Usefulness of inferior vena cava ultrasonography in outpatients with chronic heart failure

Point of Care Ultrasound (POCUS) in the Management of Heart Failure: A Narrative Review

Assessing for volume overload is a key component of both short and long-term management of heart failure patients. Physical examination findings are neither sensitive nor specific for detecting congestion, and subclinical congestion may not be evident at the time of examination. Point of care ultrasound (POCUS) is an efficient and non-invasive way to assess heart failure patients for volume overload. The aim of our narrative review is to summarize how each of the following ultrasound modalities can be used to assess for congestion in the heart failure population: 2D and Doppler echocardiography, lung ultrasound, inferior vena cava ultrasound, internal jugular vein ultrasound, and venous excess grading. While each of these modalities has their limitations, their use in the acute and outpatient space offers the potential to reduce heart failure readmissions and mortality.

Heart Failure with Reduced Ejection Fraction: The Role of Cardiovascular and Lung Ultrasound beyond Ejection Fraction

Heart failure with reduced ejection fraction (HFrEF) is considered a major health care problem with frequent decompensations, high hospitalization and mortality rates. In severe heart failure (HF), the symptoms are refractory to medical treatment and require advanced therapeutic strategies. Early recognition of HF sub- and decompensation is the cornerstone of the timely treatment intensification and, therefore, improvement in the prognosis. Echocardiography is the gold standard for the assessment of systolic and diastolic functions. It allows one to obtain accurate and non-invasive measurements of the ventricular function in HF. In severely compromised HF patients, advanced cardiovascular ultrasound modalities may provide a better assessment of intracardiac hemodynamic changes and subclinical congestion. Particularly, cardiovascular and lung ultrasound allow us to make a more accurate diagnosis of subclinical congestion in HFrEF. The aim of this review was to summarize the advantages and limitations of the currently available ultrasound modalities in the ambulatory monitoring of patients with HFrEF.

Artificial Intelligence (AI) versus POCUS Expert: A Validation Study of Three Automatic AI-Based, Real-Time, Hemodynamic Echocardiographic Assessment Tools

BACKGROUND

Point Of Care Ultra-Sound (POCUS) is an operator dependent modality. POCUS examinations usually include 'Eyeballing' the inspected anatomical structure without conducting accurate measurements due to complexity and insufficient time. Automatic real time measuring tools can make accurate measurements fast and simple and dramatically increase examination reliability while saving the operator much time and effort. In this study we aim to assess three automatic tools which are integrated into the Venue™ device by GE: the automatic ejection fraction, velocity time integral, and inferior vena cava tools in comparison to the gold standard-an examination by a POCUS expert.

METHODS

A separate study was conducted for each of the three automatic tools. In each study, cardiac views were acquired by a POCUS expert. Relevant measurements were taken by both an auto tool and a POCUS expert who was blinded to the auto tool's measurement. The agreement between the POCUS expert and the auto tool was measured for both the measurements and the image quality using a Cohen's Kappa test.

RESULTS

All three tools have shown good agreement with the POCUS expert for high quality views: auto LVEF (0.498; p < 0.001), auto IVC (0.536; p = 0.009), and the auto VTI (0.655; p = 0.024). Auto VTI has also shown a good agreement for medium quality clips (0.914; p < 0.001). Image quality agreement was significant for the auto EF and auto IVC tools.

CONCLUSIONS

The Venue™ show a high agreement with a POCUS expert for high quality views. This shows that auto tools can provide reliable real time assistance in performing accurate measurements, but do not reduce the need of a good image acquisition technique.

High Inferior Vena Cava Diameter with High Left Ventricular End Systolic Diameter as a Risk Factor for Major Adverse Cardiovascular Events, Cardiovascular and Overall Mortality among Chronic Hemodialysis Patients

Background: Little is known about the association of inferior vena cava diameter (IVCD) and left ventricular end-systolic diameter (LVESD) with mortality in patients undergoing hemodialysis (HD). Methods: The single medical center observational cohort study enrolled 241 adult chronic HD patients from 1 October 2018 to 31 December 2018. Echocardiography results of IVCD and LVESD prior to dialysis were retrieved and patients were divided into high IVCD and low IVCD groups. Patients who received HD via a tunneled cuffed catheter were excluded. Study outcomes included all-cause mortality, cardiovascular mortality, and major adverse cardiovascular events (MACE). Subgroup analyses of HD patients with high and low LVESD were also performed. Results: The incidence of all-cause mortality, cardiovascular mortality, and MACE were higher in chronic HD patients with high IVCD (p < 0.01). High IVCD patients had significantly greater all-cause mortality, cardiovascular mortality, and MACE (log-rank test; p < 0.05). High IVCD patients are also associated with an increased risk of all-cause mortality and MACE relative to low IVCD patients (aHRs, 2.88 and 3.42; 95% CIs, 1.06−7.86 and 1.73−6.77, respectively; all p < 0.05). In the subgroup analysis of patients with high or low LVESD, the high IVCD remained a significant risk factor for all-cause mortality and MACE, and the HR is especially high in the high LVESD group. Conclusions: Dilated IVCD is a risk factor for all-cause mortality and MACE in chronic HD patients. In addition, these patients with high LVESD also have a significantly higher HR of all-cause mortality and MACE.

Inferior Vena Cava Edge Tracking Echocardiography: A Promising Tool with Applications in Multiple Clinical Settings

Ultrasound (US)-based measurements of the inferior vena cava (IVC) diameter are widely used to estimate right atrial pressure (RAP) in a variety of clinical settings. However, the correlation with invasively measured RAP along with the reproducibility of US-based IVC measurements is modest at best. In the present manuscript, we discuss the limitations of the current technique to estimate RAP through IVC US assessment and present a new promising tool developed by our research group, the automated IVC edge-to-edge tracking system, which has the potential to improve RAP assessment by transforming the current categorical classification (low, normal, high RAP) in a continuous and precise RAP estimation technique. Finally, we critically evaluate all the clinical settings in which this new tool could improve current practice.

Prognostic Role of Subclinical Congestion in Heart Failure Outpatients: Focus on Right Ventricular Dysfunction

BACKGROUND

subclinical pulmonary and peripheral congestion is an emerging concept in heart failure, correlated with a worse prognosis. Very few studies have evaluated its prognostic impact in an outpatient setting and its relationship with right-ventricular dysfunction. The study aims to investigate subclinical congestion in chronic heart failure outpatients, exploring the close relationship between the right heart-pulmonary unit and peripheral congestion.

MATERIALS AND METHODS

in this observational study, 104 chronic HF outpatients were enrolled. The degree of congestion and signs of elevated filling pressures of the right ventricle were evaluated by physical examination and a transthoracic ultrasound to define multiparametric right ventricular dysfunction, estimate the right atrial pressure and the pulmonary artery systolic pressure. Outcome data were obtained by scheduled visits and phone calls.

RESULTS

ultrasound signs of congestion were found in 26% of patients and, among this cohort, half of them presented as subclinical, affecting their prognosis, revealing a linear correlation between right ventricular/arterial coupling, the right-chambers size and ultrasound congestion. Right ventricular dysfunction, TAPSE/PAPS ratio, clinical and ultrasound signs of congestion have been confirmed to be useful predictors of outcome.

CONCLUSIONS

subclinical congestion is widespread in the heart failure outpatient population, significantly affecting prognosis, especially when right ventricular dysfunction also occurs, suggesting a strict correlation between the heart-pulmonary unit and volume overload.

Point-of-care ultrasound (POCUS) for hospitalists and general internists

Point-of-care ultrasound (POCUS) is currently implemented in various medical fields by clinicians for the bedside examination of patients. Evidence supports the fact that adding an ultrasound technology in daily practice (hand-held ultrasound device), called by some 'stethoscope of the future', improves patient care and allows an earlier diagnosis in a hospital setting. In this article, we reviewed the historical evolution of the use of ultrasound in medicine and the possibilities of using POCUS for hospitalists and general internists based on the existing scientific literature.

Multiparametric vs. Inferior Vena Cava-Based Estimation of Right Atrial Pressure

Background: Right atrial pressure (RAP) can be estimated by echocardiography from inferior vena cava diameter and collapsibility (eRAP_IVC), tricuspid E/e' ratio ( eRAP E / e ' ), or hepatic vein flow (eRAP_HV). The mean of these estimates (eRAP_mean) might be more accurate than single assessments. Methods and Results: eRAP_IVC, eRAP E / e ' , eRAP_HV (categorized in 5, 10, 15, or 20 mmHg), eRAP_mean (continuous values) and invasive RAP (iRAP) were obtained in 43 consecutive patients undergoing right heart catheterization [median age 69 (58-75) years, 49% males]. There was a positive correlation between eRAP_mean and iRAP (Spearman test r = 0.66, P < 0.001), with Bland-Altman test showing the best agreement for values <10 mmHg. There was also a trend for decreased concordance between eRAP_IVC, eRAP E / e ' , eRAP_HV, and iRAP across the 5- to 20-mmHg categories, and iRAP was significantly different from eRAP E / e ' and eRAP_HV for the 20-mmHg category (Wilcoxon signed-rank test P = 0.02 and P < 0.001, respectively). The areas under the curve in predicting iRAP were nonsignificantly better for eRAP_mean than for eRAP_IVC at both 5-mmHg [0.64, 95% confidence interval (CI) 0.49-0.80 vs. 0.70, 95% CI 0.53-0.87; Wald test P = 0.41] and 10-mmHg (0.76, 95% CI 0.60-0.92 vs. 0.81, 95% CI 0.67-0.96; P = 0.43) thresholds. Conclusions: Our data suggest that multiparametric eRAP_mean does not provide advantage over eRAP_IVC, despite being more complex and time-consuming.

Ultrasound imaging of congestion in heart failure: examinations beyond the heart

Congestion, related to pressure and/or fluid overload, plays a central role in the pathophysiology, presentation and prognosis of heart failure and is an important therapeutic target. While symptoms and physical signs of fluid overload are required to make a clinical diagnosis of heart failure, they lack both sensitivity and specificity, which might lead to diagnostic delay and uncertainty. Over the last decades, new ultrasound methods for the detection of elevated intracardiac pressures and/or fluid overload have been developed that are more sensitive and specific, thereby enabling earlier and more accurate diagnosis and facilitating treatment strategies. Accordingly, we considered that a state-of-the-art review of ultrasound methods for the detection and quantification of congestion was timely, including imaging of the heart, lungs (B-lines), kidneys (intrarenal venous flow), and venous system (inferior vena cava and internal jugular vein diameter).

Diagnosis of Acute Heart Failure Using Inferior Vena Cava Ultrasound: Systematic Review and Meta-analysis

OBJECTIVES

The utility of bedside inferior vena cava (IVC) ultrasound (US) in the diagnosis of heart failure (HF) is unclear. The aim of this study was to determine whether IVC parameters in patients with acute heart failure (AHF) are statistically different from those without HF.

METHODS

The MEDLINE database of English-language publications from 1966 to August 2018 was searched. Retrospective and prospective studies that included either IVC expiratory diameter (IVC_exp ) or IVC collapsibility index (IVC-CI) values were collected in patients with and without HF. to determine whether there was a statistical difference in the IVC parameters between these groups.

RESULTS

A total of 27 articles with a total of 1472 patients with AHF were included. The standard mean differences for the IVC_exp and IVC-CI for the control group versus the AHF group were found to be statistically significant (P < .0001). The combined mean IVC_exp values were 15.11 mm (95% confidence interval [CI], 14.19-16.02 mm) for the control group and 20.26 mm (95% CI, 14.82-25.71 mm) for the AHF group. The combined mean IVC-CI values were 61.6% (95% CI, 48.4%-74.7%) for the control group and 30.5% (95% CI, 26.4%-34.6%) for the AHF group.

CONCLUSIONS

Bedside IVC US showed that a statistically significant difference existed in the IVC parameters between patients with and without AHF. Based on mean calculations, an IVC_exp of greater than 2.0 cm and an IVC-CI of less than 30% are reasonable cutoffs to suggest that a patient with acute dyspnea is more likely to have AHF than a non-AHF condition. Given the high degree of heterogeneity across the studies and the high risk of bias, larger randomized studies are warranted to explore the use of IVC US in patients with HF.

Usefulness of inferior vena cava ultrasonography in outpatients with chronic heart failure

BACKGROUND

Inferior vena cava (IVC) ultrasonography has been used for the diagnosis and prognosis of acute heart failure (HF). Its usefulness in chronic HF is less known.

HYPOTHESIS

IVC ultrasonography is a useful tool in the care of patients with chronic HF.

METHODS

For this prospective cohort study, 95 patients with chronic HF were included consecutively as they attended scheduled medical visits. Ultrasound was done with a 5-MHz convex probe device, calculating IVC collapse index (IVCCI). Follow-up time was 1 year. Outcome events were worsening HF, hospital admission for HF, HF mortality, and all-cause mortality.

RESULTS

Worsening HF occurred in 70.9% of patients with IVCCI <30% and 39.1% of patients with IVCCI >50%, with a hazard ratio (HR) of 2.8 (95% CI: 1.3-6.2) adjusted by multivariable analysis. Regarding hospitalization, 45.3% of patients with IVCCI <30% required admission, compared with 5.9% of patients with IVCCI >50%; the adjusted HR was 13.9 (95% CI: 1.7-113.0). Mortality was higher in the IVCCI <30% group, with 25.7% all-cause mortality and 18.6% HF mortality, whereas in the IVCCI >50% group these values were 13% and 4.7%, respectively. However, these differences did not reach statistical significance. ROC analysis was performed and the AUC for IVCCI was not higher than that for NTproBNP for any of the outcomes studied.

CONCLUSIONS

IVC ultrasonography is a useful tool in follow-up of patients with chronic HF, allowing identification of patients at high risk of worsening and hospitalization. However, its usefulness is not higher than that of NTproBNP.