Ultrafast Electron-Electron Scattering in Metallic Phase of 2H-NbSe_{2} Probed by High Harmonic Generation

Electron-electron scattering on the order of a few to tens of femtoseconds plays a crucial role in the ultrafast electron dynamics of conventional metals. When mid-infrared light is used for driving and the period of light field is comparable to the scattering time in metals, unique light-driven states and nonlinear optical responses associated with the scattering process are expected to occur. Here, we use high-harmonics spectroscopy to investigate the effect of electron-electron scattering on the electron dynamics in thin film 2H-NbSe_{2} driven by a mid-infrared field. We observed odd-order high harmonics up to 9th order as well as a broadband emission from hot electrons in the energy range from 1.5 to 4.0 eV. The electron-electron scattering time in 2H-NbSe_{2} was estimated from the broadband emission to be almost the same as the period of the mid-infrared light field. A comparison between experimental results and a numerical calculation reveals that competition and cooperation between the driving and scattering enhances the nonperturbative behavior of high harmonics in metals, causing a highly nonequilibrium electronic state corresponding to several thousand Kelvin.

Changes in the composition of molecular species of covalently bound and free ceramides [EOS], and their correlation with disease severity in atopic dermatitis

Ceramides are major constituents of stratum corneum (SC) intercellular lipids involved in skin barrier function. The ratio of molecular species of ceramides and their correlation with disease severity was examined in patients with atopic dermatitis (AD). Thirty-eight patients with AD and 32 healthy controls (HCs) were assessed for transepidermal water loss, SC collection and clinical assessment. The ceramide content of different molecular species in the samples was quantified using high-performance liquid chromatography coupled with tandem mass spectrometry. Unsaturated acyl chains of both covalently bound and free ceramides [EOS] were higher in AD lesional skin than those in AD non-lesional or normal HC skin. The proportion of unsaturated acyl chains (C30:1, C32:1 and C34:1) was higher than other ceramide molecular species among covalently bound and free ceramides [EOS] in patients with AD. The proportion of unsaturated acyl chains in covalently bound ceramides was positively correlated with transepidermal water loss (r = 0.600) when considering the total number of non-lesional and lesional skin. Additionally, thymus and activation-regulated chemokine (TARC) showed a positive correlation with unsaturated acyl chains proportion in AD non-lesional (r = 0.676) and lesional (r = 0.503) skin. Our study is the first to show the increase in unsaturated acyl chains of both covalently bound and free ceramides [EOS] in lesional and non-lesional skin in AD for each molecular species. This increase is associated with dryness and impaired barrier function, which correlates with TARC levels, a marker for the degree of type 2 inflammation. We speculate that type 2 inflammation exacerbation leads to abnormal epidermal lipid metabolism in the skin of patients with AD.

Dosimetric Comparison of Nodal Clinical Target Volume for Locally Advanced Non-Small Cell Lung Cancer: Options for Geometric Expansion vs. Lymph Node Stations

PURPOSE/OBJECTIVE(S)

We investigated whether dosimetric differences existed in nodal clinical target volume (CTV) using options for geometric expansion and lymph node stations based on the European Society for Radiotherapy and Oncology (ESTRO) guideline for locally advanced non-small cell lung cancer (NSCLC).

MATERIALS/METHODS

With treatment planning computed tomographic images in 17 patients who underwent radiotherapy for cT4N2M0 NSCLC from 2017 to 2022 at our institution, we retrospectively contoured nodal CTVs based on the guideline's options of: (1) geometric expansion, CTV including the nodal gross tumor volume plus 5 mm margin: (2) lymph node stations, CTV including the affected lymph node stations. The 5 mm margins for planning target volume (PTV) were added to the nodal and primary tumors' CTVs. Treatment planning of 60 Gy in 30 fractions to the PTV D50% was performed using volumetric modulated arc therapy; Dn% was irradiated dose to n% of volume of the structure; VnGy was percentage of volume of the structure at least irradiated n Gy. We compared dose-volume parameters between the two options using Wilcoxon rank sum test.

RESULTS

Primary tumors were located in the right and left lobes in 12 and five patients, and in the upper and lower lobes in 13 and four patients, respectively. Median PTV size/D95% of the options for geometric expansion and lymph node stations were 569 cc (range, 149-2005 cc)/58.2 Gy (range, 57.5-58.7 Gy) and 635 cc (range, 184-2109 cc)/58.1 Gy (range, 57.5-58.7 Gy), respectively. Median mean dose of the esophagus/heart in the two options were 12.2 Gy (range, 6.6-24.9 Gy)/3.3 Gy (range, 0.6-19.1 Gy) and 16.1 Gy (range, 13.6-30.5 Gy)/4.6 Gy (range, 0.7-18.9 Gy), respectively. Median V20 Gy/mean dose of the lungs in the options for geometric expansion and lymph node stations were 20.5% (range, 14.8-33.9%)/12.2 Gy (range, 8.7-18.4 Gy) and 24.0% (range, 15.1-36.7%)/13.5 Gy (range, 9.5-19.4 Gy), respectively. In the eight patients (47%) with lymph node metastases in stations 2 or 3, a significant dosimetric difference between the two options existed on V20 Gy of the lungs; median values of the difference were 2.8% and 0.5% with and without lymph node metastases in stations 2 or 3, respectively (p = 0.027).

CONCLUSION

Of the ESTRO guideline for the nodal CTV, using the option for geometric expansion might be able to reduce V20 Gy of the lungs in patients with lymph node metastases in stations 2 or 3.

Evaluation of the Possibility of Dose Realignment Adaptation by Shifting the Isocenter in Proton Beam Therapy for Pancreatic Cancer

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, a tumor is surrounded by the gastrointestinal (GI) tract, which is subject to changes in location, shape, and contents. Due to these inter-fractional changes, proton beam therapy (PBT) for pancreatic cancer may result in unintentionally high doses to the GI tract. Daily adaptive re-planning can solve this problem, but is not yet established with PBT due to its resource intensive characteristics. This study aims to evaluate the GI tract dose using weekly computed tomography (CTw) and the possibility of dose realignment adaptation by shifting the isocenter (IC) of the PBT plan, which does not require re-planning.

MATERIALS/METHODS

We retrospectively analyzed 6 consecutive patients with unresectable pancreatic cancer treated with real-time-image gated PBT using a fiducial marker. The planning CT was scanned at the natural expiration of respiration and a PBT plan of 60 GyE in 25 fractions (baseline plan, PLANbase) was created. The CTw images were acquired the day before start of PBT and once a week during the PBT course thereafter. The PLANbase was rigidly transferred to the CTw based on the relationship between the three-dimensional coordinates of the fiducial marker and those of the IC in the PLANbase. The PLANeval was created by recalculating the PLANbase on the CTw. We evaluated the doses to the stomach, duodenum, and intestines in the PLANeval according to the following criteria: Dmax of the stomach < 60 GyE, duodenum and intestines < 55 GyE, and D1cc of the stomach < 55 GyE, duodenum and intestines < 54 GyE. In addition, we investigated the GI tract dose realignment adaptation for the PLANeval with its IC shifted 2mm, 4mm, and 6mm in each of 6 directions (right, left, ventral, dorsal, cranial, and caudal), respectively.

RESULTS

A total of 35 PLANeval were created for the CTw. In the PLANbase of the 6 patients, the average of Dmax and D1cc of the stomach, duodenum and intestines were 50.7 GyE (range, 46.7-53.6) and 50.0 GyE (45.0-53.2), 49.2 GyE (44.3-51.7) and 48.8 GyE (43.7-51.5), and 49.2 GyE (44.8-52.0) and 48.9 GyE (44.6-51.8), respectively. In the PLANeval, the average of Dmax and D1cc of the stomach, duodenum, and intestines were 53.3GyE (43.8-61.4) and 52.8 GyE (43.2-61.1), 51.0 GyE (36.1-60.0) and 50.3 GyE (35.4-59.8), and 52.5 GyE (36.6-61.0) and 51.9 (34.4-60.9) GyE, respectively. Twenty-two of the 35 PLANeval (63 %) did not meet at least one of the GI tract dose criteria. In 11 of 22 PLANeval with higher doses to the GI tract, the IC shift resulted in GI dose reductions and all dose criteria were met. The minimum amount of the IC shift required to meet the criteria was 2 mm for 8 plans and 4 mm for 3 plans. The remaining 11 PLANeval did not meet the criteria using dose realignment adaptation by shifting the isocenter.

CONCLUSION

Adaptive replanning is necessary for PBT for pancreatic cancers due to excessive GI tract doses in more than 60% of the plans. Dose realignment adaptation by shifting the IC, which does not require re-planning, may be an option in adaptive treatment strategies.

A Risk Prediction Model for Severe Radiation Induced Lymphopenia in Patients with Pancreatic Cancer Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, radiation induced lymphopenia (RIL) is associated with a poor prognosis. However, normal tissue complication probability (NTCP) models predicting RIL in pancreatic cancer treated with concurrent chemoradiotherapy (CCRT) have yet to be developed. This study aims to develop a least absolute shrinkage and selection operator (LASSO)-based multivariate NTCP model to predict severe RIL in patients with pancreatic cancer during CCRT and to validate the model internally.

MATERIALS/METHODS

We retrospectively reviewed patients with localized pancreatic cancer who underwent CCRT using three-dimensional conformal radiation therapy from 2013 to 2021. The exclusion criteria were patients with distant metastasis; patients who did not complete RT due to tumor progression; patients who did not have absolute lymphocyte count (ALC) data available before or during RT. An ALC of < 0.5 K/μL during CCRT was defined as severe RIL. A NTCP model of severe RIL was developed by LASSO-based multivariate analysis. We used age, sex, Karnofsky performance status, maximum tumor size, carbohydrate antigen 19-9 level before RT, ALC before RT, volume of planning target volume (PTV), and dosimetric parameters for surrounding organs (including spleen, vertebrae, liver, bilateral kidneys, gastrointestinal tracts) as variables for LASSO. In addition, internal validation was performed by the bootstrap method. The predictive performance of the model was evaluated by the area under the curve (AUC) of the receiver operating characteristic curve and scaled Brier score.

RESULTS

Of the 131 patients included in the study, the median age was 68 years (range, 42-84), and 55% were male. The median ALC before RT was 1.37 K/µL (0.52-3.50). The median PTV volume was 315.4 ml (86.3-1079.3). The median dose of radiotherapy was 50.4 Gy (16.2-50.4), with 1.8 Gy per fraction. Combination chemotherapy was S-1 in 99 cases (75.6%) and gemcitabine in 32 cases (24.4%). Induction chemotherapy before CCRT was performed in 39 patients (29.8%). Severe RIL was observed in 84 (63.6%) patients. The LASSO showed that low baseline ALC (p = 0.0002), large PTV volume (p < 0.0001), and a large kidney V5 defined as the percentage of bilateral kidneys receiving 5 Gy or more (p = 0.0338) were selected as parameters of the prediction model for severe RIL (AUC = 0.917) and scaled Brier score was 0.511. As a result of internal validation by the bootstrap method, the average AUC was 0.918 (95% confidence interval, 0.849-0.954).

CONCLUSION

Severe RIL occurred frequently during CCRT for pancreatic cancer, and a NTCP model for severe RIL developed and validated internally in this study showed good predictive performance. External validation is needed before this NTCP model can be used as a benchmark for treatment planning to reduce the risk of severe RIL and for considering future treatment approaches.

Incremental lines in human cellular cementum: A histological study

OBJECTIVES

Human cellular cementum has incremental lines that demarcate individual cementum lamellae. The structural and functional details of the lines remain poorly understood. This study was designed to examine human cellular cementum using light microscopy, scanning electron microscopy, and contact microradiography and to elucidate the ultrastructure of incremental lines and their significance in cellular cementogenesis.

METHODS

Longitudinal paraffin and ground sections of human mandibular molars were prepared. Paraffin sections were stained with hematoxylin, or hematoxylin and eosin, or impregnated with silver. Hematoxylin-stained sections were observed via scanning electron microscopy using NaOH maceration. Silver-impregnated sections were further stained with hematoxylin. Hematoxylin-stained ground sections were examined using contact microradiography.

RESULTS

The incremental lines were found to be collagen fibril-poor layers. The outer area of each cementum lamella consisted of highly mineralized fibrils involved in constructing an alternating lamellar structure, whereas the inner area consisted of irregularly arranged, less highly mineralized, fibrils. The incremental lines corresponded with the innermost sites of the inner area.

CONCLUSIONS

Based on the obtained findings, we suggest that cellular cementogenesis progresses as follows. (1) Cementoblasts alternate between low-to high-activity states. (2) In the earliest low-activity stage, cementoblasts generate poorly mineralized, fibril-poor, incremental lines. (3) As cementoblasts recover activity, fibril-organization and mineralization advance in the cementum. (4) In the high-activity stage, cementoblasts reach full activity and construct the highly mineralized, alternating lamellar structure. (5) Cementoblasts revert back to the low-activity stage. (6) The above processes are repeated, thus, alternately generating the incremental lines and cementum lamellae.

Durvalumab with or without tremelimumab versus the EXTREME regimen as first-line treatment for recurrent or metastatic squamous cell carcinoma of the head and neck: KESTREL, a randomized, open-label, phase III study

BACKGROUND

Patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) have a poor prognosis. The phase III KESTREL study evaluated the efficacy of durvalumab [programmed death-ligand 1 (PD-L1) antibody] with or without tremelimumab [cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) antibody], versus the EXTREME regimen in patients with R/M HNSCC.

PATIENTS AND METHODS

Patients with HNSCC who had not received prior systemic treatment for R/M disease were randomized (2 : 1 : 1) to receive durvalumab 1500 mg every 4 weeks (Q4W) plus tremelimumab 75 mg Q4W (up to four doses), durvalumab monotherapy 1500 mg Q4W, or the EXTREME regimen (platinum, 5-fluorouracil, and cetuximab) until disease progression. Durvalumab efficacy, with or without tremelimumab, versus the EXTREME regimen in patients with PD-L1-high tumors and in all randomized patients was assessed. Safety was also assessed.

RESULTS

Durvalumab and durvalumab plus tremelimumab were not superior to EXTREME for overall survival (OS) in patients with PD-L1-high expression [median, 10.9 and 11.2 versus 10.9 months, respectively; hazard ratio (HR) = 0.96; 95% confidence interval (CI) 0.69-1.32; P = 0.787 and HR = 1.05; 95% CI 0.80-1.39, respectively]. Durvalumab and durvalumab plus tremelimumab prolonged duration of response versus EXTREME (49.3% and 48.1% versus 9.8% of patients remaining in response at 12 months), correlating with long-term OS for responding patients; however, median progression-free survival was longer with EXTREME (2.8 and 2.8 versus 5.4 months). Exploratory analyses suggested that subsequent immunotherapy use by 24.3% of patients in the EXTREME regimen arm contributed to the similar OS outcomes between arms. Grade 3/4 treatment-related adverse events (TRAEs) for durvalumab, durvalumab plus tremelimumab, and EXTREME were 8.9%, 19.1%, and 53.1%, respectively.

CONCLUSIONS

In patients with PD-L1-high expression, OS was comparable between durvalumab and the EXTREME regimen. Durvalumab alone, and with tremelimumab, demonstrated durable responses and reduced TRAEs versus the EXTREME regimen in R/M HNSCC.

Multicentric Carpotarsal Osteolysis: a Contemporary Perspective on the Unique Skeletal Phenotype

PURPOSE OF REVIEW

Multicentric carpotarsal osteolysis (MCTO) is an ultra-rare disorder characterized by osteolysis of the carpal and tarsal bones, subtle craniofacial deformities, and nephropathy. The molecular pathways underlying the pathophysiology are not well understood.

RECENT FINDINGS

MCTO is caused by heterozygous mutations in MAFB, which encodes the widely expressed transcription factor MafB. All MAFB mutations in patients with MCTO result in replacement of amino acids that cluster in a phosphorylation region of the MafB transactivation domain and account for a presumed gain-of-function for the variant protein. Since 2012, fewer than 60 patients with MCTO have been described with 20 missense mutations in MAFB. The clinical presentations are variable, and a genotype-phenotype correlation is lacking. Osteolysis, via excessive osteoclast activity, has been regarded as the primary mechanism, although anti-resorptive agents demonstrate little therapeutic benefit. This paper appraises current perspectives of MafB protein action, inflammation, and dysfunctional bone formation on the pathogenesis of the skeletal phenotype in MCTO. More research is needed to understand the pathogenesis of MCTO to develop rational therapies.

Embedding Technique versus Conventional Internal Limiting Membrane Peeling for Lamellar Macular Holes with Epiretinal Proliferation

PURPOSE

To examine the outcomes of pars plana vitrectomy (PPV) with lamellar hole-associated epiretinal proliferation (LHEP) embedding and conventional internal limiting membrane (ILM) peeling for lamellar macular holes (LMHs) with LHEP.

DESIGN

Retrospective observational study.

SUBJECTS

Forty eyes of 39 consecutive patients with LMHs and LHEP who underwent 3-port PPV with a minimum follow-up of 3 months.

METHODS

We compared the results of eyes that underwent PPV with LHEP embedding and ILM peeling (group E) with those of eyes that underwent PPV with ILM peeling only (group I) from September 2010 to September 2021. We confirmed whether the LHEP was embedded using postoperative OCT in all the cases.

MAIN OUTCOME MEASURES

Postoperative best-corrected visual acuity (BCVA) and the development of macular holes (MHs) were assessed.

RESULTS

The mean patient age was 73.3 years. The mean follow-up duration was 23.1 months. There were 23 and 17 eyes in groups E and I, respectively. Preoperative BCVA (P = 0.774) and central retinal thickness (CRT) (P = 0.800) did not differ significantly between the 2 groups. The final BCVA in group E was better than that in group I (P = 0.059). The final CRT in group E was thicker than that in group I (P < 0.001). Postoperatively, a significant improvement in BCVA was observed in group E at 3 months (P = 0.001) and at the final visit (P < 0.001). None of the eyes in group E developed postoperative MHs, whereas 5 eyes in group I developed postoperative MHs.

CONCLUSIONS

Pars plana vitrectomy using the LHEP embedding technique improved visual acuity significantly and yielded better anatomic outcomes than those with PPV using conventional ILM peeling; MH formation did not occur. Embedding LHEP is more effective than conventional surgical procedures for LMHs.

Role of glycerophosphodiester phosphodiesterase in rice leaf blades in elevated CO2 environments

Glycerophosphodiester phosphodiesterase (GDPD; EC 3.1.4.46) is involved in plant phosphate (Pi) utilization and its expression is upregulated under phosphorus (P)-deficient conditions. Although rice was grown under P-sufficient conditions, the transcript levels of specific OsGDPD were upregulated in mature rice leaf blades (LB) in elevated CO₂ (eCO₂ ) environments. Expression and subcellular localization of GDPD, and contents of Pi, sugar phosphates and carbohydrates were analysed to clarify the physiological function of GDPD in rice under eCO₂ . Under eCO₂ , expression of specific OsGDPD increased only in mature rice LB in which low Pi concentrations were observed. Moreover, eCO₂ -induced OsGDPD2 and OsGDPD3 were localized in the plastid, indicating that GDPD2 and GDPD3 may be related to plastidic functions, such as carbon assimilation. Although rice LB contained more carbohydrates under eCO₂ than under ambient CO₂ , the phosphoglucose content decreased under eCO₂ , suggesting that the need for excess phosphoglucose to synthesize carbohydrates under eCO₂ causes a local Pi deficiency. Furthermore, we confirmed that glycerol-3-phosphate produced by the catalysis of GDPD from glycerophosphodiester contributes to carbohydrate accumulation in rice LB. Our findings suggest that local Pi deficiency due to excess carbohydrate accumulation under eCO₂ influences GDPD to enhance glycerophosphodiester hydrolysis.

Diversity in the characteristics of spontaneous ruptured aortic plaques

Background

Spontaneous ruptured aortic plaques (SRAPs) act as emboli for systemic organs because SRAPs might contain CCs which cause inflammation besides mechanical obstruction. The purpose of the study is to clarify the difference of the characteristics of representative SRAPs, puff rupture and puff-chandelier rupture sampled by non-obstructive general angioscopy. (NOGA)

Methods

A total of 177 puff-chandelier ruptures which blown out spontaneously and glittered against the light of the angioscopic fiber and 105 puff ruptures which did not glitter were sampled by NOGA in patients having or suspected coronary artery disease. Sampled plaques were analyzed two kinds of methods, conventional Hematoxylin-eosin stain and methods without solvents. Samples were diagnosed if the component of atheroma was detected with either method. The percentage of content of CCs, the number of CCs, the longer and shorter diameters were compared between blood sampled from puff and puff-chandelier rupture.

Results

Samples were diagnosed as atheroma 56% of puff-chandelier rupture and 27% of puff- rupture. (p&lt;0.0001) Higher number of CCs was included in puff-chandelier rupture than in puff-rupture. (12,955 [3,977, 25,795] vs. 3,182 [909, 7,273]) The longer and shorter diameters of plaque components of puff rupture were smaller than those of puff-chandelier rupture. (p=0.0259 and p=0.0286, respectively.) CCs were tended to be included puff-chandelier rupture than puff-rupture. (53% vs. 16%, respectively; p&lt;0.0001) Visible debris was obtained only 13% of puff rupture and 26% of puff-chandelier rupture.

Conclusions

Diversity of SRAPs were shown as that puff rupture had less CCs and more fibrin than puff-chandelier rupture, suggesting that potentially less inflammation and more fibrinolytic.

Funding Acknowledgement

Type of funding sources: None.

Analysis of optic disc tilt angle in intrapapillary hemorrhage adjacent to peripapillary subretinal hemorrhage using swept-source optical coherence tomography

Purpose

To report findings on the tilt angle of optic nerve heads (ONHs) that developed intrapapillary hemorrhage with adjacent peripapillary subretinal hemorrhage (IHAPSH) using swept-source optical coherence tomography (SS-OCT).

Observations

Five consecutive patients who presented with IHAPSH were reviewed retrospectively. We reviewed five consecutive eyes from the five patients, analyzed the optic tilt angle obtained from SS-OCT B-scans, and compared the results and other clinical characteristics. All patients had larger optic disc tilt angles in the eyes with IHAPSH than in the contralateral, unaffected eye. The mean ratio of the tilt angle in the eyes with IHAPSH to that in the contralateral eye was 1.37 (95% confidence interval 1.15–1.58).

Conclusions and Importance

The ONH of IHAPSH was evaluated quantitatively with SS-OCT for the first time in this study. Larger angle tilted discs in IHAPSH-affected eyes are anatomically and histologically more vulnerable and may explain why IHAPSH develops monocularly.

Effects of liquid diet intake on nerve growth in salivary glands of growing rats

BACKGROUND

The growth of parotid glands is inhibited by liquid diet intake during growing period, while that of submandibular glands is not affected. This study examined how liquid diet intake affects nerve growth in the parotid and submandibular glands of growing rats, because nerves are closely involved in the maintenance of salivary gland structure.

MATERIALS AND METHODS

Male Wistar rats were weaned at 21 days of age. Then, rats were fed a pellet diet and a liquid diet in the control group and experimental group, respectively. At 0, 2, 4, or 8 weeks, they were euthanised by isoflurane overdose, and parotid and submandibular glands were removed. The frozen sections were made and immuno-stained with anti-protein gene product 9.5 (PGP 9.5) antibody (general nerve marker), anti-tyrosine hydroxylase (TH) antibody (sympathetic nerve marker), or anti-neuronal nitric oxide synthase (nNOS) antibody (parasympathetic nerve marker).

RESULTS

In control parotid glands, scattered punctate or short linear patterns of PGP 9.5-positive sites were observed at week 0. After 2 weeks, PGP 9.5-positive sites, some of which were arranged in long linear patterns, increased in number. There were some TH-positive sites at week 0. After 2 weeks, there were increasing numbers of TH-positive sites, often in long linear patterns. At week 0, there were very few nNOS-positive sites, and nNOS immunoreactivity increased over time. After week 4, they demonstrated linear patterns. In the experimental parotid glands, there were fewer PGP 9.5- and nNOS-positive sites than in control parotid glands at each time point, although TH immunoreactivity was similar between two groups at each time point. In control submandibular glands, few punctate exhibited PGP 9.5-positive site were observed at week 0. At week 4, PGP 9.5 immunoreaction increased and showed linear patterns. TH-positive sites demonstrated punctate or short linear patterns at week 0, and thereafter TH immunoreactivity increased and were arranged in long linear patterns. There were few nNOS-positive sites at week 0, and they gradually increased after week 4. The immunoreactivities of all antibodies in the experimental submandibular glands were similar to those in the control at each time point.

CONCLUSIONS

Parasympathetic nerve growth in rat parotid glands was inhibited by liquid diet intake during the growth period, while liquid diet intake did not affect parasympathetic nerve growth nor sympathetic nerve growth in rat submandibular glands.

Pooled analysis of drug-related interstitial lung disease and/or pneumonitis in nine trastuzumab deruxtecan monotherapy studies

Introduction

This pooled analysis of nine phase I and II trastuzumab deruxtecan (T-DXd) monotherapy studies described drug-related interstitial lung disease (ILD)/pneumonitis in patients treated with T-DXd.

Methods

Patients who received T-DXd across nine studies were included. Investigator-assessed ILD/pneumonitis events were retrospectively reviewed by an independent adjudication committee; events adjudicated as drug-related ILD/pneumonitis are summarized.

Results

The analysis included 1150 patients (breast cancer, 44.3%; gastric cancer, 25.6%; lung cancer, 17.7%; colorectal cancer, 9.3%; other cancer, 3.0%). Median treatment duration was 5.8 (range, 0.7-56.3) months, with a median of 4 (range, 1-27) prior lines of therapy. The overall incidence of adjudicated drug-related ILD/pneumonitis was 15.4% (grade 5, 2.2%). Most patients with ILD/pneumonitis experienced low-grade events (grade 1 or 2, 77.4%); 87.0% had their first event within 12 months [median, 5.4 (range, <0.1-46.8) months] of their first dose of T-DXd. Based on data review, adjudicated ILD/pneumonitis onset occurred earlier than identified by investigators for 53.2% of events [median difference in onset date, 43 (range, 1-499) days]. Stepwise Cox regression identified several baseline factors potentially associated with increased risk of adjudicated drug-related ILD/pneumonitis: age <65 years, enrollment in Japan, T-DXd dose >6.4 mg/kg, oxygen saturation <95%, moderate/severe renal impairment, presence of lung comorbidities, and time since initial diagnosis >4 years.

Conclusions

In this pooled analysis of heavily treated patients, the incidence of ILD/pneumonitis was 15.4%, with most being low grade and occurring in the first 12 months of treatment. The benefit–risk of T-DXd treatment is positive; however, some patients may be at increased risk of developing ILD/pneumonitis, and further investigation is needed to confirm ILD/pneumonitis risk factors. Close monitoring and proactive management of ILD/pneumonitis are warranted for all.

•

Interstitial lung disease (ILD)/pneumonitis is a significant adverse event related to trastuzumab deruxtecan (T-DXd).

•

This pooled analysis of nine T-DXd monotherapy studies evaluated ILD/pneumonitis risk in 1150 heavily pretreated patients.

•

Overall incidence of adjudicated T-DXd-related ILD/pneumonitis was 15.4% (grade 1 or 2, 77.4%; grade 5, 2.2%).

•

Within 12 months of their first T-DXd dose, 87.0% of patients had their first event [median, 5.4 (range, <0.1-46.8) months].

•

Proactive monitoring and prompt diagnosis and management are important to improving ILD/pneumonitis event outcomes.

The orthostatic hypotension in patients with Stanford type A aortic dissection after surgery

Funding Acknowledgements

Type of funding sources: None.

Background

Orthostatic hypotension (OH) is sometimes observed during cardiac rehabilitation in patients with surgery for aortic dissection. However, little is known about the primary determinant of OH and influence of surgical range on incidence of OH.

Purpose

The aim of this study was to elucidate the incidence of OH in patients with surgery for aortic dissection, and compare it between the patients with ascending aortic replacement surgery (ascending group) and those with ascending aorta and hemiarch or total arch replacement surgery (arch group).

Methods

We analyzed 59 patients who underwent emergent surgery due to Stanford type A aortic dissection from January 2014 to March 2018, and compared the incidence of OH between ascending group (n = 28, age 69.8 ± 11.3 years) and arch group (n = 31, age 64.1 ± 13.0 years).

Results

The incidence of OH in total patients was 30.5%. There were no significant differences in patient characteristics including body tall, body weight, antihypertensive use and progress of rehabilitation between 2 groups. The arch group showed a significant higher incidence of OH as compared with ascending group (arch group: 46.4% vs. ascending group: 16.1%, p = 0.03). Moreover, the patients who occurred OH were significantly taller than those who did not occur OH.

Conclusions

OH was observed in about one third of patients with surgery for aortic dissection and it showed a close relationship with patient’s height and the range repaired by surgical operation. More careful cardiac rehabilitation is needed for tall patients with large area replacement of aorta.

Vascular tortuosity analysis in eyes with epiretinal membrane imaged by optical coherence tomography angiography

Background

This study aimed to evaluate macular vessel tortuosity using optical coherence tomography angiography (OCTA) and its association with visual outcomes in eyes undergoing surgery for epiretinal membrane (ERM).

Methods

The study included 22 consecutive patients who underwent vitrectomy for ERM between May 2019 and July 2020 and OCTA at Osaka University Hospital. All patients underwent ophthalmologic examinations, including swept-source OCTA. Standard vitrectomy was performed, and the patients were followed up for 6 months postoperatively. Distortion of retinal vessels was calculated using two parameters: the actual vessel length in the vessel section (VL) and the direct vessel branching point distance (BD) in the three quadrants (nasal, temporal, and superior-inferior) of the macula. We analyzed the correlation between these parameters and visual outcomes.

Results

Significantly longer VL was found at 1, 3, and 6 months postoperatively (p = 0.006, 0.008, and 0.022, respectively) in the temporal quadrant compared to baseline temporal VL. Significantly shorter VL was found in nasal quadrants at 1 and 3 months (p = 0.046 and p = 0.018) in the comparison of nasal baseline VL. VL/BDs were correlated with the same postoperative best-corrected visual acuity (BCVA) at 1, 3, and 6 months (p = 0.035, 0.035, and 0.042, respectively) in the superior-inferior quadrant. A significant association of changes in VL and BCVA was found at 3 and 6 months postoperatively in the nasal quadrant (p = 0.018 and 0.0455, respectively).

Conclusions

Changes in vascular distortion after ERM surgery can be measured using OCTA. The change in vessels around the macula became more linear; this was associated with visual outcomes after surgery.

Open-label phase II study of the efficacy of nivolumab for cancer of unknown primary

BACKGROUND

Cancer of unknown primary (CUP) has a poor prognosis. Given the recent approval of immune checkpoint inhibitors for several cancer types, we carried out a multicenter phase II study to assess the efficacy of nivolumab for patients with CUP.

PATIENTS AND METHODS

Patients with CUP who were previously treated with at least one line of systemic chemotherapy constituted the principal study population. Previously untreated patients with CUP were also enrolled for exploratory analysis. Nivolumab (240 mg/body) was administered every 2 weeks for up to 52 cycles. The primary endpoint was objective response rate in previously treated patients as determined by blinded independent central review according to RECIST version 1.1.

RESULTS

Fifty-six patients with CUP were enrolled in the trial. For the 45 previously treated patients, objective response rate was 22.2% [95% confidence interval (CI), 11.2% to 37.1%], with a median progression-free survival and overall survival of 4.0 months (95% CI, 1.9-5.8 months) and 15.9 months (95% CI, 8.4-21.5 months), respectively. Similar clinical benefits were also observed in the 11 previously untreated patients. Better clinical efficacy of nivolumab was apparent for tumors with a higher programmed death-ligand 1 expression level, for those with a higher tumor mutation burden, and for microsatellite instability-high tumors. In contrast, no differences in efficacy were apparent between tumor subgroups based on estimated tissue of origin. Adverse events were consistent with the known safety profile of nivolumab. No treatment-related death was observed.

CONCLUSIONS

Our results demonstrate a clinical benefit of nivolumab for patients with CUP, suggesting that nivolumab is a potential additional therapeutic option for CUP.

Multimodal imaging of indapamide-induced bilateral choroidal effusion: a case report

Background

Indapamide, a sulfonamide diuretic used to treat hypertension, has been reported to have ocular side effects of acute angle-closure glaucoma, transient myopia and choroidal effusion whose immediate etiology is uncertain. This report aims to clarify the nature of indapamide-induced edema of the entire eyeball using multimodal imaging.

Case presentation

A 60-year-old woman who was following a long-term carbohydrate-restricted diet and receiving oral treatment for hypertension was referred to our department for eye pain. Indapamide (1 mg daily) was prescribed for uncontrolled hypertension 5 days before her visit; she took the medication for only 3 days and then stopped due to dry eye. However, she began to feel eye pain the day after her last dose, and the pain gradually intensified. She experienced no decrease in visual acuity at the initial visit; however, an extremely shallow anterior chamber was observed in both eyes, along with a slight increase in intraocular pressure. For differential diagnosis, ocular manifestations were evaluated with wide-field fundus photography, optical coherence tomography (OCT) of both anterior and posterior segments, fluorescein / indocyanine green angiography, ultrasound biomicroscopy and head magnetic resonance, showing edema of the entire eyeball. Treatment with tropicamide and phenylephrine hydrochloride drops resulted in rapid recovery of the anterior chamber depth and disappearance of the choroidal effusion within 3 days.

Conclusions

Multimodal imaging is useful for diagnosing drug-induced choroidal effusion by evaluating ocular conditions before and after treatment.

A Case of Idiopathic Dense Vitreous Hemorrhage: Suspected Rupture of a Large Retinal Arterial Macroaneurysm on the Optic Disc

We report a novel case of vitreous hemorrhage associated with suspected rupture of 2-disc-diameter retinal arterial macroaneurysm on the optic disc. A 90-year-old woman presented with blurred vision (sudden onset) in her left eye. Examination of the fundus revealed acute onset vitreous hemorrhage of unknown origin without retinal detachment. She underwent vitrectomy, but after excision of the dense vitreous hemorrhage, a 2-disc-diameter hematoma appeared on the optic disc and was removed promptly. Because the bleeding at the base of the hematoma was of arterial origin and pulsating, the first vitrectomy could not achieve hemostasis. Five days after the first surgery, we performed a second vitrectomy. This revealed a subretinal hemorrhage along the superior and inferior arcade vessels and a macular hole, which was almost completely closed with an inverted internal limiting membrane flap. Unfortunately, the macular hole reopened 41 days after the second surgery. In patients presenting with only a large hematoma on the optic disc, it might be prudent to leave the hematoma. However, this large retinal arterial macroaneurysm was on a rare location on the optic disc, making it doubly difficult for the surgeons to diagnose and choose the best option intraoperatively. The differential diagnosis for dense vitreous hemorrhage of unknown origin should include a large retinal arterial macroaneurysm on the optic disc.

OPERA tau neutrino charged current interactions

The OPERA experiment was designed to discover the vτ appearance in a vμ beam, due to neutrino oscillations. The detector, located in the underground Gran Sasso Laboratory, consisted of a nuclear photographic emulsion/lead target with a mass of about 1.25 kt, complemented by electronic detectors. It was exposed from 2008 to 2012 to the CNGS beam: an almost pure vμ beam with a baseline of 730 km, collecting a total of 1.8·1020 protons on target. The OPERA Collaboration eventually assessed the discovery of vμ→vτ oscillations with a statistical significance of 6.1 σ by observing ten vτ CC interaction candidates. These events have been published on the Open Data Portal at CERN. This paper provides a detailed description of the vτ data sample to make it usable by the whole community.

AB0136 ASSESSING THE RELATIONSHIP AMONG OBESITY, GENETIC POLYMORPHISM, AND CLINICAL PARAMETERS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Several study suggested body mass index(BMI) may influence development of rheumatoid arthritis(RA). There are conflicting reports concerning the impact of high BMI on development of RA, but several reports of obese on drug resistance and functional impairment. The relationship of genetic polymorphism on obesity is unclear in RA.

Objectives:

To examine the relationship among BMI, genetic polymorphism of obesity, disease activity of RA, laboratory parameters, and therapeutic agent of RA.

Methods:

We have carried out a retrospective observational study by systematically analyzing medical records of total 289 patients diagnosed with RA in Shinko Hospital between March 2016 and December 2019. We also conducted genotyping single nucleotide polymorphisms (SNPs) including FTO (rs1558902 and rs9939609), UCP1 (rs1800592), ADR2(rs1042713) and ADR3(rs4994) after informed consent. Obesity was defined as BMI over than 25 and patients were divided between obese (“Ob”) and non-obese (“non-Ob”). These SNPs, DAS28CRP, laboratory parameters, methotrexate dose, use of biological DMARDs were compared between Ob and non-Ob patients.

Results:

Of these 289 patients, 82.7% was female, mean age was 61.9 years and BMI was 22.4. Univariate logistic regression showed differences (p<0.1) between Ob and non Ob groups in UCP1 gene mutation(63.6% vs 78%, P=0.018), DAS(2.24 vs 1.99, P=0.033),triglyceride abnormality(23.8% vs 9.3%, P=0.021), HDL(56 vs 71, P=0.00009), HbA1c abnormality(26.5% vs 12.1%, P=0.019),γGTP(32 vs 21, P=0.00037), ALP (253 vs 230, P=0.0058), ALT (26.5 vs 20, P=0.029),and MTX dose(6 vs 8, P=0.066). Multivariate logistic regression showed that Ob group was significantly associated with HDL(OR=0.976, 95%CI 0.958 to 0.995), UCP1 gene mutation(OR=0.446, 95%CI 0.202 to 0.984), γGTP(OR=2.321, 95%CI 1.269 to 4.245), and MTX dose(OR=0.866, 0.784 to 0.957).

Conclusion:

Obesity in patients with RA had significant positive correlation with γGTP, and negative correlation with HDL, UCP gene mutation and MTX dose.

Disclosure of Interests:

None declared

POS0868 THE FORMULA TO PREDICT TACROLIMUS CONCENTRATION ACCORDING TO GENOTYPING OF CYP3A5 IS USEFUL FOR EFFECTIVE TREATMENT IN INTERSTITIAL LUNG DISEASE WITH DERMATOMYOSITIS

Background:

Tacrolimus (TAC), an immunosuppressant, can be used in second-line maintenance therapy for interstitial lung disease (ILD) in patients with dermatomyositis (DM) [1]. Although some studies reported the clinical efficacy of initial high-trough levels of TAC in combination with GC and IVCY in induction therapy for severe DM-ILD [2], there have been no useful clinical tools for deciding suitable initial dose of TAC. Genotype of polymorphisms in cytochrome P450 (CYP) 3A5 enzyme was reported to play an important role in pharmacokinetics of TAC [3], and we made a formula for deciding initial dose of TAC according to CYP3A5 genotypes in our previous study.

Objectives:

In our previous study (retrospective study), we set the target trough according to the severity for nine DM-ILD patients, six of whom were CYP3A5 *3/*3 and investigated the dose of TAC that could attain the trough using their CYP3A5 genootyping. Using these results, we developed a formula for deciding initial daily dose of TAC (target trough*weight / [(151.1, if CYP3A5 *3/*3) or (86.5, if CYP3A5 *1 allele)]). In this study, we prospectively examined the usefulness and accuracy of this formula.

Methods:

We introduced TAC for new six DM-ILD patients who visited our hospital between November 2019 and May 2020 (prospective study). The starting dose of TAC was decided by using the formula. We assessed the association between predicted and observed trough concentration of TAC at first measurement date (from day 2 to day4), using linear regression analysis. We also assessed the days for attaining the target trough concentration between the patients using the formula (prospective group) and six patients with CYP3A5 *3/*3 (retrospective group).

Results:

CYP3A5 genotype of all six DM-ILD patients were *3/*3 and underwent the TAC treatment by using the formula. The predicted and observed trough concentration of first measurement date were significantly correlated in the patients (r 2= 0.897, p=0.0041) (Fig.1). Compared with our retrospective study, target trough was more quickly attained in patients of the prospective study (Fig.2).

Conclusion:

The formula which we made for attainment target trough concentration based on CYP3A5 genotype was useful for deciding the starting dose of TAC. We also showed that we could attain the target trough concentration at early stage of initial treatment by using the formula.

References:

[1]Oddis CV and Aggarwal R. Nat Rev Rheumatol 2018;14(5):279-89.

[2]Suzuka T et al. Int J Rheum dis 2019;22: 303-13.

[3]Y. Muraki et al. Exp Ther Med 2018;15:532-38.

Figure 1.

Correlation of predicted and observed tacrolimus trough concentration at first measurement in the prospective study

Figure 2.

Days to attain the target trough concentration of tacrolimus in the prospective group and the retrospective group

Disclosure of Interests:

None declared

Impact of photoreceptor density in a 3D simulation of panretinal laser photocoagulation

Background

During panretinal photocoagulation (PRP), the outer retina, especially the photoreceptors, are destroyed. During such procedures, the impact of the retinal photocoagulation, which is performed in the same photocoagulated area, may change if it is applied to different locations with different photoreceptor densities. Thus, we aimed to evaluate the influence of photoreceptor density on PRP.

Methods

We constructed a three-dimensional (3D) average distribution of photoreceptors with 3D computer-aided design (CAD) software using previously derived photoreceptor density data and calculated the number of photoreceptors destroyed by scatter PRP and full-scatter PRP (size 400-μm on the retina, spacing 1.0 spot) using a geometry-based simulation. To investigate the impact of photoreceptor density on PRP, we calculated the ratio of the number of photoreceptors destroyed to the total number of photoreceptors, termed the photoreceptor destruction index.

Results

In this 3D simulation, the total number of photoreceptors was 96,571,900. The total number of photoreceptors destroyed by scatter PRP and full-scatter PRP were 15,608,200 and 19,120,600, respectively, and the respective photoreceptor destruction indexes were 16.2 and 19.8%, respectively.

Conclusions

Scatter PRP is expected to have 4/5 of the number of photoreceptors destroyed by full-scatter PRP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01945-z.

N-acetylcysteine attenuates PGE2 and ROS production stimulated by 4-META/MMA-based resin in murine osteoblastic cells

This study examined the effects of N-acetylcysteine (NAC) on the inflammatory reactions of murine osteoblastic cells cultured on the 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate (4-META/MMA)-based resin. Superbond C&B (SB) was used as the 4-META/MMA-based resin and placed in a 48-well cell culture plate. The cells were cultured in αMEM (control) as well as on SB and SB in αMEM with NAC (SB+NAC). They were examined using the WST-1 proliferation assay, real-time PCR, enzyme-linked immunosorbent assay (ELISA), intracellular reactive oxygen species (ROS) measurements, and cellular glutathione (GSH) detection. COX-2 and IL-6 gene expressions were upregulated in SB; however, they were suppressed by NAC. Furthermore, PGE₂ production in the culture medium was increased in SB, whereas NAC decreased the PGE₂ production. NAC lowered the ROS level in the culture medium and significantly increased the intracellular GSH level. The present in vitro study demonstrated that NAC might be effective for dental material detoxification.

Conduction gaps after pulmonary vein isolation due to high contact force ablation in patients with atrial fibrillation

Background

Catheter ablation for atrial fibrillation (AF) with high contact force (CF) has been reported to lead to the gaps after pulmonary vein isolation (PVI), and the appearance of the gaps depends on the site in the left atrium (LA).

Purpose

The aim of this study is to clarify the relationship between the gaps appearance and high CF.

Methods

In the clinical study, 74 consecutive patients (39 males, age 71±9, 46 with paroxysmal AF) underwent conventional PVI with a point-by-point radiofrequency (RF) ablation using a CF sensing catheter (TactiCath SETM). RF energy (J), number of RF point, Lesion index (LSI), force-time integral (FTI), average CF (g), and the degree of LA depression with high CF were evaluated. In the experimental study (figure), the relationship between the ablation area and the degree of depression with high CF using bovine left ventricular wall.

Results

In the clinical study, the gaps were found in 175 of 1182 sites after first path PVI ablation. The CF in the gap sites was higher than without the gap sites in RPV roof, anterior RSPV and anterior RPV carina (18.9±6.8 vs 15.0±5.7g p=0.0262, 26.4±11.6 vs 19.5±6.0g p=0.0029, 22.7±6.4 vs 19.1±5.5g, p=0.0161). Meanwhile, there were no differences in RF energy, number of RF point, LSI, FTI. High CF (≥30g) showed a depression of 3 mm or more in only RPV roof and anterior RPV (figure). In the experimental study, the ablation range narrowed as the indentation deepened with more than 30g CF (r=0.6417, p=0.0625).

Conclusion

Catheter ablation for AF with high contact force might lead to the gaps in RPV roof and anterior RPV site by the reduction of the ablation area due to depression caused by the pressure.

Extension of each contact force

Funding Acknowledgement

Type of funding source: None

Sex-related differences in geometry, plaques and shear stress related plaque-progression in human coronary arteries

Background

Atherosclerosis manifests itself differently in women compared to men. Since the pathophysiology of atherosclerotic plaques is known to be related to endothelial shear stress (ESS), it was hypothesized that female compared to male coronary arteries demonstrate a different i) ESS and ii) ESS related plaque progression.

Methods

1183 coronary arteries (male/female:944/239) from the PREDICTION trial were studied for differences in vessel geometry (plaque area (PA) and lumen area (LA)), hemodynamic parameters (flow, minimal ESS over 90 degree arc (minESS) and maximal ESS over 90 degree arc (maxESS)) and ESS related plaque progression (1 year follow up) measured as change in maximal plaque thickness and plaque burden comparing female to male arteries. Arterial geometry and ESS measures were derived from IVUS-based vascular profiling and reported per 3 mm segments. For plaque progression studies minESS was subdivided into low, mid and high (&lt;1,1–1.7,&gt;1.7 Pa). To test statistical differences univariate anova or linear mixed models were used.

Results

13030 3mm-segments (m/f: 10.465/2565) were analyzed. Female compared to male coronary arteries were smaller and presented with less plaque area (Table I). No differences in average ESS, minESS and maxESS were found for male versus female coronary arteries, partly explained by the lower flows in female arteries (Table I). The ESS-related plaque growth showed for both sexes an significant inverse relationship between maximal wall thickness (Figure, left) and plaque burden (Figure, right) and the three minESS categories. However, ESS-related plaque growth was not different for male vs females.

Conclusion

Our data demonstrated that vessel and plaque size are smaller in female compared to male coronary arteries. However, ESS and ESS related plaque progression were not different.

Shear stress related plaque progression

Funding Acknowledgement

Type of funding source: None

Coronary plaque natural history displays significant longitudinal heterogeneity along the length of individual coronary plaques

Background

The natural history of plaque growth is, among other systemic risk factors, related to the blood flow induced local shear stress. Especially at regions of low shear stress plaques are initiated. Upon plaque encroachment into the lumen, plaques will be exposed to high shear stress. Interestingly, it has been observed that individual plaques are very heterogeneous regarding the local shear stress exposure and remodeling patterns along the plaque length. However no information is available on the spatial heterogeneity of temporal changes in plaques burden. We studied the longitudinal spatial heterogeneity of plaque burden progression, regression, quiescence in human coronary plaques.

Methods

591 coronary arteries from 302 patients with coronary artery disease who presented with an acute coronary syndrome from the PREDICTION study were investigated for local plaque progression, regression, quiescence patterns after 6–10 months follow up. Arterial geometry was derived from angiography/IVUS-based vascular profiling and reported in 3 mm segments. Plaques were defined as &gt;3 consecutive segments with maximal wall thickness&gt;0.5 mm. Plaque progression was defined as &gt;5% increase, regression as &lt;−5% decrease, and quiescence as no change in plaque burden (plaque area/ total vessel area * 100%). Logistic mixed model regression analysis was performed with plaque progression features as outcome and plaque length as independent variable with vessel as random factor to account for clustering of the data.

Results

5658 3mm-segments of 661 plaques were analyzed. Plaque burden changes over time ranged from −22% to +20%, with an average of −0.4%±4% which was not significant different from 0. Among all plaques, 56% showed segments with plaque progression of more than 5%, 60% with plaque regression (&lt;−5%) and 96% of the plaques had segments that did not change over time (quiescence). On average, 17% of the plaque length displayed plaque progression, 20% regression and 63% was quiescent. The presence and number of features (progression, regression, quiescence) within the plaque were significantly related to the plaque length (figure).

Conclusion

Plaques are very heterogeneous in plaque progression patterns. Most of the plaques show within the plaque length simultaneously more than one plaque progression feature (segments that do not change in plaque burden, segments that regress or progress). The number of observed plaque progression features was related to the plaque length.

Funding Acknowledgement

Type of funding source: None

Chronotropic incompetence and exercise capacity after mitral valve surgery: the importance of blood hemoglobin level

Background

Chronotropic incompetence (CI) is sometimes observed during exercise training of cardiac rehabilitation in patients with cardiac surgery, however, little is known concerning the differences between patients with mitral valve (MV) and aortic valve (AV) surgery.

Purpose

Because the possibility exists that cardiac sympathetic nerves might be impaired by left atrium incision, we hypothesized that the incidence of CI was higher in patients with MV surgery (Mitral Valve Replacement and Mitral Valvuloplasty) as compared with patients with AV surgery (Aortic Valve Replacement). And if so, which factor determines the exercise capacity of patients after MV surgery. We thus aimed this study to elucidate the hypothesis with cardiopulmonary exercise testing (CPX).

Methods

We performed CPX by ramp loading with ergometer exercise in total 61 patients who had undergone elective cardiac valve operation (25 patients with MV surgery, age 59.2±9.9 years; 36 patients with AV surgery, age 64.6±12.3 years). We analyzed chronotropic response index (CRI), peak oxygen uptake (peak VO2/W), anaerobic threshold (AT), and peak oxygen pulse (peak VO2/HR) with CPX, and blood hemoglobin concentration (Hb).

Results

The value of CRI was significantly decreased in the patients with MV surgery compared with those with AV surgery (MV; 0.19±0.10 vs. AV; 0.41±0.17, p&lt;0.001). Peak VO2, peak VO2/HR and Hb were not significantly different between patients with MV and those with AV surgery. Patients with MV surgery showed correlations between peak VO2 and Hb (r=0.45, p&lt;0.05), AT and Hb (r=0.52, p&lt;0.01), and a strong correlation between peak VO2 and peak VO2/HR (r=0.63, p&lt;0.001), but not in those with AV surgery.

Conclusions

The present study demonstrated that higher incidence of CI was shown in patients with MV surgery as compared with those with AV surgery. The exercise capacity of patients with MV surgery was determined by peak VO2/HR and Hb. These results suggest that 1) left atrium incision impairs cardiac sympathetic nerves and causes CI, 2) peak VO2/HR which is consisted of arterio-venous oxygen difference and Hb is critical indicator for exercise capacity in patients with MV surgery with CI.

Main results

Funding Acknowledgement

Type of funding source: None