Novel method of evaluating liver stiffness using transient elastography to evaluate perioperative status in severe heart failure

Sound Touch Elastography for Noninvasive Assessment of Liver Stiffness in Patients With Chronic Heart Failure

Heart failure (HF) can damage various organs, including the liver, a phenomenon known as "cardiohepatic syndrome." The latter is characterized by liver congestion and hepatic artery hypoperfusion, which can lead to liver damage. In this study, we aimed to assess liver damage quantitatively in chronic HF (CHF) with sound touch elastography (STE). A total of 150 subjects were enrolled, including HF with reduced ejection fraction (HFrEF) groups (left ventricular ejection fraction ≤40%, n = 45), HF with mildly reduced ejection fraction (HFmrEF) groups (left ventricular ejection fraction between 41% and 49%, n = 40), and right-sided HF (RHF) groups (n = 25); normal groups (n = 40). Liver stiffness measurement (LSM) was performed in all subjects by STE. The other hepatic parameters were also measured. The LSM was 5.4 ± 1.1 kPa in normal subjects and increased slightly to 5.9 ± 0.7 kPa in patients with HFmrEF. However, the HFrEF and RHF groups had significantly higher LSMs of 8.4 ± 2.0 kPa and 10.3 ± 2.7 kPa, respectively. The LSM of HFrEF was significantly higher than that of HFmrEF, whereas the increase in LSM in patients with RHF was significant relative to HFmrEF and HFrEF. In addition, the other parameters showed abnormal values in only RHF and HFrEF. In conclusion, STE is a useful clinical technique for the noninvasive evaluation of liver stiffness associated with CHF, which could help patients with CHF manage their treatment regimens.

Transient elastography (FibroScan) in critical care: Applications and limitations

FibroScan^® is a non-invasive device that assesses the ‘hardness’ (or stiffness) of the liver via the technique of transient elastography. Because fibrous tissue is harder than normal liver, the degree of hepatic fibrosis can be inferred from the liver hardness. This technique is increasingly being employed to diagnose liver fibrosis, even in critically ill patients. It is now being used not only for diagnosis and staging of liver cirrhosis, but also for outcome prognostication. However, the presence of several confounding factors, especially in critically ill patients, may make interpretation of these results unreliable. Through this review we aim to describe the indications and pitfalls of employing FibroScan in patients admitted to intensive care units.

The Liver in Heart Failure: From Biomarkers to Clinical Risk

Heart failure (HF) is a clinical syndrome due to heart dysfunction, but in which other organs are also involved, resulting in a complex multisystemic disease, burdened with high mortality and morbidity. This article focuses on the mutual relationship between the heart and liver in HF patients. Any cause of right heart failure can cause hepatic congestion, with important prognostic significance. We have analyzed the pathophysiology underlying this double interaction. Moreover, we have explored several biomarkers and non-invasive tests (i.e., liver stiffness measurement, LSM) potentially able to provide important support in the management of this complex disease. Cardiac biomarkers have been studied extensively in cardiology as a non-invasive diagnostic and monitoring tool for HF. However, their usefulness in assessing liver congestion in HF patients is still being researched. On the other hand, several prognostic scores based on liver biomarkers in patients with HF have been proposed in recent years, recognizing the important burden that liver involvement has in HF. We also discuss the usefulness of a liver stiffness measurement (LSM), which has been recently proposed as a reliable and non-invasive method for assessing liver congestion in HF patients, with therapeutic and prognostic intentions. Lastly, the relationship between LSM and biomarkers of liver congestion is not clearly defined; more research is necessary to establish the clinical value of biomarkers in assessing liver congestion in HF patients and their relationship with LSM.

Use of liver stiffness measurements in acute decompensated heart failure: new applications of a non-invasive technique

Heart failure (HF) is a complex disease associated with multisystem organ failure, recurrent hospital admissions, and increased mortality. Acute decompensated heart failure (ADHF) increases central venous pressure (CVP) with resultant hepatic congestion, and this relationship has prognostic significance. The gold standard method of measuring CVP, right heart catheterization, is invasive and costly, prompting further investigation into more accurate non-invasive assessments in HF patients, including liver elastography. Liver elastography relies on imaging techniques to assess liver stiffness measurements (LSM), with high values equating to increased stiffness. While this was developed to assess fibrosis in liver disease, LSM also reflect increased CVP and hepatic congestion. Multiple studies involving ADHF patients, find that increased LSM are independently predictive of increased cardiac events, all-cause mortality, and worse post-operative outcome after both acute HF exacerbation and left ventricular assist device (LVAD) placement. In this review, we discuss the role of LSM as a surrogate for CVP and their applications in determining prognosis in both the ADHF and LVAD populations.

Efficacy of shear wave elasticity for predicting clinical outcomes in patients with significant tricuspid regurgitation

This study aimed to evaluate the efficacy of shear wave (SW) elasticity for assessing clinical outcomes in patients with significant tricuspid regurgitation (TR). Significant TR develops right heart failure (HF) with organ congestion, resulting in adverse outcomes, but appropriate therapeutic strategies remain unclear. The assessment of the degree of hepatic congestion using SW elasticity may be effective for determining therapeutic strategies. We prospectively enrolled 77 patients with moderate or severe TR who underwent SW elastography. Patients were divided into three groups according to the value of SW elasticity: low group (SW elasticity < 6.4 kPa, n = 26), medium group (6.4 ≤ SW elasticity < 9.5 kPa, n = 26), and high group (SW elasticity ≥ 9.5 kPa, n = 25). The endpoint was cardiovascular death or hospitalization for HF. During the median follow-up period of 17 months (range 7-39 months), cardiovascular death or hospitalization for HF occurred in seven patients of high group, in three patients of medium group, and in no patients of low group. In high group, three patients died and seven patients were hospitalized for HF. In medium group, two patients died and one patient was hospitalized. Kaplan-Meier analysis showed that the event-free survival rate was worse in high group than in other groups (log-rank test, p = 0.02). High SW elasticity was independently related to cardiac events as well as right ventricular and left ventricular dysfunction. SW elasticity was a predictor of cardiac events in patients with significant TR by assessing hepatic congestion. SW elasticity can be valuable for determining therapeutic strategies for TR.

Assessment of congestion and clinical outcomes in patients with chronic heart failure using shear wave elasticity

Aims

The relief of congestion is essential for the prevention of worsening heart failure (HF) resulting in hospitalizations. Assessment of the degree of organ congestion in the chronic phase of HF is important for determining therapeutic strategies. The aim of this study was to evaluate the efficacy of shear wave (SW) elasticity for assessing congestion and clinical outcomes in patients with chronic HF.

Methods and results

We prospectively enrolled 345 consecutive patients with chronic HF who underwent SW elastography at outpatient clinic. Patients were divided into two groups according to the median value of SW elasticity: low group (SW elasticity <6.4 kPa, n = 176) and high group (SW elasticity ≥6.4 kPa, n = 169). The endpoint was cardiovascular death or hospitalization for HF. During the median follow‐up period of 19 months (range: 7–36 months), cardiovascular death or hospitalization for HF occurred in 4 patients of low group and 27 patients of high group. In high group, 8 patients died, and 19 patients were hospitalized for HF. In low group, 3 patients died, and 1 patient was hospitalized. Kaplan–Meier analysis showed that the event‐free survival rate was worse in high group than in low group (log‐rank test, P = 0.004). After adjusting for variables, high SW elasticity was independently related to cardiac events. In multivariate regression analysis, SW elasticity was correlated with left atrial volume index, early diastolic mitral inflow velocity to mitral annular velocity ratio, and inferior vena cava diameter.

Conclusions

The SW elasticity reflected haemodynamic congestion in patients with chronic HF, which was related to cardiac events.

Correlation Between Liver Stiffness and Diastolic Function, Left Ventricular Hypertrophy, and Right Cardiac Function in Patients With Ejection Fraction Preserved Heart Failure

Objective: Ejection fraction preserved heart failure (HFpEF) is a common clinical syndrome with a high morbidity, accounting for ~50% of all heart failure patients, and a mortality comparable to that of ejection fraction reduced heart failure (HFrEF). The relationship between liver stiffness (LS) and HFpEF remains unclear. The purpose of this study was to explore the correlation between LS and the severity of HFpEF.

Methods: We performed a prospective observational study. After accepting liver transient elastography on admission, consecutive 150 hospitalized HFpEF patients were divided into three groups based on their liver elasticity value: first-third quartiles. Left ventricular diastolic function, left ventricular hypertrophy degree, right cardiac function and short-term prognosis (≤1 year) were compared among the three groups, and the correlation between liver elasticity and each indicator was analyzed.

Results: The elasticity of the liver was abnormally high in more than two-thirds of cases. The proportion of NYHA class III-IV in the third quartile group was significantly higher than that in the first quartile group (96 vs. 70%, P = 0.013). Significant differences were discovered in the level of lgNT-proBNP between the three groups (2.63 ± 0.65 vs. 2.84 ± 0.44 vs. 3.05 ± 0.71, P = 0.027). In terms of diastolic function and left ventricular hypertrophy, the ventricular septal e′ (5.01 ± 2.69 vs. 6.48 ± 2.29, P = 0.025), lateral wall e′ (6.63 ± 3.50 vs. 8.62 ± 2.73, P = 0.013), mean E/e′ (20.06 ± 7.53 vs. 13.20 ± 6.05, P = 0.001), left atrial volume index (43.53 ± 10.94 vs. 35.78 ± 13.86, P = 0.008), tricuspid regurgitation (TR) peak flow rate (3.16 ± 0.44 vs. 2.75 ± 0.50, P < 0.001), left ventricular mass index (LVMI) in male (163.2 ± 47.6 vs. 131.3 ± 38.0, P = 0.015) and in female (147.4 ± 48.6 vs. 110.6 ± 24.3, P = 0.036) was significantly different between the third quartile and the first quartile. The proportion of patients with diastolic dysfunction in the third quartile was significantly higher than that in the first quartile (70 vs. 36%, P = 0.017). In terms of right cardiac function, right ventricular fractional area change (RVFAC) (30.3 ± 5.4 vs. 36.5 ± 6.8, P < 0.001), tricuspid annular plane systolic excursion (TAPSE) (7.7 ± 5.2 vs. 14.8 ± 5.9, P = 0.010), pulmonary systolic pressure (38.0 ± 10.5 vs. 32.4 ± 10.3, P = 0.005), TR peak flow rate (3.16 ± 0.44 vs. 2.75 ± 0.50, P < 0.001), and inferior vena cava diameter (2.53 ± 0.51 vs. 1.98 ± 0.41, P < 0.001) were significantly different between the third quartile and the first quartile. More than half of HFpEF patients were combined with right ventricular dysfunction (RVD). Compared to HFpEF without RVD, HFpEF with RVD had higher male sex (53.6 vs. 30.3%, P < 0.001), higher NYHA class (3.2 ± 0.6 vs. 2.8 ± 0.6, P = 0.010), higher proportion of atrial fibrillation (45.2 vs. 18.2%, P < 0.001), and higher liver elasticity value (7.95 ± 0.60 vs. 7.31 ± 0.84, P = 0.003). In terms of short-term prognosis, the incidence of adverse cardiovascular events was significantly higher in the third quartile than in the first quartile (P = 0.003) and the second quartile (P = 0.008). Multivariate Cox proportional hazard analysis showed that adverse cardiovascular events were independently associated with NYHA class, atrial fibrillation, lgNT-proBNP and liver elasticity value (HR = 1.208, 95% CI 1.115–1.352, P = 0.002).

Conclusion: Increase of liver stiffness is common in HFpEF patients. Increased LS in HFpEF patients was significantly associated with worsen left diastolic function, left ventricular hypertrophy, and the right cardiac function. LS in HFpEF patients may be more than the result of right ventricular dysfunction. Male, atrial fibrillation, poorer NYHA class and increased liver elasticity value were significantly associated with HFpEF combined with RVD. Atrial fibrillation, poorer NYHA class, higher NT-proBNP, and increased liver elasticity value were independent predictors of poor short-term prognosis of HFpEF patients.

Liver stiffness and prediction of cardiac outcomes in patients with acute decompensated heart failure

BACKGROUND

In acute decompensated heart failure (ADHF), noninvasive markers that predict morbidity and mortality are limited. Liver stiffness measurement (LSM) increases with hepatic fibrosis; however, it may be falsely elevated in patients with ADHF in the absence of liver disease. We investigated whether elevated LSM predicts cardiac outcomes in ADHF.

METHODS

In a prospective study, we examined 52 ADHF patients without liver disease between 2016 and 2017. Patients underwent liver 2D shear wave elastography (SWE) and were followed for 12 months to assess the outcomes of left ventricular assist device (LVAD), heart transplant (HT) or death.

RESULTS

The median LSM was elevated in patients who received an LVAD or HT within 30-days compared to those who did not (median [IQR]: 55.6 [22.5 - 63.4] vs 13.8 [9.5 - 40.3] kPa, p = .049). Moreover, the risk of composite outcome was highest in the 3rd tertile (> 39.8 kPa compared to 1^st and 2^nd combined, HR 2.83, 95% CI 1.20- 6.67, p = .02). Each 1-kPa increase in LSM was associated with a 1%-increase in the incidence rate of readmissions (IRR 1.01, 95% CI 1.00-1.02, p = .01).

CONCLUSIONS

LSM may serve as a novel noninvasive tool to determine LVAD, HT, or death in patients with ADHF.

Liver stiffness as measured by transient elastography is a predictor of outcomes in patients with chronic heart failure with reduced, mid-range, and recovered left-ventricular ejection fraction

Background

Transient elastography is a noninvasive method for assessing liver stiffness (LS), which can reflect right-sided filling pressure associated with passive liver congestion in patients with HF.

Methods

A prospective, single-center observational study in which LS was measured in consecutive ambulatory patients with heart failure with reduced, mid-range, and recovered left ventricular ejection fraction, between March 2018 and June 2019. Mean follow up was 219 ± 86 days. The primary endpoint was time to first event, which was defined as a composite of cardiovascular death or HF hospitalization.

Results

Eighty-five patients were included in the final analysis. Mean age was 62 ± 10 and 68% were male. Mean ejection fraction and median NT-proBNP were, respectively, 38.7 ± 14.3% and 1140 pg/mL (interquartile range 224.3-2810.3). The median LS for the entire population was 6.3 (2.5-41.2) kPa. LS correlated with NT-proBNP (r = 0.46; p < 0.0001), total bilirubin (r = 0.47; p < 0.001), direct bilirubin (r = 0.43; p = 0.0001), gama-glutamyl-transpeptidase (r = 0.54; p < 0.0001), and alkaline phosphatase (r = 0.39; p = 0.0004). A Receiver Operating Characteristic (ROC) curve was performed and a cut point of 5.9 kPa showed sensitivity of 80% and specificity of 64.1% with area under the curve of 0.73. Using Cox proportional hazard model (independent variables: LS as a continuous variable, age, gender, NT-proBNP, LVEF, and creatinine), only LS was independently associated with the primary endpoint (hazard ratio 1.05, 95% confidence interval 1.01-1.09; for each increment of one unit of LS).

Conclusion

LS correlates with biomarkers of myocardial stretch and several liver function tests and is an independent predictor of outcomes in ambulatory patients with HF.

Ambulatory advanced heart failure patients: timing of mechanical circulatory support - delaying the inevitable?

PURPOSE OF REVIEW

Current indications for continuous-flow left ventricular assist device (cfLVAD) implantation is for patients in cardiogenic shock or inotrope-dependent advanced heart failure. Risk stratification of noninotrope dependent ambulatory advanced heart failure patients is a subject of registries designed to help shared-decision making by clinicians and patients regarding the optimal timing of mechanical circulatory support (MCS).

RECENT FINDINGS

The Registry Evaluation of Vital Information for VADs in Ambulatory Life enrolled ambulatory noninotrope dependent advanced systolic heart failure patients who had 25% annualized risk of death, MCS, or heart transplantation (HT). Freedom from composite clinical outcome at 1-year follow-up was 23.5% for the entire cohort. Seattle Heart Failure Model Score and Natriuretic pepides were predictors with modest discriminatory power. Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 4 patients had the highest risk (3.7-fold) of death, MCS or HT compared to INTERMACS profile 7.

SUMMARY

We propose individualized risk stratification for noninotrope dependent ambulatory advanced heart failure patients and include serial changes in end-organ function, nutritional parameters, frailty assessment, echocardiographic and hemodynamic data. The clinical journey of a patient with advanced heart failure should be tracked and discussed at each clinic visit for shared decision-making regarding timing of cfLVAD.

Efficacy of shear wave elastography for assessment of liver function in patients with heart failure

AIMS

Liver dysfunction is important for prognosis in heart failure (HF). Shear wave elastography (SWE), which is a novel ultrasound technique for charactering tissues, has been used in liver diseases. However, clinical implication of SWE, including dispersion slope, remains unknown in heart diseases. This study aimed to evaluate the efficacy of SWE assessing liver function in the severity of HF.

METHODS AND RESULTS

We enrolled 316 consecutive patients with or suspected heart diseases, who were classified according to the American College of Cardiology Foundation/American Heart Association stage of HF, including 37 with Stage A, 139 with Stage B, 114 with Stage C, and 26 with Stage D, and 45 normal subjects. Elasticity and dispersion slope of shear wave were assessed according to the HF stage. Elasticity and dispersion slope were not elevated in normal subjects and patients with Stage A. Elasticity was slightly increased from Stage A to Stage C and was remarkably elevated in Stage D (normal: 5.2 ± 1.1 kPa, Stage A: 5.4 ± 1.2 kPa, Stage B: 6.4 ± 1.8 kPa, Stage C: 7.8 ± 3.5 kPa, and Stage D: 17.7 ± 12.7 kPa), whereas dispersion slope was gradually increased from Stage A to Stage D (normal: 9.7 ± 1.7m/s/kHz, Stage A: 10.4 ± 1.6m/s/kHz, Stage B: 11.7 ± 2.4m/s/kHz, Stage C: 13.2 ± 3.4m/s/kHz, and Stage D: 17.6 ± 5.6 m/s/kHz). In the early HF stage, dispersion slope was elevated. In the advanced HF stage, both elasticity and dispersion slope were elevated. Liver function test abnormalities were observed only from Stage C or Stage D.

CONCLUSIONS

Dispersion slope could detect early liver damage, and the combination of elasticity and dispersion slope could clarify the progression of liver dysfunction in HF. SWE may be valuable to manage therapeutic strategies in patients with HF.

Ultrasound liver elastography beyond liver fibrosis assessment

Several guidelines have indicated that liver stiffness (LS) assessed by means of shear wave elastography (SWE) can safely replace liver biopsy in several clinical scenarios, particularly in patients with chronic viral hepatitis. However, an increase of LS may be due to some other clinical conditions not related to fibrosis, such as liver inflammation, acute hepatitis, obstructive cholestasis, liver congestion, infiltrative liver diseases. This review analyzes the role that SWE can play in cases of liver congestion due to right-sided heart failure, congenital heart diseases or valvular diseases. In patients with heart failure LS seems directly influenced by central venous pressure and can be used as a prognostic marker to predict cardiac events. The potential role of LS in evaluating liver disease beyond the stage of liver fibrosis has been investigated also in the hepatic sinusoidal obstruction syndrome (SOS) and in the Budd-Chiari syndrome. In the hepatic SOS, an increase of LS is observed some days before the clinical manifestations; therefore, it could allow an early diagnosis to timely start an effective treatment. Moreover, it has been reported that patients that were successfully treated showed a LS decrease, that reached pre-transplantation value within two to four weeks. It has been reported that, in patients with Budd-Chiari syndrome, LS values can be used to monitor short and long-term outcome after angioplasty.

Usefulness of Liver Stiffness on Ultrasound Shear-Wave Elastography for the Evaluation of Central Venous Pressure in Children With Heart Diseases

BACKGROUND

Liver stiffness on ultrasound shear-wave elastography (SWE) reflects central venous pressure (CVP) in adult patients with heart failure, but the association of liver stiffness on SWE with CVP in pediatric patients is not clear. The present study evaluated whether liver stiffness on SWE is useful as a non-invasive indicator of CVP in pediatric patients.Methods and Results:Liver stiffness was measured using ultrasound SWE in 79 patients aged <20 years with congenital heart diseases. None of the patients was found to have liver disease. Correlations between liver stiffness and other clinical variables, including CVP, were analyzed. CVP was the only factor independently and significantly correlated with liver stiffness in multivariate analysis. However, variables related to hepatic fibrosis did not correlate with liver stiffness.

CONCLUSIONS

Liver stiffness on ultrasound SWE is useful as a non-invasive indicator of CVP in children with heart diseases.

Relationship of Liver Stiffness With Congestion in Patients Presenting With Acute Decompensated Heart Failure

OBJECTIVE

The significance of liver stiffness (LS) in the setting of cardiovascular congestion during the course of acute decompensated heart failure (ADHF) is under investigation. The aim of this study was to assess LS with the use of transient elastography (TE) and its associations with volume overload as determined by means of bioimpedance vector analysis (BIVA) in ADHF.

METHODS AND RESULTS

TE (Fibroscan 502; Echosens) and BIVA (ABC-01, Medass) were performed in the first 48 hours of admission and on the day of discharge in 149 ADHF patients without known primary chronic liver disease or acute hepatitis. During hospitalization the median value of LS decreased from 12.2 kPa (interquartile range 6.3-23.6) to 8.7 (5.9-14.4) kPa (P < .001). Changes in LS correlated (P < .001) with changes in weight and BIVA parameters. LS was compared with histologic features of livers of ADHF patients who died (n = 7). Liver fibrosis 2B-4 was observed but was not associated with LS. LS at discharge was associated with increased risk of 12-month all-cause death, HF readmission, and the combined end point.

CONCLUSIONS

There was a moderate association between LS with clinical congestion and volume overload according to BIVA and no correlation with degree of histologic liver fibrosis. LS may be a marker of negative HF outcomes.

Impact of admission liver stiffness on long-term clinical outcomes in patients with acute decompensated heart failure

Liver stiffness (LS) has been reported to be a marker of liver congestion caused by elevated central venous pressure in heart failure (HF) patients. Recent studies demonstrated that LS could be non-invasively measured by virtual touch quantification (VTQ). However, its prognostic implication in patients with acute decompensated heart failure (ADHF) is unclear. This study sought to determine whether LS measured by VTQ could be a determinant of subsequent adverse events in ADHF patients. We prospectively recruited 70 ADHF patients who underwent LS measurement by VTQ on admission in our university hospital between June 2016 and April 2018. The primary outcome of interest was the composite of all-cause mortality and worsening HF. During a median follow-up period of 272 (interquartile range 122-578) days, there were 26 (37%) events, including 5 (7%) deaths and 21 (30%) cases of worsening HF. The c-index of LS for predicting the composite of adverse events was 0.77 (95% CI 0.66-0.88), and the optimal cut-off value of LS was 1.50 m/s. Adverse events were more frequently observed in patients with high LS (≥ 1.50 m/s) compared to those with low LS (< 1.50 m/s). Multivariable Cox regression analyzes revealed that higher LS was independently associated with increased subsequent risk of adverse events after adjustment for confounders. In conclusion, high admission LS was an independent determinant of worse clinical outcomes in patients with ADHF. This finding suggests that LS on admission is useful for risk stratification of patients with ADHF.

Value of Two-Dimensional Shear Wave Elastography for Assessing Acute Liver Congestion in a Bama Mini-Pig Model

BACKGROUND

To date, liver congestion is one of the most significant clinical diseases. However, few studies have profoundly investigated the development, pathology, and prognosis of the important problems associated with acute hepatic congestion.

AIMS

To explore the value of noninvasive two-dimensional shear wave elastography (2D-SWE) for assessing acute liver congestion in an animal model.

METHODS

Six healthy Bama mini-pigs were used for this research and randomly divided into the experimental group and control group. We measured the basal liver stiffness (LS) by 2D-SWE and then clamped the inferior vena cava (IVC). LS was measured after 1, 5, 10, and 15 min. We reopened the IVC of experimental group pigs and detected the LS again. All pigs were killed and obtained for a pathological microscopic examination.

RESULTS

LS was distinctly increased from 7.03 ± 0.48 to 17.18 ± 3.40 kPa (p < 0.01) within 15 min and reversed to almost normal values of 7.59 ± 0.77 kPa (p < 0.01) within 5 min. In addition, two-dimensional ultrasound images demonstrated the interesting phenomenon of spontaneous echo contrast. Most importantly, the pathologic results of experimental group pigs showed the central veins of the hepatic lobules and hepatic sinusoids were enlarged and filled with numerous erythrocytes; central lobular hepatocytic necrosis and edema were noted.

CONCLUSIONS

In conclusion, 2D-SWE is a valuable, reliable, and quantitative approach to successfully assess acute liver congestion, and it is well consistent with histopathological characteristics. Besides, acute liver congestion is an important factor influencing LS that increases LS in a reversible way.

Clinical implications of organ congestion in heart failure patients as assessed by ultrasonography

In the management of heart failure (HF), decongestion is critical for improving clinical outcomes in addition to patients' symptoms. Although physicians accept this theory, there are no established markers for the achievement of optimal decongestion status. Organ congestion, in particular liver and kidney congestion, has recently attracted substantial attention. Ultrasound methods have been introduced for assessing organ congestion, although this is merely a preliminary step. Here, we review the clinical implications of the assessment of organ congestion by ultrasound.

Evaluation of right ventricular function using liver stiffness in patients with left ventricular assist device

Objectives

Although right ventricular failure (RVF) is a major concern after left ventricular assist device (LVAD) implantation, methodologies to evaluate RV function remain limited. Liver stiffness (LS), which is closely related to right-sided filling pressure and may indicate RVF severity, could be non-invasively and repeatedly assessed using transient elastography. Here we investigated the suitability of LS as a parameter of RV function in pre- and post-LVAD periods.

Methods

The study included 55 patients with LVAD implantation as a bridge to transplantation between 2011 and 2015 whose LS was assessed using transient elastography.

Results

Seventeen patients presented with RVF, defined as requiring inotropic support for ≥30 days, nitric oxygen inhalation for ≥5 days, and/or mechanical RV support following LVAD implantation. Survival of patients with RVF was significantly worse compared with that of patients without RVF. Multivariate logistic regression analysis identified preoperative LS, LV diastolic dimension, RV stroke work index, and dilated phase of hypertrophic cardiomyopathy aetiology as significant risk factors; the combination of these parameters could improve predictive power of post-LVAD RVF with areas under the curve of 0.89. Furthermore, LS was significantly decreased by LV unloading and significantly correlated with right-sided filling pressure.

Conclusions

In addition to dilated hypertrophic cardiomyopathy aetiology, reduced RV stroke work index and small LV dimension, we demonstrated that non-invasively measured LS was a predictor of post-LVAD RVF and can be used as a parameter for the evaluation and optimization of RV function in the perioperative period.

Value of Virtual Touch Quantification Elastography for Assessing Liver Congestion in Patients With Heart Failure

BACKGROUND

Heart failure (HF) causes organ congestion, which is thought to increase organ stiffness. The virtual touch quantification (VTQ) method can be used to assess liver stiffness in patients with chronic liver diseases. This study aimed to measure liver and kidney stiffness using VTQ and to determine its value for assessing organ congestion in patients with HF.

METHODS AND RESULTS

This study included 10 normal subjects and 38 HF patients (age 52.3±16.7 years, left ventricular ejection fraction 27.0±9.4%, plasma B-type natriuretic peptide [BNP] 1,297.3±1,155.1 pg/ml). We investigated the relationships between clinical characteristics and hemodynamics and liver and kidney stiffness, and assessed the effects of medical treatment on these measurements. Liver stiffness was significantly higher in HF patients (1.17±0.13 m/s vs. 2.03±0.91 m/s, P=0.004) compared with normal subjects, but kidney stiffness was similar in both groups. Central venous pressure (CVP) (P=0.021) and BNP (P=0.025) were independent predictive factors for increased liver stiffness in HF patients. Liver stiffness decreased significantly from 2.37±1.09 to 1.27±0.33 m/s (P<0.001) after treatment. Changes in liver stiffness in HF patients significantly correlated with changes in CVP (R=0.636, P=0.014) and cardiac index (R=-0.557, P=0.039) according to univariate analysis, and with changes in CVP in multivariate analysis.

CONCLUSIONS

Liver stiffness measured by noninvasive VTQ methods can be used to assess liver congestion and therapeutic effects in patients with HF. (Circ J 2016; 80: 1187-1195).

Relation of Tricuspid Regurgitation to Liver Stiffness Measured by Transient Elastography in Patients With Left-Sided Cardiac Valve Disease

The aim of the study was to evaluate the relation between tricuspid regurgitation (TR) severity and liver stiffness (LS) in patients with TR. A total of 131 patients with various degrees of TR secondary to left-sided heart valve disease were enrolled. Severity of TR was quantitatively assessed by proximal isovelocity surface area-derived effective regurgitant orifice (ERO). Patients were divided into 2 groups: 48 with mild-moderate TR (ERO <0.4 cm(2)) and 83 with severe TR (ERO ≥0.4 cm(2)). Transient elastography was used to measure the level of LS, an established marker of liver fibrosis, with the threshold of significant LS set at ≥12.5 kPa. Patients with severe TR had a higher LS and prevalence of significant LS than those with mild-moderate TR. Furthermore, LS and significant LS independently correlated with TR-ERO, right atrial pressure and inferior vena cava (IVC) diameter. The presence of a large TR-ERO (≥0.4 cm(2)) and IVC diameter (>2.15 cm(2)) provided a high specificity of 78% for significant LS. In conclusion, the present study demonstrates that TR-ERO, right atrial pressure, and IVC diameter are important parameters associated with LS in patients with TR.