF and HFrEF (HFpEF: r = 0.625, P < 0.001, HFrEF: r = 0.618, P < 0.001). In HFpEF, the length of hospital stay in delayed use group was significantly longer than the early use group (22.2 ± 10.7 days and 38.1 ± 22.6 days, P < 0.001). The result was similar in HFrEF (22.0 ± 15.0 days and 32.1 ± 22.0 days, P = 0.008). On the other hand, there were no statistically significant differences in the length of hospital stay after initiation of TLV in both HFpEF and HFrEF. Other findings (including the severity of HF) were similar between the early use group and the delayed group in HFpEF and HFrEF.Conclusions: The time until TLV initiation after hospitalization was related to the length of hospital stay in HFpEF and HFrEF patients.

Localization profiles of natriuretic peptides in hearts of pre-hibernating and hibernating Anatolian ground squirrels (Spermophilus xanthoprymnus)

The Anatolian ground squirrel (Spermophilus xanthoprymnus) is a typical example of true mammalian hibernators. In order to adapt to extreme external and internal environments during hibernation, they lower their body temperatures, heart rates and oxygen consumption; however, pathological events such as ischemia and ventricular fibrillation do not occur in their cardiovascular systems. During the hibernation, maintenance of cardiac function is very important for survival of ground squirrels. Natriuretic peptides (NPs) are key factors in the regulation of cardiovascular hemostasis. Since NPs' role on the protection of heart during hibernation are less clear, the aim of this study was to investigate dynamic changes in NPs content in the cardiac chambers and to reveal the possible role of NPs on establishing cardiac function in ground squirrel during hibernation using immunohistochemistry. The immunohistochemical results indicate that cardiac NP expressions in atrial and ventricular cardiomyocytes were different from each other and were sex-independent. ANP and BNP were expressed in a chamber-dependent manner in female and male squirrel hearts. Furthermore, cardiac NPs expression levels in hibernation period were lower than those at the pre-hibernation period. During prehibernation period, ANP, BNP and CNP were expressed in the white and beige adipocytes of epicardial adipose tissue (EAT); while during hibernation period, the brown adipocytes of EAT were positive for BNP and CNP. These data suggest that the hibernation-dependent reduction in levels of NPs, particularly ANP, in cardiac chambers and EAT may be associated with low heart rate and oxygen consumption during hibernation. However, further studies are needed to better delineate the roles of NPs during the hibernation.

The thermogenic actions of natriuretic peptide in brown adipocytes: The direct measurement of the intracellular temperature using a fluorescent thermoprobe

In addition to the various effects of natriuretic peptides (NPs) on cardiovascular systems, increasing attention is being paid to the possibility that NPs induce adipose tissue browning and activate thermogenic program. We herein established a direct intracellular temperature measurement system using a fluorescent thermoprobe and investigated the thermogenic effects of A-type NP (ANP) on brown adipocytes. The thermoprobe was successfully introduced into rat brown adipocytes, and the temperature dependent change in fluorescence intensity ratio was measured using a fluorescence microscope. After one-hour incubation with ANP, the degree of the change in fluorescence intensity ratio was significantly higher in ANP-treated (P < 0.01) adipocytes compared to untreated controls. The ANP treatment increased uncoupling protein-1 (UCP1) mRNA levels, which is one of the markers of thermogenesis in adipocytes, while the intracellular ATP content was not changed, indicating mitochondrial uncoupled respiration. Intriguingly, these thermogenic actions of ANP were more prominent when brown adipocytes were incubated at 35 °C than at 37 °C. Moreover, the increase in the intracellular temperature and the expression of UCP1 induced by ANP were cancelled by p38MAPK inhibition. Taken together, this study directly demonstrated the thermogenic actions of ANP in brown adipocytes through the use of a novel method of intracellular temperature measurement.

Admission-to-discharge temperature reduction in decompensated heart failure is associated with rehospitalization

INTRODUCTION

Decreasing body temperature on first follow-up visit-relative to discharge-predicts early rehospitalization in heart failure (HF). We studied whether admission-to-discharge temperature reduction was associated with increased HF rehospitalization in the ESCAPE trial.

METHODS

We compared patients with or without ≥1 °C decrease in temperature from admission-to-discharge. The study endpoint was rehospitalization due to HF for up to 6 months after discharge.

RESULTS

Among 354 patients (average age 57 years, 73% men) with recorded admission and discharge temperature, 22 (6.2%) had an admission-to-discharge temperature reduction ≥1 ºC. Patients with admission-to-discharge temperature reduction ≥1 ºC had higher frequency of rehospitalization for HF (68.2% vs. 44.3%, estimated odds ratio [OR] 2.697, 95% confidence interval [CI] 1.072-6.787, P = 0.029) despite a significantly higher admission temperature. On multivariate analysis, admission-to-discharge temperature reduction ≥1 ºC predicted rehospitalization for HF (OR 2.02, 95% CI 1.028-3.966, P = 0.041) after adjustment for age, BMI, baseline Na, creatinine, ejection fraction and discharge NYHA class. A standard logistic model treating temperature change as a continuous variable, and a model using a restricted cubic spline, did not demonstrate a statistically significant relationship between temperature reduction and HF rehospitalization. Subsequently, an altered logistic model was fit expressing the log odds of HF rehospitalization as a piecewise linear function of temperature decrease; this model did demonstrate statistical significance (P = 0.013) with an estimated odds ratio of 1.140 per 0.1 ºC beyond 0.5 ºC.

CONCLUSION

Admission-to-discharge temperature reduction ≥1 ºC is an unfavorable prognostic sign associated with future rehospitalization due to HF.

Referring patients to hospice or palliative care

NPs care for patients with chronic diseases such as heart failure, chronic obstructive pulmonary disease, cancer, and dementia. As the disease progresses or patients age, disease-related symptoms may become increasingly burdensome, and these patients may benefit from hospice or palliative care. NPs can guide individuals in this process to optimize care and support at the end of life.

Acute decompensated heart failure (ADHF): A comprehensive contemporary review on preventing early readmissions and postdischarge death

Heart failure (HF) is an increasingly prevalent syndrome and a leading cause of both first hospitalization and readmissions. Strikingly, up to 25% of the patients are readmitted within 30 to 60-days, accounting for HF as the primary cause for readmission in the adult population. Given its poor prognosis, one could describe it as a "malignant condition". Acute decompensation is intrinsically related to increased right heart tele-diastolic pressures and often related to congestive symptoms. In-hospital strategies to adequately compensate and timely discharge patients are limited. Conversely, the fragile early postdischarge phase is a vulnerable period when one could potentially intervene cost-effectively to improve survival and to reduce morbidity. Promising transitional hospital-to-home programs may have a broader role in the near future, namely for selected higher risk patients. However, identifying patients at risk for hospital readmission has been challenging. Novel approaches, such as ferric carboxymaltose and valsartan/sacubitril, and reemerging drugs, particularly digoxin, may reduce hospitalizations. Despite this, optimizing the use of "older" therapies is still warranted. Right heart pressures monitoring may provide novel insights into promptly outpatient management. Unfortunately, randomized trials in the specific ADHF population are scarce. A novel paradigmatic approach is needed in order to suitably improve the currently poor prognosis of ADHF. Both improving survival and reducing hospitalizations are, therefore, primordial therapy goals. Lastly, no single drug has consistently proved to improve survival in HF with preserved ejection fraction (HFpEF); yet, some approaches may efficiently reduce hospitalizations. Awareness on HFpEF management beyond the failing heart is imperative.

Determinants of survival following hospitalization for acute heart failure

Heart failure constitutes a major public health concern in the United States and is one of the leading causes of hospitalization, readmission, and death. Due to an aging U.S. population, it is estimated that the prevalence of heart failure will increase by 25% over the coming decades, affecting approximately 3.5% of the population by the year 2030. The ability to discriminate patients admitted with acute heart failure syndromes who are at increased risk for poor post-hospitalization outcomes is thus critical to guide therapeutic decision making for healthcare providers. This review paper will discuss clinical, hemodynamic, as well as biochemical markers that have been demonstrated to predict post-discharge outcomes among patients hospitalized with acute heart failure.