Identification of BBOX1 as a Therapeutic Target in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive and highly lethal disease. Because of its heterogeneity and lack of hormone receptors or HER2 expression, targeted therapy is limited. Here, by performing a functional siRNA screening for 2-OG-dependent enzymes, we identified gamma-butyrobetaine hydroxylase 1 (BBOX1) as an essential gene for TNBC tumorigenesis. BBOX1 depletion inhibits TNBC cell growth while not affecting normal breast cells. Mechanistically, BBOX1 binds with the calcium channel inositol-1,4,5-trisphosphate receptor type 3 (IP3R3) in an enzymatic-dependent manner and prevents its ubiquitination and proteasomal degradation. BBOX1 depletion suppresses IP3R3-mediated endoplasmic reticulum calcium release, therefore impairing calcium-dependent energy-generating processes including mitochondrial respiration and mTORC1-mediated glycolysis, which leads to apoptosis and impaired cell-cycle progression in TNBC cells. Therapeutically, genetic depletion or pharmacologic inhibition of BBOX1 inhibits TNBC tumor growth in vitro and in vivo. Our study highlights the importance of targeting the previously uncharacterized BBOX1-IP3R3-calcium oncogenic signaling axis in TNBC. SIGNIFICANCE: We provide evidence from unbiased screens that BBOX1 is a potential therapeutic target in TNBC and that genetic knockdown or pharmacologic inhibition of BBOX1 leads to decreased TNBC cell fitness. This study lays the foundation for developing effective BBOX1 inhibitors for treatment of this lethal disease.This article is highlighted in the In This Issue feature, p. 1611.

THU0389 OBESITY IS A STRONG PREDICTOR OF WORSE CLINICAL OUTCOMES AND TREATMENT RESPONSES TO BIOLOGICS IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Background:

Obesity population are rising rapidly and have become a major health issue. Studies have shown that obesity is a low-grade inflammatory status characterized by increase in proinflammatory cytokines.

Objectives:

To examine the impact of overweight or obesity on disease activity and treatment responses to biologics in patients with ankylosing spondylitis (AS) in a real-world setting.

Methods:

Body mass index (BMI) is available in 1013 patients from the Chinese Ankylosing Spondylitis Imaging Cohort (CASPIC). Differences in clinical outcomes (such as BASDAI, ASDAS, BASFI, and ASAS HI) and treatment responses to biologics (ΔBASDAI and ΔASDAS) over 3, 6, 9, and 12 months are assessed between BMI categories (normal weight BMI <24 kg/m2; overweight BMI=24-28 kg/m2; obesity BMI ≥28 kg/m2) using Kruskal-Wallis test. The association between BMI and clinical characteristics and treatment responses to biologics was determined, and multivariate median regression analyses were conducted to adjust for confounders (such as age, gender, smoke, and HLA-B27).

Results:

Among 1013 patients with AS, overweight accounts for 33%, while obesity for 12.4%. There were significant differences between patients who were obese or overweight and those with a normal weight regarding clinical outcomes (BASDAI: 2.90/2.56 vs 2.21; ASDAS-CRP: 2.20/1.99 vs 1.81; BASFI: 2.13/1.69 vs 1.38; ASAS HI: 6.87/5.29 vs 5.12 and BASMI: 2.35/1.76 vs 1.62; all P<0.05). After adjusting for age, gender, smoke, and HLA-B27, obesity remained associated with higher disease activity (BASDAI: β=0.55, P=0.005; ASDAS-CRP: β=0.40, P<0.001), poorer functional capacity (BASFI: β=0.58, P=0.001), worse health index (ASAS HI: β=1.92, P<0.001) and metrology index (BASMI: β=0.71, P=0.013). For TNFi users, BMI was found to be negatively correlated with changes in disease activity (ΔBASDAI and ΔASDAS) in the multivariate regression model (all P<0.05), and overweight and obese patients showed an unsatisfactory reduction in disease activity during 3-month, 6-month, 9-month, and 12-month follow-up period, compared to normal weight patients (all P<0.05).

Conclusion:

Overweight or obesity impacts greatly on clinical outcomes and treatment responses to biologics in patients with ankylosing spondylitis, which argues strongly for obesity management to become central to prevention and treatment strategies in patients with AS.

References:

[1]Maachi M, Pieroni L, Bruckert E, et al. Systemic low-grade inflammation is related to both circulating and adipose tissue TNFalpha, leptin and IL-6 levels in obese women. Int J Obes Relat Metab Disord 2004;28:993–7.

Figure 1.

Changes of disease activity for TNFi users during 3-, 6-, 9- and 12-month follow-up according to BMI categories. a: vs. normal weight, P<0.05 in 3 months; b: vs. normal weight, P<0.05 in 6 months; c: vs. normal weight, P<0.05 in 9 months; d: vs. normal weight, P<0.05 in 12 months.

Acknowledgments:

We appreciate the contribution of the present or former members of the CASPIC study group.

Disclosure of Interests:

None declared

Radiological role in the detection, diagnosis and monitoring for the coronavirus disease 2019 (COVID-19)

OBJECTIVE

Coronavirus disease 2019 (COVID-19) has officially been declared a pandemic by the World Health Organization (WHO). Radiological examinations, especially computed tomography (CT), play an important role in the fight against COVID-19. A comprehensive and timely review of radiological role in the fight against COVID-19 remains urgent and mandatory. Hence, the aim of this review is to summarize the radiological role in the fight against COVID-19. This review of current studies on COVID-19 provides insight into the radiological role in the detection, diagnosis, and monitoring for COVID-19. The typical radiological features of COVID-19 include bilateral, multifocal, and multilobar ground glass opacification with patchy consolidation, a peripheral/subpleural or posterior distribution (or both), mainly in the lower lobes. A combination of chest CT and repeat Reverse Transcription-Polymerase Chain Reaction (RT-PCR) testing may be beneficial for the diagnosis of COVID-19 in the setting of strongly clinical suspicion. Chest CT may improve the sensitivity for COVID-19 diagnosis, but patients' exposure to radiation should be kept as low as possible especially for children and pregnant women patients.

Demonstration of Controlled-Phase Gates between Two Error-Correctable Photonic Qubits

To realize fault-tolerant quantum computing, it is necessary to store quantum information in logical qubits with error correction functions, realized by distributing a logical state among multiple physical qubits or by encoding it in the Hilbert space of a high-dimensional system. Quantum gate operations between these error-correctable logical qubits, which are essential for implementation of any practical quantum computational task, have not been experimentally demonstrated yet. Here we demonstrate a geometric method for realizing controlled-phase gates between two logical qubits encoded in photonic fields stored in cavities. The gates are realized by dispersively coupling an ancillary superconducting qubit to these cavities and driving it to make a cyclic evolution depending on the joint photonic state of the cavities, which produces a conditional geometric phase. We first realize phase gates for photonic qubits with the logical basis states encoded in two quasiorthogonal coherent states, which have important implications for continuous-variable-based quantum computation. Then we use this geometric method to implement a controlled-phase gate between two binomially encoded logical qubits, which have an error-correctable function.

Survey for toxigenic Fusarium species on maize kernels in China

Maize is currently the most important crop in China. A major concern in maize production is maize ear rot caused by Fusarium spp., which results in yield losses, reduction of seed quality and the accumulation of mycotoxins in the harvested grains. To identify the importance of the different Fusarium species in maize infection, we performed a comprehensive survey on 9,000 asymptomatic and randomly collected maize kernels. Seeds were collected from 12 different provinces covering all major maize growing areas in China and included five maize varieties. In total 1,022 Fusarium isolates were retrieved that were identified based on morphological characteristics, by species specific diagnostic PCRs and by EF1-α gene sequencing. Eight different species were identified: Fusarium verticillioides (75.34%), Fusarium graminearum (8.32%), Fusarium proliferatum (7.14%), Fusarium subglutinans (4.11%), Fusarium meridionale (1.57%), Fusarium oxysporum (1.37%), Fusarium semitectum (1.17%), and Fusarium asiaticum (0.98%). The distribution of Fusarium species was found to be different in different regions with the largest diversity observed in Hubei province, where all eight Fusarium species were isolated. Genetic chemotyping within the F. graminearum species complex indicated that all of the 85 F. graminearum isolates showed the 15-acetyldeoxynivalenol chemotype, whereas all F. asiaticum (n=10) and F. meridionale (n=16) isolates had the nivalenol chemotype even when isolated from the same maize field. To our knowledge this is the largest collection of Fusarium isolates from maize and further exploitations of this collection are discussed.

Safety, feasibility, and effect of an enhanced nutritional support pathway including extended preoperative and home enteral nutrition in patients undergoing enhanced recovery after esophagectomy: a pilot randomized clinical trial

The aims of this pilot study are to evaluate the feasibility, safety, and effectiveness of conducting an enhanced nutritional support pathway including extended preoperative nutritional support and one month home enteral nutrition (HEN) for patients who underwent enhanced recovery after esophagectomy. We implemented extended preoperative nutritional support and one month HEN after discharge for patients randomized into an enhanced nutrition group and implemented standard nutritional support for patients randomized into a conventional nutrition group. Except the nutritional support program, both group patients underwent the same standardized enhanced recovery after surgery programs of esophagectomy based on published guidelines. Patients were assessed at preoperative day, postoperative day 7 (POD7), and POD30 for perioperative outcomes and nutritional status. To facilitate the determination of an effect size for subsequent appropriately powered randomized clinical trials and assess the effectiveness, the primary outcome we chose was the weight change before and after esophagectomy. Other outcomes including body mass index (BMI), lean body mass (LBM), appendicular skeletal muscle mass index (ASMI), nutrition-related complications, and quality of life (QoL) were also analyzed. The intention-to-treat analysis of the 50 randomized patients showed that there was no significant difference in baseline characteristics. The weight (-2.03 ± 2.28 kg vs. -4.05 ± 3.13 kg, P = 0.012), BMI (-0.73 ± 0.79 kg/m2 vs. -1.48 ± 1.11 kg/m2, P = 0.008), and ASMI (-1.10 ± 0.37 kg/m2 vs. -1.60 ± 0.66 kg/m2, P = 0.010) loss of patients in the enhanced nutrition group were obviously decreased compared to the conventional nutrition group at POD30. In particular, LBM (48.90 ± 9.69 kg vs. 41.96 ± 9.37 kg, p = 0.031) and ASMI (7.56 ± 1.07 kg/m2 vs. 6.50 ± 0.97 kg/m2, P = 0.003) in the enhanced nutrition group were significantly higher compared to the conventional nutrition group at POD30, despite no significant change between pre- and postoperation. In addition, European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 scores revealed that enhanced nutritional support improved the QoL of patients in physical function (75.13 ± 9.72 vs. 68.33 ± 7.68, P = 0.009) and fatigue symptom (42.27 ± 9.93 vs. 49.07 ± 11.33, P = 0.028) compared to conventional nutritional support. This pilot study demonstrated that an enhanced nutritional support pathway including extended preoperative nutritional support and HEN was feasible, safe, and might be beneficial to patients who underwent enhanced recovery after esophagectomy. An appropriately powered trial is warranted to confirm the efficacy of this approach.

TBK1 Is a Synthetic Lethal Target in Cancer with VHL Loss

TANK binding kinase 1 (TBK1) is an important kinase involved in the innate immune response. Here we discover that TBK1 is hyperactivated by von Hippel-Lindau (VHL) loss or hypoxia in cancer cells. Tumors from patients with kidney cancer with VHL loss display elevated TBK1 phosphorylation. Loss of TBK1 via genetic ablation, pharmacologic inhibition, or a new cereblon-based proteolysis targeting chimera specifically inhibits VHL-deficient kidney cancer cell growth, while leaving VHL wild-type cells intact. TBK1 depletion also significantly blunts kidney tumorigenesis in an orthotopic xenograft model in vivo. Mechanistically, TBK1 hydroxylation on Proline 48 triggers VHL as well as the phosphatase PPM1B binding that leads to decreased TBK1 phosphorylation. We identify that TBK1 phosphorylates p62/SQSTM1 on Ser366, which is essential for p62 stability and kidney cancer cell proliferation. Our results establish that TBK1, distinct from its role in innate immune signaling, is a synthetic lethal target in cancer with VHL loss. SIGNIFICANCE: The mechanisms that lead to TBK1 activation in cancer and whether this activation is connected to its role in innate immunity remain unclear. Here, we discover that TBK1, distinct from its role in innate immunity, is activated by VHL loss or hypoxia in cancer.See related commentary by Bakouny and Barbie, p. 348.This article is highlighted in the In This Issue feature, p. 327.

Genome-wide Screening Identifies SFMBT1 as an Oncogenic Driver in Cancer with VHL Loss

von Hippel-Lindau (VHL) is a critical tumor suppressor in clear cell renal cell carcinomas (ccRCCs). It is important to identify additional therapeutic targets in ccRCC downstream of VHL loss besides hypoxia-inducible factor 2α (HIF2α). By performing a genome-wide screen, we identified Scm-like with four malignant brain tumor domains 1 (SFMBT1) as a candidate pVHL target. SFMBT1 was considered to be a transcriptional repressor but its role in cancer remains unclear. ccRCC patients with VHL loss-of-function mutations displayed elevated SFMBT1 protein levels. SFMBT1 hydroxylation on Proline residue 651 by EglN1 mediated its ubiquitination and degradation governed by pVHL. Depletion of SFMBT1 abolished ccRCC cell proliferation in vitro and inhibited orthotopic tumor growth in vivo. Integrated analyses of ChIP-seq, RNA-seq, and patient prognosis identified sphingosine kinase 1 (SPHK1) as a key SFMBT1 target gene contributing to its oncogenic phenotype. Therefore, the pVHL-SFMBT1-SPHK1 axis serves as a potential therapeutic avenue for ccRCC.

Relationship Between Cognitive Dysfunction and Systemic Metabolic Disorders in Elderly: Dementia Might be a Systematic Disease

Vascular cognitive impairment (VCI) plays an important role in dementia in elderly people, and refers to the contribution of vascular pathology to the entire spectrum of cognitive disorders, ranging from mild cognitive impairment to severe dementia, as well as the pathological spectrum, from 'pure' Alzheimer disease through degrees of vascular comorbidity to 'pure' vascular dementia. In the present study, we investigated the relationship between cognitive dysfunction and systemic metabolic disorders, by employing deep learning (DL). We studied 202 patients (73.4 ± 13.0 years), 94.6% of whom were undergoing treatment for lifestyle diseases, and 68.8% of whom had a history of cerebrovascular disorder. We evaluated cognitive dysfunction by performing a Mini Mental State Examination (MMSE). We performed general blood examination, including Complete Blood Count and Basic Metabolic Panel, and measured cerebral blood oxygenation in the prefrontal cortex (PFC) using time-resolved near infrared spectroscopy (TNIRS). We then used deep neural networks to assess the MMSE scores of the subjects based on the TNIRS parameters and the blood examination data, independently. Next, we compared predicted MMSE scores based on the TNIRS and the blood examination. There was a significant positive correlation between the TNIRS parameters and the blood examination data (r = 0.6, p < 0.01). These observations suggest that cognitive dysfunction in patients with VCI may be caused by combinations of systemic metabolic disorders such as energy and oxygen metabolisms and cerebral circulatory disturbance due to arteriosclerosis resulting from lifestyle-related diseases.

MRFAP1 plays a protective role in neddylation inhibitor MLN4924-mediated gastric cancer cell death

OBJECTIVE

MLN4924 is a second-generation small molecule inhibitor with anti-cancer activity that inhibits neddylation activation enzyme (NAE), subsequently blocking the neddylation-dependent activation of Cullin-RING E3 ligases (CRLs). Mof4 family associated protein 1 (MRFAP1) is a highly conserved, short half-life protein and one of the most up-regulated proteins in response to MLN4924 treatment. MRFAP1 has been identified as a novel cell cycle-related protein and a regulatory component monitoring and preventing genomic instability. However, whether MRFAP1 plays a role in MLN4924-mediated cancer cell death remains elusive.

PATIENTS AND METHODS

The expression of MRFAP1 in gastric cancer clinic samples was detected by Real-time PCR and Western blot. CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 system was used to knockout MRFAP1 gene in both AGS and SGC-7901 cells. The proliferation of GC cells was measured by CCK8 assay. The cell cycle distribution of GC cells was determined by fluorescence-activated cell sorting (FACS) assay. Co-immunoprecipitation assay was used to determine the interaction between MRFAP1 and P27.

RESULTS

MRFAP1 was downregulated in clinic gastric cancer samples at post-translational level. Overexpression of MRFAP1 decreased gastric cancer cells proliferation. CRISPR-mediated knockout of MRFAP1 increased the cytotoxicity of MLN4924 by augmenting MLN4924-induced G2/M arrest and apoptosis against gastric cancer cells. At the molecular level, we found that MLN4924 induced the interaction between P27 and MRFAP1, the latter associated with P27, which was further stabilized in response to MLN4924 treatment.

CONCLUSIONS

We showed a protective role of MRFAP1 in gastric cancer cells with MLN4924 treatment and suggested the potential possibility to combine MLN4924 with MRFAP1 inhibition to treat gastric cancer.

Long Non-Coding RNA HOTAIR as Ideal Biomarker for the Diagnosis of Various Carcinomas

BACKGROUND

HOTAIR is a variety of long non-coding RNA that has been recognized as a predictive factor for most cancers. This meta-analysis examined the complete investigative effectiveness of the level of HOTAIR expression for various cancers.

METHODS

Research on the diagnostic value of HOTAIR in different carcinomas was acquired by searching the online databases. Twelve studies consisting of 927 cancer cases were chosen in our research. The sensitivity as well as specificity of the involved articles was helpful to establish the summary receiver operator characteristic (SROC) curve in addition to compute the area under the SROC curve (AUC). In addition, a meta-regression test was done to determine the heterogeneity sources among available studies.

RESULTS

The combined effect sizes calculated from involved studies were as follows: sensitivity, 0.73; specificity, 0.83; PLR, 4.4; NLR, 0.32; DOR, 14; and an AUC of 0.85. Deeks' funnel plot asymmetry test showed no probable publication bias. The meta-regression analyses signified that the type of ethnicity is the major cause of heterogeneity.

CONCLUSIONS

The present meta-analysis suggested that elevated HOTAIR can be considered as a relatively accurate marker for cancer diagnosis and can be applied to support the diagnosis of various cancers.

Witnessing Quantum Resource Conversion within Deterministic Quantum Computation Using One Pure Superconducting Qubit

Deterministic quantum computation with one qubit (DQC1) is iconic in highlighting that exponential quantum speedup may be achieved with negligible entanglement. Its discovery catalyzed a heated study of general quantum resources, and various conjectures regarding their role in DQC1's performance advantage. Coherence and discord are prominent candidates, respectively, characterizing nonclassicality within localized and correlated systems. Here we realize DQC1 within a superconducting system, engineered such that the dynamics of coherence and discord can be tracked throughout its execution. We experimentally confirm that DQC1 acts as a resource converter, consuming coherence to generate discord during its operation. Our results highlight superconducting circuits as a promising platform for both realizing DQC1 and related algorithms, and experimentally characterizing resource dynamics within quantum protocols.

Overexpression of TUG1 promotes neuronal death after cerebral infarction by regulating microRNA-9

OBJECTIVE

This study aims at investigating whether TUG1 (Taurine Upregulated Gene 1) can regulate FOXO3 expression through competitive binding to microRNA-9, thus leading to increased neuronal death and promoting the occurrence and development of acute cerebral infarction.

MATERIALS AND METHODS

TUG1 and FOXO3 expressions in cerebral cortical neurons of MCAO mice, control mice and primary neurons were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The effects of TUG1 and FOXO3 on neuronal apoptosis were determined by TUNEL after cerebral infarction area was stained with TTC. The binding condition of microRNA-9, TUG1 and FOXO3 was verified by the Luciferase reporter gene assay. Western blot was performed to detect the protein expressions of B-cell lymphoma-2 (BCL-2) and BCL2-Associated X (BAX) after altering the TUG1 or FOXO3 expression in primary neurons.

RESULTS

TUG1 and FOXO3 were overexpressed in cerebral cortical neurons of MCAO mice and primary neurons. The inhibition of TUG1 or FOXO3 resulted in less neuronal apoptosis. Luciferase reporter gene assay demonstrated that TUG1 regulates FOXO3 via TUG1/microRNA-9/FOXO3 regulatory network. Besides, TUG1 inhibited BCL-2 but promoted BAX expression in primary neurons.

CONCLUSIONS

The overexpression of TUG1 can promote neuronal death after cerebral infarction in mice by competitive binding to microRNA-9 and promotion of FOXO3 expression.

Methionine and arginine supplementation alter inflammatory and oxidative stress responses during lipopolysaccharide challenge in bovine mammary epithelial cells in vitro

Mastitis, inflammation of the udder, is one of the most common diseases hampering milk yield of dairy cows. Methionine (Met) and arginine (Arg) are key nutrients with potential to regulate inflammation and oxidative stress. The aim of this study was to evaluate the effect of increased supply of Met and Arg on mRNA and protein abundance associated with innate immune response and redox balance during lipopolysaccharide (LPS) stimulation in primary bovine mammary epithelial cells (BMEC). Primary BMEC (n = 4 replicates per treatment) were pre-incubated for 12 h in media with the following amino acid combinations: ideal profile of amino acids (control; Con), increased Met supply (incMet), increased Arg supply (incArg), and increased supply of Met and Arg (incMetArg). Subsequently, cells were challenged with or without LPS (1 µg/mL) and incubated for 6 h. Data were analyzed as a 2 × 2 × 2 factorial using the MIXED procedure of SAS 9.4 (SAS Institute Inc., Cary, NC). The downregulation of SLC36A1 and SLC7A1 mRNA abundance induced by LPS was attenuated in the incArg cultures. Although challenge with LPS led to lower abundance of proteins related to the antioxidant response (NFE2L2, NQO1, GPX1), lower levels of ATG7, and lower mRNA abundance of GPX3, we found little effect in cultures with incMet or incArg. Cultures with incMet, incArg, or incMetArg led to attenuation of the upregulation of SOD2 and NOS2 induced by LPS. Abundance of phosphorylated p65 (RELA) was greater after LPS stimulation, but the response was attenuated in cultures with incMet. The greater ratio of pRELA to total RELA in responses to LPS was also attenuated in cultures with incMetArg. The greater mRNA abundance of the proinflammatory cytokine IL1B induced by LPS was attenuated in cultures with incMet, and the same trend induced by LPS on CXCL2 was also alleviated in cultures with incArg. Overall, the data suggest that greater supply of Met and Arg alleviated the proinflammatory responses triggered by LPS through controlling the abundance of proinflammatory cytokines and chemokines and activity of NF-κB. Little benefit on oxidative stress induced by LPS challenge in BMEC was detected with greater supply of Met and Arg.

MiR-17-5p promotes cervical cancer cell proliferation and metastasis by targeting transforming growth factor-β receptor 2

OBJECTIVE

MicroRNAs (miRNAs) play critical roles in post-translational gene expression. The aim of the current study was to investigate the effects of miR-17-5p in cervical cancer.

PATIENTS AND METHODS

Fifteen clinical cervical cancer tissue samples, as well as their paired adjacent noncancerous tissues, were collected. The microarray was performed to identify differential miRNAs in cervical cancer. Luciferase reporter assay was conducted to identify the target gene of selected miRNA. SiHa was transfected with mimics, inhibitors as well as negative controls of miR-17-5p and Targeting Transforming Growth Factor-β Receptor 2 (TGFBR2) open reading frame or siRNA. Cell counting kit-8 (CCK-8) assay and transwell experiment were performed to detect the proliferation rate and metastasis, respectively. Western blotting and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis were used to analyze TGFBR2 expression. Balb/c nude mice were utilized to verify the effect of miR-17-5p in vivo.

RESULTS

Microarray analysis identified miR-17-5p as our interesting miRNA, and luciferase reporter assay identified TGFBR2 as its target gene. MiR-17-5p overexpression significantly enhanced cervical cancer cell proliferation and metastasis. In-vivo study also verified that miR-17-5p overexpression stimulated cervical cancer growth.

CONCLUSIONS

MiR-17-5p enhances cervical cancer proliferation and metastasis via targeting TGFBR2. It is proposed that targeting miR-17-5p may be a promising therapeutic approach for cervical cancer.

29Prognostic safety of automatic cancellation of rest myocardial perfusion scan by machine learning: a report from multicenter REFINE SPECT registry of new generation SPECT

Background

We aimed to develop a machine learning (ML) computer score derived from stress imaging and clinical data, which indicates if the rest scan could be automatically and safely canceled in the routine stress/rest myocardial perfusion SPECT (MPS).

Methods

A total of 20414 stress/rest cases from the REFINE SPECT registry collected from 5 sites in 3 countries with Tc-99m-based MPS images, clinical data, and clinical follow-up were included in the study. All images were automatically processed at our Medical Center. The automatically generated myocardial contours were checked by experienced technologists. In total, 93 variables (26 clinical, 17 stress-test, and 50 stress-imaging variables) were used to build a LogitBoost model for prediction of adverse events (AE), including coronary revascularization, death, myocardial infarction, and unstable angina. 10-fold cross-validation was performed to separate test from validation data for the assessment of ML. The overall ML predictive performance was compared to quantitative (stress total perfusion deficit [TPD]) by the area under the receiver operating characteristic curves (AUC). ML cut-off (ML1) to simulate the decision of cancellation of the rest scan was set to result in the same % of normal scans as these determined by the normal clinical reader diagnosis on a 4-point scale in the whole population, or the same % of scans with visual summed stress scores (SSS) = 0 in the subpopulation with available SSS. A second ML cutoff (ML2) was established to achieve a 1% annual risk of AE. The annual risk of AE of the normal ML score was compared with normal clinical diagnosis and with the finding of SSS = 0.

Results

The mean follow-up interval was 4.7±1.5 years. Overall, 3542 AE were observed (3.7% annual risk). The AUC for AE was higher for ML (0.780±0.005) than for stress TPD (0.698±0.006) (p<0.001). Normal clinical diagnosis was reported in 60% cases. In 70% (14242 scans) with available segmental scores, 53% had SSS=0. ML1 and ML2 thresholds were compared with normal visual diagnosis and with SSS = 0 for AE (Figure). ML1 achieved a lower annual risk (1.5%) than normal clinical diagnosis (2.1%) or SSS = 0 (1.6% versus 2.3%) (p<0.001). The more conservative ML2 threshold with a 1% annual risk of AE resulted in a 40% canceling rate.

Figure 1

Conclusion

ML could be used to automatically cancel the rest MPS scan with the same proportion as using normal visual MPS reading, but with significantly lower AE rate in stress-only scans.

Acknowledgement/Funding

R01HL089765 from the National Heart, Lung, and Blood Institute/National Institutes of Health (NHLBI/NIH)

P2437Screening for cardiac relaxation abnormalities using surface ECG wavelets for identifying high-risk cardiac phenotypic abnormalities

Background

The impairment of myocardial relaxation is a strong predictor of all-cause mortality and has been proposed to be a potential tool for cardiovascular (CV) risk stratification. We investigated a novel signal-processed electrocardiography (spECG) technique to extract the features of abnormal myocardial relaxation as a screening tool to identify high-risk CV patients.

Methods

Time–frequency-energy features extracted from continuous wavelet-transformed spECG (Fig. A) were obtained in 1,006 cases. A machine learning model was trained for predicting abnormal myocardial relaxation as a screening tool for detecting high-risk CV patients. High-risk CV phenotype was defined as presence of LV hypertrophy, advanced LV diastolic dysfunction (grade 2 or 3), LV ejection fraction <50%, and/or significant valvular heart disease.

Results

After training with 5-fold cross validation using data from 810 patients, the machine learning model when tested in an independent hold-out validation set of 180 cases, showed an area under receiver-operating characteristic curve (AUC) of 0.83 (p<0.001) for prediction of myocardial relaxation impairment (Fig. B). A prediction of abnormal relaxation was associated with older patients (64±11 vs. 45±16 years old, p<0.001) with a higher prevalence of coronary artery disease (23% vs. 7%, p=0.004), hypertension (70% vs. 40%, p<0.001), and diabetes (30% vs. 9%, p=0.001). Furthermore, a prediction of abnormal myocardial relaxation was associated with increased likelihood of high-risk CV phenotypes (Odds ratio: 3.93, p<0.001) including LV hypertrophy (Odds ratio: 2.62, p=0.028), advanced LV diastolic dysfunction (Odds ratio: 11.4, p=0.020), and LV ejection fraction <50% (Odds ratio 10.5, p=0.025). Age and gender modified the prediction of abnormal relaxation with higher diagnostic value seen for patients under 60 years (Fig C, AUC: 0.88, p<0.001) and in male patients (Fig D, AUC: 0.87, p<0.001). The algorithm for abnormal relaxation also showed robust prediction of LV ejection fraction <50% (Fig E, AUC: 0.91, p<0.001) in male patients. spECG showed significant net reclassification improvement (0.47, p<0.001) and integrated discrimination improvement (0.16, p<0.001) over traditional surface ECG interpretation using Glasgow score for predicting abnormal relaxation and other high-risk phenotypic presentations.

ROC curves

Conclusion

The spECG provided a robust prediction of abnormal myocardial relaxation and may be a valuable screening strategy for early detection of high-risk cardiac structural and functional abnormalities.