The acute effects of furosemide in acute heart failure assessed by remote dielectric sensing. A protocol.

INTRODUCTION: Intravenous loop diuretics have been a key component in treating pulmonary oedema since the 1960s and have a Class 1 recommendation in the 2021 guidelines for acute heart failure (AHF). While the diuretic effect of loop diuretics is well established, it remains unclear how furosemide influences pulmonary congestion and cardiac filling pressures in the hyperacute phase before significant diuresis occurs. METHODS: This was a prospective study of adult patients with AHF and objective signs of pulmonary congestion admitted to the cardiac ward. Remote dielectric sensing (ReDS) will directly measure lung fluid content, and cardiac filling pressures will be assessed by echocardiography with Doppler and strain analysis. CONCLUSIONS: This study will examine if furosemide leads to a hyperacute reduction in pulmonary congestion assessed by ReDS independent of diuretic effects in patients with AHF. We hypothesise that the haemodynamic effect of furosemide shown on pulmonary congestion may explain the subjective instant relief in patients with AHF receiving furosemide. FUNDING: Dr. Grand's salary during this project is supported by a research grant from the Danish Cardiovascular Academy funded by Novo Nordisk Foundation grant number NNF20SA0067242 and by the Danish Heart Foundation. TRIAL REGISTRATION: This protocol was approved by the Scientific Ethical Committee, H-23029822, and the Danish Data Protection Agency P-2013-14703. The protocol was registered with ClinicalTrial.org on 29 August 2023 (Identifier: NCT06024889).

The Influence of Food Intake and Preload Augmentation on Cardiac Functional Parameters: A Study Using Both Cardiac Magnetic Resonance and Echocardiography.

(1) Background: To investigate how food intake and preload augmentation affect the cardiac output (CO) and volumes of the left ventricle (LV) and right ventricle (RV) assessed using cardiac magnetic resonance (CMR) and trans-thoracic echocardiography (TTE). (2) Methods: Eighty-two subjects with (n = 40) and without (n = 42) cardiac disease were assessed using both CMR and TTE immediately before and after a fast infusion of 2 L isotonic saline. Half of the population had a meal during saline infusion (food/fluid), and the other half were kept fasting (fasting/fluid). We analyzed end-diastolic (EDV) and end-systolic (ESV) volumes and feature tracking (FT) using CMR, LV global longitudinal strain (GLS), and RV longitudinal strain (LS) using TTE. (3) Results: CO assessed using CMR increased significantly in both groups, and the increase was significantly higher in the food/fluid group: LV-CO (ΔLV-CO: +2.6 ± 1.3 vs. +0.7 ± 1.0 p < 0.001), followed by increased heart rate (HR) (ΔHR: +12 ± 8 vs. +1 ± 6 p < 0.001). LV and RV achieved increased stroke volume (SV) through different mechanisms. For the LV, through increased contractility, increased LV-EDV, decreased LV-ESV, increased LV-FT, and GLS were observed. For the RV, increased volumes, increased RV-EDV, increased RV-ESV, and at least for the fasting/fluid group, unchanged RV-FT and RV-LS were reported. (4) Conclusions: Preload augmentation and food intake have a significant impact on hemodynamic and cardiac functional parameters. This advocates for standardized recommendations regarding oral intake of fluid and food before cardiac assessment, for example, TTE, CMR, and right heart catheterization. We also demonstrate different approaches for the LV and RV to increase SV: for the LV by increased contractility, and for the RV by volume expansion.

A new method to quantify left ventricular mass by 2D echocardiography.

Increased left ventricular mass (LVM) is a strong independent predictor for adverse cardiovascular events, but conventional echocardiographic methods are limited by poor reproducibility and accuracy. We developed a novel method based on adding the mean wall thickness from the parasternal short axis view, to the left ventricular end-diastolic volume acquired using the biplane model of discs. The participants (n = 85) had various left ventricular geometries and were assessed using echocardiography followed immediately by cardiac magnetic resonance, as reference. We compared our novel two-dimensional (2D) method to various conventional one-dimensional (1D) and other 2D methods as well as the three-dimensional (3D) method. Our novel method had better reproducibility in intra-examiner [coefficients of variation (CV) 9% vs. 11-14%] and inter-examiner analysis (CV 9% vs. 10-20%). Accuracy was similar to the 3D method (mean difference ± 95% limits of agreement, CV): Novel: 2 ± 50 g, 15% vs. 3D: 2 ± 51 g, 16%; and better than the "linear" 1D method by Devereux (7 ± 76 g, 23%). Our novel method is simple, has considerable better reproducibility and accuracy than conventional "linear" 1D methods, and similar accuracy as the 3D-method. As the biplane model forms part of the standard echocardiographic protocol, it does not require specific training and provides a supplement to the modern echocardiographic report.

Layer-Specific Strain Is Preload Dependent: Comparison between Speckle-Tracking Echocardiography and Cardiac Magnetic Resonance Feature-Tracking.

BACKGROUND: Speckle-tracking echocardiographic (STE) imaging and cardiac magnetic resonance feature-tracking (CMR-FT) are novel imaging techniques enabling layer-specific quantification of myocardial deformation. Conventional echocardiographic parameters are load dependent, but few studies have investigated the effects of loading conditions on STE and CMR-FT layer-specific strain and the interchangeability of the two modalities. The aim of this study was to evaluate the effects of acute preload augmentation by saline infusion on STE and CMR-FT longitudinal and circumferential layer-specific strain parameters and their intermodal agreement. METHODS: A total of 80 subjects, including 41 control subjects (mean age, 40 ± 12 years; 49% men) and 39 patients with cardiac disease (mean age, 47 ± 15 years; 92% men) were examined using STE and CMR-FT layer-specific strain analysis before and after saline infusion (median, 2.0 L) with quantification of transmural global longitudinal strain (GLS), epicardial GLS, endocardial GLS, transmural global circumferential strain (GCS), epicardial GCS, and endocardial GCS in addition to epicardial-endocardial gradients. Bland-Altman plots and Pearson correlation coefficients were used to evaluate agreement between the two modalities across all strain parameters. RESULTS: Acute saline infusion increased all STE and CMR-FT layer-specific strain parameters in both groups. STE and CMR-FT GLS increased by 1.4 ± 1.5% and 1.5 ± 2.0% (P < .001) in control subjects and by 0.9 ± 1.8% and 0.9 ± 1.9% (P < .001) in patients with cardiac disease. STE and CMR-FT GCS increased by 2.0 ± 2.2% and 1.8 ± 2.3% (P < .001) in control subjects and by 1.8 ± 2.3% and 1.7 ± 3.6% in patients with cardiac disease (P < .001 and P = .03). STE longitudinal strain correlated strongly with corresponding CMR-FT longitudinal strain (GLS, epicardial GLS, and endocardial GLS: r = 0.81, r = 0.82, and r = 0.81, respectively) despite poor intermodal agreement (bias ± limits of agreement, -2.84 ± 4.06%, 0.16 ± 3.68%, and 2.33 ± 3.52%, respectively) whereas GCS, epicardial GCS, and endocardial GCS correlated weakly between the two modalities (r = 0.28, r = 0.19, and r = 0.34, respectively) and displayed poor intermodal agreement (bias ± limits of agreement, -1.33 ± 6.86%, 4.43 ± 6.49%, and -9.92 ± 8.55%, respectively). CONCLUSIONS: STE and CMR-FT longitudinal and circumferential layer-specific strain parameters are preload dependent in both control subjects and patients with cardiac disease. STE and CMR-FT longitudinal layer-specific strain parameters are strongly correlated, whereas circumferential layer-specific strain parameters are weakly correlated. STE and CMR-FT longitudinal and circumferential strain should not be used interchangeably, because of poor intermodal agreement.

Impact of surgical aortic valve replacement on global and regional longitudinal strain across four flow gradient patterns of severe aortic stenosis.

To evaluate the impact of surgical aortic valve replacement (SAVR) on global (GLS) and regional longitudinal strain (RLS) across four flow-gradient patterns of severe aortic stenosis (AS) 3 months after surgery. A total of 103 patients with severe AS (aortic valve area < 1.0 cm2) were examined by speckle tracking echocardiography the day before SAVR and at 3-months follow-up. Patients were stratified into four flow-gradient patterns by stroke volume index (>35 mL/m2 vs. ≤35 mL/m2) and mean transaortic gradients (>40 mmhg vs. ≤40 mmhg): normal-flow, high gradient (NF/HG); low-flow, high gradient (LF/HG); normal-flow, low gradient (NF/LG); low-flow, low gradient (LF/LG). Strain analysis comprised GLS and RLS at a basal (BLS), mid-ventricular (MLS) and apical level (ALS). Patients with high gradients improved GLS (NF/HG: 16.1 ± 3.5 % vs. 17.3 ± 3.4 %, p = 0.03 and LF/HG: 15.4 ± 3.6 % vs. 16.9 ± 3.1 %, p = 0.03), BLS (NF/HG: 12.7 ± 3.1 % vs. 14.2 ± 3.1 %, p = 0.003 and LF/HG: 11.4 ± 3.2 % vs. 13.8 ± 2.7 %, p = 0.005) and MLS (NF/HG: 15.4 ± 3.3 % vs. 16.5 ± 3.3 %, p = 0.04 and LF/HG: 14.5 ± 3.1 % vs. 16.2 ± 2.7 %, p = 0.01) whereas patients with low gradients showed no improvements three months after SAVR. ALS did not change significantly in any group. Patients with high gradients demonstrated a reduction in left ventricular (LV) mass index (p < 0.001) and N-terminal pro-Brain Natriuretic Peptide levels (p < 0.001) following SAVR in contrast to patients with low gradients. Patients with high gradient severe AS improve GLS and RLS three months after SAVR with concomitant reduction of LV mass and neurohormonal activation whereas patients with low gradients do not improve longitudinal strain, LV mass or neurohormonal activation.

Layer-specific longitudinal strain detects transmural dysfunction in chronic severe aortic regurgitation before and after aortic valve surgery.

To assess if layer-specific longitudinal strain (LS) provides incremental diagnostic and prognostic value compared to global longitudinal strain (GLS) in patients with chronic severe aortic regurgitation (AR) scheduled for aortic valve surgery. Forty-one patients were examined with speckle tracking echocardiography before surgery along with 15 healthy age-matched controls. Paired strain analyses before and after surgery were available in 31 patients. Layer-specific LS analysis enabled assessment of epicardial GLS (GLSepi), endocardial GLS (GLSendo), and conventional GLS. Strain parameters were indexed to end-diastolic volume (EDV; GLS/EDV) to account for increased preload. The prognostic value of layer-specific LS was evaluated using the primary outcome of persistent LV dilatation (LVEDV ≥ 175 mL) three months after surgery. Absolute (GLS, GLSepi, GLSendo) and EDV-indexed layer-specific LS (GLS/EDV, GLSepi/EDV, GLSendo/EDV) were impaired in severe AR compared to controls at baseline (GLS:17.0 ± 3.2 vs. 20.6 ± 2.0; GLSepi:14.6 ± 2.8 vs. 18.1 ± 1.9; GLSendo:20.2 ± 3.7 vs. 23.8 ± 2.2%; GLS/EDV:0.09 ± 0.05 vs. 0.21 ± 0.05; GLSepi/EDV:0.08 ± 0.04 vs. 0.18 ± 0.04; GLSendo/EDV:0.11 ± 0.06 vs. 0.24 ± 0.05%/mL; all p < 0.001). In severe AR, GLS, GLSepi and GLSendo decreased after surgery whereas GLS/EDV, GLSepi/EDV and GLSendo/EDV increased (all p < 0.001). Impaired absolute and EDV-indexed layer-specific LS were all associated with the primary outcome (all p ≤ 0.01). Area under the curve analysis revealed similar prognostic value of GLSepi, GLSendo and GLS (GLS:0.86; GLSepi:0.87; GLSendo:0.86; p = n.s.). EDV-indexed LS did not improve the predictive value significantly (GLS/EDV:0.93; GLSepi/EDV: 0.93; GLSendo/EDV:0.92; p = n.s.). Layer-specific LS detects transmural dysfunction in chronic severe AR and predicts persistent LV dilation after surgery. Layer-specific LS or EDV-indexed LS does not provide incremental prognostic value compared to conventional GLS.