OP0112 THE EVER-LARGEST ASIAN GWAS FOR SYSTEMIC SCLEROSIS AND TRANS-POPULATION META-ANALYSIS IDENTIFIED SEVEN NOVEL LOCI AND A CANDIDATE CAUSAL SNP IN A CIS-REGULATORY ELEMENT OF THE FCGR REGION

Background

Genome-wide association studies (GWASs) have identified 29 disease-associated single nucleotide polymorphisms (SNPs) for systemic sclerosis (SSc) in non-human leukocyte antigen (HLA) regions (1-7). While these GWASs have clarified genetic architectures of SSc, study subjects were mainly Caucasians limiting application of the findings to Asians.

Objectives

The study was conducted to identify novel causal variants for SSc specific to Japanese subjects as well as those shared with European population. We also aimed to clarify mechanistic effects of the variants on pathogenesis of SSc.

Methods

A total of 114,108 subjects comprising 1,499 cases and 112,609 controls were enrolled in the two-staged study leading to the ever-largest Asian GWAS for SSc. After applying a strict quality control both for genotype and samples, imputation was conducted using the reference panel of the phase 3v5 1,000 genome project data combined with a high-depth whole-genome sequence data of 3,256 Japanese subjects. We conducted logistic regression analyses and also combined the Japanese GWAS results with those of Europeans (6) by an inverse-variance fixed-effect model. Polygenicity and enrichment of functional annotations were evaluated by linkage disequilibrium score regression (LDSC), Haploreg and IMPACT programs. We also constructed polygenic risk score (PRS) to predict SSc development.

Results

We identified three (FCRLA-FCGR, TNFAIP3, PLD4) and four (EOMES, ESR1, SLC12A5, TPI1P2) novel loci in Japanese GWAS and a trans-population meta-analysis, respectively. One of Japanese novel risk SNPs, rs6697139, located within FCGR gene clusters had a strong effect size (OR 2.05, P=4.9×10-11). We also found the complete LD variant, rs10917688, was positioned in cis-regulatory element and binding motif for an immunomodulatory transcription factor IRF8 in B cells, another genome-wide significant locus in our trans-ethnic meta-analysis and the previous European GWAS. Notably, the association of risk allele of rs10917688 was significant only in the presence of the risk allele of the IRF8. Intriguingly, rs10917688 was annotated as one enhancer-related histone marks, H3K4me1, in B cells, implying that FCGR gene(s) in B cells may play an important role in the pathogenesis of SSc. Furhtermore, significant heritability enrichment of active histone marks and a transcription factor C-Myc were found in B cells both in European and Japanese populations by LDSC and IMPACT, highlighting a possibility of a shared disease mechanism where abnormal B-cell activation may be one of the key drivers for the disease development. Finally, PRS using effects sizes of European GWAS moderately fit in the development of Japanese SSc (AUC 0.593), paving a path to personalized medicine for SSc.

Conclusion

Our study identified seven novel susceptibility loci in SSc. Downstream analyses highlighted a novel disease mechanism of SSc where an interactive role of FCGR gene(s) and IRF8 may accelerate the disease development and B cells may play a key role on the pathogenesis of SSc.

References

[1]F. C. Arnett et al. Ann Rheum Dis, 2010.

[2]T. R. Radstake et al. Nat Genet, 2010.

[3]Y. Allanore et al. PLoS Genet, 2011.

[4]O. Gorlova et al. PLoS Genet, 2011.

[5]C. Terao et al. Ann Rheum Dis, 2017.

[6]E. López-Isac et al. Nat Commun, 2019.

[7]W. Pu et al. J Invest Dermatol, 2021.

Disclosure of Interests

None declared

Heavily T2-weighted imaging findings of spinal cord swelling in dogs with intervertebral disc extrusion

This study investigated causes of attenuation of cerebrospinal fluid (CSF) signal on heavily T2-weighted (T2W) images in dogs with thoracolumbar disc extrusion. Medical records and magnetic resonance images were retrospectively reviewed. Dogs were classified into the following grades; grade 1, non-ambulatory paraparesis; grade 2, paraplegia with deep pain perception and grade 3, paraplegia without deep pain perception. The length of intramedullary T2W hyperintensity of the spinal cord, cranial/ caudal expansion of extradural compressive materials (ECM), and the CSF signal attenuation were measured. Ratios to the second lumbar vertebra (L2) were calculated for the length of intramedullary T2W hyperintensity (T2W:L2), cranial/caudal expansion of ECM (ECML:L2), and CSF signal attenuation (CSF:L2). The dogs were classified into focal or extended T2W hyperintensity groups according to the length [focal, shorter than length of L2; extended, longer than L2]. The area of EMC and the spinal canal were measured on transverse images at the lesion deriving occupancy ratio. The correlation between CSF:L2 and other data were analysed, and CSF:L2 was compared between the grades. In dogs with intramedullary T2W hyperintensity, the locations of CSF attenuation and the hyperintensity were compared if those locations were matched. Fifty-five dogs were included, 36 of which showed intramedullary T2W hyperintensity. Twenty-two of 36 dogs were considered as match of the location of the CSF attenuation and hyperintensity. CSF:L2 was significantly correlated with T2W:L2 in dogs with extended T2W hyperintensity (p = 0.0002), while CSF:L2 was significantly correlated with ECML:L2 in dogs with focal or no T2W hyperintensity (p = 0.0103 and p = 0.0364, respectively). CSF:L2 in grade 3 was significantly greater than those in patients who were grade 1 or 2 (both p < 0.001). In conclusion, higher CSF:L2, which was frequently seen in grade 3, would be most consistent with a higher T2W:L2 which might indicate spinal cord swelling.

Impact of heart rate reduction on recurrence after catheter ablation of persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Johnson & Johnson KK

OnBehalf

OCVC Arrhythmia Investigators

Background

Predicting heart rate (HR) after restoration of sinus rhythm (SR) remains one of the challenges when performing catheter ablation (CA) of persistent atrial fibrillation (AF).

Purpose

To evaluate the association between pre-ablation HR during AF and post-ablation HR during SR, and whether the HR reduction is associated with AF recurrence.

Methods

The analysis was performed from the EARNEST-PVI trial, a randomized controlled trial designed to assess a CA strategy for persistent AF, which was conducted in the Osaka region of Japan. After excluding patients with beta-blocker prescription, a total of 216 patients (median age, 67 years; 20% female; 23% long-standing persistent AF) with AF rhythm at baseline and SR at discharge were enrolled in this study. Baseline HR during AF and post-ablation HR during SR was measured on admission and at discharge using the 12-lead electrocardiograms, respectively.

Results

There was a mild correlation between baseline HR (median 82 [interquartile range 72-95] bpm) and post-ablation HR (78 [48-117] bpm) (r = 0.27, p &lt;0.001). Reduction in HR was positively associated with baseline HR (r = 0.79, p &lt;0.001) and was negatively associated with post-ablation HR (r = - 0.37, p &lt;0.001). During the follow-up of 1 year, 56 patients (25.9%) experienced AF recurrence. HR reduction had the higher diagnostic accuracy in predicting AF recurrence than HR at baseline and HR after CA (area under the curve, 0.625; 95% confidence interval, 0.557–0.690; p = 0.003). AF recurrence rate was significantly higher in 141 patients with smaller HR reduction (cut-off, &lt;14bpm) than those with larger HR reduction (31.9% vs. 14.7%, p = 0.009). After adjustment of age, gender, long-standing persistent AF, and CA strategy, HR reduction of &lt;14 bpm was a significant predictor of AF recurrence (hazard ratio, 2.32; 95% confidence interval, 1.20–4.51; p = 0.013).

Conclusions

There was a mild correlation between HR during AF and HR after restoration of SR in patients underwent CA of persistent AF. HR reduction after restoration of SR predicted AF recurrence.

Association between myocardial wall thickness and left ventricular functional recovery after catheter ablation of atrial fibrillation in patients with reduced ejection fraction

Background

Catheter ablation of atrial fibrillation (AFCA) is an effective treatment to develop left ventricular (LV) functional recovery. However, the degree of recovery differs between individuals due to the different extent of myocardial fibrosis and scarring.

Purpose

To examine whether pre-ablation LV wall thickness (WT) and its regional heterogeneity predict LV functional recovery after AFCA in patients with LV systolic dysfunction.

Methods

Of 3682 consecutive patients who underwent first-time AFCA between January 2012 and September 2020 in our institution, 174 (age, 63±10 years; male, 83%; ischemic cardiomyopathy, 14%) with a baseline LV ejection fraction (LVEF) of &lt;40% were retrospectively evaluated. They were subjected to 256-slice MDCT scanning at baseline and 3 months after AFCA. Baseline WT was evaluated by 16-segment model. Mean and standard deviation (SD) of 16 regional WT were calculated in both end-systolic and end-diastolic phase.

Results

LVEF significantly improved from 30±7% to 57±17% (p&lt;0.001) after AFCA. Increase in LVEF (delta-LVEF) was positively correlated with baseline end-diastolic WT (r=0.31, p&lt;0.001) and negatively correlated with SD of end-systolic WT (r=−0.21, p=0.007). Independent of WT measurements, delta-LVEF was negatively correlated with LV end-diastolic volume (r=−0.42, p&lt;0.001). We created a scoring system to predict the degree of wall motion recovery using the median value of the 3 variables; assigned 1 point each for end-diastolic WT &gt;7.4mm, SD of end-systolic WT &lt;1.61mm, and LV end-diastolic volume &lt;125ml. The model successfully predicted improvement in LVEF after AFCA (0 point (N=13) vs. 1 point (N=72) vs. 2–3 point (N=89), 11±16% vs. 20±17% vs. 33±12%, p&lt;0.001).

Conclusion

Myocardial WT and its regional heterogeneity as well as LV end-diastolic volume predicted functional recovery after AFCA in patients with reduced LVEF.

Funding Acknowledgement

Type of funding sources: None.

Cardiac phenotypes in the acute-phase of microscopic polyangiitis involves dilatation of the left atrium caused by LV diastolic dysfunction

Background

Microscopic polyangiitis (MPA) is a type of primary systemic vasculitis that affects various organs, especially the lungs and kidneys. However, few reports regarding cardiac features of MPA patients were found.

Purpose

We aim to investigate the echocardiographic parameters of acute-phase MPA.

Methods and results

This single-center retrospective study included 15 patients with MPA (Mean age at 72.2±7.1 years, women 73.3%) who underwent echocardiography within two weeks of commencing steroid therapy for induction or reinduction. The echocardiography parameters of the patients were compared with those of 30 age and sex-matched controls. In the MPA group, the commonly affected organs were kidneys (93.3%) and lungs (46.7%); 5 patients (33.3%) had a history of hypertension, which had a similar frequency as the control group. No significant difference in left ventricular (LV) diameter, LV ejection fraction, e', or inferior vena cava diameter was observed between the two groups. However, the MPA group showed significantly higher left atrial (LA) diameter (p=0.033) and LA volume index (p=0.001), as well as higher early diastolic filling velocity (E-wave, p=0.015; E/A, p=0.043; E/e', p=0.041), diastolic pulmonary venous flow velocity (p=0.013), trans-tricuspid pressure gradient (p=0.019), and shorter deceleration time (p=0.038), associated with mildly thicker ventricular walls of left ventricle (LV) than the control group. Moreover, serum levels of C-reactive protein showed significant correlation between E wave (r=0.58, p=0.023), E/A (r=0.67, p=0.006), and deceleration time (r=−0.69, p=0.005) in the MPA group. These results may indicate that in MPA, increased LV stiffness, rather than impairment of LV relaxation was contributed to LV diastolic function, resulting in LA enlargement.

Conclusion

Patients with acute-phase MPA had LA dilatation associated with LV diastolic dysfunction. This finding indicates the importance of cardiac assessment in patients with MPA.

Funding Acknowledgement

Type of funding sources: None.

Reappraising the role of baseline plasma C-reactive protein levels on recurrence after catheter ablation of persistent atrial fibrillation: insight from EARNEST-PVI trial

Background

Subclinical inflammation is an important pathogenesis of developing and sustaining atrial fibrillation (AF). Because AF itself contribute to the inflammatory response, the role of baseline subclinical inflammation on AF recurrence after catheter ablation (CA) remains controversial in patients with persistent AF.

Purpose

To evaluate whether baseline plasma C-reactive protein (CRP) levels, a sensitive marker of inflammation, are associated with AF recurrence following CA.

Methods

The analysis was performed from the EARNEST-PVI trial, a randomized controlled trial designed to assess a CA strategy for persistent AF, which was conducted in the Osaka region of Japan. A total of 441 patients (median age, 67 years; 26% female; 25% long-standing persistent AF) whose plasma CRP levels were measured at baseline were included in this study.

Results

At baseline, a median (interquartile range) of plasma CRP level was 0.10 [0.06–0.19] mg/dl. Plasma CRP levels significantly increased at discharge (0.83 [0.21–1.84] mg/dl, p&lt;0.001) and decreased 1 year after CA (0.10 [0.05–0.20] mg/dl, p=0.040) compared to the baseline value. During the follow-up of 1 year, 115 patients (26%) experienced AF recurrence, and the incidence was significantly higher in 124 patients with low CRP levels at baseline (cut-off ≤0.06 mg/dl) than the other 317 patients (33.9% vs. 23.0%, p=0.017). After adjustment of age, gender, body mass index, long-standing persistent AF, CA strategy, and plasma brain natriuretic peptide levels, low plasma CRP levels was a significant predictor of AF recurrence (hazard ratio, 1.51; 95% confidence interval, 1.02–2.24; p=0.042).

Conclusions

Low plasma CRP levels at baseline predicted AF recurrence in the EARNEST-PVI trial. Reappraising the role of CRP on AF recurrence may be needed in patients with persistent AF.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Johnson & Johnson KK

Renal function and arrhythmia outcomes in persistent atrial fibrillation patients after catheter ablation: subanalysis of the EARNEST-PVI trial

Background

Atrial fibrillation (AF) reduces the renal function. Renal dysfunction and AF often coexist. Catheter ablation (CA) of persistent AF can maintain a sinus rhythm and may improve the renal function.

Purpose

We sought to elucidate whether the estimated glomerular filtration rate (eGFR) in patients with persistent AF was increased after CA, especially with the presence of an AF recurrence.

Methods

We enrolled 487 persistent AF patients whose eGFR data were available both before and 1-year after the CA out of 512 patients in the EARNEST-PVI trial.

Results

The mean age was 65±9 year and 113 patients (24.8%) had long-standing persistent AF. We compared the eGFR at baseline with that 1-year after the CA. AF recurrences were recognized in 118 patients (25.8%). The eGFR was similar between the group without recurrence and that with recurrence at baseline (without AF recurrence vs. with AF recurrence; 63.8±14.3 vs. 62.7±13.6 mL/min/1.73m2, p=0.46). In patients without AF recurrence, the G1, G2, G3a, G3b, G4, and G5 were 13 (3.8%), 198 (58.4%), 98 (28.9%), 26 (7.7%), 3 (0.9%), and 1 (0.3%), respectively at baseline. In the patients with AF recurrence, the G1, G2, G3a, G3b, G4, and G5 were 3 (2.5%), 68 (57.8%), 38 (32.2%), 6 (5.1%), 3 (2.5%), and 0 (0%), respectively at baseline. The ΔeGFR was significantly higher in the patients without AF recurrence than in those with AF recurrence (without AF recurrence vs. with AF recurrence; 5.1 [−0.3, 10.8] vs. 3.0 [−3.0, 7.6], p=0.0033). In the patients without AF recurrence, a better eGFR class at 1-year after the CA than in those before the CA was recognized in 75 patients (22.1%), while it was recognized in 19 patients (16.1%) with AF recurrences.

Conclusion

Successful catheter ablation in patients with persistent AF led to a better renal outcome.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This study was funded by Medtronic, Johnson & Johnson, and Abbott.

Conversion surgery of Stage IV gastric cancer with peritoneal dissemination after nivolumab

A 69-year-old man was clinically diagnosed as stage IV gastric cancer with peritoneal dissemination. We performed systemic chemotherapy consisting of S-1 plus oxaliplatin as a first line, and ramucirumab plus nab-paclitaxel as a second line. However, CT and EGD revealed growth of the primary tumor and the lymph nodes along the lesser curvature and adjacent to the cardia. In addition, CT revealed ascites in the rectovesical pouch. Therefore, treatment was switched to nivolumab. After 3 treatment courses, CT revealed shrinkage of lymph nodes and disappearance of ascites. After 12 courses of nivolumab, however, EGD revealed growth of the tumors in the stomach with minor hemorrhage, prompting the consideration of gastrectomy. At the time of laparotomy, the peritoneal dissemination had completely disappeared, and peritoneal cytology was negative. Therefore, total gastrectomy with D2 and paraaortic lymphadenectomy was performed, after 21 months following the initial diagnosis. To our knowledge, there are no previous reports that have demonstrated the disappearance of peritoneal dissemination and ascites in response to nivolumab, resulting in curative gastrectomy.

Comparative Treatment Outcome in T3N0 Glottic Cancer With and Without Vocal Fold Fixation Receiving Radiation Therapy and Concurrent Low-Dose Intra-Arterial Cisplatin Infusion

OBJECTIVES

Selective radiotherapy and concomitant intra-arterial cisplatin infusion (m-RADPLAT) with a lower cisplatin dosage have been performed for organ and function preservation in patients with locally advanced squamous cell carcinoma of the larynx (SCC-L), and results showing a lower rate of adverse events have been reported. This study evaluated the treatment outcomes of patients with T3N0 glottic SCC-L with or without vocal fold fixation (VFF) who were treated with m-RADPLAT.

METHODS

We retrospectively reviewed the data of 33 patients with T3N0 SCC-L who received m-RADPLAT.

RESULTS

The vocal fold in patients with VFF 3 months after completing m-RADPLAT resumed normal movement in 15 patients (83%) and persisted fixation in 3 (17%). The 3-year local control, laryngeal cancer-specific survival, and overall survival rates of patients with or without VFF were 88.9% and 86.7%, 94.1% and 93.3%, and 88.9% and 86.7%, respectively. Additionally, the 3-year freedom from laryngectomy, laryngectomy-free survival, and laryngo-esophageal dysfunction-free survival rates of patients with or without VFF were 94.4% and 86.7%, 88.9% and 73.3%, and 83.3% and 73.3%, respectively. Grade 3 or higher toxicities were observed in all patients: leukopenia in 4 patients (12%), neutropenia in 5 (15%), anemia in 2 (6%), thrombocytopenia in 3 (9%), and mucositis in 2 (6%).

CONCLUSIONS

This study demonstrated that m-RADPLAT yielded VFF improvement and a favorable survival while maintaining laryngeal function not only in patients with T3N0 glottic SCC-L without VFF but also in patients with VFF.

Anesthetic management using costoclavicular brachial plexus block with patient-controlled analgesia in Pediatrics: A case report

Anesthetic management using costoclavicular brachial plexus block with patient-controlled analgesia in pediatrics: a case report Abstract The costoclavicular brachial plexus block (CBPB) has been receiving increasing attention as an effective technique for upper arm surgery conducted without phrenic paralysis. However, studies in children are lacking. CBPB was applied to a 10 year-old girl undergoing scheduled radial and ulnar osteotomy due to multiple cartilaginous exostoses and ulnar lengthening. CBPB was performed with a bolo administration of 10 mL of 0.25% levobupivacaine, and the catheter was sequentially replaced in the right costoclavicular space. After surgery, a continuous infusion of 0.17% levobupivacaine through a catheter was initiated at 2 mL/h, along with patient-controlled analgesia (PCA) of 3 mL 0.17% levobupivacaine with a 60-minute lock out. The patient complained of 5/10 pain on the numerical rating scale (NRS) 2 hours after surgery, which improved immediately after bolus administration. The analgesia induced by CBPB was otherwise effective (NRS ≤ 2). CBPB with PCA may provide adequate analgesia in pediatric cases.

Diagnostic Accuracy of Diastolic Fractional Flow Reserve for Functional Evaluation of Coronary Stenosis

Background

In the resting conditions, narrowing the window of coronary pressure measurements from the whole cardiac cycle to diastole improves diagnostic performance of coronary pressure–derived physiological index. However, whether this also applies to the hyperemic conditions has not yet been thoroughly evaluated.

Objectives

The purpose of this study was to assess whether diastolic fractional flow reserve (diastolic FFR) has better diagnostic performance in identifying ischemia-causing coronary lesions than conventional FFR in a prospective, multicenter, and independent core laboratory–based environment.

Methods

In this prospective multicenter registry at 29 Japanese centers, we compared the diagnostic performance of FFR, diastolic FFR, resting distal to aortic coronary pressure (Pd/Pa), and diastolic pressure ratio (dPR) using myocardial perfusion scintigraphy (MPS) as the reference standard in 378 patients with single-vessel coronary disease.

Results

Inducible myocardial ischemia was found on MPS in the relevant myocardial territory of the target vessel in 85 patients (22%). In the receiver-operating curve analyses, diastolic FFR had comparable area under the curve (AUC) compared with FFR (AUC_{diastolic FFR}: 0.66; 95% confidence interval [CI]: 0.58-0.73, vs AUC_FFR: 0.66; 95% CI: 0.58-0.74, P = 0.624). FFR and diastolic FFR showed significantly larger AUCs than resting Pd/Pa (0.62; 95% CI: 0.54-0.70; P = 0.033 and P = 0.046) but did not show significantly larger AUCs than dPR (0.62; 95% CI: 0.55-0.70; P = 0.102 and P = 0.113).

Conclusions

Diastolic FFR showed a similar diagnostic performance to FFR as compared with MPS. This result reaffirms the use of FFR as the most accurate invasive physiological lesion assessment. (Diagnostic accuracy of diastolic fractional flow reserve (d-FFR) for functional evaluation of coronary stenosis; UMIN000015906)

Floral and pollination characteristics of Eriocaulon heleocharioides, an extinct species in the wild, for evidence-based conservation management

Generally, floral characteristics and pollination are important factors enhancing the quality and quantity of reproductive output for regeneration in plant conservation. However, lack of evidence-based management could decrease fitness under ex-situ conservation. We investigated the capitulum and pollination characteristics of Eriocaulon heleocharioides Satake (Eriocaulaceae), which is extinct in the wild, to develop an evidence-based conservation management plan incorporating previously ignored reproductive characteristics. To evaluate the functional characteristics of capitula, pollen-ovule ratio, and reproductive status (maximum pollination success/florivory damage) were investigated along six flowering sequences of capitulum. To evaluate the effect of plant density on pollen transfer, high- and low-density plots were established. Total deposited pollen on stigma, insect visitation, and visit duration per capitulum were observed. A significantly lower pollen-ovule ratio was observed in the first of six capitula, reflecting higher female functionality. The highest pollination success was found in the second-fourth capitula, whereas florivory increased along the terminal capitula position. High plant density affected the pollen deposited on stigmas via insect visitation and low pollinator visit duration. Different capitula in E. heleocharioides could have different effects: different sexual functionality, enhancement of reproductive output both in quality and quantity through active pollen transfer, and escaping from florivores. High plant density could facilitate outcross-pollen transfer in E. heleocharioides. Multiple perspectives are important for determining potential reproductive success in ex-situ conservation. Thus, density management reflecting capitulum characteristics could improve the efficiency of conservation efforts for E. heleocharioides.

In vitro evidence of propagation of superoxide dismutase-1 protein aggregation in canine degenerative myelopathy

Canine degenerative myelopathy (DM) is a progressive and fatal neurodegenerative disorder that has been linked to mutations in the superoxide dismutase 1 (SOD1) gene. The accumulation of misfolded protein aggregates in spinal neurons and astrocytes is implicated as an important pathological process in DM; however, the mechanism of protein aggregate formation is largely unknown. In human neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), cell-to-cell propagation of disease-relevant proteins has been demonstrated. Therefore, in this study, propagation of aggregation-forming property of mutant SOD1 protein in DM in vitro was investigated. This study demonstrated that aggregates composed of canine wild type SOD1 protein were increased by co-transfection with canine mutant SOD1 (E40K SOD1), indicating intracellular propagation of SOD1 aggregates. Further, aggregated recombinant SOD1 proteins were released from the cells, taken up by other cells, and induced further aggregate formation of normally folded SOD1 proteins. These results suggest intercellular propagation of SOD1 aggregates. The hypothesis of cell-to-cell propagation of SOD1 aggregates proposed in this study may underly the progressive nature of DM pathology.

POS0824 THE LONG-TERM CLINICAL COURSE OF MUSCULAR VASCULITIS DEPENDING ON THE ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY STATUS: A RETROSPECTIVE OBSERVATIONAL STUDY

Background:

Skeletal muscle is known as one of the organ involvements of primary systemic vasculitis.1,2 Muscle inflammation is detected by magnetic resonance imaging, and necrotizing vasculitis is proved by muscle biopsy.3 As with systemic vasculitis or single organ vasculitis, glucocorticoid (GC) and immunosuppressants are used in its treatment.4 There are not many reports about muscular vasculitis, and its long-term clinical course after initial treatment, including the rates of relapse and mortality, remains unclear.

Objectives:

To identify the predictors of relapse and mortality in patients with muscular vasculitis, especially focusing on the status of anti-neutrophil cytoplasmic antibody (ANCA).

Methods:

We retrospectively reviewed patients diagnosed with necrotizing vasculitis with muscle involvements in our hospital between 2004 and 2020. In all cases, muscular vasculitis was identified by muscle biopsy or magnetic resonance imaging. To focus on the clinical features of muscular vasculitis, we excluded patients with such severe organ involvements as cardiovascular, abdominal, cerebral, severe renal, and severe pulmonary involvements. We compared the 5-year cumulative incidence of relapse, the overall survival rate, and the dose of GC over 5 years between the ANCA-positive and ANCA-negative groups. A relapse was defined as any new or worsened state of disease activity requiring an escalation of GC dose. Gray’s method was used for assessing the cumulative incidence of relapse. The log-rank test was used for assessing overall survival. The Mann-Whitney U test was used for assessing the dose of GC. The possible factors for relapse in 5 years in a univariate analysis were selected for a multivariate analysis using the Cox proportional hazards model.

Results:

Forty-nine patients were enrolled. The median age of onset was 77 (69-82) years and 71.4% were women. There were 30 ANCA-positive patients (90.0% with anti-myeloperoxidase) and 19 ANCA-negative patients. The median age and the number of patients with renal involvements were higher in the ANCA-positive group than in the ANCA-negative group (73.0 ± 9.29 years vs. 79.5 ± 20.28 years, p=0.0062 and 7/30 [23.3%] vs. 0/19 [0.0%], p=0.034, respectively). The Birmingham Vasculitis Activity Score (ver. 3), the induction dose of GC, and the rate of immunosuppressants use were not significantly different between the two groups. During the observational period, 24 patients relapsed. The 5-year cumulative incidence of relapse was significantly higher in the ANCA-positive group than in the ANCA-negative group (p=0.026) (Figure 1). The Cox proportional hazards model revealed that the presence of ANCA was an independent risk factor for relapse (hazard ratio: 3.15; 95% confidence interval 1.06–9.38; p=0.040). During the observational period, 9 patients died (3 died from cancer, 1 from interstitial pneumonia, 1 from cerebral hemorrhage, 1 from infection, and 3 from unknown reasons). The ANCA-positive group exhibited a higher mortality rate than the ANCA-negative group without a statistical significance (p=0.12). The 5-year cumulative dose of GC was larger in the ANCA-positive group than in the ANCA-negative group without a statistical significance (14786 [11246–19138] mg vs. 10088 [7129–12634] mg, p=0.12).

Conclusion:

In muscular vasculitis, the presence of ANCA is an independent risk factor for long-term relapse. Stratified treatment depending on the ANCA status may reduce the relapse rate and the occurrence of side effects of GC in patients with muscular vasculitis.

References:

[1]Kitching AR et al. Nat Rev Dis Primers 2020; 6(1): 71.

[2]Hernández-Rodríguez J et al. J Autoimmun 2014; 48-49: 84-9.

[3]Ushiyama S et al. Rheumatol Int 2020; 40(10): 1667-74.

[4]Ganeshanandan LR et al. Semin Arthritis Rheum 2020; 50(3): 503-8.

Disclosure of Interests:

None declared

Efficacy and Safety of Ramucirumab/nab-paclitaxel for Previously Treated Advanced Gastric Cancer in Community Hospitals

As the nanoparticle albumin-bound paclitaxel (nab-PTX) is free of ethanol and premedication, the duration of administration is shorter and patients can drive themselves to and from the hospital. In the 2018 Japanese gastric cancer treatment guidelines, ramucirumab (RAM) plus weekly nab-PTX is conditionally recommended for previously treated patients with advanced gastric cancer. Here, we retrospectively analysed the efficacy and safety of RAM+nab-PTX for such patients in community hospitals. From January 2018 to December 2019, 43 patients with metastatic and recurrent gastric cancer received RAM+nab-PTX treatment. Six patients (13.9%) were older than 80 years and 9 patients (20.9%) showed ECOG-PS 2. Progression-free survival (PFS), overall survival (OS), overall response rate (ORR), disease control rate (DCR), and adverse events (AEs) were reviewed retrospectively. Median PFS was 114 days (95% confidence interval [CI]: 84-190) and median OS was 297 days (95% CI: 180-398). ORR and DCR were 32.4% and 72.2%, respectively. The incidence rates of ≥grade 3 neutropenia and febrile neutropenia were 53.5% and 2.3%, respectively. No treatment-related deaths occurred. RAM plus nab-PTX combination therapy demonstrated manageable toxicity even patients who were elderly or had an ECOG-PS 2. This treatment is useful in community hospital settings.

The utility of a novel approach to quantify dyssynchrony by multidetector computed tomography

Funding Acknowledgements

Type of funding sources: None.

Background

Quantification of left ventricular (LV) dyssynchrony is of great interest for resynchronization therapy (CRT). Recently, cardiac computed tomography (CCT) is feasible for evaluation of dyssynchrony. Our aim was to assess a novel simplified approach using CCT to quantify LV dyssynchrony.

Methods

We studied 346 consecutive patients with a wide range of QRS width and ejection fractions (EF). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT (Brilliance 256 iCT, Philips Medical Systems) was performed before CRT. After CCT scan, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and a time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software "Myocardial Contraction Map" (Argus, Inc Ehime, Japan). The standard deviation of all segments modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT.

Results

%SD was feasible in all patients, respectably. %SD was significantly different between the different QRS duration groups; narrow QRS (&lt;120ms): 9 ± 5%, relatively wide QRS (120-150 ms): 11 ± 6%, and significantly wide QRS (&gt;150 ms): 14 ± 7% (p &lt;0.001). Moreover, there was significantly difference in %SD between the different morphology groups; normal: 9 ± 7%, Non-left bundle branch block (Non-LBBB): 10 ± 6%, LBBB: 17 ± 7% (p &lt;0.001).

Conclusion

This novel simplified approach by CCT can quantify dyssynchrony in different QRS duration and morphology groups. This method has promise for clinical applications to the evaluation of patients for CRT.

Abstract Figure.

High incidence of left atrial dysfunction and low voltage zone in patients requiring multiple atrial fibrillation ablation

Background

While multiple catheter ablation for recurrent atrial fibrillation (AF) is effective for the maintenance of sinus rhythm, some of patients have ablation-refractory AF. Left atrial (LA) dysfunction and the presence of low voltage zone (LVZ) are associated with recurrence after AF ablation. The association between recurrence and LA dysfunction/ LVZ among patients undergoing multiple AF ablation remains unclear.

Purpose

We aimed to compare (i)LA function, (ii)the prevalence of LVZ among patients undergoing first, second and third or more AF ablation procedures. Further, we investigated whether LA dysfunction and LVZ are associated with recurrence after multiple procedures.

Methods

We retrospectively analyzed 460 patients undergoing AF ablation procedures including first, second and third or more sessions from January 2017 to October 2019 in our institute. Before each session, 256-slice MDCT was performed under sinus rhythm to measure pre-ablation LA emptying fraction (LAEF) as the representative of LA function. At the end of each session, we checked the presence of LVZ, which was defined as regions where bipolar peak-to-peak voltage was &lt;0.5mV. All patients underwent pulmonary vein isolation (PVI). If necessary, additional ablation (e.g. linear ablation, non-PV foci ablation and LVZ ablation) was performed.

Results

Out of 460 sessions, 295 were first (follow-up years: 1.5 [0.8, 2.0]), 134 were second (1.0 [0.5, 1.8]), and 31 were third or more sessions (1.2 [0.7, 2.0]). As the number of sessions increased, the recurrence rate was increased (19% vs. 31% vs. 61%, first vs. second vs. ≥third, P&lt;0.0001), LAEF decreased (39.7±10.5% vs. 32.6±10.1% vs. 25.3±11.8%, P&lt;0.0001) and the incidence of LVZ increased (18% vs. 34% vs. 68%, P&lt;0.0001) (Figure 1). In patients with recurrence (N=104) after multiple ablation (second or more sessions), LAEF was lower and the prevalence of LVZ was higher than those without recurrence (N=61) (LAEF: 27.3±10.3% vs. 33.5±10.5%, with vs. without, P=0.0003; LVZ: 57% vs. 31%, P=0.0014).

Conclusions

As the number of sessions increased, the recurrence rate was increased. The prevalence of LA dysfunction and LVZ was high in patients requiring multiple ablation procedure. LA dysfunction and LVZ possibly reflect arrhytmogenic substrate causing recurrence of ablation-refractory AF. We should carefully consider repeated AF ablation in patients with severe LA dysfunction and extensive LVZ.

Figure 1

Funding Acknowledgement

Type of funding source: None

Three-year outcomes after deferral of revascularization based on instantaneous wave-free ratio or fractional flow reserve: insights from the J-CONFIRM Registry

Background

The safety of deferral of revascularization based on instantaneous wave-free ratio (iFR) is established in randomized controlled trials. However, there is little data regarding long-term outcomes after deferral of revascularization based on iFR in real-world practice.

Purpose

We sought to assess clinical outcomes after deferral of revascularization based on iFR in clinical practice as compared with those based on fractional flow reserve (FFR).

Methods

This is a post hoc analysis of the J-CONFIRM registry (long-term outcomes of Japanese patients with deferral of coronary intervention based on fractional flow reserve in multicenter registry), in which 1262 patients with 1447 lesions deferred the revascularization based on FFR. Of these, both FFR and iFR were measured in 399 patients with 452 lesions. The patients were classified into the two groups: the iFR group (iFR &gt;0.89; 308 patients with 348 lesions) and the FFR group (FFR &gt;0.80; 740 patients with 855 lesions). The primary study endpoint was the 3-year target vessel failure (TVF) including cardiac death, target-vessel related myocardial infarction (TVMI), and clinically driven target vessel revascularization (CDTVR).

Results

Mean iFR was 0.96±0.04 in the iFR group. Mean FFR was significantly lower in the iFR group than in the FFR group (0.87±0.05 vs. 0.89±0.05, p=0.002). The iFR group included 35 lesions (11.4%) with FFR ≤0.80. At 3 years, the rate of TVF on a lesion basis were not significantly different between the iFR and FFR groups (8.8% vs. 6.1%, p=0.10), whereas CDTVR rate was significantly higher in the iFR group than in the FFR group (8.5% vs. 5.3%, p=0.044). Cardiac death and TVMI on a patient basis rarely occurred in both groups during the 3-year follow-up (0.33% vs. 0.77%, p=0.47; 0.66% vs. 0.56%, p=0.85, respectively).

Conclusion

At 3 years, TVF rate in deferred lesions was numerically higher in the iFR group than in the FFR group, driven by a higher rate of CDTVR. However, cardiac death and TVMI was very rare in both groups, highlighting the safety of both iFR- and FFR-based deferral of revascularization in daily practice.

Funding Acknowledgement

Type of funding source: None

Pre-ablation left atrial function predicts the presence of low voltage zone in patients undergoing paroxysmal atrial fibrillation ablation: OLAF-LVZ predictive score

Background

Preoperative left atrial (LA) function is associated with paroxysmal atrial fibrillation (PAF) ablation outcome. The presence of left atrial low voltage zone (LVZ) is also associated with recurrence. We hypothesized that reduced pre-ablation LA function reflects the presence of LVZ.

Purpose

We investigated the association between baseline LA function and the presence of LVZ in patients undergoing initial PAF ablation. Further, we sought to create the new predictive scoring for the presence of LVZ.

Methods

Consecutive 305 patients who underwent LA voltage mapping during initial PAF ablation from January 2017 to October 2019 in our institute were retrospectively analyzed. We performed 256-slice MDCT at baseline. As the representative of LA function, we calculated LA emptying fraction (LAEF), where LAEF = {[(maximum LAV) − (minimum LAV)]/(maximum LAV)} x 100. LVZ was defined as regions where bipolar peak-to-peak voltage was &lt;0.5mV. We performed the univariate and multivariate analysis to assess the association between LAEF and the presence of LVZ. Second, we performed receiver operating characteristic (ROC) analysis for the prediction of LVZ. We combined multivariate predictors and created the predictive scoring for LVZ.

Results

Out of 305 pts, 56 pts (18%) had LVZ in LA. In univariate analysis, low body mass index, higher percentage of female sex, higher age, higher E/e', larger maximum LA volume and lower LAEF (29.3±11.8% vs. 41.2±9.7, P&lt;0.0001) was associated with the presence of LVZ. In multivariate logistic regression analysis, Low LAEF revealed the strongest predictor for LVZ (LAEF; Odds ratio [OR]/10% increase: 0.54, 95% CI: 0.39–0.82, P=0.0016). High age and female sex also remained as the independent predictors (Age; OR/10 y.o. increase: 1.80, 1.23–3.03, P=0.0042, Female; OR: 2.51, 1.15–5.49, P=0.0213). In ROC analysis, LAEF had moderate predictive accuracy for the presence of LVZ. (Area under the ROC curve: 0.77, Best cut-off value: 31%, P&lt;0.0001) (Figure 1). We created OLAF-LVZ predictive score by combining Old age (1 point, ≥65), LAEF (2 points, LAEF ≤31%) and Female sex (1 point). OLAF score had gradient effect on the incidence of LVZ (2%, 11%, 25%, 45%, 71%, OLAF score; 0, 1, 2, 3, 4, respectively, P&lt;0.0001) (Figure 2).

Conclusions

In PAF patients, preoperative LAEF was strongly associated with the presence of LVZ. LVZ might reflect the myocardial injury causing LA dysfunction. OLAF-LVZ predictive score: combination of Old age (≥65), Female sex, and LAEF (≤31%) could be useful to stratify the risk of the presence of LVZ.

Funding Acknowledgement

Type of funding source: None

Quantitative analysis of dyssynchrony assessed by multidetector computed tomography can predict clinical outcome after cardiac resynchronization therapy

Background

The degree of mechanical dyssynchrony has been suggested as a predictor for long-term survival after cardiac resynchronization therapy (CRT). There have been little reports of dyssynchrony assessment with the use of cardiac computed tomography (CCT).

Methods

We studied 35 heart failure (HF) patients (average age 67±10 years) referred for CRT with NYHA III-IV heart failure, left ventricular (LV) ejection fraction (EF) 20±10% (all ≤35%), and QRS duration 156±22 ms (all ≥120ms). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT was performed before CRT. Based on CCT, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and the time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software “Myocardial Contraction Map”. The standard deviation modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT. The predefined primary end-point was the first HF hospitalization or death over 2 years.

Results

%SD was feasible in all patients, respectably. There were 16 events over 2 years; 11 HF hospitalizations and 5 deaths. Patients with %SD ≥22% (optimal cutoff for outcome by ROC curve analysis) had a better clinical outcome than patients with %SD &lt;22% (p=0.01, Figure).

Conclusion

Patients who had %SD ≥22% assessed by MDCT had a particularly favorable event-free survival following CRT, and this appears to be an important prognostic marker.

Funding Acknowledgement

Type of funding source: None

Evaluation of the local atrial function by regional speckle tracking imaging using intracardiac echocardiography

Background

It has been reported that low voltage areas and conduction abnormalities detected by electrophysiology catheters in the left atrium (LA) represent regional degeneration and fibrosis of the atrium and are related to a poor atrial fibrillation (AF) ablation outcome. Assessment of the local atrial function is clinically useful because atrial degeneration does not occur uniformly throughout the atrium. Though evaluating the global atrial function using speckle tracking imaging (STI) by transthoracic echocardiography (TTE) has been attempted, TTE does not have a sufficient image quality to assess local atrial STI.

Purpose

To evaluate the local atrial function by STI using intracardiac echocardiography (ICE) and to elucidate the characteristics of the STI in normal and abnormal voltage regions in the LA.

Methods

We included 9 patients undergoing AF ablation with written informed consent for this prospective observational study. After pulmonary vein isolation, we performed voltage mapping of the LA in sinus rhythm using a CARTO system (Biosense). Abnormal regions and normal regions were defined as those with low voltage areas (&lt;0.5 mV) and those with normal voltages, respectively. Echo images were recorded by an ACUSON SC2000 (Siemens) and SOUNDSTAR catheter (Biosense). We inserted the SOUNDSTAR catheter into the LA to obtain clear images, recorded the STI of the anterior and inferior wall, and performed an offline analysis of the atrial strain with an eSie VVI work station (Siemens) and the LA voltage data with CARTO system at each site simultaneously (left figure). We compared the strain during the atrial contraction phase (Sct) between the normal and abnormal regions.

Results

Among the study population, 5 patients had low voltage areas in the LA. We evaluated the STI at 26 normal regions and 44 abnormal regions. The typical regional speckle tracking waveform in the normal region was similar to a jugular vein pressure waveform (right figure). There was a difference in the amplitude of the Sct between the groups; it was significantly smaller in the abnormal regions (normal and abnormal regions, 9.8±5.0% and 5.6±3.8%, p=0.0001). The duration of the Sct was significantly more prolonged in the abnormal regions than normal regions (98.8±26.3ms and 118.2±33.9ms, p=0.015).

Conclusions

This pilot study demonstrated that the local atrial function was evaluable by STI using ICE and that the regional strain tracking waveform during the atrial contraction phase in abnormal voltage regions was smaller and more prolonged than that in normal regions. An evaluation of the regional STI with an ICE may be useful to detect regional abnormalities of the atrium.

Representative case

Funding Acknowledgement

Type of funding source: None

Screening for obstructive sleep apnea in atrial fibrillation patients at their home before catheter ablation using watch peripheral arterial tonometry

Background

Catheter ablation of atrial fibrillation (AF) is effective, but certain patients experience AF recurrences. Obstructive sleep apnea (OSA) is a risk factor for AF recurrence. Watch peripheral arterial tonometry (WP) has a good correlation with polysomnography (PSG) in terms of the apnea-hypopnea index (AHI) and is easier to perform than PSG. Patients in AF have a high prevalence of OSA. Whether all patients with AF should be evaluated for OSA before catheter ablation is still controversial.

Purpose

To elucidate the prevalence and predictors of OSA using WP as a home sleep apnea test in AF patients before catheter ablation.

Methods

This study was conducted under a retrospective, single-center, observational design. Patients who received AF ablation without a prior diagnosis of sleep apnea and assessment of their AHI using WP were included in this analysis. The patients were mounted with a WP device by themselves at their own home. Twenty-two patients who were already diagnosed with OSA were excluded.

Results

Seven hundred seventy-four (65±11 years, 567 males, 440 paroxysmal AF) out of 776 patients were successfully mounted with WP devices on their own and underwent an OSA assessment. Their mean body mass index (BMI) was 24.1±3.5 kg/m2. The mean AHI was 20.1±15.6. Only 88 (11.4%) patients had a normal AHI (AHI&lt;5). Mild OSA (5≤AHI&lt;15), moderate OSA (15≤AHI&lt;30), and severe OSA (AHI≥30) were observed in 274 (35.4%), 252 (32.6%), and 160 (20.7%) patients, respectively. A BMI≥25 (odds ratio [OR]; 2.42, 95% confidence interval [CI]; 1.74–3.37, p&lt;0.001), male sex (1.70, 1.19–2.44, p=0.0037), non-paroxysmal AF (1.90, 1.35–2.66, p=0.0002), hypertension (1.70, 1.24–2.33, p=0.009), and left atrial volume index ≥30 (OR=1.51, CI 1.06–2.16, p=0.022) were significant predictors of moderate or severe OSA by a multivariate analysis, while an Epworth sleepiness scale ≥11 was not a predictor of moderate or severe OSA (OR=0.99, CI 0.66–1.49, p=0.95). However, 44.2% of non-obese patients (BMI &lt;25) had moderate-severe OSA.

Conclusion Almost

All patients successfully underwent WP to diagnose OSA. AF patients had a high prevalence of OSA, and screening OSA would be important in AF patients receiving ablation even if patients do not have sleepiness or are obese. We cannot deny OSA in AF patients before catheter ablation without performing screening tests for OSA.

Funding Acknowledgement

Type of funding source: None

Sex differences in the predictors of recurrent atrial fibrillation after catheter ablation: insights from the Kansai Plus Atrial Fibrillation (KPAF) registry

Background

The impact of sex differences on the clinical outcomes of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) is controversial. We previously reported that females experienced more frequent AF recurrences than males after the index and last RFCA procedures.

Purpose

To identify the risk factors associated with recurrent AF in females and males after RFCA of AF.

Methods

We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry). We enrolled 5010 consecutive patients who underwent an initial RFCA of AF at 26 centers (64±10 years; 1369 [27.3%] females; non-paroxysmal AF, 35.7%). The median follow-up duration was 2.9 years.

Results

The incidence of AF recurrences after a single procedure was 43.3% in females and 39.0% in males. After a multivariate adjustment at baseline, the significant predictors of AF recurrence in females after the index RFCA were non-paroxysmal AF (hazard ration [HR],1.59; 95% confidence interval [CI],1.31–1.93, p&lt;0.0001), a history of AF ≥2 years (HR,1.47; 95% CI,1.24–1.74, p&lt;0.0001), coronary artery disease (HR,1.43; 95% CI,1.03–1.98, p=0.0035), and an estimated glomerular filtration rate (eGFR)&lt;60 mL/min/1.73m2 (HR,1.46; 95% CI,1.10–1.95, p=0.0086). On the other hand, significant predictors of AF recurrence in males after the index RFCA were non-paroxysmal AF (HR,1.54; 95% CI,1.37–1.73, p&lt;0.0001), a history of AF ≥2 years (HR,1.40; 95% CI,1.26–1.56, p&lt;0.0001), the number of antiarrhythmic drugs (HR,1.06; 95% CI,1.003–1.13, p=0.040), a left atrial diameter≥40mm (HR,1.13; 95% CI,1.007–1.27, p=0.038), and dilated cardiomyopathy (HR,1.55; 95% CI,1.07–2.26, p=0.021), however, an eGFR&lt;60 mL/min/1.73m2 was not associated with AF recurrence in males (HR, 1.00; 95% CI, 0.88–1.13, p=0.97).

Conclusion

The Kansai Plus Atrial Fibrillation Registry revealed a distinct sex difference in terms of the predictors of recurrent AF after RFCA. Non-Paroxysmal AF and a long history of AF were common risk factors both in females and males. However, renal dysfunction was a significant predictor of AF recurrence in females, while it was not a risk of recurrence in males.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Research Institute for Production Development in Kyoto, Japan.

Chest complications in immunocompromised patients without acquired immunodeficiency syndrome (AIDS): differentiation between infectious and non-infectious diseases using high-resolution CT findings

AIM

To differentiate between infectious and non-infectious diseases occurring in immunocompromised patients without acquired immunodeficiency syndrome (AIDS) using high-resolution computed tomography (HRCT).

MATERIALS AND METHODS

HRCT images of 555 patients with chest complications were reviewed retrospectively. Infectious diseases (n=341) included bacterial pneumonia (n=123), fungal infection (n=80), septic emboli (n=11), tuberculosis (n=15), pneumocystis pneumonia (n=101), and cytomegalovirus pneumonia (n=11), while non-infectious diseases (n=214) included drug toxicity (n=84), infiltration of underlying diseases (n=83), idiopathic pneumonia syndrome (n=34), diffuse alveolar haemorrhage (n=8), and pulmonary oedema (n=5). Lung parenchymal abnormalities were compared between the two groups using the χ² test and multiple logistic regression analysis.

RESULTS

The χ2 test results showed significant differences in many HRCT findings between the two groups. Multiple logistic regression analysis results indicated the presence of nodules with a halo and the absence of interlobular septal (ILS) thickening were the significant indicators that could differentiate infectious from non-infectious diseases. ILS thickening was generally less frequent among most infectious diseases and more frequent among most non-infectious diseases, with a good odds ratio (7.887, p<0.001). The sensitivity and accuracy for infectious diseases in the absence of ILS thickening were better (70% and 73%, respectively) than those of nodules with a halo (19% and 48%, respectively), while the specificity in the nodules with a halo was better (93%) than that of ILS thickening (78%).

CONCLUSIONS

The presence of nodules with a halo or the absence of ILS thickening tends to suggest infectious disease. Specifically, ILS thickening seems to be a more reliable indicator.