P1252Diagnostic performance of quantitative flow ratio from coronary angiography versus fractional flow reserve from computed tomography

Background

QFR and FFRCT are recently developed, less-invasive techniques for functional assessment of coronary artery disease.

Objectives

We compared the diagnostic performance between fractional flow reserve derived from computed tomography (FFRCT) and quantitative flow ratio (QFR) derived from coronary angiography, using FFR as the standard reference.

Methods

We measured FFRCT, QFR and FFR in 152 patients (233 vessels) with stable coronary artery disease.

Results

QFR was highly correlated with FFR (r=0.78, p<0.001), while FFRCT was moderately correlated with FFR (r=0.63, p<0.001). Both QFR and FFRCT showed good agreements with FFR, presenting small values of mean difference and root-mean-squared deviation (FFR -QFR: 0.02±0.09 and FFR -FFRCT: 0.03±0.11). The AUC of QFR was significantly greater than that of 3D-QCA-derived %DS (0.93 vs. 0.78; difference: 0.15; 95% CI: 0.09 to 0.20; p<0.001). The AUC of FFRCTwas significantly greater than that of CCTA-derived %DS (0.82 vs. 0.70; difference: 0.12; 95% CI: 0.05 to 0.19; p<0.001). The AUC of QFR was significantly greater than that of FFRCT (0.93 vs. 0.82; difference: 0.11; 95% CI: 0.05 to 0.16; p<0.001). The sensitivity, specificity, positive predictive value, and negative predictive valueof QFR ≤0.80 for predicting FFR ≤0.80 were 90%, 82%, 81%, and 90%, respectively. Those of FFRCT ≤0.80 for predicting FFR ≤0.80 were 82%, 70%, 70%, and 82%, respectively. The diagnostic accuracy of QFR ≤0.80 for predicting FFR ≤0.80 was 85% [95% confidence interval: 81% to 89%], while that of FFRCT≤0.80 for predicting FFR ≤0.80was 76% [95% confidence interval: 70% to 80%].

Figure 1. Comparison of FFR ≤0.80 predictors

Conclusions

Both QFR and FFRCTpossessed the ability to accurately evaluate the functional severity of coronary stenosis.

6108Efficacy of the PCSK9 inhibitor for lipid-rich coronary plaque reduction: a near-infrared spectroscopy analysis

Background

Recently, some studies have highlighted proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors produce incremental low-density lipoprotein cholesterol (LDL-C) lowering effect. However, it is unknown whether the lipid composition of plaque changes is associated with serum LDL-C reduction due to PCSK9 inhibitors administration.

Purpose

The purpose of this study was to determine the effects of PCSK9 inhibitor (PCSK9i) on coronary plaque component in patients with a history of coronary artery disease (CAD) assessed by near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS).

Methods

A total of 67 non-culprit coronary segments were identified in 34 patients. These lesions were analyzed utilizing NIRS-IVUS at baseline and follow-up coronary angiography (CAG). The subjects were divided into two groups according to lipid-lowering treatment; administration of PCSK9i group (PCSK9i: 19 segments, 9 patients) and traditional statin treatment group (Control: 48 segments, 25 patients). The change of lipid-rich plaque distribution between baseline and follow-up NIRS-IVUS was defined as the change of maximal lipid core burden index (LCBI) score for each of the 4-mm longitudinal segments (maxLCBI4mm).

Results

Mean duration from baseline to follow-up CAG was 239.4±52.4 days in the PCSK9i group and 341.0±84.1 days in the Control group (p<0.001). Despite the higher total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the PCSK9i group at baseline (206.6±40.9 mg/dl vs. 168.5±37.1 mg/dl, 131.5±35.4 mg/dl vs. 100.0±29.5 mg/dl; respectively, p<0.001 for both), the PCSK9i group was significantly lower TC and LDL-C at the follow-up (111.5±23.5 mg/dl vs. 157.4±27.8 mg/dl, 40.8±15.7 mg/dl vs. 86.2±19.6 mg/dl; respectively, p<0.001 for both). Furthermore, the PCSK9i group induced greater regression of maxLCBI4mm than that of Control group (99.6±156.6 vs. 27.9±118.0, p=0.046) (Figure).

Figure 1

Conclusion

Compared with traditional statin therapy, PCSK9i treatment resulted in a greater decrease in lipid component in non-culprit coronary plaques. Therefore, PCSK9i may be useful option in preventing from adverse coronary events for the patients with CAD.

P974Efficacy of plaque debulking for bifurcated or ostial lesion by directional coronary atherectomy before 2nd generation drug eluting stent (PERFECT2)

Objectives

We sought to evaluate the efficacy of plaque debulking by directional coronary atherectomy (DCA) before 2nd generation drug-eluting stent (DES) implantation for bifurcated coronary lesions.

Background

Percutaneous coronary intervention (PCI) for bifurcated lesions still remains complex and challenging in terms of restenosis or stent thrombosis regardless of whether simple or complex stenting used.

Methods

Patients with bifurcated lesions were enrolled in this prospective multicenter registry. Pre-2nd generation DES plaque debulking with a novel DCA was conducted. All patients were scheduled to perform a follow up (9–12 months) angiography (coronary angiography or coronary computed tomography). The primary end point was the target vessel failure (TVF) at follow-up. Secondary end points were procedure-related events and major adverse cardiac events at 1 year.

Results

A total of 77 patients with bifurcated lesions were enrolled. PCI with DCA was performed successfully in all without any major procedure-related event and only 1 case needed complex stenting. TVF rate at 9–12 months follow up was 3.9% (3 of 77) and those were all associated with revascularization of the target vessel. Restenosis was only observed at ostial of main-branch in 3cases. No death, no coronary artery bypass grafting, and no myocardial infarction were reported in the patients within the first year.

Figure1

Conclusion

DCA before 2nd generation DES implantation can possibly avoid complex stenting and provide a good mid-term outcome in patients with bifurcated lesions.

Acknowledgement/Funding

None

Nanaomycin K, a new epithelial-mesenchymal transition inhibitor produced by the actinomycete "Streptomyces rosa subsp. notoensis" OS-3966

A new nanaomycin analog, nanaomycin K, was isolated from a cultured broth of actinomycete strain "Streptomyces rosa subsp. notoensis" OS-3966. Nuclear magnetic resonance (NMR) analyses revealed that the planar structure of nanaomycin K had an ergothioneine moiety. To determine the absolute configuration, nanaomycin K was semisynthesized using standards of nanaomycin E and l-ergothioneine. The natural and semisynthetic nanaomycin K were identified as the same compounds based on retention time, mass spectrometry, ¹H NMR, and optical rotation data. Nanaomycin K showed cytotoxicity against Madin-Darby canine kidney (MDCK) cells undergoing transforming growth factor (TGF) β1-induced epithelial-mesenchymal transition.

Genome-wide association study revealed novel loci which aggravate asymptomatic hyperuricaemia into gout

Objective

The first ever genome-wide association study (GWAS) of clinically defined gout cases and asymptomatic hyperuricaemia (AHUA) controls was performed to identify novel gout loci that aggravate AHUA into gout.

Methods

We carried out a GWAS of 945 clinically defined gout cases and 1003 AHUA controls followed by 2 replication studies. In total, 2860 gout cases and 3149 AHUA controls (all Japanese men) were analysed. We also compared the ORs for each locus in the present GWAS (gout vs AHUA) with those in the previous GWAS (gout vs normouricaemia).

Results

This new approach enabled us to identify two novel gout loci (rs7927466 of CNTN5 and rs9952962 of MIR302F) and one suggestive locus (rs12980365 of ZNF724) at the genome-wide significance level (p<5.0×10^–8). The present study also identified the loci of ABCG2, ALDH2 and SLC2A9. One of them, rs671 of ALDH2, was identified as a gout locus by GWAS for the first time. Comparing ORs for each locus in the present versus the previous GWAS revealed three ‘gout vs AHUA GWAS’-specific loci (CNTN5, MIR302F and ZNF724) to be clearly associated with mechanisms of gout development which distinctly differ from the known gout risk loci that basically elevate serum uric acid level.

Conclusions

This meta-analysis is the first to reveal the loci associated with crystal-induced inflammation, the last step in gout development that aggravates AHUA into gout. Our findings should help to elucidate the molecular mechanisms of gout development and assist the prevention of gout attacks in high-risk AHUA individuals.

Abstract 5237: Development of a gene expression database of renal cell carcinoma cases by NGS-combined HiCEP to identify tumor markers

Objectives: High coverage expression profiling (HiCEP) is an AFLP-based comprehensive gene expression analysis technique invented in Japan. HiCEP has two unique characteristics. First, it can detect low amounts of mRNA with high sensitivity and reliability. Second, HiCEP enables highly quantitative and reproducible mRNA expression analyses. However, it requires complicated processes, including TA cloning of isolated transcripts, to obtain sequence information on detected peaks. We performed next-generation sequencing (NGS)-combined HiCEP and tried to establish a gene expression database of renal cell carcinoma (RCC) cases to identify effective tumor markers.

Materials and methods: We collected cancerous and macroscopically non-cancerous regions from 83 RCC cases. Of these, six cases with clear cell RCC were analyzed by HiCEP. Total RNA was extracted from the cancerous and non-cancerous tissues of six clear cell RCC cases, and transcribed to cDNA. The cDNA was synthesized and subjected to digestion with the restriction enzymes MspI or MseI, followed by adapter ligation. Selective PCR by 256 kinds of primer pairs was used to amplify the HiCEP fragments, and products with fluorescently-labeled primer were then analyzed by capillary electrophoresis. HiCEP fragments were sequenced using a next-generation sequencer (ion PGM, Thermo Fisher Scientific). We compared the expression levels of HiCEP peaks in cancerous tissues with those in non-cancerous tissues.

Results: We detected several HiCEP peaks in cancerous tissues that showed five times higher expression than in normal tissues. We determined the sequences of the HiCEP fragments by NGS, and developed the first ever cancerous tissue HiCEP fragment database.

Conclusion: We successfully established an RCC gene expression database by NGS-combined HiCEP. We are now performing replication analyses and further analyses of blood samples from the same RCC cases to be able to identify diagnostic and prognostic markers of RCC.

Citation Format: Makoto Kawaguchi, Hirotaka Matsuo, Ryoko Araki, Seiko Shimizu, Mikiya Takao, Akiyoshi Nakayama, Yosuke Kitamura, Masumi Abe, Keiichi Ito, Nariyoshi Shinomiya. Development of a gene expression database of renal cell carcinoma cases by NGS-combined HiCEP to identify tumor markers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5237.

Functional Characterization of Clinically-Relevant Rare Variants in ABCG2 Identified in a Gout and Hyperuricemia Cohort

ATP-binding cassette subfamily G member 2 (ABCG2) is a physiologically important urate transporter. Accumulating evidence demonstrates that congenital dysfunction of ABCG2 is an important genetic risk factor in gout and hyperuricemia; recent studies suggest the clinical significance of both common and rare variants of ABCG2. However, the effects of rare variants of ABCG2 on the risk of such diseases are not fully understood. Here, using a cohort of 250 Czech individuals of European descent (68 primary hyperuricemia patients and 182 primary gout patients), we examined exonic non-synonymous variants of ABCG2. Based on the results of direct sequencing and database information, we experimentally characterized nine rare variants of ABCG2: R147W (rs372192400), T153M (rs753759474), F373C (rs752626614), T421A (rs199854112), T434M (rs769734146), S476P (not annotated), S572R (rs200894058), D620N (rs34783571), and a three-base deletion K360del (rs750972998). Functional analyses of these rare variants revealed a deficiency in the plasma membrane localization of R147W and S572R, lower levels of cellular proteins of T153M and F373C, and null urate uptake function of T434M and S476P. Accordingly, we newly identified six rare variants of ABCG2 that showed lower or null function. Our findings contribute to deepening the understanding of ABCG2-related gout/hyperuricemia risk and the biochemical characteristics of the ABCG2 protein.

Genome-wide meta-analysis identifies multiple novel loci associated with serum uric acid levels in Japanese individuals

Gout is a common arthritis caused by elevated serum uric acid (SUA) levels. Here we investigated loci influencing SUA in a genome-wide meta-analysis with 121,745 Japanese subjects. We identified 8948 variants at 36 genomic loci (P<5 × 10-8) including eight novel loci. Of these, missense variants of SESN2 and PNPLA3 were predicted to be damaging to the function of these proteins; another five loci-TMEM18, TM4SF4, MXD3-LMAN2, PSORS1C1-PSORS1C2, and HNF4A-are related to cell metabolism, proliferation, or oxidative stress; and the remaining locus, LINC01578, is unknown. We also identified 132 correlated genes whose expression levels are associated with SUA-increasing alleles. These genes are enriched for the UniProt transport term, suggesting the importance of transport-related genes in SUA regulation. Furthermore, trans-ethnic meta-analysis across our own meta-analysis and the Global Urate Genetics Consortium has revealed 15 more novel loci associated with SUA. Our findings provide insight into the pathogenesis, treatment, and prevention of hyperuricemia/gout.

Post-occlusional hyperemia for fractional flow reserve assessment and pull-back curve analysis

Balloon occlusion is a potential method for inducing hyperemia to measure post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR). The objective of this study was to determine the clinical usefulness of post-occlusional hyperemia. FFRs measured using post-occlusional hyperemia caused by 30 (FFR_occl30) and 60 s (FFR_occl60) of balloon occlusion after PCI were compared in 60 lesions from 60 patients. The duration of hyperemia was also measured. There was a strong correlation between FFR_occl30 and FFR_occl60 (r = 0.969, p < 0.01). The duration of hyperemia was significantly longer with FFR_occl60 than with FFR_occl30 (68 ± 23 vs. 37 ± 15 s, p < 0.01). The time required for pullback curve analysis was around 45 s. However, in 7 (12%) cases, the duration of hyperemia with FFR_occl60 was < 45 s, which was not enough for pull-back curve analysis. To predict the duration of hyperemia with FFR_occl60 ≥ 45 s, the receiver operating characteristic curve analysis revealed a cut-off value of 25 s of hyperemia with FFR_occl30. FFR_occl30 is sufficient for diagnostic purposes. FFR_occl60 is suitable for pull-back curve analysis in select cases based on predictions made using the duration of hyperemia with FFR_occl30.

Clinical practice guideline for renal hypouricemia (1st edition)

Renal hypouricemia (RHUC) is a disease caused by dysfunction of renal urate reabsorption transporters; however, diagnostic guidance and guidelines for RHUC have been lacking, partly due to the low evidence level of studies on RHUC. This review describes a world-first clinical practice guideline (CPG) and its first version in English for this condition. It was developed following the "MINDS Manual for Guideline Development" methodology, which prioritizes evidence-based medicine. It was published in Japanese in 2017 and later translated into English. The primary goal of this CPG is to clarify the criteria for diagnosing RHUC; another aim is to work towards a consensus on clinical decision-making. One of the CPG's unique points is that it contains textbook descriptions at the expert consensus level, in addition to two clinical questions and recommendations derived from a systematic review of the literature. The guidance shown in this CPG makes it easy to diagnose RHUC from simple blood and urine tests. This CPG contains almost all of the clinical foci of RHUC: epidemiology, pathophysiology, diagnostic guidance, clinical examinations, differential diagnosis, and complications, including exercise-induced acute kidney injury and urolithiasis. A CPG summary as well as a clinical algorithm to assist healthcare providers with a quick reference and notes from an athlete for both physicians and patients are included. We hope that this CPG will help healthcare providers and patients to make clinical decisions, and that it will promote further research on RHUC.

Risk factors increasing blood pressure in Japanese colorectal cancer patients treated with bevacizumab

Bevacizumab has been reported to increase blood pressure. However, the factors, including patient characteristics and laboratory data contributing to this side effect remain unclear. Therefore, we investigated the relationships between increased blood pressure and bevacizumab administration, patient characteristics, and laboratory data. Between April 2007 and January 2018, factor analysis was retrospectively conducted by monitoring increases in blood pressure, the status of bevacizumab administration, patient characteristics, and laboratory data before the first administration in Japanese patients with colorectal cancer who satisfied the criteria for this study. Sixty-seven patients were included, 34 of whom (50.7%) had an increase in blood pressure after bevacizumab administration. On univariate analysis, liver metastasis, antihypertensive drug use, systolic blood pressure at rest before the first bevacizumab administration, body mass index, creatinine, and blood platelet count were significantly different between the two groups. Multivariate analysis was conducted using increased blood pressure as an objective variable and the factors extracted by the univariate analysis as explanatory variables. The results suggested that liver metastasis, antihypertensive drugs, systolic blood pressure at rest before the first bevacizumab administration, and creatinine were associated with the increase in blood pressure. Furthermore, a log-rank test performed based on Kaplan-Meier curves demonstrated that liver metastasis in patients not taking antihypertensive drugs and antihypertensive drug use in patients without liver metastasis were significantly associated with increased blood pressure. Additionally, liver metastasis in patients with antihypertensive drug use was significantly associated with increased blood pressure. Our findings suggest that liver metastasis and antihypertensive drug use, which was previously reported, are risk factors for increased blood pressure.

Angiogram based fractional flow reserve in patients with dual/triple vessel coronary artery disease

OBJECTIVE

To assess the performance of angiography derived Fractional Flow Reserve (FFRangio) in multivessel disease (MVD) patients undergoing angiography.

BACKGROUND

FFR is the reference standard for physiologic assessment of coronary stenosis and guidance of revascularization, especially in patients with MVD, yet it remains grossly underutilized. The non-wire based FFRangio performs well in non-MVD patients, but its accuracy in MVD is unknown.

METHODS

A prospective clinical study was conducted at Gifu Heart Centre, Japan. Patients underwent physiologic assessment of all relevant coronary lesions using wire-based FFR (wbFFR) and FFRangio. Primary outcome was diagnostic performance (sensitivity, specificity, accuracy) for FFRangio with wbFFR as reference. Other outcomes were the correlation between wbFFR/FFRangio, time required for wbFFR/FFRangio measurements, and the effect of wbFFR/FFRangio on the reclassification of coronary disease severity.

RESULTS

Fifty patients (118 lesions in total) were included. Mean age was 72 ± 9 years, 72% were male, 36% had triple vessel disease and the average SYNTAX score was 13. The mean measurement of wbFFR and FFRangio were 0.83 ± 0.12 and 0.81 ± 0.11, respectively. Accuracy, sensitivity and specificity for FFRangio were 92.3% (95% CI 79.1-98.4%), 92.4% (95% CI 84.3-97.2%) and 92.4% (95% CI 87.4-97.3%), respectively. Pearson's r between wbFFR and FFRangio was 0.83. FFRangio measurement was faster than wbFFR (9.6 ± 3.4 vs. 15.0 ± 8.9 min, p < 0.001).

CONCLUSIONS

In patients with MVD, FFRangio shows good correlation and excellent diagnostic performance compared to wbFFR, and measuring FFRangio is faster than wbFFR. These results highlight the potential clinical benefits of utilizing FFRangio among patients with MVD.

Nanaomycin I and J: New nanaomycins generated by mycothiol-mediated compounds from "Streptomyces rosa subsp. notoensis" OS-3966

Two new nanaomycin analogs, nanaomycin I and J, were isolated from a cultured broth of an actinomycete strain, "Streptomyces rosa subsp. notoensis" OS-3966. In our previous study, we have confirmed the occurrence of nanaomycin I (m/z = 482 [M + H]⁺) that lacks a pseudo-disaccharide from the mycothiol of nanaomycin H under same culture condition. In this study, to confirm the structure of nanaomycin I, the strain "S. rosa subsp. notoensis" OS-3966 was re-cultured and the target compound with m/z = 482 [M + H]⁺ was isolated. Furthermore, we discovered another new analog, designated as nanaomycin J in isolating nanaomycin I. The NMR analyses revealed that the structures of nanaomycin I and J are N-acetylcysteine S-conjugates without a pseudo-disaccharide and N-acetylcysteine S-conjugates without a myo-inositol of nanaomycin H, respectively. The relative configurations of the tetrahydropyrane moiety of nanaomycin I and J were determined by rotating-frame overhauser effect spectroscopy (ROESY) analysis. Absolute configurations of the N-acetylcysteine moiety of nanaomycin I and J were determined by advanced Marfey's analyses for acid hydrolysis of de-sulfurized nanaomycin I and J with Raney nickel. Nanaomycin I and J showed moderate cytotoxicity against several human tumor cell lines.

An Application of Photoactivatable Substrate for the Evaluation of Epithelial-mesenchymal Transition Inhibitors

Epithelial-mesenchymal transition (EMT), phenotypic changes in cell adhesion and migration, is involved in cancer invasion and metastasis, hence becoming a target for anti-cancer drugs. In this study, we report a method for the evaluation of EMT inhibitors by using a photoactivatable gold substrate, which changes from non-cell-adhesive to cell-adhesive in response to light. The method is based on the geometrical confinement of cell clusters and the subsequent migration induction by controlled photoirradiation of the substrate. As a proof-of-concept experiment, a known EMT inhibitor was successfully evaluated in terms of the changes in cluster area or leader cell appearance, in response to biochemically and mechanically induced EMT. Furthermore, an application of the present method for microbial secondary metabolites identified nanaomycin H as an EMT inhibitor, potentially killing EMTed cells in disseminated conditions. These results demonstrate the potential of the present method for screening new EMT inhibitors.

A novel pathway for the photooxidation of catechin in relation to its prooxidative activity

In the present study, we evaluated the prooxidative mode of action of photoirradiated (+)-catechin at 400 nm in relation to reactive oxygen species generation and its possible application to disinfection. Photoirradiation of (+)-catechin at a concentration of 1 mg/mL yielded not only hydrogen peroxide (H2O2) but hydroxyl radical (·OH) in a total amount of approximately 20 μM in 10 min. As a result, photoirradiated catechin killed Staphylococcus aureus, and a > 5-log reduction in viable bacteria counts was observed within 20 min. Liquid chromatography-high-resolution-electrospray ionization-mass spectrometry showed that photoirradiation decreased the (+)-catechin peak (molecular formula C15H14O6) whilst it increased two peaks of a substance with the molecular formula C15H12O6 with increasing irradiation time. Nuclear magnetic resonance analysis revealed that the two C15H12O6 peaks were allocated to intramolecular cyclization products that are enantiomers of each other. These results suggest that photoirradiation induces oxidation of (+)-catechin resulting in the reduction of oxygen to generate H2O2. This H2O2 is then homolytically cleaved to ·OH, and alongside this process, (+)-catechin is finally converted to two intramolecular cyclization products that are different from the quinone structure of the B ring, as proposed previously for the autoxidation and enzymatic oxidation of catechins.