Nocturnal thoracic volume overload and post-discharge outcomes in patients hospitalized for acute heart failure

The prognostic value of systemic vascular resistance in heart failure patients with permanent atrial fibrillation: a retrospective study

Heart failure (HF) and permanent atrial fibrillation (AF) interact mutually, exacerbating hemodynamic effects and causing adverse outcomes and increased healthcare costs. Monitoring hemodynamic indicators in patients with these comorbidities is crucial for effective clinical management. Transthoracic impedance cardiography (ICG) has been widely employed in assessing hemodynamic status in clinical settings. Given the limited research on the prognostic significance of ICG parameters in HF with permanent AF, we undertook this study. A total of 66 HF patients with permanent AF were included in this retrospective study, and the primary outcome was rehospitalization due to worsening HF within 180-day post-discharge. Cox regression analysis was performed to explore the connection between ICG-evaluated parameters and the outcome risk. Receiver operating characteristic (ROC) curve analysis determined the optimal cutoff values of risk factors, subsequently applied in plotting Kaplan Meier (KM) survival curves. Multivariate Cox regression analysis revealed that systemic vascular resistance (SVR) both on admission and at discharge independently predicted rehospitalization for worsening HF. ROC analysis established optimal SVR cutoff values: 320.89 (kPa s/L) on admission and 169.94 (kPa s/L) at discharge (sensitivity 70%, specificity 94.4%, area under the curve (AUC) 0.831, respectively, sensitivity 90%, specificity 55.6%, AUC 0.742). KM survival curves analysis showed that patients with SVR > 320.89 (kPa s/L) on admission had an 8.14-fold (P < 0.001) increased risk of the end-point event compared with those with SVR ≤ 320.89 (kPa s/L). Similarly, patients with SVR > 169.94 (kPa s/L) at discharge faced a risk elevated by 6.57 times (P = 0.002) relative to those with SVR ≤ 169.94 (kPa s/L). In HF patients with permanent AF, SVR measured by ICG emerges as an independent risk factor and clinical predictor for HF deterioration-related readmission within 180 days after discharge. Higher SVR levels, both upon admission and at discharge, correlate with an incremental rehospitalization risk.

Chronotype of Lung Fluid Levels in Patients with Chronic Heart Failure

Background: The variation in lung fluid levels dependent on chronotype in patients with chronic heart failure is unclear. Remote dielectric sensing (ReDS^TM) is a novel non-invasive system to quantify the lung fluids, which may correlate to intracardiac filling pressures. We aimed to understand the variation in ReDS measurements by chronotype in patients with chronic heart failure. Methods: The patients who were hospitalized for heart failure exacerbations between November 2021 and March 2022 were prospectively included. ReDS values were measured at clinically stable conditions at the following three time points during the day: 5:00 (morning), 12:00 (noon), and 21:00 (night) (manufacture-recommended reference of ReDS value: between 25% and 35%). Results: Twelve patients were included. The median age was 84 (75, 90) years and four patients (33%) were men. The median plasma B-type natriuretic peptide was 235 (178, 450) pg/mL. The median ReDS value was 38% (23%, 41%) in the morning. The ReDS value decreased significantly at the noon measurement, down to 28% (23%, 29%) (p = 0.005) and again increased significantly at the night measurement, up to 31% (27%, 42%) (p = 0.002). The patients were clinically stabilized during the observational period. Conclusions: the lung fluid level varied considerably in patients with chronic heart failure following clinical stabilization.

Nocturnal thoracic volume overload and post-discharge outcomes in patients hospitalized for acute heart failure

Aims

Volume overload and perturbations of pulsatile haemodynamics may precipitate acute heart failure (AHF). Nocturnal thoracic volume overload due to rostral fluid shift during recumbency undetected by daytime measures may impact nighttime haemodynamics and post‐discharge outcomes.

Methods and results

A total of 63 patients (median 60 years, 79.4% men, and left ventricular ejection fraction 29.4%) hospitalized for AHF were enrolled. Once clinical euvolaemia was achieved, noninvasive pulsatile haemodynamics were assessed during daytime followed by circadian monitoring (6 p.m. to 5 a.m.) of thoracic fluid content and thoracic fluid content index (TFCi) using impedance cardiography, normalized electromechanical activation time ratio (EMAT%) using acoustic cardiography, and mean blood pressure using ambulatory blood pressure monitoring before discharge. The primary endpoints were composited of the first hospitalization for heart failure and death from any cause. Patients were also followed for the repeated heart failure hospitalizations. During a median follow‐up duration of 16 months, 33 patients encountered primary composite endpoints (52.4%), and there were 42 hospitalizations developed among 25 patients. An overnight increase in TFCi along with persistently prolonged EMAT% and low mean blood pressure was observed in the eventful group. Overnight increase in TFCi (ΔTFCi, the difference between the measures at 4 a.m. and 6 p.m.) was an independent predictor of primary composite events (hazard ratio and 95% confidence interval: 1.58, 1.07–2.33; P = 0.022) and recurrent composite events (2.22, 1.51–3.26; P < 0.001), after adjusting for potential confounding factors. A high ΔTFCi (≥0.5/kΩ/m²) significantly correlated with higher post‐discharge events (hazard ratio 6.25; 95% confidence interval 2.30–16.96; P < 0.001) in comparison with a low ΔTFCi (<0.5/kΩ/m²). ΔTFCi was significantly associated with EMAT%, estimated glomerular filtration rate, and left ventricular ejection fraction, but not with parameters of pulsatile haemodynamics.

Conclusions

Nocturnal thoracic volume overload in AHF before discharge, indicating the presence of residual volume overload unidentified by daytime measures, may predict post‐discharge outcomes.