Correction to: CD4 T cell count is positively associated with lumbar spine bone mass in HIV-infected men under the age of 50 years

Two sentences in the Discussion section were incorrect.

P997Improving left atrial appendage occluder size determination by using 3-dimensional printing model of the left atrial appendage

Introduction

Given the complexity of left atrial appendage (LAA) structure, current 2D based LAA occluder (LAAO) size prediction system using transesophageal echocardiography (TEE) has limitations.

Objective

To assess the accuracy of LAAO size determination method by implantation simulation using a 3D printed model compared with a conventional method based on TEE.

Methods

We retrospectively reviewed 57 cases with percutaneous LAAO using Amplatzer Cardiac Plug and Amulet from 2014 to 2018. We excluded cases without cardiac CT (21 cases) or with peri-device leakage or inappropriate position of the device on six months follow up TEE (6 cases), or with paroxysmal atrial fibrillation (2 cases). We finally included 28 cases with anatomically and physiologically properly implanted LAAO, using the final size of the implanted devices as a standard for the size prediction accuracy. We generated 3D printing model from cardiac CT images. LAAO size was determined with device implantation simulation using 3D printing model and occluder devices (Figure C), and conventional 2D TEE measurements by two experienced cardiologists who were blinded to the size of the finally implanted device.

Results

The accuracy in size of 3D printed left atrium (LA) models, compared with CT image sources, were validated by measuring the distance between artifacts which were intentionally implanted to LA model during image processing. There was minimal bias (−0.11 mm) between 3D images and printed LA models (Figure A). As plotted in Figure B, LAAO sizing by implantation simulation with 3D printing model showed excellent agreement with actually implanted LAAO size (r=0.927; bias=0.7±2.5), while LAAO sizing by 2D TEE measurements remained poor (r=0.544; bias 2.3±6.7).

Conclusions

LAAO size determination by using 3D printing model of LAA showed excellent accuracy. A prospective study to evaluate the clinical utility of this method should be done in future.

P4758Label adherence of non-vitamin K antagonist oral anticoagulants and clinical outcomes in patients with atrial fibrillation: A nationwide study

Background

Dose adjustment of non-vitamin K antagonist oral anticoagulants (NOACs) is indicated in some patients with atrial fibrillation (AF), based on selected patient factors or concomitant medications.

Purpose

We assessed the frequency of label adherence of NOAC dosing among AF patients and the associations between off-label NOAC dosing and clinical outcomes in real-world clinical practice.

Methods

We evaluated 53,649 AF patients treated with a NOAC using Korean National Health Insurance Service database during the period from January 2013 to December 2016. NOAC doses were classified as either underdosed or overdosed, consistent with U.S. Food and Drug Administration labeling. Cox proportional hazards regression was performed to investigate the effectiveness and safety outcomes including stroke or systemic embolism, major bleeding, and all-cause mortality.

Results

Overall, 16,757 NOAC-treated patients (31.2%) were underdosed, 4,492 were overdosed (8.4%), and 32,400 (60.4%) were dosed appropriately according to drug labeling. Compared with patients with label adherence, those who were underdosed or overdosed were older (71±8 and 75±7 years of age vs. 70±9 years of age, respectively; p<0.001), more likely female (39% and 53% vs. 38%, respectively; p<0.001), and had higher CHA2DS2-VASc scores (4.6±1.7 and 5.3±1.7 vs. 4.5±1.8, respectively; p<0.001). NOAC overdosing was associated with increased risk for stroke or systemic embolism (5.76 vs. 4.03 events/100 patient-years, p<0.001), major bleeding (4.77 vs. 2.94 events/100 patient-years, p<0.001), and all-cause mortality (5.43 vs. 3.05 events/100 patient-years, p<0.001) compared with label-adherent use.

Figure 1

Conclusion

In routine clinical practice, a significant proportion (almost 2 in 5) of AF patients received NOAC doses inconsistent with drug labeling. NOAC overdosing is associated with increased risk for stroke or systemic embolism, major bleeding, and all-cause mortality in Asian patient with AF.

P1012Radiofrequency catheter ablation of accessory pathways at the site of prior valve surgery

Background

Radiofrequency catheter ablation (RFCA) for accessory pathways (APs) at the site of prior valve surgery remains challenging. We aimed to clarify the factors associated with successful RFCA for such APs.

Methods

Upon reviewing a RFCA registry and previous case reports, we included nine patients who underwent RFCA of APs at the site of prior valve surgery (total-VS group; age, 34.0 [24.5–45.0] years; men, 4/9) and 196 patients who underwent RFCA of APs with no history of valve surgery (no-VS group; age, 40.5 [23.0–54.0] years; men, 114/196). Electrophysiological features, procedural details, and outcomes were examined.

Results

AP exhibited decremental conduction in four of nine patients in the total-VS group. The number of RFCA attempts was significantly higher in the total-VS group than in the no-VS group (10.0 [4.5–14.5] vs 2.0 [1.0–3.0]; p<0.001). In four patients who underwent mitral valve surgery, successful RFCA was achieved using the transaortic approach, coronary sinus approach, or bipolar ablation. In three patients who underwent tricuspid valve surgery, successful RFCA was achieved using the above-prosthetics or trans-prosthetics approach. In two patients, RFCA failed. The trans-prosthetics approach and bipolar ablation technique were effective. The transaortic and coronary sinus approaches were occasionally effective. The transseptal approach was ineffective. Based on the success rate and accessibility, we suggest a stepwise approach to RFCA of APs at the site of prior mitral or tricuspid valve surgery (Figure).

Stepwise approach to AP at valve surgery

Conclusions

Successful RFCA of APs at the site of prior valve surgery can be achieved by detailed mapping of the areas both above and below the prosthetic valve, as well as by ensuring effective radiofrequency energy delivery using various catheter approaches and RFCA techniques.

P5660Clinical impact of polycythemia on cardiovascular outcome from the general population: a nationwide cohort study

Background

Although adverse effect of anemia had been reported, effect of polycythemia on cardiovascular outcome from the general population had not been revealed yet.

Methods

We included 451,107 subjects who received national health examinations from the Korean National Health Insurance Service-based National Sample Cohort from 2009–2013. Medical records were screened from January 2002 to investigate the subjects' disease-free baseline period. They were followed until December 2013. We divided male and female subjects into four categories each based on hemoglobin level (normal, moderate to severe and mild anemia, polycythemia) to assess each outcome.

Results

During 1,735,964 person·years, 12,107 major adverse cardiovascular and cerebrovascular events (MACCE), 862 incident acute myocardial infarction (MI), 5,850 incident ischemic stroke, and 2,430 incident atrial fibrillation (AF) were observed. Compared to normal hemoglobin range group, polycythemia group showed higher MACCE (HR=1.23 [1.12–1.35] in male, HR=1.79 [1.20–2.67] in female, each p<0.001), incident MI (HR=1.37 [1.05–1.79] in male, HR=3.46 [1.06–14.00] in female, each p<0.001), incident ischemic stroke (HR=1.27 [1.10–1.46] in male, HR=1.72 [1.02–2.91] in female, each p<0.001), and incident AF (HR=1.46 [1.21–1.74] in male, HR=2.13 [1.03–4.77] in female, each p<0.001). Each outcome was linearly increased with the increase of hemoglobin among subjects with polycythemia (p<0.001), and with the decrease of hemoglobin among subjects with anemia (each p<0.001, U-shaped relationship). These relationship was more profound in obese female younger than 60-year-old.

Conclusion

Not only anemia but also polycythemia were significantly associated with higher rate of MACCE including death, incident MI, ischemic stroke, and AF among the general population.

P1875Nonspecific intraventricular conduction delay is associated with future occurrence of atrial fibrillation in patients with structurally normal heart and sinus rhythm

Background

This study aimed to elucidate long-term prognosis of nonspecific intraventricular conduction delay (NIVCD) in patients with structurally normal heart.

Methods

We included 107,838 patients (age, 52.1±15.5 years; men, 46.8%) who underwent electrocardiography in outpatient clinics or medical checkup (model 1). NIVCD was defined as QRS duration ≥110 ms and incompatibility with bundle branch block. The patients with structurally normal heart and sinus rhythm were assigned to the NIVCD group and normal QRS group according to propensity score with matching variables of age, sex, hypertension, and diabetes (model 2), and additional PR interval (model 3). Baseline characteristics, electrocardiographic parameters, and clinical outcomes were compared in model 1, 2, and 3, respectively.

Results

In model 1, the frequencies of male and preexisting atrial fibrillation (AF) were significantly higher in the NIVCD group than in the normal QRS group. In model 2, sinus rate and PR interval were significantly slower and longer in the NIVCD group than in the normal QRS group. In model 3, cumulative incidence of AF was significantly higher in the NIVCD group than in the normal QRS group during follow-up of 8.8±2.9 years (Figure). NIVCD significantly increased risk of AF (hazard ratio, 2.571; 95% confidence interval, 1.074–6.156; p=0.034). NIVCD did not significantly increase risk of sick sinus syndrome, complete atrioventricular block, and heart failure.

Atrial fibrillation-free survival

Conclusions

NIVCD is associated with slow sinus rate and prolonged PR interval. NIVCD is an independent risk factor of AF in patients with structurally normal heart.

208Effect of hypertension duration and systolic blood pressure on dementia in patients with atrial fibrillation

Background

Atrial fibrillation (AF) is associated with a higher risk for cognitive impairment and dementia, with or without a history of clinical stroke. There are a paucity of data on the associations of hypertension duration and blood pressure (BP) level with risk of dementia in patients with AF.

Purpose

We examined associations of duration of hypertension and secondly, systolic blood pressure (SBP) levels with incidence of dementia among patients with AF.

Methods

We enrolled a total 196,388 patients aged ≥50 years who were newly diagnosed as AF and undergoing hypertension treatment from the Korean National Health Insurance Service database (2005–2016). Starting from AF diagnosis, participants were followed up until the date of dementia, death, or December 31, 2016. To incorporate the effect of BP level and hypertension duration changes over time on dementia incidence, we constructed time-updated multivariable Cox models in which BP levels and hypertension duration were updated at each participants' regular national health examination visits (at 0–7 years of follow-up). Similarly, age, BP medications, and health-related behaviors were included as time-varying covariates in these models.

Results

During 1,016,744 person-years of follow-up, there were 32,692 dementia events. A cubic spline curve using continuous hypertension duration measures suggested a linear association between increase of hypertension duration and dementia risk. One-year increase of hypertension duration increased the adjusted risk of dementia with a hazard ratio (HR) of 1.17 [95% confidence interval (CI) 1.13–1.22]. In patients with hypertension duration <6 years, SBP of ≥140 mmHg was significantly associated with higher dementia risk, compared to SBP of <130 mmHg (in patients with hypertension duration <3 years: adjusted HR 1.08, 95% CI 1.01–1.16; and in those with 3 ≤ hypertension duration <6 years: adjusted HR 1.13, 95% CI 1.07–1.20), whereas no significant association between SBP and dementia risk in those with hypertension duration ≥6 years.

SBP and dementia in different duration

Conclusion

In patients with AF, the increase of hypertension duration was strongly associated with increased risk of dementia. Uncontrolled SBP was also associated with higher dementia risk. But, this effect of SBP might be attenuated in patients with longer hypertension duration. These findings suggest more emphasis needed on BP control in AF patients with earlier phase of hypertension (duration <6 years).

Acknowledgement/Funding

The Korean Ministry of Education, Science and Technology (NRF-2017R1A2B3003303) and the Korean Ministry of Health & Welfare (HI16C0058, HI15C1200)

P5710Clinical applications of machine learning for prediction of incident atrial fibrillation from the general population: a nationwide cohort study

Background

To evaluate the ability of machine learning algorithms to predict incident atrial fibrillation (AF) from the general population using health examination items.

Methods

We included 483,343 subjects who received national health examinations from the Korean National Health Insurance Service-based National Sample Cohort (NHIS-NSC). We trained deep neural network model (DNN) of a deep learning system and decision tree model (DT) of a machine learning system using clinical variables and health examination items (including age, sex, body mass index, history of heart failure, hypertension or diabetes, baseline creatinine, and smoking and alcohol intake habits) to predict incident AF using a training dataset of 341,771 subjects constructed from the NHIS-NSC database. The DNN and DT were validated using an independent test dataset of 141,572 remaining subjects. C-indices of DNN and DT for prediction of incident AF were compared with that of conventional logistic regression model.

Results

During 1,874,789 person·years (mean±standard-deviation age 47.7±14.4 years, 49.6% male), 3,282 subjects with incident AF were observed. In the validation dataset, 1,139 subjects with incident AF were observed. The c-indices of the DNN and DT for incident AF prediction were 0.828 [0.819–0.836] and 0.835 [0.825–0.844], and were significantly higher (p<0.01) than conventional logistic regression model (c-index=0.789 [0.784–0.794]).

Conclusions

Application of machine learning using simple clinical variables and health examination items was helpful to predict incident AF in the general population. Prospective study is warranted to construct an individualized precision medicine.

64Risk of dementia in patients treated with non-vitamin k antagonist oral anticoagulant or warfarin for nonvalvular atrial fibrillation

Background

Evidence is accumulating that use of oral anticoagulants (OACs) decreases the risk of dementia in patients with atrial fibrillation (AF), but it is unclear if there is a difference between non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin in protecting against dementia.

Purpose

To compare the risk of dementia between patients taking either NOAC or warfarin using a nationwide cohort data covering the entire Korean population.

Methods

Using the Korean national health insurance service database, 68,984 new OAC users with non-valvular AF aged ≥50 years and no prior diagnosis of dementia were identified during the period of 2013–2016 (39,687 NOAC users and 29,297 warfarin users). Starting from OAC initiation, participants were followed up until the date of dementia, death, or December 31, 2016. We compared the rates of dementia in 1:1 propensity score-matched cohorts of NOAC (n=18,925) and warfarin users (n=18,925).

Results

During the 52,259 person-years of follow-up, there were 2,750 dementia events. Use of NOAC was associated with significant lower risk of dementia [hazard ratio (HR) 0.75, 95% confidence interval (CI) 0.69–0.81], compared with warfarin. The risk reduction was prominent for vascular dementia (HR 0.60, 95% CI 0.52–0.71), whereas there was no significant difference in the risk of Alzheimer dementia (HR 0.92, 95% CI 0.83–1.02). Restricting the analyses to patients with no stroke diagnosis prior to OAC initiation (primary prevention) showed no significant difference between NOAC and warfarin in any types of dementia, but in the subgroup with prior stroke (secondary prevention), NOAC significantly reduced the risk of overall (HR 0.70, 95% CI 0.63–0.78) and vascular dementia (HR 0.59, 95% CI 0.49–0.69).

Subgroup analysis according to stroke Hx Patient N Overall dementia Alzheimer dementia Vascular dementia HR (95% CI) P for interaction HR (95% CI) P for interaction HR (95% CI) P for interaction Total 37,850 0.75 (0.69–0.81) 0.92 (0.83–1.02) 0.60 (0.52–0.71) Without prior stroke 24,773 0.90 (0.78–1.05) 0.948 0.98 (0.83–1.15) 0.235 0.85 (0.56–1.28) 0.863 With prior stroke 13,077 0.70 (0.63–0.78) 0.90 (0.79–1.03) 0.59 (0.49–0.69) CI, confidence interval; HR, hazard ratio.

KM curves of dementia incidence

Conclusion

In this propensity-weighted nationwide cohort of non-valvular AF patients, NOAC was associated with reduced risk of dementia, compared with warfarin. This association was the most pronounced for vascular dementia in patients with prior stroke.

Acknowledgement/Funding

The Korean Ministry of Education, Science and Technology (NRF-2017R1A2B3003303) and the Korean Ministry of Health & Welfare (HI16C0058, HI15C1200)

P345Catheter ablation for atrial fibrillation is associated with lower incidence of stroke, major bleeding and death: data from Korean health registries

Background

Compared with antiarrhythmic drug therapy, catheter ablation of AF reduces the number of AF episodes, prolongs the time in sinus rhythm, and improves quality of life. However, it is still unclear if catheter ablation for atrial fibrillation (AF) affects the prognosis or merely is a symptomatic treatment. Our objective was to compare long-term outcome regarding stroke, major bleeding and death in AF patients with and without ablation, and in relation to long-term exposure to anticoagulants.

Methods

We identified all 800,084 patients with a diagnosis of AF from 2006 to 2015 in the Korean national health insurance service database. During a 10-year period, 10,979 AF ablations were performed among 9,768 individuals. Propensity scores for the likelihood of AF ablation were obtained by logistic regression. Propensity score (PS) matching was used to construct two cohorts of equal size (n=9,768) with similar characteristics in 16 dimensions.

Results

Patients who had undergone catheter ablation were younger (57.2 vs. 65.6 years, P<0.001) and healthier (mean CHA2DS2-VASc scores 2.5±1.7 vs. 3.6±2.1, P<0.001) than other patients with AF. Mean follow-up was 5.5±3.1 years. After propensity score matching, in the ablated group, 472 patients suffered ischemic stroke/systemic embolism (SE) compared with 1,682 in the matched non-ablated (annual rates 2.92 vs. 1.10%, P<0.001). Major bleeding occurred in 439 and 1,219 patients in ablated and non-ablated (annual rates 2.07 vs. 1.01%, P<0.001). A total of 306 ablated and 1,439 non-ablated patients died (annual rates 2.31 vs. 0.69%, P<0.001). After multivariable adjustments, catheter ablation was associated with lower risk of ischemic stroke [hazard ratio (HR) 0.51, 95% confidence interval (CI) 0.38–0.67), lower risk of major bleeding (HR 0.65, 95% CI 0.57–0.75) and with lower mortality risk (HR 0.39, 95% CI 0.34–0.46). The reduction of stroke/SE and mortality was observed after AF ablation regardless thromboembolic risk. Major bleeding was reduced only among patients with CHA2DS2-VASc score ≥2 (HR 0.70, 95% CI 0.59–0.84).

Conclusion

We found a strong association between ablation and survival. Ablation may be associated with lower incidence of ischemic stroke and major bleeding in patients with AF. The reduction of stroke/SE and mortality was observed regardless thromboembolic risk after AF ablation. But the risk of major bleeding was reduced only in patients with high thromboembolic risk factors.

P1027The risk of dementia and catheter ablation for atrial fibrillation: a nationwide cohort study

Background

Atrial fibrillation (AF) is associated with all forms of dementia, including Alzheimer's disease. Catheter ablation of AF reduces the number of AF episodes, prolongs the time in sinus rhythm, and improves quality of life. However, it is still unclear if catheter ablation for AF improve cognitive function and prevent dementia. Our objective was to compare long-term outcome regarding dementia and type of dementia in AF patients with and without ablation, and about long-term exposure to anticoagulants.

Methods

We identified all 801,701 patients with a diagnosis of AF from 2006 to 2015 in the Korean national health insurance service database. During ten years, 10,979 AF ablations were performed among 9,768 individuals. Propensity scores for the likelihood of AF ablation were obtained by logistic regression. Propensity score (PS) matching was used to construct two cohorts of equal size (n=9,768) with similar characteristics in 16 dimensions.

Results

Patients who had undergone catheter ablation were younger (57.2 vs. 65.6 years, P<0.001) and healthier (mean CHA2DS2-VASc scores 2.5±1.7 vs. 3.6±2.1, p<0.001) than other patients with AF. Mean follow-up was 5.5±3.1 years. After propensity score matching, in the ablated group, 184 patients suffered dementia compared with 650 in the matched non-ablated (annual rates 0.42 vs. 1.08%, P<0.001). While a total of 134 ablated and 379 non-ablated patients had Alzheimer disease (annual rates 0.31 vs. 0.62%, p<0.001), 40 ablated and 191 non-ablated patients had vascular disease (annual rates 0.09 vs. 0.31%, p<0.001). After multivariable adjustments, catheter ablation was associated with lower risk of dementia (hazard ratio [HR] 0.46, 95% confidence interval [CI] 0.37–0.58), lower risk of Alzheimer disease (HR 0.61, 95% CI 0.46–0.79) and lower risk of vascular dementia (HR 0.27, 95% CI 0.19–0.38). Although the reduction of dementia and Alzheimer disease was observed after AF ablation regardless of thromboembolic risk, vascular dementia was reduced only among patients with CHA2DS2-VASc score ≥2 (HR 0.29, 95% CI 0.20–0.42).

The risk of dementia, RFCA vs. no-RFCA Type Propensity score matched ablation group vs. no ablation group adjusted HR (95% CI) P-value Overall dementia 0.46 (0.37–0.58) <0.001 Alzheimer dementia 0.61 (0.46–0.79) <0.001 Vascular dementia 0.27 (0.19–0.38) <0.001

Conclusion

Ablation may be associated with a lower incidence of dementia and both type of dementia in patients with AF. This finding appears more pronounced in patients with high thromboembolic risk factors.

CD4 T cell count is inversely associated with lumbar spine bone mass in HIV-infected men under the age of 50 years

HIV-infected men under the age of 50 years had a lower bone mass compared to that of HIV-uninfected men. Lower CD4 T cell counts, independent of whether antiretroviral therapy (ART) was used, were associated with lower BMD. HIV-infected patients with low CD4 T cell counts may need follow-up and intervention regarding bone health, including younger patients.

INTRODUCTION

HIV-infected patients have a low bone mineral density (BMD) owing to multifactorial interaction between common osteoporosis risk factors and HIV-related factors, including chronic inflammation and ART. Although HIV infection and ART might affect bone metabolism, little data is available for patients aged under 50 years. We aimed to investigate the association of HIV infection-induced low CD4 T cell counts and ART with BMD in men aged under 50 years.

METHODS

We performed an age- and body mass index-matched case-control study. BMD values of HIV-infected and HIV-uninfected men (< 50 years) were compared, and HIV-infected men were stratified by CD4 T cell counts and ART use.

RESULTS

After adjusting confounders, HIV-infected men with CD4 T cell counts ≥ 500 cells/μL (n = 28) and < 500 cells/μL (n = 139) had lower BMD at the femoral neck (FN, p < 0.001) and total hip (TH, p < 0.001) than HIV-uninfected men (n = 167). HIV-infected men with CD4 T cell counts < 500/μL had lower BMD at the lumbar spine (LS, p = 0.034) than those with counts of ≥ 500 cells/μL, but not at FN and TH. The CD4 T cell count (γ = 0.169, p = 0.031) was positively correlated with BMD at LS. There was no significant difference in the BMD (p = 0.499-> 0.999) between the ART-naïve (n = 75) and ART-user group (n = 92).

CONCLUSIONS

Despite their relatively younger age, HIV-infected men had a lower BMD than HIV-uninfected men. Lower CD4 T cell counts, irrespective of ART, might result in lower bone mass.

Abstract OT2-04-02: A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress

Background

In patients with early stage breast cancer, regional nodal irradiation (RNI) is added to whole breast irradiation (WBI) in order to control microscopic regional disease and to prevent systemic spread of cancer. According to recent randomized trials (MA.20 and EORTC 22922-10925), prophylactic RNI was associated with improvement in disease-free survival (DFS) in the patients with high-risk node negative or pN1 breast cancer. However, systemic agents now known to improve loco-regional control, such as taxane or endocrine therapy, were prescribed to a small percentage of patients in the studies. The benefit of RNI found in the previous studies might be attributed to incorporation of less effective systemic treatments. The impact of prophylactic RNI in pN1 breast cancer should be evaluated in the patients receiving modern systemic treatment. The current study was conducted to compare the effect of post-lumpectomy WBI vs WBI plus RNI on DFS in pN1 breast cancer patients who received adjuvant taxane-based chemotherapy.

Methods

This study is a multicenter, phase 3, randomized controlled non-inferiority trial (NCT03269981). Eligibility criteria are ≥ 20 years female; pathologically proven invasive carcinoma of the breast; one to three positive axillary lymph nodes (pN1) in pathologic specimen; receiving breast-conserving surgery followed by taxane-based chemotherapy; having adjuvant endocrine therapy or anti-HER2 treatment according to molecular subtype of tumor. Patients are randomly assigned in a 1:1 ratio to receive WBI or WBI plus RNI. Patient randomization was stratified by molecular subtype of tumor (i.e. luminal A/luminal B/luminal HER2/HER2-enriched/triple-negative) and methods of axillary management (i.e. sentinel lymph node biopsy/axillary lymph node dissection). The primary outcome is DFS. The secondary outcomes include DFS according to molecular subtype, treatment-related toxicity, and patient's quality of life per EORTC QLQ-C30 and QLQ-BR23. Patients will be followed for survival and disease recurrence for seven years. A total of 1,926 patients are planned to be enrolled, with recruitment initiated in April 2017. As of June 2018, a total of 236 patients were enrolled.

Acknowledgement

This study was supported by a grant from the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (grant number: HA17C0043010018).

Citation Format: Kim H, Park W, Choi DH, Ahn SJ, Kim SS, Kim ES, Lee JH, Lee KC, Kim JH, Lee H-S, Kim JH, Kim MY, Park HJ, Kim K, Song SH, Kwon J, Lee IJ, Kim TH, Kim TG, Chang AR, Cho O, Jeong BK, Ha B, Lee J, Ki Y. A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-04-02.

Abstract P5-07-10: The prognostic significance of estrogen formation as a consequence of aromatase expression in tumor microenvironment

Estrogen synthesis via aromatase in adipose tissue has an important role in progression of postmenopausal breast cancer. The increased local concentrations of estrogen in breast cancer via aromatase overexpression within the tumor tissue have been demonstrated by some investigators. Although aromatase inhibitor is the standard endocrine therapy for postmenopausal breast cancer patients, it is not uncommon for patients to have poor compliance to the drugs due to their side effects. This research is based on the hypothesis that if aromatase expression is related to prognosis and if therapeutic effect varies depending on the degree of aromatase expression, then this study may be able to suggest a new guideline in terms of choosing between aromatase inhibitors and tamoxifen.

Methods: 154 postmenopausal breast cancer patients who underwent surgery and aromatase inhibitor therapy in Busan Paik Hospital, Inje University from January 2005 to December 2010 were enrolled. Patients with DCIS or stage IV breast cancer were excluded. Patients' clinicopathological data were collected and TMA blocks were created for immunohistochemistry studies to examine aromatase expression.

Results: The recurrence has occured in 7 patients (6.9%). Stage, tumor size and number of lymph node metastasis were related to increased risk of recurrence (p=0.051, 0.043, 0.001). The aromatase expression in cancer cells had significant correlation with clinical stage (p=0.041). There was also a positive correlation between Ki67 and aromatase expression in cancer tissue (p=0.006). However, aromatase expression in cancer, stromal, and adipose tissue had no relationship with recurrence (p=0.410, 0.627, 0.552).

Correlation between clinicopathologic factors and aromatase expression (Linear by linear association and Spearman's correlation coefficient test)Site of aromatase expressionERPRKi67P53BMIStageIn Cancer0.6060.5920.0060.4510.9560.041In Stroma0.2200.4710.5840.3290.3670.229In Adipose0.9880.2650.1590.1170.7701.000

Conclusions: Aromatase expression in cancer cells was correlated with clinical stage. This implies that aromatase expression might have a role of prognostic marker in addition to role of treatment indicator. There was no direct correlation between aromatase expression and recurrence.

Citation Format: Kim TH, Lee A, Han JW, Jung SJ, Byun K-D. The prognostic significance of estrogen formation as a consequence of aromatase expression in tumor microenvironment [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-10.

On the High Formability of AZ31-0.5Ca Magnesium Alloy

In this work, we investigated the effect of Ca on the formability of the AZ31 Mg alloy. For this purpose, the microstructure, texture, mechanical properties and formability of AZ31 Mg alloy samples containing 0.5 wt. % Ca (AZ31-0.5Ca) were studied. For comparison, the performance of Ca-Free AZ31 alloy samples with similar grain size was also investigated. In addition, formability of this alloy was reached at a high punch speed. The results of this work showed that the addition of 0.5 wt. % Ca can enhance the formability of the AZ31 alloy, which was three times greater than that of the Ca-Free AZ31 alloy. The improved formability was attributed to the formation of (Mg,Al)₂Ca particles (~1 μm), which, in turn, contribute to reducing the intensity of the strong basal texture during the primary processing of the alloy. The in-grain misorientation axis analysis determined by electron back-scattered diffraction and critical resolved shear stress calculations carried out by the viscoplastic self-consistent model showed that the non-basal slip systems could be activated in the AZ31-0.5Ca alloy.

Note: Double-layered polyimide film heater with low magnetic field generation

We designed a double-layered polyimide film heater where the direction of the injection current of each layer is opposite to that of the other layer to reduce the magnetic field. The width of the heater is 0.125 mm and the resistance is 21.2 Ω. This specially designed heater successfully demonstrated temperature controllability within 10 mK for an atomic cell in an atom spin gyroscope while minimizing the generation of the magnetic field to within 1 nT.

Comparison of Perioperative Renal Function Between Epidural and Intravenous Patient-Controlled Analgesia After Living-Donor Hepatectomy: A Retrospective Study

BACKGROUND

Sympathetic blockade associated with epidural analgesia was reported to be a risk factor for acute kidney injury (AKI) following liver resection. The purpose of this study was to compare the incidence of AKI after living-donor hepatectomies according to the type of patient-controlled analgesia (PCA).

METHODS

A total of 316 patients after living-donor hepatectomy were retrospectively analyzed; 148 patients in the epidural PCA group and 168 patients in the intravenous (IV) PCA group were evaluated. AKI was defined as an increase in serum creatinine ≥0.3 mg/dL, ie, 1.5-fold from the baseline, or a reduction in the urine output in the first 48 hours after surgery, based on the Acute Kidney Injury Network criteria. Logistic regression analysis was performed to identify the independent risk factors for AKI after living-donor hepatectomy.

RESULTS

Baseline characteristics were similar between the 2 groups except the age. Volumes of fluids and colloids administered intraoperatively were greater in the epidural PCA group (P < .001 and P = .006, respectively). The incidence of AKI did not show significant differences between the 2 groups (8.1% vs 7.1%; P = .747). In multivariate analysis, preoperative serum alanine transaminase level ≥50 U/L was identified as a risk factor for postoperative AKI. However, epidural PCA failed to be a risk factor for postoperative AKI.

CONCLUSIONS

The type of PCA did not affect the incidence of postoperative AKI after living-donor hepatectomy. Despite significant differences in the postoperative hemodynamics, the incidence of AKI was similar between 2 groups.

Risk Factors for Dropout From the Liver Transplant Waiting List of Hepatocellular Carcinoma Patients Under Locoregional Treatment

BACKGROUND

In new organ allocation policy, patients with hepatocellular carcinoma (HCC) experience a 6-month delay in being granted Model for End-Stage Liver Disease exception points. However, it may not be fair for patients at risk of early progression of HCC.

METHODS

All patients who were diagnosed as United Network for Organ Sharing (UNOS) stage 1 or 2 of HCC between January 2004 and December 2012 were included. Patients who received surgical resection or liver transplant (LT) as a primary treatment and who did not receive any treatment for HCC were excluded. Patients with baseline Model for End-Stage Liver Disease score ≥22 were also excluded because they have a higher chance of receiving LT. Patients who developed extrahepatic progression within 1 year were considered as high-risk for early recurrence after LT.

RESULTS

A total of 586 patients were included. Mean (SD) age was 59.9 (10.3) years and 409 patients (69.8%) were men. The cumulative incidence of estimated dropout was 8.9% at 6 months; size of the maximum nodule (≥3 cm) and nonachievement of complete response were independent factors. Extrahepatic progression developed in 16 patients (2.7%) within 1 year; size of the maximum nodule (4 cm) and alpha-fetoprotein level (>100 ng/mL) were independent predictors.

CONCLUSIONS

The estimated dropout rate from the waiting list within 6 months was 8.9%. Advantage points might be needed for patients with maximum nodule size ≥3 cm or those with noncomplete response. However, in patients with maximum nodule size ≥4 cm or alpha-fetoprotein level >100 ng/mL, caution is needed.