Pulmonary pressure-flow responses to exercise in heart failure treated with angiotensin receptor neprilysin inhibitor

BACKGROUND

The role of the angiotensin receptor neprilysin inhibitor (ARNI) in cardiac function, particularly its impact on pulmonary circulation, remains underexplored. Recent studies have described abnormal mean pulmonary artery pressure (mPAP)-cardiac output (CO) responses as having the potential to assess the disease state. The aim of this study was to assess the effects of ARNI on pulmonary circulation in heart failure. We measured echocardiographic parameters post 6-min walk (6 MW) and compared the changes with baseline and follow-up. Our hypothesis was that pulmonary pressure-flow relationship of the pulmonary circulation obtained by 6 MW stress echocardiography would be improved with treatment.

METHODS

We prospectively enrolled 39 heart failure patients and conducted the 6 MW test indoors. Post-6 MW echocardiography measured echocardiographic variables, and CO was derived from electric cardiometry. Individualized ARNI doses were optimized, with follow-up echocardiographic evaluations after 1 year.

RESULTS

Left ventricular (LV) volume were significantly reduced (160.7 ± 49.6 mL vs 136.0 ± 54.3 mL, P < 0.001), and LV ejection fraction was significantly improved (37.6 ± 11.3% vs 44.9 ± 11.5%, P < 0.001). Among the 31 patients who underwent 6 MW stress echocardiographic study at baseline and 1 year later, 6 MW distance increased after treatment (380 m vs 430 m, P = 0.003). The ΔmPAP/ΔCO by 6 MW stress decreased with treatment (6.9 mmHg/L/min vs 2.8 mmHg/L/min, P = 0.002). The left atrial volume index was associated with the response group receiving ARNI treatment for pulmonary circulation.

CONCLUSIONS

Initiation of ARNI was associated with improvement of left ventricular size and LVEF. Additionally, the 6 MW distance increased and the ΔmPAP/ΔCO was improved to within normal range with treatment.

Echocardiographic artificial intelligence for pulmonary hypertension classification

OBJECTIVE

The classification of pulmonary hypertension (PH) is crucial for determining the appropriate therapeutic strategy. We investigated whether machine learning (ML) algorithms may assist in echocardiographic PH prediction, where current guidelines recommend integrating several different parameters.

METHODS

We obtained physical and echocardiographic data from 885 patients who underwent right heart catheterisation (RHC). Patients were classified into three groups: non-PH, precapillary PH and postcapillary PH, based on values obtained from RHC. Using 24 parameters, we created predictive models employing four different classifiers and selected the one with the highest area under the curve. We then calculated the macro-average classification accuracy for PH on the derivation cohort (n=720) and prospective validation data set (n=165), comparing the results with guideline-based echocardiographic assessment obtained from each cohort.

RESULTS

Logistic regression with elastic net regularisation had the highest classification accuracy, with areas under the curves of 0.789, 0.766 and 0.742 for normal, precapillary PH and postcapillary PH, respectively. The ML model demonstrated significantly better predictive accuracy than the guideline-based echocardiographic assessment in the derivation cohort (59.4% vs 51.6%, p<0.01). In the independent validation data set, the ML model's accuracy was comparable to the guideline-based PH classification (59.4% vs 57.8%, p=0.638).

CONCLUSIONS

This preliminary study suggests promising potential for our ML model in predicting echocardiographic PH. Further research and validation are needed to fully assess its clinical utility in PH diagnosis and treatment decision-making.

Correlation between energy loss index and B-type natriuretic peptide: a vector flow mapping study

BACKGROUND

Vector Flow Mapping (VFM) and Energy Loss (EL) evaluation are emerging echocardiographic techniques that offer detailed insights into cardiac function. This study aimed to explore the relationship between EL parameters and B-type natriuretic peptide (BNP) levels, a well-established marker of heart failure severity.

METHODS

Our study prospectively enrolled 62 patients experiencing shortness of breath and suspected heart failure, who underwent echocardiography and had BNP levels measured between January 2018 and August 2020. Patients were stratified based on BNP levels, and their clinical and echocardiographic characteristics were evaluated. Univariate and multivariate regression analyses were performed to assess the correlation between BNP levels and various echocardiographic variables, including VFM parameters.

RESULTS

Patients were stratified into two groups based on their BNP levels: BNP < 200 pg/ml (n = 53) and BNP ≥ 200 pg/ml (n = 9). Patients with BNP ≥ 200 pg/ml presented significantly different clinical and echocardiographic characteristics, such as older age, larger left ventricular mass and volume indices, higher pulmonary artery systolic pressure, higher E/e' ratio, and larger EL parameters. Multivariate regression analysis demonstrated the E/e' ratio and ELA (EL during Atrial contraction phase/A wave ratio as significant determinants of logBNP. Receiver operating characteristic curve analysis showed ELA/A > 36.0 J/m2 as a significant predictor of high BNP with 89% sensitivity and 85% specificity. ELA/A demonstrated an incremental diagnostic value over elevated left atrial pressure for predicting high BNP (C statistic = 0.98 vs 0.74, P = 0.006).

CONCLUSION

This study provides novel insights into the potential utility of EL parameters as auxiliary indicators of cardiac load, thereby enhancing our understanding of heart failure.

Reducing echocardiographic examination time through routine use of fully automated software: a comparative study of measurement and report creation time

BACKGROUND

Manual interpretation of echocardiographic data is time-consuming and operator-dependent. With the advent of artificial intelligence (AI), there is a growing interest in its potential to streamline echocardiographic interpretation and reduce variability. This study aimed to compare the time taken for measurements by AI to that by human experts after converting the acquired dynamic images into DICOM data.

METHODS

Twenty-three consecutive patients were examined by a single operator, with varying image quality and different medical conditions. Echocardiographic parameters were independently evaluated by human expert using the manual method and the fully automated US2.ai software. The automated processes facilitated by the US2.ai software encompass real-time processing of 2D and Doppler data, measurement of clinically important variables (such as LV function and geometry), automated parameter assessment, and report generation with findings and comments aligned with guidelines. We assessed the duration required for echocardiographic measurements and report creation.

RESULTS

The AI significantly reduced the measurement time compared to the manual method (159 ± 66 vs. 325 ± 94 s, p < 0.01). In the report creation step, AI was also significantly faster compared to the manual method (71 ± 39 vs. 429 ± 128 s, p < 0.01). The incorporation of AI into echocardiographic analysis led to a 70% reduction in measurement and report creation time compared to manual methods. In cases with fair or poor image quality, AI required more corrections and extended measurement time than in cases of good image quality. Report creation time was longer in cases with increased report complexity due to human confirmation of AI-generated findings.

CONCLUSIONS

This fully automated software has the potential to serve as an efficient tool for echocardiographic analysis, offering results that enhance clinical workflow by providing rapid, zero-click reports, thereby adding significant value.

Unsupervised cluster analysis reveals different phenotypes in patients after transcatheter aortic valve replacement

Aims

The aim of this study was to identify phenotypes with potential prognostic significance in aortic stenosis (AS) patients after transcatheter aortic valve replacement (TAVR) through a clustering approach.

Methods and results

This multi-centre retrospective study included 1365 patients with severe AS who underwent TAVR between January 2015 and March 2019. Among demographics, laboratory, and echocardiography parameters, 20 variables were selected through dimension reduction and used for unsupervised clustering. Phenotypes and outcomes were compared between clusters. Patients were randomly divided into a derivation cohort (n = 1092: 80%) and a validation cohort (n = 273: 20%). Three clusters with markedly different features were identified. Cluster 1 was associated predominantly with elderly age, a high aortic valve gradient, and left ventricular (LV) hypertrophy; Cluster 2 consisted of preserved LV ejection fraction, larger aortic valve area, and high blood pressure; and Cluster 3 demonstrated tachycardia and low flow/low gradient AS. Adverse outcomes differed significantly among clusters during a median of 2.2 years of follow-up (P < 0.001). After adjustment for clinical and echocardiographic data in a Cox proportional hazards model, Cluster 3 (hazard ratio, 4.18; 95% confidence interval, 1.76-9.94; P = 0.001) was associated with increased risk of adverse outcomes. In sequential Cox models, a model based on clinical data and echocardiographic variables (χ2 = 18.4) was improved by Cluster 3 (χ2 = 31.5; P = 0.001) in the validation cohort.

Conclusion

Unsupervised cluster analysis of patients after TAVR revealed three different groups for assessment of prognosis. This provides a new perspective in the categorization of patients after TAVR that considers comorbidities and extravalvular cardiac dysfunction.

Deep learning approach for analyzing chest x-rays to predict cardiac events in heart failure

Background

A deep learning (DL) model based on a chest x-ray was reported to predict elevated pulmonary artery wedge pressure (PAWP) as heart failure (HF).

Objectives

The aim of this study was to (1) investigate the role of probability of elevated PAWP for the prediction of clinical outcomes in association with other parameters, and (2) to evaluate whether probability of elevated PAWP based on DL added prognostic information to other conventional clinical prognostic factors in HF.

Methods

We evaluated 192 patients hospitalized with HF. We used a previously developed AI model to predict HF and calculated probability of elevated PAWP. Readmission following HF and cardiac mortality were the primary endpoints.

Results

Probability of elevated PAWP was associated with diastolic function by echocardiography. During a median follow-up period of 58 months, 57 individuals either died or were readmitted. Probability of elevated PAWP appeared to be associated with worse clinical outcomes. After adjustment for readmission score and laboratory data in a Cox proportional-hazards model, probability of elevated PAWP at pre-discharge was associated with event free survival, independent of elevated left atrial pressure (LAP) based on echocardiographic guidelines (p < 0.001). In sequential Cox models, a model based on clinical data was improved by elevated LAP (p = 0.005), and increased further by probability of elevated PAWP (p < 0.001). In contrast, the addition of pulmonary congestion interpreted by a doctor did not statistically improve the ability of a model containing clinical variables (compared p = 0.086).

Conclusions

This study showed the potential of using a DL model on a chest x-ray to predict PAWP and its ability to add prognostic information to other conventional clinical prognostic factors in HF. The results may help to enhance the accuracy of prediction models used to evaluate the risk of clinical outcomes in HF, potentially resulting in more informed clinical decision-making and better care for patients.

Classification of chest X-ray images by incorporation of medical domain knowledge into operation branch networks

BACKGROUND

This study was conducted to alleviate a common difficulty in chest X-ray image diagnosis: The attention region in a convolutional neural network (CNN) does not often match the doctor's point of focus. The method presented herein, which guides the area of attention in CNN to a medically plausible region, can thereby improve diagnostic capabilities.

METHODS

The model is based on an attention branch network, which has excellent interpretability of the classification model. This model has an additional new operation branch that guides the attention region to the lung field and heart in chest X-ray images. We also used three chest X-ray image datasets (Teikyo, Tokushima, and ChestX-ray14) to evaluate the CNN attention area of interest in these fields. Additionally, after devising a quantitative method of evaluating improvement of a CNN's region of interest, we applied it to evaluation of the proposed model.

RESULTS

Operation branch networks maintain or improve the area under the curve to a greater degree than conventional CNNs do. Furthermore, the network better emphasizes reasonable anatomical parts in chest X-ray images.

CONCLUSIONS

The proposed network better emphasizes the reasonable anatomical parts in chest X-ray images. This method can enhance capabilities for image interpretation based on judgment.

Clinical course and decision-making in heart failure by preload stress echocardiography: a preliminary study

AIMS

Abnormal left ventricular diastolic response to preload stress can be an early marker of heart failure (HF). The aim of this study was to assess clinical course in patients with HF with preserved ejection fraction (HFpEF) who underwent preload stress echocardiography. In the subgroup analysis, we assessed the prognosis of patients with unstable signs during preload stress classified by treatment strategies.

METHODS AND RESULTS

We prospectively conducted preload stress echocardiographic studies between January 2006 and December 2013 in 211 patients with HFpEF. Fifty-eight patients had abnormal diastolic reserve during preload stress (unstable impaired relaxation: unstable IR). Of 58 patients with unstable IR, 19 patients were assigned to additional therapy by increased or additional therapy and 39 patients were assigned to standard therapy. Composite outcomes were prespecified as the primary endpoint of death and hospitalization for deteriorating HF. During a median period of 6.9 years, 19 patients (33%) reached the composite outcome. Unstable group with standard therapy had significantly shorter event-free survival than stable group. Patients with uptitration of therapy had longer event-free survival than those with standard therapy group after adjustment of laboratory data (hazard ratio, 0.20, 95% confidence interval, 0.05-0.90; P = 0.036); the 10 year event-free survival in patients with and without uptitration of therapy was 93% and 51%, respectively (P = 0.023).

CONCLUSIONS

Patients with unstable sign had significantly shorter event-free survival than patients with stable sign. After additional therapy, the prognosis of patients with unstable signs improved. This technique may impact decision-making for improving their prognosis.

Deep Learning for Detection of Exercise-Induced Pulmonary Hypertension Using Chest X-Ray Images

Background

Stress echocardiography is an emerging tool used to detect exercise-induced pulmonary hypertension (EIPH). However, facilities that can perform stress echocardiography are limited by issues such as cost and equipment.

Objective

We evaluated the usefulness of a deep learning (DL) approach based on a chest X-ray (CXR) to predict EIPH in 6-min walk stress echocardiography.

Methods

The study enrolled 142 patients with scleroderma or mixed connective tissue disease with scleroderma features who performed a 6-min walk stress echocardiographic test. EIPH was defined by abnormal cardiac output (CO) responses that involved an increase in mean pulmonary artery pressure (mPAP). We used the previously developed AI model to predict PH and calculated PH probability in this cohort.

Results

EIPH defined as ΔmPAP/ΔCO >3.3 and exercise mPAP >25 mmHg was observed in 52 patients, while non-EIPH was observed in 90 patients. The patients with EIPH had a higher mPAP at rest than those without EIPH. The probability of PH based on the DL model was significantly higher in patients with EIPH than in those without EIPH. Multivariate analysis showed that gender, mean PAP at rest, and the probability of PH based on the DL model were independent predictors of EIPH. A model based on baseline parameters (age, gender, and mPAP at rest) was improved by adding the probability of PH predicted by the DL model (AUC: from 0.65 to 0.74; p = 0.046).

Conclusion

Applying the DL model based on a CXR may have a potential for detection of EIPH in the clinical setting.

Effects of Radiofrequency Catheter Ablation on Cardiac Reserve Using Preload Stress Echocardiography in Paroxysmal and Persistent Atrial Fibrillation

The effects of catheter ablation on exercise tolerance and quality of life in patients with atrial fibrillation (AF) have been reported. We assessed cardiac function in more detail using the leg positive pressure (LPP) technique and found that contractile reserve is particularly important in relation to exercise tolerance and prognosis. In this study, we used the LPP technique to examine changes in contractile reserve immediately after ablation and 6 months later. We prospectively enrolled patients who underwent catheter ablation for AF at 2 institutes. We performed LPP stress echocardiography 2 to 3 days after (FU-1) and 6 months after (FU-2) ablation to examine changes in cardiac function indexes. The primary end point was improvement in contractile reserve. Ultimately, 109 patients (mean age 67.4 ± 9.6 years; 70% men) underwent 2 sessions of LPP stress echocardiography. The median CHA₂DS₂-VAS_C score was 2 (interquartile range 13). From FU-1 to FU-2, the change in the stroke volume index after the LPP maneuver increased in patients with paroxysmal and persistent AF with low CHA₂DS₂-VAS_C scores (both p <0.05). Regardless of AF subtype, contractile reserve at FU-2 improved in patients with low CHA₂DS₂-VAS_C scores compared with that at FU-1. In contrast, patients with high CHA₂DS₂-VAS_C scores had no change. In conclusion, patients with AF with a low CHA₂DS₂-VAS_C score had improved contractile reserve after ablation, whereas patients with high scores did not show any improvement. Aggressive interventions in patients with high scores may lead to better management after catheter ablation.

A preliminary study of the safety and effectiveness of isoproterenol loading transesophageal echocardiography in atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

In patients with sludge or severe spontaneous echo contrast (SEC) in the left atrial appendage (LAA), isoproterenol loading transesophageal echocardiography (ISP-TEE) has been reported to check the presence of thrombus in the LAA, as the sludge or severe SEC disappears (Figure 1).

Purpose

The aim of this study was to assess the safety of ISP-TEE for the identification of LAA thrombus and the hemodynamic changes in the LAA caused by ISP loading.

Methods

We prospectively enrolled 25 patients with atrial fibrillation (AF) and sludge or SEC in the LAA who underwent ISP-TEE from April 2020 to July 2021. ISP was administered intravenously to achieve the target heart rate (HR) defined as follows: Max HR [beats per minutes: bpm] = 220 – age (years), Target HR [bpm] = Max HR × 0.8. Patients with tachycardia exceeding Max HR before ISP administration, hemodynamic instability, and other contraindications to ISP were excluded from the study. To assess the safety of ISP-TEE, we evaluated patients’ condition, changes in systolic blood pressure (sBP) and HR before and after ISP loading. We also assessed the presence or absence of worsening heart failure, new arrhythmias other than atrial fibrillation, and cerebral infarction or transient ischemic attack during the examination, and after 24 hours. Hemodynamic evaluation was performed using LAA blood flow velocity, LAA tissue Doppler imaging (TDI) velocity, and LAA volume fraction (LAAVF) defined as follows: LAAVF (%) = (Max LAA volume – Min LAA volume) / Max LAA volume × 100. Quantification of LAA volume was performed using the stacked-contour method of a 3-dimensional TEE full-volume acquisition.

Results

Among 25 patients, 13 patients had sludge or grade3 SEC, 7 patients had grade2 SEC, 5 patients had grade1 SEC. HR after ISP loading was significantly higher than before loading, but sBP did not change significantly before and after ISP loading. No complications due to ISP loading were observed during examination and after 24 hours. After ISP loading, there were 18 patients with grade 1 SEC or no SEC (classified as Group1), 7 patients had residual sludge or grade 2 to 3 SEC (classified as Group2). The differences in LAA blood flow velocity between before and after ISP loading was faster in Group1 than in Group2: 13.0 ± 10.5 vs 2.6 ± 4.2. p = 0.019. The differences in TDI velocity was also faster in Group1 than in Group2: 1.46 ± 1.14 vs 0.19 ± 0.50, p = 0.010. The differences in LAAVF was higher in Group1 than in Group2: 13.7 ± 10.3 vs 2.2 ± 2.0, p = 0.009.

Conclusions

In our study, no complications were observed in ISP-TEE for the identification of LAA thrombus. Patients with grade 1 SEC or no SEC, the LAA function was increased by ISP loading. These results may provide insights into the mechanisms of ISP loading on SEC in the LAA. Abstract Figure.

Deterioration of biventricular strain is an early marker of cardiac involvement in confirmed sarcoidosis

AIMS

Risk assessment of developing cardiac involvement in systemic sarcoidosis can be challenging because of limited data. Recently, attention has been given to left ventricular and right ventricular (LV and RV) involvement in cardiac sarcoidosis (CS) and its prevalence, relevance, and prognostic value. The aim of this study was to assess the role of biventricular strain to predict prognosis in confirmed sarcoidosis patients.

METHODS AND RESULTS

LV and RV longitudinal strains (LSs) were evaluated by 2D speckle tracking in 139 consecutive confirmed sarcoidosis patients without other pre-existing structural heart diseases, and 52 age- and gender-matched control subjects. The primary endpoint was CS-related events (cardiac death or development of cardiac involvement). Sarcoidosis without cardiac involvement had significantly lower LV and RV free wall LS compared with control subjects. Basal LS had a higher area under the curve for differentiation of sarcoidosis in patients without cardiac involvement compared to control (cut-off value: -18% with 89% sensitivity and 69% specificity). During a median period of 50 months, the occurrence of CS-related events was observed in 20 patients. In a multivariate analysis, basal LV LS and RV free wall LS were associated with the events [hazard ratio (HR) 0.72, P < 0.001 and HR: 0.83, P = 0.006, respectively]. Patients with impaired biventricular function had significantly shorter event-free survival than those with preserved biventricular function (P < 0.001).

CONCLUSION

Deterioration of biventricular strain was associated with CS-related events. This information might be useful for clinical evaluation and follow-up in sarcoidosis.

Clinical Utility of Overlap Time for Incomplete Relaxation to Predict Cardiac Events in Heart Failure

BACKGROUND

The overlap time of transmitral flow can be a novel marker of subclinical left ventricular dysfunction for predicting adverse events in heart failure (HF). We aimed to (1) investigate the role of overlap time of the E-A wave in association with clinical parameters and (2) evaluate whether the overlap time could add prognostic information with respect to other conventional clinical prognosticators in HF.

METHODS

We prospectively evaluated 153 patients hospitalized with HF (mean age 68 ± 15 years; 63% male). The primary endpoint was readmission following HF or cardiac death.

RESULTS

During a median period of 25 months, 43 patients were readmitted or died. Overlap time appeared to be associated with worse outcomes. After adjustment for readmission scores and ratios of diastolic filling period and cardiac cycle length in a Cox proportional-hazards model, overlap time was associated with event-free survival, independent of elevated left atrial pressure based on guidelines. When overlap time was added to the model based on clinical variables and elevated left atrial pressure, the C-statistic significantly improved from 0.70 (95% CI: 0.63-0.77) to 0.77 (95% CI: 0.69-0.83, compared) (P = 0.035).

CONCLUSION

This preliminary study suggested that prolonged overlap time may have potential for predicting readmission and cardiac mortality risk assessment in patients with HF.

Predictive value of left atrial function for latent paroxysmal atrial fibrillation as the cause of embolic stroke of undetermined source

BACKGROUND

In patients with embolic stroke of undetermined source (ESUS), paroxysmal atrial fibrillation (AF) is often diagnosed, however, the risk of paroxysmal AF in ESUS has not been well described. Several studies have suggested a linkage between left atrial (LA) functional parameters and risk of AF in stroke patients. The aim of this study was to assess the role of LA functional parameters as predictors of latent paroxysmal AF in ESUS on admission.

METHODS

Between January 2015 and December 2019, consecutive stroke patients with suspected ESUS at admission were prospectively included in this study. They were under hospital electrocardiographic monitoring for detection of new-onset AF. Various echocardiographic parameters including left atrial strain were assessed for association with new-onset AF.

RESULTS

We gathered 1082 consecutive patients with ischemic stroke. After exclusions, 121 patients with suspected ESUS at admission formed the study cohort. New-onset AF was detected in 46 (38%) patients during hospital electrocardiographic monitoring (median follow-up: 18 days). LA pump and reservoir strains were significantly and independently associated with new-onset AF. Receiver operating characteristic analysis for the association with new-onset AF showed that the areas under the curve (AUCs) of clinical parameters plus one of each strain (LA pump strain: AUC: 0.86±0.04 and LA reservoir strain: AUC: 0.76±0.05) models were significantly better than plus LA volume index (AUC: 0.68±0.04, compared p-values <0.05).

CONCLUSIONS

LA strain was significantly associated with new development of AF. Patients with impaired LA function at admission should be carefully monitored to find AF.

Cardiac reserve by 6-minute walk stress echocardiography in systemic sclerosis

Objectives

There is a high prevalence of left ventricular diastolic dysfunction (LVDD) in systemic sclerosis (SSc) which is associated with high mortality. Thus, early detection of LVDD could be important in management of SSc. We hypothesised that exercise echocardiography in SSc patients with normal resting haemodynamics may expose early phase LVDD, which could affect its prognosis, defined as cardiovascular death and unplanned hospitalisation for heart failure.

Methods

Between January 2014 and December 2018, we prospectively enrolled 140 patients with SSc who underwent 6-minute walk (6MW) stress echocardiographic studies with normal range of estimated mean pulmonary arterial pressure (mPAP) (<25 mm Hg) and mean pulmonary artery wedge pressure (mPAWP) (<15 mm Hg) at rest. We used ΔmPAP/Δcardiac output (CO) to assess pulmonary vascular reserve and ΔmPAWP/ΔCO to assess LV cardiac reserve between resting and post-6MW.

Results

During a median period of 3.6 years (IQR 2.0–5.1 years), 25 patients (18%) reached the composite outcome. Both ΔmPAP/ΔCO and ΔmPAWP/ΔCO in patients with events were significantly greater than in those without events (8.9±3.8 mm Hg/L/min vs 3.0±1.7 mm Hg/L/min; p=0.002, and 2.2±0.9 mm Hg/L/min vs 0.9±0.5 mm Hg/L/min; p<0.001, respectively). Patients with both impaired LV cardiac reserve (ΔmPAWP/ΔCO>1.4 mm Hg/L/min) and impaired pulmonary vascular reserve (ΔmPAP/ΔCO>3.0 mm Hg/L/min) had worse outcomes compared with those without these abnormalities (p<0.001).

Conclusion

The 6MW stress echocardiography revealed impaired LV cardiac reserve in SSc patients with normal resting haemodynamics. Furthermore, LV cardiac reserve independently associates with clinical worsening in SSc, providing incremental prognostic utility, in addition to pulmonary vascular parameters.

Deep Learning for Detection of Elevated Pulmonary Artery Wedge Pressure Using Standard Chest X-Ray

BACKGROUND

To accurately diagnose and control heart failure (HF), it is important to carry out a simple assessment of elevated pulmonary arterial wedge pressure (PAWP). The aim of this study was to develop and validate an objective method for detecting elevated PAWP by applying deep learning (DL) to a chest x-ray (CXR).

METHODS

We enrolled 1013 consecutive patients with a right-heart catheter between October 2009 and February 2020. We developed a convolutional neural network to identify patients with elevated PAWP (> 18 mm Hg) as the actual value of PAWP to be used in the dataset for training. In the prospective validation dataset used to detect elevated PAWP, the area under the receiver operating characteristic curve (AUC) was calculated using the DL model that evaluated the CXR.

RESULTS

In the prospective validation dataset, the AUC of the DL model with CXR was not significantly different from the AUC produced by brain natriuretic peptide (BNP) and the echocardiographic left-ventricular diastolic dysfunction (DD) algorithm (DL model: 0.77 vs BNP: 0.77 vs DD algorithm: 0.70; respectively; P = NS for all comparisons); it was, however, significantly higher than the AUC of the cardiothoracic ratio (DL model vs cardiothoracic ratio [CTR]: 0.66, P = 0.044). The model based on 3 parameters (BNP, DD algorithm, and CTR) was improved by adding the DL model (AUC: from 0.80 to 0.86; P = 0.041).

CONCLUSIONS

Applying the DL model based on a CXR (a classical, universal, and low-cost test) is useful for screening for elevated PAWP.

Deep learning for screening of pulmonary hypertension using standard chest X-ray

Background

Early detection of pulmonary hypertension (PH) is crucial to ensure that patients receive timely treatment for the progressive clinical course. The chest X-ray (CXR), a routine method at hospitals, has recommended in order to reveal features supportive of a diagnosis of PH. However, it is well known that the sensitivity and specificity are low.

Purpose

We tested the hypothesis that application of artificial intelligence (AI) to the CXR could identify PH.

Methods

We retrospectively enrolled 900 data with paired CXR and right heart catheter (RHC), including the pulmonary artery pressure, from October 2009 to December 2018. We trained a convolutional neural network to identify patients with PH as actual value of pulmonary artery pressure, using the CXR alone (Figure). The diagnosis of PH was performed using hemodynamic measurements according to the most recent World Symposium standards: mean PAP ≥20 mmHg. We have compared the area under the curve (AUC) by human observers, measurements of CXR images, and AI for detection of PH.

Results

Subjects were divided into two groups with PH (439 patients; mean age, 66±14 years; 233 male) and without PH (461 patients; mean age, 68±12 years; 278 male). In an independent set, AI was the highest diagnostic ability for detection of PH (AUC: 0.71). The AUC by the AI algorithm was significantly higher than the AUC by measurements of CXR images and human observers (0.71 vs. 0.60 and vs. 0.63, all compared p&lt;0.05).

Conclusion

Applying AI to the CXR (a classical, universal, low-cost test) permits the CXR images to serve as a powerful tool to screen for PH.

Neural network

Funding Acknowledgement

Type of funding source: None

Association between Sarcopenia/Lower Muscle Mass and Short-Term Regression of Deep Vein Thrombosis Using Direct Oral Anticoagulants

Advanced age, obesity, and muscle weakness are independent factors in the onset of deep vein thrombosis (DVT). Recently, an association between sarcopenia and DVT has been reported. We hypothesized that sarcopenia related factors, observed by ultrasonography, are associated with the regression effect on the thrombus following anticoagulation therapy. The present study focused on gastrocnemius muscle (GCM) thickness and the GCM's internal echogenic brightness. We examined the association with DVT regression following direct oral anticoagulants (DOACs) treatment.The prospective cohort study period was between October 2017 and August 2018. We enrolled 46 patients diagnosed with DVT by ultrasonography, who were aged >60 years old and treated with DOACs. Sarcopenia was evaluated using the Asian Working Group for Sarcopenia flowchart. The average DOACs treatment period was 94 days, and 29 patients exhibited thrombus regression. On univariate logistic regression analysis, sarcopenia, average GCM diameter index, and gastrocnemius integrated backscatter index were significantly associated with thrombus regression. In a multivariate model, only the average GCM diameter index correlated with thrombus regression.The average GCM diameter index is associated with DVT regression treated with DOACs. Considering the GCM diameter during DVT treatment can be a marker to make a decision for the treatment of DVT.

Association of Local Epicardial Adipose Tissue Depots and Left Ventricular Diastolic Performance in Patients With Preserved Left Ventricular Ejection Fraction

BACKGROUND

Although full-volume quantification of epicardial adipose tissue (EAT) is a predictor of LV diastolic dysfunction (LVDD), how localized EAT depots are linked to LVDD remains unclear. We evaluated the effect of local EAT depots on LV diastolic function parameters in patients with preserved LV ejection fraction (LVEF).Methods and Results:From 423 consecutive patients who underwent cardiac CT angiography, we recruited 252 with sinus rhythm and normal LVEF. The EAT volume index (EATV/body surface area) and the localized EAT thickness around the right coronary artery (EAT_RCA), left anterior descending artery (EAT_LAD), left circumflex artery (EAT_LCX), right ventricle (EAT_RV), left ventricle (EAT_LV), right atrium (EAT_RA), and left atrium (EAT_LA) were measured using cardiac CT. In the LVDD group (n=71), the EATV index (75±30 vs. 64±28 mL/m², P=0.010), EAT_LCX(10.7±3.8 vs. 9.4±3.4 mm, P=0.008), and EAT_LV(2.6±1.6 vs. 2.1±1.4 mm, P=0.024) were greater than in the non-LVDD group (n=181). In contrast, EAT_LCXand EAT_LVwere markedly associated with decreased lateral e' and increased lateral E/e'. Multiple regression analysis indicated that EAT_LCXand EAT_LVwere strongly associated with LV diastolic function parameters.

CONCLUSIONS

Localized EAT depots are linked to altered mitral annular motion. Further study is warranted to clarify whether localized EAT depots are functionally linked to the clinical manifestations of LVDD.

540 Assessment of left ventricular ejection fraction from echocardiographic images using machine learning algorithm

Background

Precise and reliable echocardiographic assessment of LVEF is needed for clinical decision-making. LVEF is currently determined through an observer dependent process that requires manual tracing. To remove this manual tracing step, which is both time-consuming and user dependent, automatic computer aided diagnosis systems may be useful in the clinical setting.

Purpose

The aim of this study was to evaluate whether a 3-dimensional convolutional neural networks (3DCNN) could estimate left ventricular ejection fraction (LVEF) and differentiate types of heart failure (preserved EF/reduced EF) using conventional 2-dimensional echocardiographic images.

Methods

We developed a deep learning model to automatically estimate LVEF from echocardiographic data. The 3DCNN model was trained on a dataset of 340 patients. The dataset creation consisted of three main steps: firstly, for each exam, cine-loops showing the parasternal and apical views were manually selected; then, 10 sequential frames were extracted from each 1 beat and; finally, each frame was pre-processed to fit the learning model. Each patient has 2 views, resulting in a total of 6,800 images. Reference LVEF measurement was calculated by two highly experienced readers in each case.

Results

A good correlation was found between estimated LVEF based on apical 2 and 4 chamber views and reference LVEF (r =0.88, p &lt;0.001) (Figure). For classification of heart failure types based on LVEF (LVEF ≥50% or &lt;50%), the area under the receiver-operating characteristic curve by the 3DCNN algorithm was over 0.95.

Conclusions

The 3DCNN can be applied to estimate and classify the LVEF in the clinical setting. Furthermore, this work will serve as a driver for future research using million image databases.

Abstract 540 Figure.

P1526 Updated prevalence of lambls excrescences using the latest three-dimensional transesophageal echocardiography

Background

Lambl’s excrescences (LEs), filiform strands that occur at sites of cardiac valves, have been suggested the cause cryptogenic stroke. The diagnosis is primarily based upon the echocardiographic study, but conventional two-dimensional transthoracic echocardiography has limitation to detect such as small strands. Latest three dimensional-transesophageal echocardiography (3D-TEE) have high-resolution images with many slices, so small structures are able to be clearly visible and detected.

Purpose

The aim of this study was to assess the prevalence of LEs using the latest 3D-TEE images.

Methods

We retrospectively reviewed consecutive 140 patients who underwent 3D-TEE from November 2018 to May 2019. Forty-seven patients were excluded due to unmeasurable, such as mitral valve prolapse, severe aortic stenosis, prosthetic valves and poor-quality images. We carefully evaluated the mitral and aortic valve leaflets in order to find mobile string structure (diameter &lt;1 mm and length 1–20 mm) in each cardiac cycle. Total analyzed images were over 50 slices per one patient.

Results

Among 93 patients, 83 patients (89%) was detected the presence of LEs. No difference in age and gender were found between patients with LEs and patients without LEs. Of the total 83 patients, there were 35 patients with strands on mitral valve, 32 patients with strands on aortic valve, and 16 patients with strands on both valves. Distribution of LEs at each valve leaflet were shown in Figure. Right coronary cusp of aortic valve (42%) and P2 of mitral valve (35%) were high prevalence among leaflets.

Conclusions

3D-TEE provides an update prevalence of LEs. The prevalence of LEs might be potentially high in the real world.

Abstract P1526 Figure.

Improvement of global longitudinal strain following high-dose chemotherapy and autologous peripheral blood stem cell transplantation in patients with amyloid light-chain cardiac amyloidosis: a case report

Background

Cardiac amyloidosis (CA) is a secondary form of cardiomyopathy where abnormal accumulation of amyloid protein in the myocardial interstitium causes cardiac hypertrophy and myocardial fibrosis. If primary CA advances to heart failure, most patients do not survive for very long after the diagnosis.

Case summary

A 40-year-old man was admitted to our hospital for dyspnoea, progressive anaemia, and decreased appetite. He has diagnosed with amyloid light-chain (AL) amyloidosis. Although BD treatment (bortezomib + dexamethasone) and medical treatment were started, there was no sign of improvement. Then, high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (auto-PBSCT) was initiated. Pretreatment echocardiography revealed typical findings of CA, such as ventricular wall thickening, valvular thickening, diastolic dysfunction, and pericardial effusion. Global longitudinal strain (GLS) was significantly reduced, and bull's-eye mapping showed typical apical sparing. After auto-PBSCT, GLS gradually improved and was almost normal after 2 years. Other echocardiographic parameters, functional status, and laboratory data also showed that there was significant regression of CA.

Discussion

Although the prognosis in primary CA is extremely poor, we achieved long-term survival in a patient with effective high-dose chemotherapy and auto-PBSCT. Global longitudinal strain may be a useful marker of prognosis, regression, and recovery.

Transition of Spleen Volume Long After Pediatric Living Donor Liver Transplantation for Biliary Atresia

PURPOSE

After undergoing the Kasai procedure for biliary atresia (BA), most patients develop severe splenomegaly that tends to be improved by liver transplantation. However, fluctuations in splenic volume long after transplantation remain to be elucidated.

PATIENTS AND METHODS

Seventy-one consecutive patients who had undergone pediatric living donor liver transplantation (LDLT) for BA were followed up in our outpatient clinic for 5 years. They were classified into 3 groups according to their clinical outcomes: a good course group (GC, n = 41) who were maintained on only 1 or without an immunosuppressant, a liver dysfunction group (LD, n = 18) who were maintained on 2 or 3 types of immunosuppressants, and a vascular complication group (VC, n = 11). Splenic and hepatic volumes were calculated by computed tomography in 464 examinations and the values compared before and after the treatment, especially in the VC group.

RESULTS

Splenic volume decreased exponentially in the GC group, with splenic volume to standard spleen volume ratio (SD) being 1.59 (0.33) 5 years after liver transplantation. Splenic volume to standard spleen volume ratios were greater in the VC and LD groups than in the GC group. Patients in the VC group with portal vein stenosis developed liver atrophy and splenomegaly, whereas those with hepatic vein stenosis developed hepatomegaly and splenomegaly. Interventional radiation therapy tended to improve the associated symptoms.

CONCLUSIONS

Fluctuations in splenic volume long after pediatric LDLT for BA may reflect various clinical conditions. Evaluation of both splenic and hepatic volumes can facilitate understanding clinical conditions following pediatric LDLT.

Simulation training for medical emergencies in the dental setting using an inexpensive software application

INTRODUCTION

Every dental provider needs to be educated about medical emergencies to provide safe dental care. Simulation training is available with simulators such as advanced life support manikins and robot patients. However, the purchase and development costs of these simulators are high. We have developed a simulation training course on medical emergencies using an inexpensive software application. The purpose of this study was to evaluate the educational effectiveness of this course.

MATERIALS AND METHODS

Fifty-one dental providers participated in this study from December 2014 to March 2015. Medical simulation software was used to simulate a patient's vital signs. We evaluated participants' ability to diagnose and treat vasovagal syncope or anaphylaxis with an evaluation sheet and conducted a questionnaire before and after the scenario-based simulation training.

RESULTS

The median evaluation sheet score for vasovagal syncope increased significantly from 7/9 before to 9/9 after simulation training. The median score for anaphylaxis also increased significantly from 8/12 to 12/12 (P < .01). For the item "I can treat vasovagal syncope/anaphylaxis adequately," the percentage responding "Strongly agree" or "Agree" increased from 14% to 56% for vasovagal syncope and from 6% to 42% for anaphylaxis with simulation training.

CONCLUSIONS

This simulation course improved participants' ability to diagnose and treat medical emergencies and improved their confidence. This course can be offered inexpensively using a software application.

A clinical application of preload stress echocardiography for predicting future hemodynamic worsening in patients with early-stage heart failure

AIM

To improve the prognosis of patients with heart failure, risk stratification in their early stage is important. We assessed whether the change in transmitral flow (TMF) velocity pattern during preload augmentation can predict future hemodynamic worsening in early-stage heart failure patients with impaired relaxation TMF pattern.

METHODS

We designed a prospective cohort study that included 155 consecutive patients with impaired relaxation (IR) pattern at rest. Preload stress echocardiography was achieved using leg-positive pressure (LPP), and changes in TMF pattern during the LPP was observed during baseline echocardiographic examination. The patients whose TMF pattern developed to pseudonormal (PN) pattern throughout the study period were classified into the change to PN group, and patients whose TMF pattern stayed in IR pattern were classified into the stay in IR group.

RESULTS

The median follow-up period was 17 months. The average age was 68 ± 11 years old, and 97 patients (63%) were male. Among 155 patients, 27 were classified into the change to PN group. A Cox proportional hazard analysis confirmed that the change in the peak atrial systolic TMF velocity during the LPP (ΔA, hazard ratio = 0.58 per 1SD; 95% CI = 0.39-0.88, P = 0.010) was the powerful independent predictor of change into PN pattern. Kaplan-Meier analysis revealed that the patients with ΔA ≤ -7 cm/s had more likely to develop into PN pattern than patients with ΔA > -7 cm/s (P = 0.001).

CONCLUSIONS

Evaluation of a response in TMF during the LPP might provide an incremental diagnostic value to detect future overt heart failure in patients with early-stage heart failure.

Electronic Structure of Ce-Doped and -Undoped Nd_{2}CuO_{4} Superconducting Thin Films Studied by Hard X-Ray Photoemission and Soft X-Ray Absorption Spectroscopy

In order to realize superconductivity in cuprates with the T^{'}-type structure, not only chemical substitution (Ce doping) but also postgrowth reduction annealing is necessary. In the case of thin films, however, well-designed reduction annealing alone without Ce doping can induce superconductivity in the T^{'}-type cuprates. In order to unveil the origin of superconductivity in the Ce-undoped T^{'}-type cuprates, we have performed bulk-sensitive hard x-ray photoemission and soft x-ray absorption spectroscopy on superconducting and nonsuperconducting Nd_{2-x}Ce_{x}CuO_{4} (x=0, 0.15, and 0.19) thin films. By postgrowth annealing, core-level spectra exhibited dramatic changes, which we attributed to the enhancement of core-hole screening in the CuO_{2} plane and the shift of chemical potential along with changes in the band filling. The result suggests that the superconducting Nd_{2}CuO_{4} film is doped with electrons despite the absence of the Ce substitution.

Right Ventricular Function and Beneficial Effects of Cardiac Rehabilitation in Patients With Systolic Chronic Heart Failure

BACKGROUND

It has been recognized that a comprehensive cardiac rehabilitation (CR) program improves mortality in patients with chronic heart failure. On the other hand, the magnitude of the improvement in exercise capacity after CR differs among individuals. The aim of this study was to assess the echocardiographic determinants of responders to CR using preload stress echocardiography.

METHODS

We prospectively enrolled 58 chronic heart failure patients with reduced left ventricular ejection fraction (aged 62 ± 11 years; 69% male; left ventricular ejection fraction 43% ± 7%) who had received optimized medical treatment in a CR program for 5 months. We performed preload echocardiographic studies using leg positive pressure (LPP) to assess the echocardiographic parameters during preload augmentation. We defined 41 patients as a development cohort to assess the predictive value of echocardiographic variables. Next, we validated results in the remaining 17 patients as a validation cohort.

RESULTS

In the development cohort, significant improvement in peak oxygen uptake (VO₂) (>10%) after CR was observed in 58% patients. In a multivariable logistic regression model, the significant predictor of improvement in exercise capacity was right ventricular (RV) strain during LPP (odds ratio: 3.96 per 1 standard deviation; P = 0.01). An RV strain value of -16% during LPP had a good sensitivity of 0.79 and a specificity of 0.71 to identify patients with improvement in peak VO₂. In the validation cohort, an optimal cutoff value of RV strain value was the same (area under the curve: 0.77, sensitivity: 0.78, specificity: 0.65).

CONCLUSIONS

RV strain during LPP may be an echocardiographic parameter for assessing beneficial effects of CR.

Element Selectivity in Second-Harmonic Generation of GaFeO_{3} by a Soft-X-Ray Free-Electron Laser

Nonlinear optical frequency conversion has been challenged to move down to the extreme ultraviolet and x-ray region. However, the extremely low signals have allowed researchers to only perform transmission experiments of the gas phase or ultrathin films. Here, we report second harmonic generation (SHG) of the reflected beam of a soft x-ray free-electron laser from a solid, which is enhanced by the resonant effect. The observation revealed that the double resonance condition can be met by absorption edges for transition metal oxides in the soft x-ray range, and this suggests that the resonant SHG technique can be applicable to a wide range of materials. We discuss the possibility of element-selective SHG spectroscopy measurements in the soft x-ray range.

Effect of the Epicardial Adipose Tissue Volume on the Prevalence of Paroxysmal and Persistent Atrial Fibrillation

BACKGROUND

Although increasing evidence suggests that epicardial adipose tissue volume (EATV) is associated with atrial fibrillation (AF), it is controversial whether there is a dose-response relationship of increasing EATV along the continuum of AF. We evaluated the effect of the EATV on the prevalence of paroxysmal AF (PAF) and persistent AF (PeAF) and the relationships with cardiac structure and functional remodeling.Methods and Results:Subjects who underwent multidetector computed tomography (MDCT) coronary angiography because of symptoms suggestive of coronary artery disease were divided into sinus rhythm (SR) (n=112), PAF (n=133), and PeAF (n=71) groups. The EATV index (EATV/body surface area, mL/m²) was strongly associated with the prevalence of PAF and PeAF on the model adjusted for known AF risk factors. The effect of the EATV index on the prevalence of PeAF, but not on that of PAF, was modified by the left atrial (LA) dimension, suggesting that extension of the LA dimension is related to EATV expansion in PeAF. The cutoff value of the EATV index for the prevalence was higher in PeAF than in PAF (64 vs. 55 mL/m², P<0.01).

CONCLUSIONS

The EATV index is associated with the prevalence of PAF and PeAF, and its cutoff values are predictive for PAF and PeAF development independently of other AF risk factors.

Tensile-Strain-Dependent Spin States in Epitaxial LaCoO_{3} Thin Films

The spin states of Co^{3+} ions in perovskite-type LaCoO_{3}, governed by the complex interplay between the electron-lattice interactions and the strong electron correlations, still remain controversial due to the lack of experimental techniques which can directly detect them. In this Letter, we revealed the tensile-strain dependence of spin states, i.e., the ratio of the high- and low-spin states, in epitaxial thin films and a bulk crystal of LaCoO_{3} via resonant inelastic soft x-ray scattering. A tensile strain as small as 1.0% was found to realize different spin states from that in the bulk.

Endotoxin Metabolism Reflects Hepatic Functional Reserve in End-Stage Liver Disease

BACKGROUND

The hepatic clearance of endotoxin (Et) may reflect hepatic functional reserve and ischemic injury to hepatocytes. Therefore, we examined the relationships between Et activity (EA) and the metrics Pediatric End-Stage Liver Disease (PELD)/Model of End-Stage Liver Disease (MELD) score and alanine transaminase (ALT) levels in the postoperative period.

METHODS

We performed 8 living-donor liver transplantations (LDLTs) for biliary atresia at our center from April 2012 to December 2012. EA was measured by means of an Et activity assay (EAA) in samples collected from a vein 1 day before LDLT, from the portal vein during the intraoperative anhepatic phase, from an artery 1 hour after reperfusion, from an artery on postoperative day (POD) 1, and from an artery or vein at PODs 7 and 14.

RESULTS

EAs generally remained at low levels. EA at the reperfusion period was significantly lowest. The correlation coefficient for the preoperative MELD/PELD score and the EAA was 0.837, and the corresponding P value was .009; thus, there was a significant relationship between the preoperative MELD/PELD score and the EAA. The correlation coefficients for ALT at POD 1 and EA during the anhepatic phase, at 1 hour after reperfusion, and at POD 1 were 0.64, 0.43, and 0.38, respectively, and the P values for these correlations were .08, .67, and .34. Thus, we observed that ALT and EA generally tended to be somewhat directly correlated, but no significant relationships between these 2 metrics were observed.

CONCLUSIONS

Endotoxin metabolism reflects the hepatic functional reserve capacity of end-stage liver disease.

Local Thickness of Epicardial Adipose Tissue Surrounding the Left Anterior Descending Artery Is a Simple Predictor of Coronary Artery Disease - New Prediction Model in Combination With Framingham Risk Score

BACKGROUND

Compared with global cardiac adiposity, the local accumulation of fat surrounding coronary arteries might have a more direct impact on coronary artery disease (CAD). Here, we compared the local epicardial adipose tissue (EAT) thickness and global cardiac adiposity volumes for predicting CAD.Methods and Results:A total of 197 consecutive subjects underwent 320-slice multi-detector computed tomography coronary angiography and were segregated into CAD (≥1 coronary artery branch stenosis ≥50%) and non-CAD groups. EAT thickness was measured at the right coronary artery (EAT_RCA), the left anterior descending artery (EAT_LAD), and the left circumflex artery (EAT_LCX). Although EAT_RCAand EAT_LCXwere similar between the 2 groups, EAT_LADwas larger in the CAD group than in the non-CAD group (5.45±2.16 mm vs. 6.86±2.19 mm, P<0.001). EAT_LAD, after correcting for confounding factors, was strongly associated with CAD (r=0.276, P<0.001) and Gensini score (r=0.239, P<0.001). On multiple regression analysis, Framingham risk score combined with EAT_LADwas a strong predictor of CAD (adjusted R²=0.121; P<0.001).

CONCLUSIONS

The local fat thickness surrounding the LAD is a simple and useful surrogate marker for estimating the presence, severity, and extent of CAD, independent of classical cardiovascular risk factors.

Antibody Drug Treatment for Steroid-Resistant Rejection After Pediatric Living Donor Liver Transplantation: A Single-Center Experience

BACKGROUND

Antibody drugs have been used to treat steroid-resistant rejection (SRR) after liver transplantation. Although anti-thymocyte globulin has been used for SRR after liver transplantation in place of muromonab-CD3 since 2011 in Japan, the effectiveness of anti-thymocyte globulin after pediatric living-donor liver transplantation (LDLT) has not yet been reported. The aim of this study was to evaluate the effectiveness of antibody drug treatment for SRR after pediatric LDLT in our single center.

METHODS

Between May 2001 and December 2013, 220 pediatric LDLTs were performed. Initial immunosuppression after LDLT included tacrolimus and methylprednisolone therapy. Acute rejection was diagnosed by use of a liver biopsy and the administration of steroid pulse treatment, and SRR was defined as acute rejection refractory to the steroid pulse treatment.

RESULTS

Acute rejection and SRR occurred in 74 (33.6%) and 16 patients (7.3%), respectively. The graft survival rates of non-SRR and SRR were 92.4% and 87.5%, respectively (P = .464). The median concentration of alanine aminotransferase before and after the administration of antibody drug was 193.5 mU/mL (range, 8-508) and 78 mU/mL (range, 9-655), respectively (P = .012). The median rejection activity index before and after the administration of antibody drugs was 5 (range, 2-9) and 1 (range, 0-9), respectively (P = .004). After antibody drug treatment, 12 patients had cytomegalovirus infections, 2 patients had Epstein-Barr virus infections, 3 patients had respiratory infections, and 1 patient had encephalitis. The cause of death in 1 patient with SRR was recurrence of infant fulminant hepatic failure.

CONCLUSIONS

Antibody drug treatment for SRR after pediatric LDLT is safe and effective.