Respiratory failure and bioelectrical phase angle are independent predictors for long-term survival in acute heart failure

Effectiveness of a cardiac rehabilitation program on biomechanical, imaging, and physiological biomarkers in elderly patients with heart failure with preserved ejection fraction (HFpEF): FUNNEL + study protocol

BACKGROUND

Patients with heart failure with preserved ejection fraction (HFpEF) have a low functional status, which in turn is a risk factor for hospital admission and an important predictor of survival in HFpEF. HFpFE is a heterogeneous syndrome and recent studies have suggested an important role for careful, pathophysiological-based phenotyping to improve patient characterization. Cardiac rehabilitation has proven to be a useful tool in the framework of secondary prevention in patients with HFpEF. Facilitating decision-making and implementing cardiac rehabilitation programs is a challenge in public health systems for HFpEF management. The FUNNEL + study proposes to evaluate the efficacy of an exercise and education-based cardiac rehabilitation program on biomechanical, physiological, and imaging biomarkers in patients with HFpEF.

METHODS

A randomised crossover clinical trial is presented among people older than 70 years with a diagnosis of HFpEF. The experimental group will receive a cardiac rehabilitation intervention for 12 weeks. Participants in the control group will receive one educational session per week for 12 weeks on HFpEF complications, functional decline, and healthy lifestyle habits. VO2peak is the primary outcome. Biomechanical, imaging and physiological biomarkers will be assessed as secondary outcomes. Outcomes will be assessed at baseline, 12 weeks, and 24 weeks.

DISCUSSION

Identifying objective functional parameters indicative of HFpEF and the subsequent development of functional level stratification based on functional impairment ("biomechanical phenotypes") may help clinicians identify cardiac rehabilitation responders and non-responders and make future clinical decisions. In this way, future pharmacological and non-pharmacological interventions, such as exercise, could be improved and tailored to improve quality of life and prognosis and reducing patients' hospital readmissions, thereby reducing healthcare costs.

TRIAL REGISTRATION

NCT05393362 (Clinicaltrials.gov).

Bioelectrical Impedance Analysis and Body Composition in Cardiovascular Diseases

Nutritional status and body composition in cardiovascular (CV) patients are important aspects of their performance. Bioelectrical impedance analysis (BIA) is a noninvasive method that provides reliable information about bioelectrical parameters which reflect nutritional status and body composition data. The aim of this paper was to describe BIA, its advantages, limitations, and clinical applications in CV patients. The PubMed database was searched for all papers showing the use of BIA in CV conditions until January 1, 2023. A total of 42 papers regarding BIA application in CV patients were identified. Phase angle, Z200/5 parameter, and membrane capacitance are the BIA parameters that can be used for nutritional status assessment in CV patients, mainly in heart failure and after myocardial infarction. Among secondary body composition parameters, fat mass can be used for obesity assessment which is a CV risk factor. Body cell mass can be used together which the direct BIA parameters for nutritional status assessment which is an important factor in treatment outcome, quality of life, and disease prognosis. Total body water can be used for hydration assessment in heart failure and during invasive procedures. To conclude, BIA is a noninvasive method that provides essential information about the general condition of the body which is the result of nutritional and hydration status in CV patients.

The role of bioelectrical phase angle in patients with heart failure

The most challenging feature of heart failure (HF) still remains the evaluation of congestion. Residual congestion at discharge and the difficulties in perfectly dosing therapies in order to balance the hydration status of the patient are the most worrisome issues when dealing with HF.The use of bioimpedance vector analysis (BIVA) might promote a different approach in the general management of patients with HF. BIVA is a reliable, fast, bedside tool able to assess the congestion status. It proved to be helpful to physicians for diagnosing congestive status, managing therapies, and providing prognostic information in the setting of HF.Bioelectrical Phase Angle (PhA) - as derived from equations related to the parameters of BIVA - recently surged as a possible biomarker for patients with HF. Studies provided data about the application of PhA in the clinical management and in the overall risk stratification of HF patients.Basically, the use of PhA might be considered as a holistic evaluation of patients with HF which includes the need for a multiparametric approach able to effectively depict the clinical status of patients. There is no definite biomarker able to comprehensively describe and identify all the features of HF patient, but scores based on molecules/techniques able to explore the different pathogenetic mechanisms of HF are desirable.The aim of this review was to provide a comprehensive evaluation of literature related to PhA role in HF and the impact of this biomarker on clinical management and risk stratification of HF patients.

Assessment of Volume Status in Hospitalized Patients With Chronic Heart Failure

Assessment of volume status in hospitalized patients with heart failure is a critically important diagnostic skill that clinicians utilize frequently. However, accurate assessment is challenging and there is often significant inter-provider disagreement. This review serves as an appraisal of current methods of volume assessment amongst different categories of evaluation including patient history, physical exam, laboratory analysis, imaging, and invasive procedures. Within each category, this review highlights methods that are particularly sensitive or specific, or those that carry impactful positive or negative likelihood ratios. Utilization of the information that this review provides will allow clinicians to determine volume status of hospitalized heart failure patients more accurately and more precisely in order to provide appropriate and effective therapies.

The Pre-Discharge Oxygen Uptake Efficiency Slope Predicts One-Year Cardiovascular Events in Acute Decompensated Heart Failure Patients

(1) Background: Heart failure is a complex disease leading to functional disability. Cardiopulmonary exercise testing (CPET) is the gold standard in assessing aerobic capacity and formulating function-based prognostic stratification; however, patients with acute heart failure after medical treatment usually remain with markedly reduced exercise capacity, leading to early termination of CPET with submaximal testing results. The current study aimed to assess the cardiorespiratory fitness and characteristics of CPET variables of patients after acute heart failure treatment and determine potential CPET variables with prognostic value. (2) Methods: We recruited patients during hospitalization after management of acute heart failure, and pre-discharge CPET was performed. All enrolled patients were followed for one year for major adverse cardiovascular events (MACE). (3) Results: 85 patients were enrolled, with average left ventricular ejection fraction of 30.52%, and peak oxygen consumption of 10.85 mL/min/kg at baseline. The one-year MACE was 50%. Oxygen uptake efficiency slope (OUES) was a significant event predictor, with lower one-year MACE in those with OUES ≥ 1.25 (p < 0.001). Cox regression analysis showed a 5.421-fold increased risk of MACE in those with OUES < 1.25 (p = 0.004). (4) Conclusions: The current results suggested OUES is a significant prognostic indicator in patients with acute heart failure. This also emphasized the critical role of CPET in patients with heart failure for prognostic stratification.

Proteomics of the phase angle: Results from the population-based KORA S4 study

BACKGROUND & AIMS

The phase angle (PhA) measured with bioelectrical impedance analysis is considered to reflect the interrelated components body cell mass and fluid distribution based on technical and physical aspects of the PhA measurement. However, the biomedical meaning of the PhA remains vague. Previous studies mainly assessed associations of the PhA with numerous diseases and health outcomes, but few connected protein markers to the PhA. To broaden our understanding of the biomedical background of the PhA, we aimed to explore a proteomics profile associated with the PhA and related biological factors.

METHODS

The study sample encompassed 1484 participants (725 women and 759 men) aged 55-74 years from the population-based Cooperative Health Research in the Region of Augsburg (KORA) S4 study. Proteomics measurements were performed with a proximity extension assay. We employed boosting with stability selection to establish a set of markers that was strongly associated with the PhA from a group of 233 plasma protein markers. We integrated the selected protein markers into a network and enrichment analysis to identify gene ontology (GO) terms significantly overrepresented for the selected PhA protein markers.

RESULTS

Boosting with stability selection identified seven protein markers that were strongly and independently associated with the PhA: N-terminal prohormone brain natriuretic peptide (NT-proBNP), insulin-like growth factor-binding protein 2 (IGFBP2), adrenomedullin (ADM), myoglobin (MB), matrix metalloproteinase-9 (MMP9), protein-glutamine gamma-glutamyltransferase 2 (TGM2), and fractalkine (CX3CL1) [beta coefficient per 1 standard deviation increase in normalized protein expression values on a log 2 scale (95% confidence interval): -0.12 (-0.15, -0.08), -0.13 (-0.17, -0.09), -0.14 (-0.18, -0.10), 0.10 (0.07, 0.14), 0.07 (0.04, 0.10), 0.08 (0.05, 0.11), -0.06 (-0.10, -0.03), respectively]. According to the enrichment analysis, this protein profile was significantly overrepresented in the following top five GO terms: positive regulation of cell population proliferation (p-value: 1.32E-04), extracellular space (p-value: 1.34E-04), anatomical structure formation involved in morphogenesis (p-value: 2.92E-04), regulation of multicellular organismal development (p-value: 5.72E-04), and metal ion homeostasis (p-value: 8.86E-04).

CONCLUSION

Implementing a proteomics approach, we identified six new protein markers strongly associated with the PhA and confirmed that NT-proBNP is a key PhA marker. The main biological processes that were related to this PhA's protein profile are involved in regulating the amount and growth of cells, reinforcing, from a biomedical perspective, the current technical-based consensus of the PhA to reflect body cell mass.

Preoperative Phase Angle as a Risk Indicator in Cardiac Surgery-A Prospective Observational Study

Background: The phase angle (PhA) can be used for prognostic assessments in critically ill patients. This study describes the perioperative course of PhA and associated risk indicators in a cohort of elective cardiac surgical patients. Methods: The PhA was measured in 168 patients once daily until postoperative day (POD) seven. Patients were split into two groups depending on their median preoperative PhA and analyzed for several clinical outcomes; logistic regression models were used. Results: The PhA decreased from preoperative (6.1° ± 1.9°) to a nadir on POD 2 (3.5° ± 2.5°, mean difference −2.6° (95% CI, −3.0°; −2.1°; p < 0.0001)). Patients with lower preoperative PhA were older (71.0 ± 9.1 vs. 60.9 ± 12.0 years; p < 0.0001) and frailer (3.1 ± 1.3 vs. 2.3 ± 1.1; p < 0.0001), needed more fluids (8388 ± 3168 vs. 7417 ± 2459 mL, p = 0.0287), and stayed longer in the ICU (3.7 ± 4.5 vs. 2.6 ± 3.8 days, p = 0.0182). Preoperative PhA was independently influenced by frailty (OR 0.77; 95% CI 0.61; 0.98; p = 0.0344) and cardiac function (OR 1.85; 95%CI 1.07; 3.19; p = 0.028), whereas the postoperative PhA decline was independently influenced by higher fluid balances (OR 0.86; 95% CI 0.75; 0.99; p = 0.0371) and longer cardiopulmonary bypass times (OR 0.99; 95% CI 0.98; 0.99; p = 0.0344). Conclusion: Perioperative PhA measurement is an easy-to-use bedside method that may critically influence risk evaluation for the outcome of cardiac surgery patients.