Water extractability of the zinc protoporphyrin IX-myoglobin complex from Parma ham is pH-dependent

The bright red color of Parma ham is mainly derived from zinc protoporphyrin IX (ZnPP), which exists in both water-soluble and insoluble states. Water-soluble ZnPP mainly binds to hemoglobin, however, the presence of water-insoluble ZnPP remains unexplained. Therefore, we aimed to elucidate how ZnPP exists in a water-insoluble state by focusing on its binding substance. Depending on the skeletal muscle, water-insoluble ZnPP comprised 30-50% of total ZnPP. The ZnPP water extractability was positively correlated with muscle pH. Water-insoluble ZnPP was extractable with a high-pH solution and existed as a complex with myoglobin or hemoglobin; nevertheless, myoglobin-binding ZnPP was more abundant. Furthermore, the water solubility of the myoglobin globin moiety at pH 5.5-6.0 was reduced by ZnPP binding. These results suggest that water-insoluble ZnPP mainly exists as a ZnPP-Mb complex, with low solubility attributed to the low pH of the ham.

CD8+ T cell memory induced by successive SARS-CoV-2 mRNA vaccinations is characterized by shifts in clonal dominance

mRNA vaccines against the spike glycoprotein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) elicit strong T cell responses. However, a clonal-resolution analysis of T cell responses to mRNA vaccination has not been performed. Here, we temporally track the CD8+ T cell repertoire in individuals who received three shots of the BNT162b2 mRNA vaccine through longitudinal T cell receptor sequencing with peptide-human leukocyte antigen (HLA) tetramer analysis. We demonstrate a shift in T cell responses between the clonotypes with different kinetics: from early responders that expand rapidly after the first shot to main responders that greatly expand after the second shot. Although the main responders re-expand after the third shot, their clonal diversity is skewed, and newly elicited third responders partially replace them. Furthermore, this shift in clonal dominance occurs not only between, but also within, clonotypes specific for spike epitopes. Our study will be a valuable resource for understanding vaccine-induced T cell responses in general.

Dissociation of ferriheme from oxidized heme proteins and re-reduction of ferriheme to ferroheme are crucial for the formation of zinc protoporphyrin IX in nitrite/nitrate-free dry-cured meat products

Zinc protoporphyrin IX (ZnPP) is the dominant red pigment in nitrate/nitrite-free dry-cured meat products such as Parma ham, and it is considered to be a potential alternative to nitrite/nitrate for reddening dry-cured meat products. Ferroheme and ferriheme dissociated from heme proteins in meat were proposed as substrates to form ZnPP. To elucidate their specific formation mechanism, nitric oxide, carbon monoxide, and azide were used to stable heme in heme proteins. The exogenous hemoglobin derivatives bound with these ligands showed lower heme dissociation compared with exogenous oxyhemoglobin and did not contribute to ZnPP formation. Meanwhile, azide inhibited almost all ZnPP formation by binding to ferriheme, indicating ferriheme dissociation from oxidized heme proteins, predominantly for ZnPP formation. Free ferriheme could not be converted to ZnPP unless it was reduced to ferroheme. Overall, ferriheme dissociated from oxidized heme proteins was the dominant substrate for conversion to ZnPP after re-reduction to ferroheme.

Development of Quantitative Real-Time PCR and Loop-Mediated Isothermal Amplification Assays for the Surveillance and Diagnosis of Herpes B Virus Infection

Herpes B virus (BV) is a zoonotic virus which can be transmitted from macaques to humans, which is often associated with high mortality rates. Because macaques often exhibit asymptomatic infections, individuals who come into contact with these animals face unexpected risks of BV infections. A serological test is widely performed to investigate BV infections. However, the assay's sensitivity and specificity appeared to be inadequate, and it does not necessarily indicate ongoing viral shedding. Here, we developed LAMP and qPCR assays aiming to detect BVs with a high sensitivity and specificity in various macaque species and validated them using oral swab samples collected from 97 wild cynomolgus macaques living in Thailand. Our LAMP and qPCR assays detected more than 50 and 10 copies of the target sequences per reaction, respectively. The LAMP assay could detect BV within 25 min, indicating its advantages for the rapid detection of BV. Collectively, our findings indicated that both assays developed in this study exhibit advantages and usefulness for BV surveillance and the diagnosis of BV infections in macaques. Furthermore, for the first time, we determined the partial genome sequences of BVs detected in cynomolgus macaques in Thailand. Phylogenetic analysis revealed the species-specific evolution of BV within macaques.

Distribution of Aedes mosquito species along the rural-urban gradient in Lambaréné and its surrounding

BACKGROUND

Aedes albopictus and Aedes aegypti are known for their potential as vectors of dengue (DENV) and chikungunya (CHIKV) viruses. However, entomological surveys are mostly carried out during epidemics. In Gabon where outbreaks of both viruses have occurred, there is no vector control program targeting these arboviruses. Therefore, we assessed the presence of Aedes species along a rural-urban gradient in Lambaréné (Gabon) and its surroundings and determined ecological factors associated to their presence.

METHODS

An entomological survey was conducted in Lambaréné and its surrounding rural areas. Mosquitoes were collected with aspirators around human dwellings, and ecological and environmental data were collected from each study area. Morphological identification keys were used to identify Aedes species. RNA was extracted from pools of female mosquitoes and amplified by RT-qPCR to detect the presence of DENV and CHIKV.

RESULTS

Overall, the most common vector collected was Aedes albopictus (97%, 4236/4367 specimens), followed by Aedes aegypti (3%, 131/4367). Albopictus vectors was more abundant in the rural area (Wilcoxon signed-rank test, Z = 627, P = 0.043) than in the urban area. In the urban area, a higher number of mosquitoes (45%) were recorded in the economic zone (zone 3) than in the historical and administrative zones (zone 1 and 2). In the rural area, the proportions of species numbers were significantly higher along the south rural transect (92%) compared to the north rural transect (Wilcoxon signed-rank test, Z = 43, P ˂ 0.016). We also noted a high abundance of vectors in environments characterized by monocultures of Hevea brasiliensis (Hevea) and Manihot esculenta (cassava) (Kruskal-Wallis H-test, H = 25.7, df = 2, P < 0.001). Finally, no mosquito pools were positive for either DENV or CHIKV.

CONCLUSION

Aedes albopictus was the dominant vector across the study sites due to its high invasiveness capacity. This presence re-affirms the potential for local transmission of both DENV and CHIKV, as indicated previously by serological surveys conducted in our study area, even though no transmission was detected during the current study. These findings underscore the need for regular arbovirus surveillance in the study region, with the aim of supporting vector control efforts in the event of outbreaks.

Comparison of genome replication fidelity between SARS-CoV-2 and influenza A virus in cell culture

Since the emergence of COVID-19, several SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) variants have emerged and spread widely. These variants are produced through replication errors of the viral genome by viral RNA-dependent RNA polymerase (RdRp). Seasonal epidemics of influenza are also known to occur because of new variants of influenza A virus (IAV), which are generated by the introduction of mutations by viral RdRp with low fidelity. Variants with different antigenicities appear because of mutations in envelope glycoproteins. In this study, we calculated and compared the mutation rates in genome replication of IAV and SARS-CoV-2. Average mutation rates per passage were 9.01 × 10-5 and 3.76 × 10-6 substitutions/site for IAV and SARS-CoV-2, respectively. The mutation rate of SARS-CoV-2 was 23.9-fold lower than that of IAV because of the proofreading activity of the SARS-CoV-2 RdRp complex. Our data could be useful in establishing effective countermeasures against COVID-19.

Genetic Diversity of Hepatitis B and C Viruses Revealed by Continuous Surveillance from 2015 to 2021 in Gabon, Central Africa

Viral hepatitis remains one of the largest public health concerns worldwide. Especially in Central Africa, information on hepatitis virus infections has been limited, although the prevalence in this region has been reported to be higher than the global average. To reveal the current status of hepatitis B and C virus (HBV and HCV) infections and the genetic diversity of the viruses, we conducted longitudinal surveillance in Gabon. We detected 22 HBV and 9 HCV infections in 2047 patients with febrile illness. Genetic analyses of HBV identified subgenotype A1 for the first time in Gabon and an insertion generating a frameshift to create an X-preC/C fusion protein. We also revealed that most of the detected HCVs belonged to the "Gabon-specific" HCV subtype 4e (HCV-4e), and the entire nucleotide sequence of the HCV-4e polyprotein was determined to establish the first reference sequence. The HCV-4e strains possessed resistance-associated substitutions similar to those of other HCV-4 strains, indicating that the use of direct-acting antiviral therapy may be complex. These results provide a better understanding of the current situation of hepatitis B and C virus infections in Central Africa and will help public health organizations develop effective countermeasures to eliminate chronic viral hepatitis in this region.

Clonal spreading of tumor-infiltrating T cells underlies the robust antitumor immune responses

The repertoire of tumor-infiltrating T cells is an emerging method for characterizing effective antitumor T-cell responses. Oligoclonal expansion of the tumor T-cell repertoire has been evaluated; however, their association with antitumor effects is unclear. We demonstrate here that the polyclonal fraction of the tumor-reactive T-cell repertoire, consisting of relatively minor clones, increased in tumor-bearing mice treated with monoclonal anti-PD-L1 or anti-CD4, which correlated with antitumor effects. Meanwhile, the size of the oligoclonal fraction consisting of major clones remained unchanged. Moreover, the polyclonal fraction was enriched in progenitor exhausted T cells, which are essential for a durable antitumor response, and was more dependent on CCR7+ migratory dendritic cells, which are responsible for priming tumor-reactive T cells in the tumor-draining lymph nodes. These results suggest that the expansion of diverse tumor-reactive clones ("clonal spreading") represents characteristics of antitumor T-cell responses induced by anti-CD4 and anti-PD-L1 treatment.

Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28}  cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25}  cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

Long-term validation of a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the rapid detection of SARS-CoV-2 from March 2020 to October 2021 in Central Africa, Gabon

BACKGROUND

Despite the development of several methods for diagnosing COVID-19, long-term validation of such methods remains limited. In the early phase of the COVID-19 pandemic, we developed a rapid and sensitive diagnostic method based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) methodology, which is suitable for point-of-care application or for use in resource-limited settings to detect SARS-CoV-2. To assess the applicability of the RT-LAMP assay technique to resource-limited regions, such as rural areas in Africa, and to verify the usability of the method against various SARS-CoV-2 variants, the method was validated using clinical samples collected longitudinally during the pandemic.

METHODOLOGY/PRINCIPAL FINDINGS

First, the sensitivity of the RT-LAMP assay for detecting 10 SARS-CoV-2 variants was evaluated using viral RNA samples extracted from cell culture with a portable battery-supported device, resulting in the successful detection of 20-50 copies of the viral genome within 15 min, regardless of the variant. COVID-19 positive samples collected in Gabon between March 2020 and October 2021 were used to evaluate the sensitivity of the assay and to calculate the copy number of the SARS-CoV-2 genome. More than 292 copies of the viral genome were detected with 100% probability within 15 min in almost all tests.

CONCLUSIONS

This long-term validation study clearly demonstrated the applicability of the RT-LAMP assay for the clinical diagnosis of COVID-19 in resource-limited settings of Africa, such as rural areas in Gabon. The results show the potential of the assay as a promising COVID-19 diagnostic method, especially in rural and remote regions located far from the official diagnosis facilities in urban or semi-urban areas.

Re-emergence of dengue, chikungunya, and Zika viruses in 2021 after a 10-year gap in Gabon

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DENV-1, CHIKV, and ZIKV were detected in Gabon in 2021.

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DENV appeared to switch to serotype 1 from serotype 2 and 3 since 2010.

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Aedes albopictus‒adapted CHIKV appears to circulate repeatedly in Central Africa.

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The recent Gabonese ZIKV strain was genetically different from the previous strain.

Mosquito-borne viral infections are a major concern in endemic areas, such as Africa. Although outbreaks have been reported throughout Africa, only a few surveillance studies have been conducted in Gabon since the outbreaks of dengue virus (DENV) and chikungunya virus (CHIKV) in 2010. Therefore, the current situation is unknown. This study aimed to investigate the presence of arboviruses, especially DENV (serotypes 1–4), CHIKV, and Zika virus (ZIKV), in Gabon, Central Africa. Between 2020 and 2021, we collected 1060 serum samples from febrile patients and screened them against viruses using reverse transcription-quantitative PCR. We detected two DENV serotypes 1 (DENV-1), one CHIKV, and one ZIKV, and subsequently analyzed the genome sequences. To determine the genetic diversity and transmission route of the viruses, phylogenetic analysis was performed using complete or partial genome sequences. The DENV-1 and CHIKV strains detected in this study were closely related to the previous Gabonese strains, whereas the recent ZIKV strain was genetically different from a strain detected in 2007 in Gabon. This study provides new genomic information on DENV-1, CHIKV, and ZIKV that were detected in Gabon and insight into the circulation of the viruses in the country and their introduction from neighboring African countries.

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century.

Identification of novel orthonairoviruses from rodents and shrews in Gabon, Central Africa

In Africa, several emerging zoonotic viruses have been transmitted from small mammals such as rodents and shrews to humans. Although no clinical cases of small mammal-borne viral diseases have been reported in Central Africa, potential zoonotic viruses have been identified in rodents in the region. Therefore, we hypothesized that there may be unrecognized zoonotic viruses circulating in small mammals in Central Africa. Here, we investigated viruses that have been maintained among wild small mammals in Gabon to understand their potential risks to humans. We identified novel orthonairoviruses in 24.6 % of captured rodents and shrews from their kidney total RNA samples. Phylogenetic analysis revealed that the novel viruses, Lamusara virus (LMSV) and Lamgora virus, were closely related to Erve virus, which was previously identified in shrews of the genus Crocidura and has been suspected to cause neuropathogenic diseases in humans. Moreover, we show that the LMSV ovarian tumour domain protease, one of the virulence determination factors of orthonairoviruses, suppressed interferon signalling in human cells, suggesting the possible human pathogenicity of this virus. Taken together, our study demonstrates the presence of novel orthonairoviruses that may pose unrecognized risks of viral disease transmission in Gabon.

Potential and action mechanism of favipiravir as an antiviral against Junin virus

Favipiravir is a nucleoside analogue that inhibits the replication and transcription of a broad spectrum of RNA viruses, including pathogenic arenaviruses. In this study, we isolated a favipiravir-resistant mutant of Junin virus (JUNV), which is the causative agent of Argentine hemorrhagic fever, and analyzed the antiviral mechanism of favipiravir against JUNV. Two amino acid substitutions, N462D in the RNA-dependent RNA polymerase (RdRp) and A168T in the glycoprotein precursor GPC, were identified in the mutant. GPC-A168T substitution enhanced the efficiency of JUNV internalization, which explains the robust replication kinetics of the mutant in the virus growth analysis. Although RdRp-N462D substitution did not affect polymerase activity levels in a minigenome system, comparisons of RdRp error frequencies showed that the virus with RdRp-D462 possessed a significantly higher fidelity. Our next generation sequence (NGS) analysis showed a gradual accumulation of both mutations as we passaged the virus in presence of favipiravir. We also provided experimental evidence for the first time that favipiravir inhibited JUNV through the accumulation of transition mutations, confirming its role as a purine analogue against arenaviruses. Moreover, we showed that treatment with a combination of favipiravir and either ribavirin or remdesivir inhibited JUNV replication in a synergistic manner, blocking the generation of the drug-resistant mutant. Our findings provide new insights for the clinical management and treatment of Argentine hemorrhagic fever.

Development of antivirals requires cautious and extensive assessment of action mechanism as well as potential for emergence of resistant phenotype of the virus. In recent years, favipiravir has been put forward as a promising candidate for the treatment of Argentine hemorrhagic fever (AHF) caused by Junin virus (JUNV). We, therefore, aimed to provide experimental evidence on action mechanism of favipiravir to help guide its clinical use. Here we show that favipiravir causes lethal mutation that impairs virus infectivity. More importantly, we demonstrate that the virus has the capability to escape favipiravir selective pressure by acquiring two amino acid substitutions on glycoprotein precursor and polymerase proteins. This observation raises concern over the use of only favipiravir in therapeutic regimens. To overcome this risk, we show that combination of favipiravir with other nucleoside analogues demonstrates a synergistic effect and suppresses the ability of JUNV to escape drug pressure. Favipiravir, ribavirin, and remdesivir have a broad spectrum of antiviral activity. Therefore, combination therapies of these drugs would be expected to have potential therapeutic effects for not only AHF but also the diseases caused by a variety of viruses, including emerging RNA viruses.

A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa

The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants.

Fabrication of Hydrogen Boride Thin Film by Ion Exchange in MgB2

In this study, hydrogen boride films are fabricated by ion-exchange treatment on magnesium diboride (MgB₂) films under ambient temperature and pressure. We prepared oriented MgB₂ films on strontium titanate (SrTiO₃) substrates using pulsed laser deposition (PLD). Subsequently, these films were treated with ion exchangers in acetonitrile solution. TOF-SIMS analysis evidenced that hydrogen species were introduced into the MgB₂ films by using two types of ion exchangers: proton exchange resin and formic acid. According to the HAXPES analysis, negatively charged boron species were preserved in the films after the ion-exchange treatment. In addition, the FT-IR analysis suggested that B-H bonds were formed in the MgB₂ films following the ion-exchange treatment. The ion-exchange treatment using formic acid was more efficient compared to the resin treatment; with respect to the amount of hydrogen species introduced into the MgB₂ films. These ion-exchanged films exhibited photoinduced hydrogen release as observed in a powder sample. Based on the present study, we expect to be able to control the morphology and hydrogen content of hydrogen boride thin films by optimising the ion-exchange treatment process, which will be useful for further studies and device applications.

Unrecognized introduction of SARS-CoV-2 variants of concern to Central Africa: Import and local transmission of B.1.1.7 in Gabon in the very early stage of the variant spread to the African continent

The rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variant of concern with higher infectivity has already resulted in the enormous increase in infection cases worldwide. We report an unrecognized introduction of the variant B.1.1.7 in Gabon in December 2020, which was the initial phase of the variant introduction to Africa. The B.1.1.7 variant was also detected in a hospitalized patient in January 2021, indicating a rapid spread of the variant in Gabon since its first detection. Phylogenetic analysis revealed that the detected B.1.1.7 variants originated from the distinct regions, strongly suggesting that the B.1.1.7 variant had been repeatedly introduced to Gabon since December 2020. These results provide insights on the unrecognized risks of infections with variants of concern, and show the necessity to conduct continuous genomic monitoring for immediate alert and control of novel SARS‐CoV‐2 variant infections.

Surveillance of the major pathogenic arboviruses of public health concern in Gabon, Central Africa: increased risk of West Nile virus and dengue virus infections

BACKGROUND

Increasing arbovirus infections have been a global burden in recent decades. Many countries have experienced the periodic emergence of arbovirus diseases. However, information on the prevalence of arboviruses is largely unknown or infrequently updated because of the lack of surveillance studies, especially in Africa.

METHODS

A surveillance study was conducted in Gabon, Central Africa, on arboviruses, which are a major public health concern in Africa, including: West Nile virus (WNV), dengue virus (DENV), Zika virus (ZIKV), yellow fever virus (YFV), chikungunya virus (CHIKV), and Rift Valley fever virus (RVFV). Serological and molecular assays were performed to investigate past infection history and the current status of infection, using serum samples collected from healthy individuals and febrile patients, respectively.

RESULTS

The overall seroprevalence during 2014-2017 was estimated to be 25.3% for WNV, 20.4% for DENV, 40.3% for ZIKV, 60.7% for YFV, 61.2% for CHIKV, and 14.3% for RVFV. No significant differences were found in the seroprevalence of any of the viruses between the male and female populations. However, a focus on the mean age in each arbovirus-seropositive individual showed a significantly younger age in WNV- and DENV-seropositive individuals than in CHIKV-seropositive individuals, indicating that WNV and DENV caused a relatively recent epidemic in the region, whereas CHIKV had actively circulated before. Of note, this indication was supported by the detection of both WNV and DENV genomes in serum samples collected from febrile patients after 2016.

CONCLUSIONS

This study revealed the recent re-emergence of WNV and DENV in Gabon as well as the latest seroprevalence state of the major arboviruses, which indicated the different potential risks of virus infections and virus-specific circulation patterns. This information will be helpful for public health organizations and will enable a rapid response towards these arbovirus infections, thereby preventing future spread in the country.

Identification of potential novel hosts and the risk of infection with lymphocytic choriomeningitis virus in humans in Gabon, Central Africa

OBJECTIVES

Lymphocytic choriomeningitis virus (LCMV), a human pathogenic arenavirus, is distributed worldwide. However, no human cases have been reported in Africa. This study aimed to investigate the current situation and potential risks of LCMV infection in Gabon, Central Africa.

METHODS

A total of 492 human samples were screened to detect LCMV genome RNA and anti-LCMV IgG antibodies using reverse transcription-quantitative PCR and enzyme-linked immunosorbent assay (ELISA), respectively. ELISA-positive samples were further examined using a neutralization assay. Viral RNAs and antibodies were also analyzed in 326 animal samples, including rodents, shrews, and bushmeat.

RESULTS

While no LCMV RNA was detected in human samples, the overall seroprevalence was 21.5% and was significantly higher in male and adult populations. The neutralization assay identified seven samples with neutralizing activity. LCMV RNA was detected in one species of rodent (Lophuromys sikapusi) and a porcupine, and anti-LCMV IgG antibodies were detected in four rodents and three shrews.

CONCLUSIONS

This study determined for the first time the seroprevalence of LCMV in Gabon, and revealed that local rodents, shrews, and porcupines in areas surrounding semi-urban cities posed an infection risk. Hence, LCMV infection should be considered a significant public health concern in Africa.

Paratenon of the cruciate ligaments of the knee: a macroscopic and histological study of human fetuses

BACKGROUND

The paratenon is a sheath-like connective tissue that allows the tendon to move with minimal friction. The careful removal of the paratenon along the cruciate ligaments is a critical step of knee surgery. Thus, orthopedic surgeons and interventional radiologists consider the paratenon as a basic anatomical tissue along a ligament, not along a tendon.

MATERIALS AND METHODS

We performed macroscopic and histological observations of cruciate ligament-associated paratenons in 43 human fetuses.

RESULTS

This tissue usually had a thick armor-like appearance that was distant from the infrapatellar fat pad. The anterior cruciate ligament, rather than the posterior ligament, was deeply embedded in the paratenon. The paratenon contained abundant arteries and veins and, at and near the crossing between the cruciate ligaments, had a well-developed venous plexus. Notably, there were abundant fused veins in the paratenon venous plexus, and prenatal knee movements (especially rotation) seemed to restrict its blood supply, leading to the development of a large cavity by way of advancing fusion of veins in the degenerating plexus. This unique manner of cavitation likely expanded the joint cavity.

CONCLUSIONS

Differences in knee movements in utero seemed to cause differences in the thickness of the paratenon among fetuses. New-borns might have limited knee flexion due to a mass-effect of the thick paratenon around the cruciate ligaments. A slight twisting or rotation at the knee may help to release the knee, because it can break the fetal paratenon and accelerate cavitation.

National Standard and New Reference Material for Specific Heat Capacity Measurements

Thermal analysis and calorimetry share a close relationship in the field of thermal research. With regards to the specific heat capacity, researchers have been able to realize absolute measurement techniques by utilizing drop, conduction, and adiabatic methods that are used in calorimetry. Furthermore, it is possible to optimize differential scanning calorimetry, which is a comparative measurement technique for the specific heat capacity used in thermal analysis, by improving the absolute measurement techniques. At the National Metrology Institute of Japan (NMIJ), we developed a new certified reference material (CRM) for comparatively measuring the specific heat capacity, the single-crystalline silicon-NMIJ CRM 5806a, using a new type of cryogenic adiabatic calorimeter equipped with a pulse-tube refrigerator working in the temperature range from 50 to 350 K. This CRM was produced in accordance with the quality specifications of NMIJ, and complies with the ISO/IEC 17025, ISO 17034, and ISO GUIDE 35 standards. This paper reports on the procedure for fabricating this CRM and using it to perform specific heat capacity measurements at low temperatures. The specific heat capacity was measured using a differential scanning calorimeter in the temperature range from 280 to 340 K. NMIJ CRM 5806a was used to calibrate the heat flow. It was found that the uncertainty evaluation became easier because one factor of the uncertainty evaluation could be removed using the CRM. We show that the development of the CRM using the adiabatic calorimeter has led to an improvement in the specific heat capacity measurement results obtained by the differential scanning calorimeter.

Dynamic structural reconstruction of (guanidinium+)2(benzene-1,4-disulfonate2−) host crystal by guest adsorption

Guanidinium (G⁺) and benzene-1,4-disulfonate (BDS²⁻) form a rigid electrostatic cation–anion crystal lattice, which undergoes an interesting dynamic structural reconstruction through guest adsorption–desorption processes.

[Evaluation of Risk Factors for Immune-Related Adverse Events Associated with Treatment with Immune Checkpoint Inhibitors]

OBJECTIVE

Risk factors for immune-related adverse events(irAEs)associated with immune checkpoint inhibitors(ICIs) remain to be obscure. Therefore, we evaluated the patient background and clinical findings to identify risk factors for the development of irAEs.

METHODS

The subjects consisted of 86 patients treated with ICIs between August 2018 and March 2020. They were classified into 2 groups who developed irAEs(irAE group)and did not develop irAEs(non-irAE group).

RESULTS

The median age of the subjects was 70 years(39-84 years), and there were 65 males. The underlying disease was non-small cell lung cancer in 51 patients, gastric cancer in 14, renal cell cancer in 9, urothelial cancer in 11, and MSI-high small bowel cancer in 1. The irAE group, in whom treatment with ICIs was discontinued, included 16 patients(18.6%), and the non-irAE group included 70 patients(81.4%). The median number of treatment cycles was 8(1-91), and the median treatment period was 4 months(1-45 months). Evaluation in our hospital revealed no significant background factors, such as gender, age, or the treatment period, as risk factors for the development of eras. Lung disorders were frequently observed after the third-line treatment and in patients with non-small cell lung cancer.

CONCLUSION

At present, the prediction of the development of irAEs is difficult. Careful follow-up observation and early irAEs management are important. In addition, further studies are necessary to identify risk factors for the development of irAEs.

Angioscopic evaluation of vascular healing at 1 and 12 months after drug-coated stent implantation

Background

Polymer- and carrier-free Biolimus-A9-coated stent (DCS) is expected better vascular healing compared with conventional durable polymer drug-eluting stents (DES). Moreover, DCS had been demonstrated in clinical trials to allow one-month short dual antiplatelet therapy, which might achieve sufficient healing at only 1 month after implantation. However, the process of vascular healing after DCS implantation has not been elucidated by angioscopic observation.

Purpose

To evaluate the process of vascular healing at 1 month and 12 months after DCS implantation.

Methods

This study included 57 patients treated with DCS or durable polymer everolimus-eluting stents (EES) in our hospital from April 2017 to April 2019. Firstly, the angioscopic findings of DCS at 1 month (n=16) and 12 months (n=14) after implantation were respectively compared with EES at 12 months after implantation (EES-12, n=35) as a standard healing status of DES. Secondary, angioscopic findings of DCS at 1 month and 12 months after implantation were compared among the serially observed eight patients. Neointimal coverage (NIC) grade, yellow colour grade, and the presence of thrombus were evaluated. NIC grade was classified as grade 0 (no neointimal coverage), grade 1 (struts were bulged into lumen but covered), grade 2 (struts were embedded in the neointima but visible), or grade 3 (struts were fully embedded and invisible). Yellow colour grade was classified as grade 0 (white), grade 1 (light yellow), grade 2 (yellow), or grade 3 (intensive yellow).

Results

At 1 month after DCS implantation, dominant NIC grade was lower (0.3±0.5 vs. 1.5±0.7, p&lt;0.001) and the frequency of thrombus was higher (38% vs. 6%, p=0.008) than EES-12. On the other hands, at 12 months after DCS implantation, dominant NIC grade was higher (2.1±0.6 vs. 1.5±0.7, p=0.013) and the frequency of thrombus was not different (7% vs. 6%, p=1.000) in comparison with EES-12. By serial observation of DCS, dominant NIC grade was higher at 12 months than at 1 month (2.3±0.5 vs. 0.4±0.5, p&lt;0.001), while yellow colour grade (1.0±0.5 vs. 1.5±1.2, p=0.227) and the frequency of thrombus adhesion (0% vs. 38%, p=0.200) were not different.

Conclusion

Compared with EES-12, vascular healing of DCS was inferior at 1 month but superior at 12 months.

Figure 1

Funding Acknowledgement

Type of funding source: None

The features and trends of out-of-hospital cardiac arrests in Japanese working generation: long-term aspects of a prospective, nationwide, population-based registry

Background

Despite sudden cardiac death (SCD) in working generation is a crucial issue in terms of public health, social and economic significance, the long-term SCD condition in working generation is unclear.

Purpose

This study aimed to clarify the features and long-term trends of SCD in working generation from 2005 through 2016 in Japan, using a prospective, nationwide, population based out-of-hospital cardiac arrest (OHCA) registry.

Methods

We performed data analysis of the nation-wide registry in Japan who experienced OHCA during the 12 years. Working generation was defined as 20 to 69 years and we analyzed only definitive cardiogenic OHCA as an approximation of SCD.

Results

The number of definitive cardiogenic OHCA of working generation during the period was 66,214 and 31% of the events in whole population was working generation. Definitive cardiogenic OHCA in working generation in terms of both number and percentage of the population had been decreased from 6522 (0.07‰) in 2005 to 4910 (0.06‰) in 2016, bystander cardiopulmonary resuscitation (CPR) and usage of automated external defibrillator (AED) ratio increased from 32.7% in 2005 to 49.6% in 2016, and 0.3% in 2005 to 14.7% in 2016 respectively, and the survival rate after one-month improved year by year, from 12.8% in 2005 to 34.0% in 2016 (picture below). Among non-medical bystanders, CPR was most often performed by colleagues in this generation, while AED use rate by colleague was smaller, and the time from witness to initial defibrillation was significantly longer than by passerby. Good prognosis was observed in terms of one-month survival ratio and neurological outcome for those undergoing CPR by colleague and passerby compared with other bystanders. For 12 years, although the degree varies, all non-medical bystander had same tendency; bystander CPR and usage of AED ratio increased, and the survival rate after one-month and neurological outcome improved year by year.

Conclusions

Not only the number but the incidence of cardiogenic OHCA in working generation has been decreased in Japan. The positive prognosis of this generation may be related to CPR by colleagues.

Figure 1. OHCA number & 1-month survival rate

Funding Acknowledgement

Type of funding source: None

Onset, severity and recovery of immediate orthostatic hypotension in normals and symptomatic patients: active standing and head-up tilt differ

Background

Orthostatic hypotension (OH) occurring almost immediately (i.e., immediate OH, iOH) after movement to standing position is common, and may cause collapse due to instability or syncope. However, while “classic” OH (cOH) which typically occurs later is well-studied, iOH has received less attention.

Objectives

This study was designed to better understand blood pressure (BP) alterations associated with iOH in normal subjects and in symptomatic patients (pts) and to compare findings with both Active standing and Head-up tilt (HUT).

Methods

We studied 118 patients comprising 4 groups: 1) Normals (n=38), 2) Vasovagal syncope (VVS: n=27), 3) cOH (n=37), and 4) Primary Autonomic Failure (PAF, n=16). We compared timing and magnitude of BP fall and recovery during both drug-free “active standing” (≤10 min) and HUT (70°, ≤20 min). Continuous ECG and beat-to-beat BP were recorded. Statistical significance was tested using paired-t test and ANOVA as appropriate (significance: p≤0.05).

Results

Sex and BMI were similar among groups, but PAF pts tended to be older (62±17 yrs) vs Normals (44±16 yrs), VVS (32±12) and OH (45±21 yrs) pts. Time from upright posture to BP nadir was shorter with active standing vs HUT [p&lt;0.005] except in PAF pts [p=NS]. Similarly, magnitude of BP fall (mmHg) tended to be greater with active standing in all groups (Normals −33±21 vs −20±18; VVS −28±16 vs −20±14; OH −37±16 vs −30±23; PAF −38±16 vs −34±28). Finally, except for PAF pts, BP recovery to baseline was shorter with active standing vs HUT (Table).

Conclusion

Active standing and HUT differ in evaluation of symptomatic pts. “Active standing” is associated with lesser time to BP nadir, greater BP fall, and faster BP recovery than with HUT. Additionally, iOH BP nadir typically occurs ≤15–20s after upright posture with rapid recovery necessitating beat-to-beat recordings to assess accurately.

Funding Acknowledgement

Type of funding source: None

First evidence for continuous circulation of hepatitis A virus subgenotype IIA in Central Africa

Although a high seroprevalence of antibodies against hepatitis A virus (HAV) has been estimated in Central Africa, the current status of both HAV infections and seroprevalence of anti-HAV antibodies remains unclear due to a paucity of surveillance data available. We conducted a serological survey during 2015-2017 in Gabon, Central Africa, and confirmed a high seroprevalence of anti-HAV antibodies in all age groups. To identify the currently circulating HAV strains and to reveal the epidemiological and genetic characteristics of the virus, we conducted molecular surveillance in a total of 1007 patients presenting febrile illness. Through HAV detection and sequencing, we identified subgenotype IIA (HAV-IIA) infections in the country throughout the year. A significant prevalence trend emerged in the young child population, presenting several infection peaks which appeared to be unrelated to dry or rainy seasons. Whole-genome sequencing and phylogenetic analyses revealed local HAV-IIA evolutionary events in Central Africa, indicating the circulation of HAV-IIA strains of a region-specific lineage. Recombination analysis of complete genome sequences revealed potential recombination events in Gabonese HAV strains. Interestingly, Gabonese HAV-IIA possibly acquired the 5'-untranslated region (5'-UTR) of the rare subgenotype HAV-IIB in recent years, suggesting the present existence of HAV-IIB in Central Africa. These findings indicate a currently stable HAV-IIA circulation in Gabon, with a high risk of infections in children aged under 5 years. Our findings will enhance the understanding of the current status of HAV infections in Central Africa and provide new insight into the molecular epidemiology and evolution of HAV genotype II.

Switching of Electron and Ion Conductions by Reversible H2O Sorption in n-Type Organic Semiconductors

Polar H₂O molecules generally act as trapping sites and suppress the electron mobility of n-type organic semiconductors, making chemical design of H₂O-tolerant and responsive n-type semiconductors an important step toward multifunctional electron-ion coupling devices. The introduction of effective electrostatic interactions between potassium ions (K⁺) and carboxylate (-COO^-) anions into the electron-transporting naphthalenediimide π-framework enables the design of high-performance H₂O-tolerant n-type semiconductors with a reversible H₂O adsorption-desorption ability, where the electron mobility and K⁺ ionic conductivity were coupled with the reversible H₂O sorption behavior. The reversible H₂O adsorption into the crystals enhanced the electron mobility from 0.04 to 0.28 cm² V^-1 s^-1, whereas the K⁺ ionic conductivity decreased from 3.4 × 10^-5 to 4.7 × 10^-7 S cm^-1. Because this reversible electron-ion conducting switch is responsive to H₂O sorption behavior, it is a strong candidate for H₂O gating carrier transport systems.

P92 A novel method of correcting the left ventricular stroke volume by Doppler echocardiography: comparison with multidetector computed tomography

Background

Although transthoracic Doppler echocardiography is widely used for estimating left ventricular stroke volume (SV), accelerated blood flow in the left ventricular (LV) outflow tract may lead to overestimation. SV can be calculated accurately from left ventricular end-systolic and end-diastolic volume determined by multi-detector computed tomography (MDCT). However, radiation exposure as well as the use of contrast medium hampers its routine use.

Purpose

The purpose of this study was to examine whether the correction of SV measured by pulsed wave Doppler echocardiography (SVdop) can accurately predicts SV obtained by MDCT (SVct).

Methods： We enrolled consecutive 61 patients who underwent both MDCT and transthoracic echocardiography. Patients with moderate or severe valvular diseases and valve replacement surgery were excluded. Correction of SV was explored with SVct as a reference.

Results： Univariate analysis showed that SVdop (r = 0.42, P = 0.0007) and patient age (r=-0.50, P &lt; 0.0001) were significantly correlated with SVct. On the other hand, left ventricular ejection fraction calculated by Teicholz method (EFteich) (r = 0.19, P = 0.14), systolic blood pressure (r = 0.07, P = NS), and LV mass index (r=-0.02, P = NS) were not correlated with SVct. Multivariate analysis showed that SVdop, patient age and EFteich were the independent predictive factors for SVct (R2 = 0.49, P &lt; 0.0001). Based on these correlations, we postulated SV as: corrected SV = SVdop × 0.40 + EFteich × 0.46 – age × 0.67 + 44.77. As expected, the correlation between corrected SV and SVct significantly improved (r = 0.70, P &lt; 0.0001). Bland-Altman plot analysis showed that corrected SV significantly reduced the variation between SVdop and SVct, and diminished the overestimation of SVdop (Figure).

Conclusion： The new correction formula of SVdop may correct the overestimation of SV obtained by pulsed wave Doppler echocardiography, although the formula remains to be validated in a separate cohort of patients.

Abstract P92 Figure

Re-emergence of dengue virus serotype 3 infections in Gabon in 2016-2017, and evidence for the risk of repeated dengue virus infections

OBJECTIVES

Dengue outbreaks, mainly caused by dengue virus serotype 2 (DENV-2), occurred in 2007 and in 2010 in Gabon, Central Africa. However, information on DENV infections has been insufficient since 2010. The aim of this study was to investigate the current DENV infection scenario and the risk of repeated infections in Gabon.

METHODS

During 2015-2017, serum samples were collected from enrolled febrile participants and were tested for DENV infection using RT-qPCR. DENV-positive samples were analyzed for a history of previous DENV infection(s) using ELISA. The complete DENV genome was sequenced to analyze the phylogeny of Gabonese DENV strains.

RESULTS

DENV-3 was exclusively detected, with a high rate of anti-DENV IgG seropositivity among DENV-3-positive participants. DENV-3 showed higher infection rates in adults and the infection was seasonal with peaks in the rainy seasons. Phylogenetic analysis revealed that Gabonese DENV-3 originated from West African strains and has been circulating continuously in Gabon since at least 2010, when the first DENV-3 case was reported.

CONCLUSIONS

These findings indicate stable DENV-3 circulation and the risk of repeated DENV infections in Gabon, highlighting the need for continuous monitoring to control DENV infections.

Ongoing evolution of hepatitis B virus during viremia in patients with febrile in Central Africa

Hepatitis B virus (HBV) infection remains to be a major public health issue worldwide, although there is currently a safe vaccine and effective antiviral treatments. In surveillance of infectious diseases in Gabon, HBV viremia was detected in patients with febrile. Whole-genome sequencing was conducted to characterize the HBV strains currently circulating in Gabon and to investigate HBV genome diversity during viremia. Phylogenetic analysis revealed the existence of former subgenotype A5, which exhibits a particular pattern of distribution from several West and Central African countries to Haiti. Furthermore, sequencing analysis identified two similar HBV strains mixed in one sample, and a very rare 1-base pair insertion in the viral precore region. This insertion caused a frameshift mutation, indicating the production of an aberrant fusion protein of the HBV x and e antigens. Our data showed that the detected HBV strain was possibly in an "evolving" state during viremia, a phase of active replication.

P4512Impact of pulmonary artery catheter on all-cause death of patients with acute heart failure with preserved ejection fraction: Short-term results from the PURSUIT-HFpEF registry

Background

Appropriate pulmonary artery catheter (PAC) use may effectively decrease mortality in acute heart failure patients. The concept that the pulmonary artery catheter (PAC) is a valuable tool for hemodynamic monitoring when used in appropriately selected patients and by physicians trained well to interpret and apply the data correctly provided has not been evaluated adequately yet in acute heart failure patients with preserved ejection fraction (HFpEF).

Methods

The PERSUIT-HFpEF Registry is a prospective, observational, multicenter cohort study on prognosis of HFpEF in Japan. Patients hospitalized for heart failure (diagnosed by using Framingham criteria) who met both of the following criteria were enrolled: 1) a left ventricular ejection fraction of 50% or more as measured at the local site by echocardiography; 2) an elevated level of N terminal pro brain natriuretic peptide (NT proBNP) (400 pg per milliliter or more) or brain natriuretic peptide (BNP) (100 pg per milliliter or more). In the present study, we evaluated the impact of PAC on all-cause death of the patients with HFpEF. PAC use was left at the discretion of attending physicians.

Results

The PERSUIT-HFpEF Registry enrolled 486 patients (81±9 years, 259 females, mean follow-up duration 198±195 days). Of these, data of PAC usage was available in 434 patients. Patients were further stratified according to use of a PAC: PAC 153 patients vs. non-PAC 281 patients. Length of hospitalization was numerically shorter in the PAC group than in the non-PAC group [20.3±14.7 vs. 22.5±17.4 days, p=0.182]. Kaplan-Meier estimated 1-year all-cause death rate was significantly lower in the PAC group than in the non-PAC group (9.5% vs. 19.1%, p=0.019). PAC use was associated with significant risk reduction of all-cause death [hazard ratio (HR) 0.425, 95% confidence interval (CI), 0.203–0.890, p=0.023] in the crude analysis. The significant risk reduction still existed after multivariate adjustment including potential confounders [HR 0.427, 95% CI, 0.185–0.984, p=0.046]

Kaplan Meier analysis

Conclusions

In the real-world Asian registry data, PAC use was associated with the improved all-cause death rate, suggesting that the PAC might be a useful guidance tool for treatment of the patients with HFpEF.

Acknowledgement/Funding

Roche diagnostics FUJIFILM Toyama Chemical

P321A single factor related to left atrial pressure overload is useful for prognosis in elderly patients with heart failure with preserved ejection fraction: PURSUIT HFpEF study

Background

E/e' and the ratio of diastolic elastance (Ed)/arterial elastance (Ea) = (E/e')/(0.9 × systolic blood pressure), indices of left atrial (LA) pressure overload, are elevated in elderly women with heart failure with preserved ejection fraction (HFpEF). The severity of diastolic dysfunction is assessed by a combination of several indices of LA volume and pressure overload. However, which overload is more important as a single factor for the prognosis of these patients remains undefined.

Methods

We enrolled patients with HFpEF showing sinus rhythm (n=145; left ventricular ejection fraction >50%; men/women, 56/89; mean age, 80.5 years). Blood examination and transthoracic echocardiography were performed before discharge. All-cause mortality and admission for cardiac events were evaluated after more than 1 year (mean, 370 days).

Results

The all-cause mortality rate was 11% (16/145). There were significant differences in age (p=0.005), serum N-terminal pro-brain natriuretic peptide (NT-proBNP) level (p<0.001), LA volume index (p=0.018), E/e' (p=0.022), and Ed/Ea (p=0.016) between patients with and without all-cause mortality. When cutoff points for mortality by receiver operating characteristic curve analysis were examined, the area under the curve in LA volume index (0.564) was slightly smaller than that in age (0.734), NT-proBNP level (0.732), E/e' (0.695), and Ed/Ea (0.709). Kaplan-Meier survival analysis clearly showed that age >85 years (p<0.001), NT-proBNP level >888 pg/mL (p=0.003), E/e' >14.4 (p=0.020), and Ed/Ea >0.153 (p<0.001) were determinant factors for mortality. Cox hazard ratios were also significant in these indices (p=0.002, p=0.012, p=0.028, and p=0.001, respectively). In the case of all-cause mortality or admission for cardiac events, the results were nearly similar as those in the case of all-cause mortality. Ed/Ea exhibited a larger Cox hazard ratio for prognosis than E/e' in the multivariate analysis.

Conclusions

LA pressure overload compared to volume overload was a useful marker for prognosis in elderly patients with HFpEF. As a single index for LA pressure overload in noninvasive echocardiographic findings, Ed/Ea may be more suitable than E/e'.

P786Plasma volume status is associated with the change in nutritional status during hospitalization in acute decompensated heart failure patients with preserved left ventricular ejection fraction

Introduction

Plasma volume (PV) expansion has an essential role in heart failure (HF). PV can be estimated by a simple formula using hematocrit and body weight, and PV status (PVS) provides prognostic information in patients (pts) with chronic HF. Nutritional status (NS) based on the prognostic nutritional index (PNI) and NS change during hospitalization have been shown to predict prognosis in pts admitted with acute decompensated HF (ADHF).

Purpose

We sought to assess the hypothesis that PVS is associated with NS change during hospitalization in pts with HF with preserved LVEF (HFpEF) who are admitted with ADHF.

Methods

We prospectively studied 411 pts who were admitted for ADHF with LVEF ≥50% and survived to discharge. Body weight measurement and venous blood sampling were performed on admission and at discharge. PVS was defined as follows: actual PV = (1 − hematocrit) × [a + (b × body weight)] (a=1530 in males and a=864 in females, b=41.0 in males and b=47.9 in females); ideal PV = c × body weight (c=39 in males and c=40 in females); and PVS = [(actual PV − ideal PV)/ideal PV] × 100 (%). PNI was calculated as 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (per mm3). The pts were divided into 3 groups by PNI: normal (>38), moderate malnutrition (35–38), and severe malnutrition (<35). During admission, pts who remained in the moderate or severe malnutrition group or whose NS worsened were defined as no improvement in NS. Follow-up data was obtained in 203 cases. They were followed for up to 18 months, and the incidence of all-cause death was evaluated.

Results

On admission, PVS in the moderate (n=71, 13.3±13.9%) or severe malnutrition group (n=69, 14.8±10.8%) was significantly higher than in the normal PNI group (n=271, 5.4±10.8%, p<0.001). During hospitalization, 123 pts had no NS improvement. Admission PVS was significantly higher in pts with no NS improvement than in pts with improved NS (13.9±11.2% vs 5.9±12.8%, p<0.0001). In multivariate logistic regression analysis, admission PVS was independently associated with no NS improvement during hospitalization (OR 1.06, 95% CI 1.03–1.08, p<0.0001). Receiver operating characteristics curve analysis revealed that the optimal cut-off value of admission PVS for predicting no NS improvement was 9.4% (sensitivity: 72%, specificity: 63%). The area under the curve for predicting no NS improvement using admission PVS was significantly greater than for other independent factors (Figure 1A). During the follow-up period (median 12.4 months), 68 of 203 patients had all-cause death. Kaplan-Meier analysis showed that the patients with no NS improvement had a significantly higher risk of all-cause death (Figure 1B).

Figure 1

Conclusions

In this multicenter study, admission PVS was shown to be associated with poor improvement in NS during hospitalization in HFpEF pts admitted for ADHF.

Acknowledgement/Funding

Roche diagnostics, FUJIFILM Toyama Chemical

P6356Comparisons of clinical outcomes in patients with heart failure with preserved ejection fraction with and without atrial fibrillation: results from a multicenter PURSUIT-HFpEF registry

Background

The presence of atrial fibrillation (AF) has been demonstrated to be associated with poor clinical outcomes in heart failure patients with reduced ejection fraction.

Objective

This study aimed to elucidate the impact of the presence of atrial fibrillation (AF) on the clinical characteristics, therapeutics, and outcomes in patients with heart failure and preserved ejection fraction (HFpEF).

Methods

PURSUIT-HFpEF is a multicenter prospective observational study including patients hospitalized for acute heart failure with left ventricular ejection fraction of >50%. Patients with acute coronary syndrome or severe valvular disease were excluded.

Results

Of 486 HFpEF patients (age, 80.8±9.0 years old; male, 47%) from 24 cardiovascular centers, 199 (41%) had AF on admission. Patients with AF had lower systolic blood pressures (142±27 vs. 155±35mmHg, p<0.0001) and higher heart rates (91±29 vs. 82±26bpm, p<0.0001) than those without. There was no difference in the usage of inotropes or mechanical ventilation between the 2 groups. A higher quality of life score (EQ5D, 0.72±0.27 vs. 0.63±0.30, p=0.002) was observed at discharge in patients with than without AF. In addition, AF patients tended to demonstrate lower in-hospital mortality rates (0.5% vs. 2.4%, p=0.09) and shorter hospital stays (20.3±12.1 vs. 22.6±18.4 days, p=0.09) than those without. During a mean follow up of 360±111 days, mortality (14.1% vs. 15.3) and heart failure re-hospitalization rates (13.1% vs. 13.9%) were comparable between the 2 groups.

Conclusion

In contrast to heart failure patients with reduced ejection fraction, AF on admission was not associated with poor long-term clinical outcomes among HFpEF patients. Several in-hospital outcomes were better in patients with AF than in those without.

Acknowledgement/Funding

None

P1649Prognostic significance of serum cholinesterase in patients with acute decompensated heart failure with preserved ejection fraction: insights from PURSUIT-HFpEF registry

Background

Comorbidities strongly influence the prognosis in heart failure with preserved ejection fraction (HFpEF). Malnutrition is one of the most important comorbidities among heart failure patients. Serum cholinesterase (CHE), one of the markers of malnutrition, was reported to be a prognostic factor in patients with chronic heart failure. In addition, we previously reported prognostic significance of CHE from a single center registry data of acute decompensated heart failure (ADHF). The aim of this study is to conduct external validation of the prognostic role of CHE using multi-center HFpEF registry.

Methods and results

Patients data were extracted from The Prospective mUlticenteR obServational stUdy of patIenTs with Heart Failure with Preserved Ejection Fraction (PURSUIT HFpEF) study. PURSUIT-HFpEF study is a prospective multicenter observational study in which collaborating hospitals in Osaka recorded clinical, echocardiographic, and outcome data of patients with ADHF and preserved ejection fraction. Between June 2016 and January 2018, 381 patients were enrolled and we excluded patients without sufficient laboratory data and in-hospital death. Finally, we analyzed 204 patients with survival discharge. Laboratory data including CHE and echocardiography were obtained just before discharge. The endpoint of this study is the composite of all-cause death and worsening heart failure re-admission (cardiac event). During a follow up period of 0.92±0.37 years, 49 patients had cardiac event. CHE was significantly lower in patients with than without cardiac event (183±67 vs 223±71 U/L, p<0.0001). At multivariate Cox analysis, CHE (p=0.0020) was significantly associated with cardiac event, independently of NT-pro BNP after adjustment of age, sex, eGFR and hemoglobin. ROC curve analysis showed that AUC of CHE for the prediction of cardiac event was 0.706 (95% CI 0.638–0.768). Kaplan-Meier analysis showed that patients with low CHE (<211U/L defined by median) had a significantly greater risk of cardiac event (35% vs 13% p=0.0002).

Figure 1

Conclusion

Serum cholinesterase level is the useful prognostic marker for the prediction of cardiac event in patients with ADHF with preserved ejection fraction.

Acknowledgement/Funding

Roche diagnostics, FUJIFILM Toyama Chemical

128Change in geriatric nutritional risk index predicts one-year mortality in patients with heart failure with preserved ejection fraction

Background

Malnutrition is associated with adverse prognosis in heart failure patients. However, in patients with heart failure with preserved ejection fraction (HFpEF), the effects of change in nutritional status during hospitalization on prognosis is unknown. Geriatric nutritional risk index (GNRI) is a widely used objective index for evaluating nutritional status. Low GNRI (<92) has moderate or severe nutritional risk and high GNRI (≥92) has no or low nutritional risk.

Purpose

The purpose of this study was to clarify the effect of change in GNRI during hospitalization on one-year mortality and the association between the value of GNRI and one-year mortality in patients with HFpEF.

Methods

We prospectively registered patients with HFpEF in PURSUIT-HFpEF registry when they were hospitalized for heart failure in 29 hospitals. Preserved ejection fraction was defined as more than 50% of left ventricular ejection fraction. Of the 486 patients who registered PURSUIT-HFpEF, 228 cases with one-year follow-up data were examined. GNRI was calculated as follows: 14.89 × serum albumin (g/dl) + 41.7 × body mass index/22.

Results

Mean age was 81±10 years and 100 patients (44%) were male. During a median [interquartile range] follow-up period of 374 [342, 400] days, 28 patients (12%) died. Mortality was significantly higher in patients with low GNRI at admission (n=65) than those with high GNRI at admission (n=163) (26% vs. 9%, log-rank P=0.011) and higher in patients with low GNRI at discharge (n=109) than those with high GNRI at discharge (n=119) (22% vs. 6%, log-rank P=0.002). Multivariate analysis with Cox proportional hazard model with patient characteristics at admission revealed that low GNRI at admission was independently associated with mortality (hazard ratio: 0.96, 95% CI: 0.93–0.99, P=0.035) and that with patient characteristics at discharge revealed that low GNRI at discharge was independently associated with mortality (hazard ratio: 0.94, 95% CI: 0.91–0.97, P<0.001). We also compared mortality by dividing patients into 4 group according to whether GNRI was high or low at the time of admission and discharge. Patients with low GNRI at admission and at discharge (n=59) exhibited the highest mortality, on the other hand, patients with high GNRI at admission and low GNRI at discharge (n=50) exhibited higher mortality than those with high GNRI both at admission and at discharge (n=113) (Low and low: 28% vs. High and low: 14% vs. High and high: 6% vs. Low and high: 0%, log-rank P=0.010).

All cause mortality

Conclusion

GNRI at admission or at discharge was independently associated with one-year mortality in patients with HFpEF. Moreover, worsening GNRI during hospitalization is associated with the worse prognosis. It is important to prevent lowering GNRI during treatment of acute decompensated HFpEF.

Acknowledgement/Funding

Roche Diagnostics, FUJIFILM Toyama Chemical

P1831Prediction of cardiovascular events by atheromatous plaques detected by non-obstructive general angioscopy: two-year results of EAST-NOGA Registry

Background

Non-obstructive general angioscopy (NOGA) has revealed the intimal damages or atheromatous plaques as well as its spontaneous rupture of the aorta. Recent study revealed that plaque debris or different size of cholesterol crystals were detected in the blood above the spontaneous ruptured aortic plaque observed by NOGA and these plaque materials might cause the peripheral organ damages as the embolic source. These various morphological changes may cause the acute aortic events or atheroembolic events on the peripheral organs, such as brain, kidney, peripheral artery and so on.

Purpose

EAST-NOGA (Evaluation of AtheroSclerotic and rupture events by Non-Obstructive General Angioscopy) is a multi-center prospective observational study to assess the relationship between the findings of NOGA and future cardiovascular events.

Methods

Five hundred and seventy-seven patients with atherosclerotic cardiovascular disease who underwent NOGA study. The major cerebrocardiovascular events including cardiovascular death, non-fatal myocardial infarction, non-fatal cerebral infarction, and acute aortic syndrome were accumulated during the 2-year follow-up after NOGA study.

Results

The median number of aortic atheromatous plaques was 6 [IQR: 3–12]. A total of 514 patients were followed up (89.1%). The mean follow-up duration was 757±120 days. Major adverse cardiovascular events developed in 23 (4.5%) during 2 years follow-up. Patients with MACE and cerebral infarction, had significantly greater number of aortic atheromatous plaques (11 [5–19] vs. 6 [3–11], p<0.001, 12 [4–20] vs. 6 [3–12], p=0.014, respectively). In a univariate analysis, the number of aortic atheromatous plaques and ruptured plaque were significant predictors of MACE (HR: 1.09 95% confidence interval 1.05–1.14, p<0.001) and (HR: 1.12, 95% confidence interval 1.02–1.23, p=0.02). In a multivariate logistic analysis, the number of aortic atheromatous plaques is one of the independent predictors of MACE (HR 1.05, 95% confidence interval 1.00–1.10, p=0.032).

Conclusion

The number of atheromatous plaques identified by NOGA has a significant relation to the onset of cerebral infarction, which suggest the atheromatous plaque were vulnerable and ruptured spontaneously, then cause the aortogenic cerebral infarction. The NOGA study would be useful for predicting the futured atheroembolic events.

Acknowledgement/Funding

None

Abstract PD4-04: Role of breast MRI in predicting pathologically negative nodes after neoadjuvant chemotherapy in cN0 patients in the I-SPY2 trial

Background

In clinically node-negative (cN0) breast cancer patients with triple negative (TN) and HER2+ disease and breast pathological complete response (breast pCR), low rates of nodal positivity after neoadjuvant chemotherapy (NAC) have been demonstrated. In these patients, the omission of surgical axillary staging has been proposed. However, this information is not routinely known preoperatively. We aimed to validate the correlation between pathologic breast response and pathologic nodal status, and evaluate the relationship between response of the breast tumor on MRI and pathologic nodal status after NAC in cN0 patients in the I-SPY2 trial.

Methods

We identified all patients with cT1-4 cN0 breast cancer prior to NAC from graduated arms of the I-SPY2 trial, a prospective neoadjuvant chemotherapy trial. Absence of residual disease post-NAC was defined as longest diameter (LD) of 0 mm on MRI. Breast pCR was defined as the absence of invasive tumor in the breast at surgery. Associations between ypN0 and patient, MRI, and tumor characteristics were assessed using chi-square tests and univariate regression.

Results

Of 365 cT1-4 cN0 patients included, 128 had HR+/HER2- tumors (35%), 60 HR+/HER2+ tumors (16%), 34 HR-/HER2+ tumors (9%) and 143 TN tumors (39%). Overall, 283 patients (78%) were ypN0 after NAC and 152 patients (42%) had a breast pCR. ypN0 rate was higher in patients with a breast pCR than those with residual disease (93% vs 66%, p&lt;0.001). Patients with HR-/HER2+ and TN tumors were more likely to be ypN0 (97% and 87% respectively) than patients with HR+/HER2- and HR+/HER2+ disease (66% and 71% respectively, p&lt;0.001). Other characteristics associated with ypN0 were tumor grade (grade I 57%, grade II 66%, grade III 84%; p=0.002), MammaPrint Classification (High Risk 1 68% and High Risk 2 87%; p&lt;0.001) and absence of residual tumor in the breast on MRI (87% vs 72% in patients with evidence of tumor on MRI post-NAC/pre-surgery; p=0.003).

In patients with HR-/HER2+, HR+/HER2+, HR-/HER2+ or TN disease and a breast pCR, ypN0 rate was respectively 82%, 96%, 96% and 97% (table 1). In patients with HR+/HER2-, HR+/HER2+, HR-/HER2+ or TN disease and with no evidence of residual disease in the breast on MRI, rate of ypN0 was 71%, 80%, 94% and 96% respectively.

Conclusion

In cT1-4 cN0 breast cancer patients with HR+/HER2+, HR-/HER2+ and TN tumors and a breast pCR, ypN0 rates after NAC are extremely high. In patients with HR-/HER2+ and TN tumors with no residual breast disease on MRI after NAC and pre-surgery, ypN0 rates are high enough to consider omission of axillary surgery. In patients with HR+ tumors, MRI is unsufficiently predictive for pathological response and can therefore not be used to select ypN0 patients. Research on the prediction of ypN0 in cN+ I-SPY2 patients is ongoing.

Nodal status in patients with pCR and absence of residual disease on MRI Number of positive nodesBreast Cancer Subtype0123AllBreast pCR     HR+/HER2-27(82)2(6)4(12)033(100)HR+/HER2+24(96)01(4)025(100)HR-/HER2+24(96)1(4)0025(100)TN67(97)2(3)0069(100)Absence of residual disease on MRI     HR+/HER2-24(71)7(21)3(9)034(100)HR+/HER2+16(80)3(15)01(5)20(100)HR-/HER2+15(94)1(6)0016(100)TN54(96)2(4)0056(100)

Citation Format: van der Noordaa ME, Esserman L, Yau C, Mukhtar R, Price E, Hylton N, Abe H, Wolverton D, Crane EP, Ward KA, Nelson M, Niell BL, Oh K, Brandt KR, Bang DH, Ojeda-Fournier H, Eghtedari M, Sheth PA, Bernreuter WK, Umphrey H, Rosen MA, Dogan B, Yang W, Joe B, van 't Veer L, Hirst G, Lancaster R, Wallace A, Alvaredo M, Symmans F, Asare S, Boughey JC, I-SPY2 Consortium. Role of breast MRI in predicting pathologically negative nodes after neoadjuvant chemotherapy in cN0 patients in the I-SPY2 trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD4-04.

Abstract OT2-01-02: Thoracic interfascial nerve blocks versus paravertebral block for improving quality of recovery after breast cancer surgery: A randomized, double-blind, non-inferiority trial

Background: Chronic pain after breast cancer surgeryhas harmful effects on patients' daily life. Paravertebral block (PVB) can prevent not only acute but chronic pain after breast cancer surgery, although the block is not easily put into practice because of technical difficulty or necessity to change patients' position. Thoracic interfascial nerve blocks (TINB) have been reported that it gives similar analgesic efficacy as PVB as with fewer risks, however there are no reports comparing analgesic efficacy of PVB with TINB. Although there are several scales evaluating postoperative pain including visual analog scale (VAS) or numerical rating scale, Quality of Recovery (QoR) have been set up to assess the impact of postoperative morbidity on patients' ability to return to normal function and quality of life. Among those assessment scales, QoR-40 has been mainly applied. It consists of 40 questions including five dimensions: psychologic support, physical comfort, emotional state, physical independence, and pain. There is a report suggesting that PVB improve QoR-40 after ambulatory breast tumor resection.

Methods: This is a single center single arm phase 2 study for early breast cancer patients. Exclusion criteria are pregnant and parturient women, allergy to local anesthetics, significant psychiatric or mental disorders, and patients with chronic pain. All blocks are subjected to ultrasound guidance. Patients were randomized to receive PVB with 40 ml ropivacaine or TINB with 60 ml ropivacaine. TINB consisted of modified PECS II block and transversus thoracic muscle plane block. For assessment of QoR, QoR-40 score which was consisted of 5 elements including postoperative pain was used. The trial was activated in July 2016.

Statistical Method: We conducted a pilot study on 16 patients who received a PVB during breast cancer surgery. Based on the standard deviation (SD) of QoR-40 on postoperative day (POD) 1, the SD was set to 7.2. Since the non-inferiority limit needs to be reduced to about half as much as the effect quantity used in the average value superiority test, it is set to 8, which is half of the effect quantity 16 in the pilot study. When one-sided test with α error = 0.025 and β error = 0.2, about 13 cases in each group are required. Given that dropout rate is about 30-40%, 18 cases in each group were taken as the number of subject cases.

Results: Thirty-six patients were accrual, 18 of PVB group and 18 of TINB group. Two patients declined the trial, 36/38 (95%) acceptors completed the trial. Total of QoR-40 scores on POD 1 was designated as the primary outcome. For secondary outcomes, both QoR-40 score and pain score were assessed on POD 3 and in postoperative month(s) 1, 3, 6, 12. Other secondary outcomes included pain score by POD 1, incidence of rescue analgesia, time to rescue analgesia, incidence of nausea and vomiting. All patients provided written informed consent before undergoing any study-related procedures.

Conclusions: This trial will provide non-inferiority that TINB preserve the effect of QoR as good as PVB after breast cancer surgery.

If interested, please contact T Horiuchi at t_horiuchi@seichokai.or.jp.

Clinical trial information: UMIN000023340

Citation Format: Abe H, Horiuchi T, Teramoto A, Tanaka Y, Takei Y, Nagahata T. Thoracic interfascial nerve blocks versus paravertebral block for improving quality of recovery after breast cancer surgery: A randomized, double-blind, non-inferiority trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-01-02.

Abstract P2-07-03: Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden

Background: Patients achieving a pathologic complete response (pCR) following neoadjuvant therapy have significantly improved event-free survival relative to those who do not; and pCR is an FDA-accepted endpoint to support accelerated approval of novel agents/combinations in the neoadjuvant treatment of high risk early stage breast cancer. Previous studies have shown that recurrence risk increased with increasing burden of residual disease (as assessed by the RCB index). As well, these studies suggest that patients with minimum residual disease (RCB-I class) also have favorable outcomes (comparable to those achieving a pCR) within high risk tumor subtypes. In this study, we assess whether integrating RCB with MRI functional tumor volume (FTV), which in itself is prognostic, can improve prediction of distant recurrence free survival (DRFS); and identify a subset of patients with minimal residual disease with comparable DRFS as those who achieved a pCR. Imaging tools can then be used to identify the subset that will do well early and guide the timing of surgical therapy.

Method: We performed a pooled analysis of 596 patients from the I-SPY2 TRIAL with RCB, pre-surgical MRI FTV data and known follow-up (median 2.5 years). We first assessed whether FTV predicts residual disease (pCR or pCR/RCB-I) using ROC analysis. We applied a power transformation to normalize the pre-surgical FTV distribution; and assessed its association with DRFS using a bi-variate Cox proportional hazard model adjusting for HR/HER2 subtype. We also fitted a bivariate Cox model of RCB index adjusting for subtype; and assessed whether adding pre-surgical FTV to this model further improves association with DRFS using a likelihood ratio (LR) test. For the Cox modeling, penalized splines approximation of the transformed FTV and RCB index with 2 degrees of freedom was used to allow for non-linear effects of FTV and RCB on DRFS.

Result: Pre-surgical MRI FTV is significantly associated with DRFS (Wald p&lt;0.00001), and more effective at predicting pCR/RCB-I than predicting pCR alone (AUC: 0.72 vs. 0.65). Larger pre-surgical FTV remains associated with worse DRFS adjusting for subtype (Wald p &lt;0.00001). The RCB index is also significantly associated with DRFS adjusting for subtype (Wald p&lt;0.00001). Adding FTV to a model containing RCB and subtype further improves association with DRFS (LR p=0.0007). RCB-I patients have excellent DRFS (94% at 3 years compared to 95% in the pCR group). Efforts are underway to identify an optimal threshold for dichotomizing pre-surgical FTV and FTV change measures for use in combination with pCR/RCB-I class to generate integrated RCB (iRCB) groups as a composite predictor of DRFS.

Conclusion: Pre-surgical MRI FTV is effective at predicting minimal residual disease (RCB0/I) in the I-SPY 2 TRIAL. Despite the association between FTV and RCB, FTV appears to provide independent added prognostic value (to RCB and subtype), suggesting that integrating MRI volume measures and RCB into a composite predictor may improve DRFS prediction.

Citation Format: Hylton NM, Symmans WF, Yau C, Li W, Hatzis C, Isaacs C, Albain KS, Chen Y-Y, Krings G, Wei S, Harada S, Datnow B, Fadare O, Klein M, Pambuccian S, Chen B, Adamson K, Sams S, Mhawech-Fauceglia P, Magliocco A, Feldman M, Rendi M, Sattar H, Zeck J, Ocal I, Tawfik O, Grasso LeBeau L, Sahoo S, Vinh T, Yang S, Adams A, Chien AJ, Ferero-Torres A, Stringer-Reasor E, Wallace A, Boughey JC, Ellis ED, Elias AD, Lang JE, Lu J, Han HS, Clark AS, Korde L, Nanda R, Northfelt DW, Khan QJ, Viscusi RK, Euhus DM, Edmiston KK, Chui SY, Kemmer K, Wood WC, Park JW, Liu MC, Olopade O, Tripathy D, Moulder SL, Rugo HS, Schwab R, Lo S, Helsten T, Beckwith H, Haugen PK, van't Veer LJ, Perlmutter J, Melisko ME, Wilson A, Peterson G, Asare AL, Buxton MB, Paoloni M, Clennell JL, Hirst GL, Singhrao R, Steeg K, Matthews JB, Sanil A, Berry SM, Abe H, Wolverton D, Crane EP, Ward KA, Nelson M, Niell BL, Oh K, Brandt KR, Bang DH, Ojeda-Fournier H, Eghtedari M, Sheth PA, Bernreuter WK, Umphrey H, Rosen MA, Dogan B, Yang W, Joe B, I-SPY 2 TRIAL Consortium, Yee D, Pusztai L, DeMichele A, Asare SM, Berry DA, Esserman LJ. Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-07-03.

Abstract PD4-03: MRI detection of residual disease following neoadjuvant chemotherapy (NAC) in the I-SPY 2 TRIAL

Background: Detecting residual disease accurately using MRI after NAC to identify both responders and non-responders is essential for de-escalating therapy or redirecting patients to more effective treatment. The purpose of this study is to determine if the combination of longest diameter (LD) and functional tumor volume (FTV) from dynamic contrast enhanced (DCE-) MRI is superior to FTV alone or LD alone for assessing treatment response after neoadjuvant therapy in breast cancer patients.

Methods: Data from patients in the graduated drug arms of the I-SPY 2 trial were included in the analysis. Both LD and FTV were assessed using DCE-MRI after neoadjuvant therapy. LD was measured by the site radiologist as the longest dimension of the enhanced area on early post-contrast images. Functional tumor volume (FTV) was assessed as the sum of voxels with enhancement above specific thresholds within the pre-defined region-of-interest (ROI). A linearized variable was derived to represent the combination of FTV and LD. The area under the receiver operating characteristic curve (AUC) was used to evaluate the assessment of treatment response, pathologic complete response (pCR), defined as no invasive disease in the breast and lymph nodes, and in-breast pCR, defined as no invasive disease in the breast only. The analysis was performed in the full cohort and in breast cancer subtype defined by hormone receptor status and HER2 status.

Results: Among the patient cohort of N=675 with FTV and LD, 247 (37%) did and 428 (41%) did not achieve pCR after neoadjuvant therapy. pCR rates varied among HR/HER2 subtypes (HR+/HER2-: 19%; HR+/HER2+: 38%; HR-/HER2+: 71%; HR-/HER2- (triple negative, TN): 43%). In-breast pathologic complete response rates were slightly higher in each group (full: 41%; HR+/HER2-: 23%; HR+/HER2+: 43%; HR-/HER2+: 72%; HR-/HER2-: 49%). Table 1 shows AUCs for assessing pCR using FTV alone, LD alone, and the variable combining FTV and LD. Higher AUCs were observed in all patient groups using the combined variable. AUC of 0.79 (95% CI: 0.77, 0.81) was observed for the combined variable to assess pCR in the full cohort. AUCs varied from 0.69 to 0.86 among HR/HER2 subgroups (HR+/HER2-: 0.69; HR+/HER2+: 0.74; HR-/HER2+: 0.86; HR-/HER2-: 0.80), with no difference in assessing pCR or in-breast pCR. The performance is best for the HR- subtypes.

Conclusions: Both FTV and LD can be used in the assessment of invasive disease residual after neoadjuvant therapy. The combined variable of FTV and LD achieved highest AUCs, compared to using individual variable alone. Tools to improve performance in the HR+ subsets are underway.

AUCs of MR measurements for identifying pCR  FTV alone (95% CI)LD alone (95% CI)Combined (95% CI)FullWith subtype adj.0.73 (0.71, 0.75)0.77 (0.74, 0.79)0.79 (0.77, 0.81)FullWithout subtype adj0.69 (0.65, 0.73)0.72 (0.68, 0.76)0.75 (0.71, 0.79)HR+/HER2- 0.68 (0.60, 0.77)0.68 (0.59, 0.77)0.69 (0.61, 0.77)HR+/HER2+ 0.65 (0.56, 0.75)0.72 (0.64, 0.80)0.74 (0.66, 0.82)HR-/HER2+ 0.69 (0.55, 0.83)0.82 (0.71, 0.92)0.86 (0.77, 0.95)HR-/HER2- (TN) 0.72 (0.66, 0.79)0.73 (0.67, 0.80)0.80 (0.74, 0.85)

Citation Format: Li W, Newitt D, Yun BL, Kornak J, Joe B, Yau C, Abe H, Wolverton D, Crane E, Ward K, Nelson M, Niell B, Drukteinis J, Oh K, Brandt K, Bang DH, Ojeda H, Eghtedari M, Sheth P, Bernreuter W, Umphrey H, Rosen M, Dogan B, Yang W, Esserman L, Hylton N. MRI detection of residual disease following neoadjuvant chemotherapy (NAC) in the I-SPY 2 TRIAL [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD4-03.

Abstract P5-02-04: Not presented

This abstract was not presented at the conference.

Citation Format: Sheth D, Pineda F, Karczmar G, Abe H. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-02-04.