Monitoring the response to treatment of acute heart failure patients by ultrasonographic inferior vena cava collapsibility index

Inferior vena cava diameter and risk of acute decompensated heart failure rehospitalisations

OBJECTIVES

Inferior vena cava (IVC) diameter may be a surrogate for volume status in acute decompensated heart failure (ADHF). The utility of IVC diameter measurement is under studied. The aim of this study was to assess the relationship between IVC diameter, clinical variables and ADHF rehospitalisations.

METHODS

Retrospective chart review of 200 patients admitted for ADHF from 2018 to 2019 with transthoracic echocardiogram during index hospitalisation. Charts were assessed for ADHF rehospitalisation within 1 year.

RESULTS

The median age was 64, 30.5% were female, and average left ventricular ejection fraction was 41%±20%. IVC diameter correlated to pulmonary arterial (PA) pressure (R=0.347, p<0.001) and body surface area (BSA) (R=0.424 p<0.001). IVC diameter corrected for BSA correlated to PA pressure (R=0.287, p<0.001) and log N-terminal B-type natriuretic peptide (NT-proBNP) (R=0.247, p≤0.01). Patients rehospitalised within 1 year had significantly greater mean IVC diameter compared with those not rehospitalised (p<0.001) while there was no difference in mean net weight lost during index hospitalisation or mean log NT-proBNP. Patients with IVC diameter greater than 2.07 cm had significantly increased ADHF rehospitalisation (85.6% vs 49.3%, log rank p<0.001) with HR 2.44 (95% CI 1.85 to 3.23, p<0.001). In multivariable Cox regression only IVC diameter (p<0.001), presence of tricuspid regurgitation (p=0.02) and NYHA class III/IV (p<0.001) independently predicted ADHF rehospitalisation within 1 year.

CONCLUSIONS

IVC diameter is predictive of rehospitalisation in patients with ADHF and may identify patients in need of greater monitoring and diuresis.

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.

Monitoring patients with acute dyspnea with serial point-of-care ultrasound of the inferior vena cava (IVC) and the lungs (LUS): a systematic review

PURPOSE

The primary aim was to investigate if treatment guided by serial ultrasound of the inferior vena cava-collapsibility index (IVC-CI) and B-lines on lung ultrasound (LUS) could reduce mortality, readmissions, and length of stay (LOS) in acutely dyspneic patients admitted to a hospital, compared to standard monitoring. The secondary aim was to determine how the changes of B-lines and IVC-CI are correlated to vitals and symptoms.

METHODS

A systematic search was conducted on PubMed, Embase, Cochrane, Google Scholar, Web of Science, Scopus, OpenGrey, ProQuest, and databases for ongoing trials. The risk of bias was assessed according to study design.

RESULTS

Of the 8258 studies identified, 50 were selected for full-text screening, and 24 studies were chosen for data extraction (19 pre-post-, two non-randomized controlled-, two randomized controlled-, and one retrospective cohort study), covering 2040 patients. Most studies were single-center and had small study populations with only heart failure patients. The risk of bias was high. No studies evaluated how the difference between two ultrasound measurements correlated with the primary outcomes. Seven studies reported that a decline in either B-lines or IVC size, or an increased IVC-CI reduced mortality, readmissions, and LOS when correlated to a single ultrasound measurement. All studies showed changes in the IVC-CI and B-lines, but these were not related to vitals or symptoms.

CONCLUSION

B-lines and IVC-CI are dynamic variables that change over time and with treatment. A single ultrasound measurement can influence prognostic outcomes, but it remains uncertain if repeated scans can have the same impact.

Inferior vena cava ultrasonography in the assessment of intravascular volume status and fluid responsiveness in the emergency department and intensive care unit: A critical analysis review

Rapid evaluation of intravascular volume status is vital; either excessive or limited fluid administration may result in adverse patient outcomes. In this narrative review, critical analysis of pertinent diagnostic accuracy studies is developed to delineate the role of inferior vena cava ultrasound measurements in the assessment of both intravascular volume status and fluid responsiveness in the emergency department and intensive care unit. In addition, limitations, and technical considerations of inferior vena cava ultrasound measurements as well as directions for future research are thoroughly discussed.

Preoperative assessment of inferior vena cava collapsibility index by ultrasound is not a reliable predictor of post-spinal anesthesia hypotension

BACKGROUND

Post-spinal anesthesia hypotension is of common occurrence, and it hampers tissue perfusion. Several preoperative factors determine patient susceptibility to hypotension. This study aimed to assess the effectiveness of the Inferior Vena Cava Collapsibility Index (IVCCI) for predicting intraoperative hypotension.

METHODS

One hundred twenty-nine adult patients who were scheduled for elective surgical procedures after administration of spinal (intrathecal) anesthesia were included in the study. Ultrasound evaluation of the Inferior Vena Cava (IVC) was done in the preoperative area, and the patients were shifted to the Operating Room (OR) for spinal anesthesia. An independent observer recorded the change in blood pressure after spinal anesthesia inside the OR.

RESULTS

Twenty-five patients developed hypotension (19.37%). Baseline systolic blood pressure and mean blood pressures were statistically higher in those patients who developed hypotension (p = 0.001). The logistic regression analysis for IVCCI and the incidence of hypotension showed r² of 0.025. Receiver Operating Characteristic (ROC) curve analysis demonstrated the Area Under the Curve (AUC) of 0.467 (95% Confidence Interval, 0.338 to 0.597; p = 0.615).

CONCLUSIONS

Preoperative evaluation of IVCCI is not a good predictor for the occurrence of hypotension after spinal anesthesia.

Estimation of the plasma volume status of elderly patients with acute decompensated heart failure using bedside clinical, biological, and ultrasound parameters

OBJECTIVE

Assessment of intravascular volume status to ensure optimization before hospital discharge could significantly reduce readmissions. It is difficult to evaluate congestion on clinical signs during an episode of acute heart failure (ADHF) in elderly patients.

HYPOTHESIS

There is an association between various volume overload parameters in patients older than 75 years.

METHODS

We performed a single-center prospective longitudinal study of patients older than 75 years hospitalized for acute heart failure. We analyzed the association between congestion assessment based on clinical signs, inferior vena cava (IVC) diameter measured by ultrasound, biological evaluation with N terminal pro brain natriuretic peptide (NT-proBNP), and estimated plasma volume (EPV) during decongestive therapy. We also monitored changes in renal function.

RESULTS

Fifty consecutive ADHF patients (85.2 ± 5.9 years, 68% female) were included in the study. At admission, a dilated, noncompliant IVC was found in all patients. The strongest correlations between different parameters of volume overload estimation were found between IVC and jugular vein distention (r = .8; p < .001), then IVC and oedema (r = .6; p < .001), IVC and crackles (r = .3; p < .036), then IVC and NT-proBNP (r = .3; p = .02). There was no correlation between EPV and signs of congestion. Patients who had no congestive signs on clinical or IVC examination at Day 2, more often presented with acute renal failure.

CONCLUSION

In ADHF patients older than 75 years, clinical and IVC evaluation of intravascular congestion correlate well. The concomitant assessment of clinical signs and IVC may prevent depletion-related renal failure.

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.

Can Inferior Vena Cava Diameter and Collapsibility Index Be a Predictor in Detecting Preoperative Intravascular Volume Change in Pediatric Patients?

Background: Inferior vena cava (IVC) ultrasound measurement is a reliable indicator used in the assessment of intravascular volume status. The aim of this study was to evaluate intravascular volume changes in pediatric patients by measuring the IVC diameter and collapsibility index (CI) in children whose oral feeding was restricted preoperatively. Material and Methods: From May 2018 to October 2018, a total of 55 pediatric patients who were scheduled for surgery were included in this prospective, observational, cohort study. Fasting and satiety IVC diameters and CIs of patients were determined by ultrasonographic evaluation twice: in the preoperative preliminary evaluation, when the patients were satiated, and before surgery, during a fasting period of 6–8 hours. Ultra-sonographic data were recorded and compared between fasting and satiety periods. Results: In the grey scale (B-mode), mean IVC diameter was significantly higher when the patients were satiated, compared to the measurements made just before surgery during the fasting period. In the M-mode, the mean IVC diameter was significantly higher only during the inspiratory phase when the patients were satiated, while during the expiratory phase it was detected to be statistically similar. Mean CI was significantly higher in the immediate preoperative period, compared to the assessment made when satiated. Conclusion: Preoperative ultrasound IVC diameter and CI measurement can be a practical and useful method for evaluating preoperative intravascular volume in children.

Role of Pocket Ultrasound in Assessing Intravascular Volume to Guide Management in Heart Failure Patients with Renal Impairment

Introduction

Inpatient management of patients with heart failure (HF) and renal impairment is challenging. We sought to evaluate the role of pocket ultrasound (US)-guided management of this patient population.

Methods

We prospectively included patients with acute HF exacerbation and renal impairment admitted to the HF service in our University hospital from January 2017 to August 2018. We compared the outcomes of patients who received US-guided management with those who received standard of care management. The main study outcome was the change in estimated glomerular filtration rate (eGFR). Multivariable logistic analysis was used to adjust for basic demographics and risk factors.

Results

A total of 211 patients with renal impairment presenting with acute HF exacerbation (mean age 66.8 ± 14.6 years, 41% females, 62% white) were enrolled in the study, of whom 69 (32.7%) received US-guided management and 151 (68%) received standard of care management. The change in the eGFR was significantly lower in US-guided group than in the group receiving standard of care (1.1 ± 4.3% vs. − 11.15 ± 2.9%; p = 0.04). No significant difference was observed between the patient groups in the length of stay (6.45 ± 0.38 vs. 6.44 ± 0.56; days; p = 0.98) and in the 30-day HF readmission rate (hazard ratio 1.27, 95% confidence interval 0.28–5.6; p = 0.75).

Conclusion

Ultrasound-guided management of patients admitted with acute HF exacerbation and renal impairment may be beneficial in preserving kidney function. US provides a simple easily accessible tool to guide the management of patients with HF.

The value of the inferior vena cava ultrasound in the decision to hospitalise in patients with acute decompensated heart failure; the best sonographic measurement method?

OBJECTIVES

The primary aim of this study was to determine the value of the inferior vena cava (IVC) ultrasound in the decision to hospitalise acute decompensated heart failure (ADHF) patients. Our secondary aim was to find the most successful IVC measurement method in monitoring volume status.

METHODS

ADHF patients were accepted over a 1-year period in this study. Patients' vital signs, laboratory tests and IVC measurements measured by six methods (in B- and M-mode; maximum, minimum diameter and caval index) performed on an hourly basis were recorded. The presence of any statistically significant difference between the IVC measurement methods, laboratory tests and vital parameters between the hospitalised and discharged patients was calculated. ROC curves were produced in order to determine the ability of parameters to differentiate two groups. Spearman's correlation test was used to investigate correlation between the IVC measurement methods and patients' urine outputs.

RESULTS

A total of 71 patients were included in the study; 42 of these were hospitalised and 29 were discharged. Potassium, brain natriuretic peptide, respiration rate, urine output, maximum and minimum IVC diameters differed significantly between the two groups. Minimum IVC diameter measured in M-mode was identified as a weak marker with 65% sensitivity and 64% specificity (+PPV: 73%; -NPV:54%) for hospitalisation. Change in maximum IVC diameter measured in B-mode exhibited a high degree of correlation with change in body fluid (cc: 0.802).

CONCLUSION

IVC ultrasound may have a limited value in the decision to hospitalise ADHF patients. But Maximum IVC diameter may be an ideal method for monitoring hypervolemic patients' volume status.

CLINICAL TRIALS IDENTIFIER

NCT02725151.

Lung Ultrasound: A "Biomarker" for Fluid Overload?

Fluid overload is associated with poor outcomes in patients with acute kidney injury as well as end-stage kidney disease. Lung ultrasound (LUS) has been used in many different settings and specialties including the emergency department, intensive care unit, trauma, cardiology, and nephrology. Although LUS has been a valuable tool in assessing pulmonary congestion, LUS findings may not always be pathognomonic for pulmonary congestion. Furthermore, the feasibility of doing an extensive LUS examination as has been done in research studies may be hard to implement within the clinical setting. This review will go over the use of LUS to evaluate for fluid overload, compare LUS with other markers of fluid overload, review limitations of LUS, and suggest potential future directions in the use of LUS in nephrology.

Differences in pharmacological property between combined therapy of the vasopressin V2-receptor antagonist tolvaptan plus furosemide and monotherapy of furosemide in patients with hospitalized heart failure

BACKGROUND

Tolvaptan has been shown to improve congestion in heart failure patients. The purpose of this study was to evaluate the pharmacology and clinical efficacy of combined tolvaptan and furosemide therapy.

METHODS

This study included 40 patients with systemic volume overload who were hospitalized for heart failure. Patients who showed no improvement in the condition after receiving 20 mg intravenous furosemide were included and were randomly selected to receive tolvaptan as an add-on to furosemide or to receive an increased dose of furosemide. We evaluated the bioelectrical impedance analyzer parameters, the parameters of the inferior vena cava using echocardiography, vital signs, body weight, urine output, and laboratory data for 5 days.

RESULTS

In the changes from baseline between intracellular water volume (ICW) and extracellular water volume (ECW) after additional use of tolvaptan or furosemide from Day 1 to Day 5, there were no significant differences observed between ICW and ECW over 5 days in the tolvaptan + furosemide group, although differences were found in the furosemide group from Day 2 onward. Changes in the respiratory collapse of inferior vena cava increased significantly, and systolic blood pressure decreased significantly only in the furosemide group.

CONCLUSIONS

The present study clearly demonstrates that combined therapy with tolvaptan and furosemide removed excess ICW and ECW to an equal extent, while furosemide alone primarily removed ECW, including intravascular water.

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.

Utilization of Ultrasound to Assess Volume Status in Heart Failure

Heart failure (HF) represents a significant financial burden to the US health care system, affecting approximately 5.7 million Americans. By 2030, the prevalence of HF is expected to increase by 23%. Clinicians generally evaluate volume status in patients with HF by visualizing jugular venous distension to estimate right atrial pressure; a method with an estimated accuracy of only 50%. Currently, the only endorsed methods for acute HF diagnosis in the 2017 American College of Cardiology (ACC) guidelines are brain natriuretic peptide (BNP) or N-terminal pro-B-type natriuretic peptide (NT-proBNP), pre-discharge BNP or NT-proBNP, and myocardial fibrosis markers. However, serial testing of BNP to monitor therapy remains controversial. Moreover, an elevated BNP cannot be attributed solely to a cardiac cause. Given the limitations of the current methods, a robust tool is needed to reliably assess volume status in HF patients. It is now known that hemodynamic congestion from increases in intracardiac pressure occurs days to weeks prior to the onset of typical HF symptoms, such as weight gain and shortness of breath. It has been postulated that assessing the inferior vena cava (IVC) diameter with a portable ultrasound, may be the simple, reliable, and cost-effective method of evaluating right atrial pressure, and thus, the severity of HF. Given this exciting new tool in assessing volume status in patients with HF, we pose the question of whether this imaging modality can be used to risk-stratify patients and guide management. The aim of this paper is to highlight the many benefits of portable ultrasound in assessing volume status in this population, and to discuss whether this imaging modality can help guide physicians in the management of their HF patients.

A Five-Step Vascular Ultrasound Examination in Heart Failure: The First Two Years of the "ABCDE" G-SIUMB Multicenter Study 2018-2022

The aim of this study is the creation of a 5-step ultrasound examination to evaluate and monitor Heart Failure (HF) patients during hospitalization and follow-up. "ABCDE" is the acronym of an Italian multicentre study composed of a consecutive sample of HF patients admitted from the Emergency to the Internal Medicine/Geriatric Departments of several Italian hospitals. The "ABCDE" score includes the evaluations of A, the Ankle-brachial index (ABI), B, the B-lines, C, the Carotid intima media thickness (CIMT), D, the Diameter of the abdominal aorta and of the inferior cave vein and E, the echocardiographic assessment of the ejection fraction. This paper reports the preliminary results. Up to now, the "ABCDE" multicenter study seems an exciting opportunity to create an integrative ultrasound approach in HF. The definitive confirmation of these preliminary results and the effective usefulness of the "ABCDE" will be available in 2022, at the end of the study.

Clinical correlates of hand-held ultrasound-guided assessments of the inferior vena cava in patients with acute decompensated heart failure

BACKGROUND

Accurately assessing volume status in acutely decompensated heart failure (ADHF) can be challenging. Inferior vena cava (IVC) dynamics by echocardiography allow indirect assessment of volume status in these patients. Recently introduced hand-held ultrasound devices are promising. We aimed to describe the clinical correlates of volume status assessment using a hand-held ultrasound device in ADHF.

METHODS

In this prospective study, we evaluated 106 patients admitted with ADHF. First scan was performed within 24 hours of admission and timed in reference to first dose of intravenous diuretic. Daily resting and inspiratory (sniff) IVC diameters were measured according to standard echocardiography methods during hospitalization including the day of discharge. IVC collapsibility index (IVC-CI = Maximum IVC diameter-Inspiratory IVC diameter/maximum diameter; <0.5 representing hypervolemia) was calculated. Primary study endpoint was 30-day readmission. Research activities were independent of clinical decision-making.

RESULTS

Data for 106 patients was analyzed. Mean age was 66.7 ± 13.8 years, of which 53.8% were females, and a mean ejection fraction was 39 ± 18%. Initial scan of the IVC was obtained at an average time of 5.2 ± 8.04 hours from first diuretic dose. 81.2% of patients at admission had an IVC-CI <0.5. 63.2% patients had an IVC-CI <0.5 at discharge. There were no significant differences in age, length of stay, diuretic dose, or 30-day readmissions between patients with a discharge IVC-CI <0.5 vs ≥ 0.5.

CONCLUSION

Hand-held ultrasound assessment of IVC-CI in ADHF patients, although a feasible concept, is unable to predict 30-day readmissions in our study. Further prospective studies are necessary.

Effectiveness of serial focused ultrasound of the lungs and inferior vena cava for monitoring patients with acute dyspnea: a systematic review protocol

OBJECTIVE

The objective of this review is to evaluate the effectiveness of serial focused ultrasound of the lungs (FLUS) and/or inferior vena cava (IVC) compared to standard care for monitoring patients with acute dyspnea.

INTRODUCTION

Acute dyspnea is one of the most common complaints reported by patients in hospital emergency departments, and has high in-hospital mortality rates. The current methods of monitoring patients with acute dyspnea lack both sensitivity and specificity. Point-of-care FLUS and IVC is a promising monitoring tool, but an overview of the existing evidence is absent.

INCLUSION CRITERIA

This review will include studies of adult patients admitted to hospital with acute dyspnea that is examined via FLUS, IVC or both a minimum of twice during hospitalization compared to standard care.

METHODS

The following electronic databases will be searched: PubMed, Cochrane, Embase, Scopus, Web of Science and Google Scholar. Gray literature will be sought in OpenGrey and ProQuest. The search is limited to articles written in English, Danish, Swedish, Norwegian and German. Articles published before 2003 will be excluded from the search and duplicates will be removed. Two independent reviewers will screen and critically appraise the included studies and perform the data extraction. If possible, data will be synthesized with statistical meta-analysis; otherwise, data will be presented in narrative form.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42018116608.

Comparison between inferior vena cava ultrasound, lung ultrasound, bioelectric impedance analysis, and natriuretic peptides in chronic heart failure

BACKGROUND

Heart failure (HF) is an important healthcare problem. Knowing volume status in outpatients with chronic HF to adjust treatment and to avoid decompensations is a challenge. The aim of this study is comparing the usefulness of inferior vena cava (IVC) ultrasound, lung ultrasound, bioelectrical impedance analysis (BIA), and natriuretic peptides in the follow-up of outpatients with chronic HF.

METHODS

This was a prospective cohort study. Ninety-nine patients with chronic HF were included consecutively as they attended scheduled medical visits. The different techniques were performed on the day of the clinic visit, and the result was hidden from the patients and the responsible medical team. Follow-up time was 1 year. Outcome events checked were a combination of death or hospitalization, due to HF.

RESULTS

Thirty-six patients (36.4%) died or were hospitalized for HF. They had a significantly lower IVC collapse, and a greater number of lung B-lines and higher NTproBNP levels compared to patients who remained stable. There were no differences in the BIA parameters. After multivariable analysis, cut-off points of IVC collapse <30%, number of pulmonary B lines greater than 5, and NTproBNP levels greater than 2000 pg/ml were associated with increased risk of HF death or admission. NTproBNP had the best area under the curve.

CONCLUSION

Evaluation of congestion in outpatients with chronic HF may be based on NTproBNP, IVC ultrasound, or lung ultrasound; they are useful in identifying patients at high risk of hospitalization or death due to HF.

Relationship of inferior vena cava collapsibility to ultrafiltration volume achieved in critically ill hemodialysis patients

Background

Ultrasound (US) assessment of intravascular volume may improve volume management of dialysis patients. We investigated the relationship of intravascular volume evaluated by inferior vena cava (IVC) US to net volume changes with intermittent hemodialysis (HD) in critically ill patients.

Methods

A retrospective cohort of 113 intensive care unit patients in 244 encounters had clinical assessment of intravascular volume followed by US of respiratory/ventilatory variation of IVC diameter, and had HD within 24 h. IVC collapsibility index (IVC CI)=(IVCmax–IVCmin)/IVCmax*100%. Volume management was guided by clinical data plus IVC US findings. Intradialytic hypotension (IDH) was categorized by severity from none to inability to tolerate HD.

Results

Linear regression correlating n-weighted proportions of encounters achieving net volume removal of ≥0.5 L, ≥1.0 L, ≥1.5 L, and ≥2.0 L strongly correlated across the range of IVC CI (R²=0.87–0.64). Sensitivity and specificity analysis showed IVC CI was a better predictor than IVCmax of achieving net ultrafiltration (UF) volumes. Mean central venous pressure, pulmonary artery occlusion pressure, and cardiac output were poor predictors by logistic regression and receiver operating curve analyses. IVC CI <20% was the approximate optimal cutoff for achieving ≥0.5 L to ≥2.0 L net UF volumes. Net volume change achieved tended to be less than recommended and may have been limited by the development of IDH. Severity of IDH did not correlate with UF rate in mL/kg/h. χ² analysis showed pre-US clinical intravascular volume assessments had poor concordance with IVC CI categories.

Conclusion

IVC US may be a useful tool for predicting whether critically ill patients will achieve volume removal with HD.

Results of ACCORDIAN in ACCORD with lower blood pressure begetting lower mortality in patients with diabetes

Acute decompensated heart failure (ADHF) is a common reason for admission to the hospital, and readmission is frequent. Multiple factors contribute to rehospitalizations, but inadequate assessment of volume status leading to persistent congestion is an important factor. We sought to determine if focused cardiac ultrasound (FCU) of the inferior vena cava (IVC), as a surrogate of volume status, would predict readmission of ADHF patients after index hospitalization. Patients admitted with a primary diagnosis of ADHF were prospectively enrolled. All patients underwent FCU of the IVC on admission and then daily. 82 patients were enrolled. Patients demonstrated improvement in heart failure physical examination findings and symptoms during the hospitalization. There was a reduction in the size of the IVC and a significant increase in patients with small collapsible vena cava. Logistic regression analysis of physical examination, patient symptoms, and IVC parameters at discharge demonstrated IVC collapsibility and patient reported dyspnea improvement as the only significant variables to predict readmission or emergency department visit. FCU assessment of IVC size and collapsibility may be useful in patients with ADHF to predict risk of being readmitted within 30 days of hospital discharge.

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.

Focused cardiac ultrasound as a predictor of readmission in acute decompensated heart failure

Acute decompensated heart failure (ADHF) is a common reason for admission to the hospital, and readmission is frequent. Multiple factors contribute to rehospitalizations, but inadequate assessment of volume status leading to persistent congestion is an important factor. We sought to determine if focused cardiac ultrasound (FCU) of the inferior vena cava (IVC), as a surrogate of volume status, would predict readmission of ADHF patients after index hospitalization. Patients admitted with a primary diagnosis of ADHF were prospectively enrolled. All patients underwent FCU of the IVC on admission and then daily. 82 patients were enrolled. Patients demonstrated improvement in heart failure physical examination findings and symptoms during the hospitalization. There was a reduction in the size of the IVC and a significant increase in patients with small collapsible vena cava. Logistic regression analysis of physical examination, patient symptoms, and IVC parameters at discharge demonstrated IVC collapsibility and patient reported dyspnea improvement as the only significant variables to predict readmission or emergency department visit. FCU assessment of IVC size and collapsibility may be useful in patients with ADHF to predict risk of being readmitted within 30 days of hospital discharge.

Dynamic Limb Bioimpedance and Inferior Vena Cava Ultrasound in Patients Undergoing Hemodialysis

Assessment of volume status in critically ill patients poses a challenge to clinicians. Measuring changes in the inferior vena cava (IVC) diameter using ultrasound is becoming a standard tool to assess volume status. Ultrasound requires physicians with significant training and specialized expensive equipment. It would be of significant value to be able to obtain this measurement continuously without physician presence. We hypothesize that dynamic changes in limb's bioimpedance in response to respiration could be used to predict changes in IVC. Forty-six subjects were tested a hemodialysis session. Impedance was measured via electrodes placed on the arm. Simultaneously, the IVC diameter was assessed by ultrasound. Subjects were asked to breathe spontaneously and perform respiratory maneuvers using a respiratory training device. Impedance (dz) was determined and compared with change in IVC diameter (dIVC; r = 0.76, p < 0.0001). There was significant relationship between dz and dIVC (p< 0.0001). Receiver-operator curves for dz at thresholds of dIVC (20% to70%) demonstrated high predictive power with areas under the curves (0.87-0.99, p < 0.0001). This evaluation suggests that real-time dynamic changes in limb impedance are capable of tracking a wide range of dynamic dIVC. This technique might be a suitable surrogate for monitoring real-time changes in dIVC to assess intravascular volume status.

Correlation of IVC Diameter and Collapsibility Index With Central Venous Pressure in the Assessment of Intravascular Volume in Critically Ill Patients

Objective

The objective of our study is to assess the correlation between inferior vena cava (IVC) diameters, central venous pressure (CVP) and the IVC collapsibility index for estimating the volume status in critically ill patients.

Methods

This cross-sectional study used the convenient sampling of 100 adult medical intensive care unit (ICU) patients for a period of three months. Patients ≥ 18 years of age with an intrathoracic central venous catheter terminating in the distal superior vena cava connected to the transducer to produce a CVP waveform were included in the study. A Mindray diagnostic ultrasound system model Z6 ultrasound machine (Mindray, NJ, USA) was used for all examinations. An Ultrasonic Transducer model 3C5P (Mindray, NJ, USA) for IVC imaging was utilized. A paired sampled t-test was used to compute the p-values.

Results

A total of 32/100 (32%) females and 68/100 (68%) males were included in the study with a mean age of 50.4 ± 19.3 years. The mean central venous pressure maintained was 10.38 ± 4.14 cmH2O with an inferior vena cava collapsibility index of 30.68 ± 10.93. There was a statistically significant relation among the mean CVP pressure, the IVC collapsibility index, the mean maximum and minimum IVC between groups as determined by one-way analysis of variance (ANOVA) (p < 0.001). There was a strong negative correlation between CVP and IVC collapsibility index (%), which was statistically significant (r = -0.827, n = 100, p < 0.0005). A strong positive correlation between CVP and maximum IVC diameter (r = 0.371, n = 100, p < 0.0005) and minimum IVC diameter (r = 0.572, n = 100, p < 0.0005) was found.

Conclusion

There is a positive relationship of CVP with minimum and maximum IVC diameters but an inverse relationship with the IVC collapsibility index.

Pocket-sized focused cardiac ultrasound: strengths and limitations

Focused cardiac ultrasound (FCU) has emerged in recent years and has created new possibilities in the clinical assessment of patients both in and out of hospital. The increasing portability of echocardiographic devices, with some now only the size of a smartphone, has widened the spectrum of potential indications and users, from the senior cardiologist to the medical student. However, many issues still need to be addressed, especially the acknowledgment of the advantages and limitations of using such devices for FCU, and the extent of training required in this rapidly evolving field. In recent years, an increasing number of studies involving FCU have been published with variable results. This review outlines the evidence for the use of FCU with pocket-echo to address specific questions in daily clinical practice.