Impact of the New ESTRO-ACROP Target Volume Delineation Guideline on Breast-Related Complications after Implant-Based Reconstruction and Postmastectomy Radiotherapy

PURPOSE/OBJECTIVE(S)

The European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) recently updated a new target volume delineation guideline for postmastectomy radiotherapy (PMRT) after implant-based reconstruction. This study aimed whether this change has impact on breast-related complications.

MATERIALS/METHODS

We retrospectively reviewed patients who underwent PMRT after mastectomy with tissue expander or permanent implant insertion from 2016 to 2021. In total, 412 patients were included; 277 received RT by the new ESTRO-ACROP target delineation (ESTRO-T), and 135 received RT by conventional target delineation (CONV-T). The primary endpoint was comparison between the target groups of major breast-related complication, including infection, capsular contracture, deformity and necrosis requiring re-operation or re-hospitalization during follow-up after RT or delayed implant replacement. Complications were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0., and capsular contracture was graded by the Baker Classification.

RESULTS

The median follow-up was 29.5 months (range, 0.3-76.8). The 1-, 2-, and 3-year incidence rates of major breast-related complication were 5.7%, 10.0%, and 11.6% in the ESTRO-T group, and 8.2%, 13.8%, and 14.7% in the CONV-T groups; it did not show a difference between the groups (P = 0.55). In multivariate analyses, target delineation is not significantly associated with the major complications (hazard ratio [HR] = 0.93; P = 0.83, Table 1). There was no significant difference between the ESTRO-T and CONV-T groups in the incidence of any breast-related complications (3-year cumulative incidence, 37.3% vs. 29.4%, respectively; P = 0.28). Symptomatic RT-induced pneumonitis rates were 2.7% in the ESTRO-T group (7 patients) and 2.2% in the CONV-T group (3 patients). Only one local recurrence event occurred in the ESTRO-T group, which was within the ESTRO-target volume.

CONCLUSION

Target volume delineation according to the new ESTRO-ACROP guideline did not reduce the risk of major or any breast-related complications. As the dosimetric benefits of heart and lung have been reported, further analyses with long-term follow-up are necessary to evaluate whether it could be connected to better clinical outcomes.

Benzisothiazolinone: Pharmacokinetics, Tissue Distribution, and Mass Balance Studies in Rats

Humans are continuously exposed to benzisothiazolinone (BIT), which is used as a preservative, through multiple routes. BIT is known to be a sensitizer; in particular, dermal contact or aerosol inhalation could affect the local toxicity. In this study, we evaluated the pharmacokinetic properties of BIT in rats following various routes of administration. BIT levels were determined in rat plasma and tissues after oral inhalation and dermal application. Although the digestive system rapidly and completely absorbed orally administered BIT, it underwent severe first-pass effects that prevented high exposure. In an oral dose escalation study (5-50 mg/kg), nonlinear pharmacokinetic properties showed that C_max and the area under the curve (AUC) increased more than dose proportionality. In the inhalation study, the lungs of rats exposed to BIT aerosols had higher BIT concentrations than the plasma. Additionally, the pharmacokinetic profile of BIT after the dermal application was different; continuous skin absorption without the first-pass effect led to a 2.13-fold increase in bioavailability compared with oral exposure to BIT. The [¹⁴C]-BIT mass balance study revealed that BIT was extensively metabolized and excreted in the urine. These results can be used in risk assessments to investigate the relationship between BIT exposure and hazardous potential.

Systemic proinflammatory-profibrotic response in aortic stenosis patients with diabetes and its relationship with myocardial remodeling and clinical outcome

Background

It is unclear whether and how diabetes mellitus may aggravate myocardial fibrosis and remodeling in the pressure-overloaded heart. We investigated the impact of diabetes on the prognosis of aortic stenosis (AS) patients and its underlying mechanisms using comprehensive noninvasive imaging studies and plasma proteomics.

Methods

Severe AS patients undergoing both echocardiography and cardiovascular magnetic resonance (CMR) (n=253 of which 66 had diabetes) comprised the imaging cohort. The degree of replacement and diffuse interstitial fibrosis by late gadolinium enhancement (LGE) and extracellular volume fraction (ECV) was quantified using CMR. Plasma samples were analyzed with the multiplex proximity extension assay for 92 proteomic biomarkers in a separate biomarker cohort of severe AS patients (n=100 of which 27 had diabetes).

Results

In the imaging cohort, diabetic patients were older (70.4±6.8 vs. 66.7±10.1 years) and had a higher prevalence of ischemic heart disease (28.8% vs. 9.1%), with more advanced ventricular diastolic dysfunction. On CMR, diabetic patients had increased replacement and diffuse interstitial fibrosis (LGE% 0.3 [0.0–1.6] versus 0.0 [0.0–0.5], p=0.009; ECV% 27.9 [25.7–30.1] versus 26.7 [24.9–28.5], p=0.025) (Figure 1).

Plasma proteomics analysis of the biomarker cohort revealed that 9 proteins (E-selectin, interleukin-1 receptor type 1, interleukin-1 receptor type 2, galectin-4, intercellular adhesion molecule 2, integrin beta-2, galectin-3, growth differentiation factor 15, and cathepsin D) are significantly elevated in diabetic AS patients (Figure 2). Pathway over-representation analyses of the plasma proteomics with Gene Ontology terms indicated that pathways related to inflammatory response and extracellular matrix components were enriched, suggesting that diabetes is associated with systemic effects that evoke proinflammatory and profibrotic response to the pressure-overloaded myocardium.

During follow-up (median 6.3 years [IQR 5.2–7.2]) of the imaging cohort, 232 patients received aortic valve replacement (AVR) with 53 unexpected heart failure admissions or death. Diabetes was a significant predictor of heart failure and death, independent of clinical covariates and AVR (hazard ratio 1.88, 95% confidence interval 1.06–3.31, p=0.030).

Conclusion

Plasma proteomic analyses indicate that diabetes potentiates the systemic proinflammatory and profibrotic milieu in AS patients. These systemic biological changes underlie the increase of myocardial fibrosis, diastolic dysfunction, and worse clinical outcomes in severe AS patients with concomitant diabetes.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): National Research Foundation of Korea

Augmented risk of ischemic stroke in hypertrophic cardiomyopathy patients without documented atrial fibrillation

Background

Ischemic stroke is a common complication in patients with hypertrophic cardiomyopathy (HCM) (1). Although atrial fibrillation (AF) is a well-established risk factor for ischemic stroke in HCM, the risk of ischemic stroke in patients with HCM without documented AF is less recognized (1, 2). This study aimed to determine the risk of ischemic stroke and identify its risk factors in patients with HCM without documented AF.

Methods

This nationwide population-based cohort study used the Korean National Health Insurance database. After excluding patients with a prior history of AF, thromboembolic events, cancer, or the use of anticoagulants, we identified 8,328 HCM patients without documented AF and 1:2 propensity score-matched 16,656 non-HCM controls. The clinical outcome was an incident ischemic stroke.

Results

During a mean follow-up of approximately 6 years, ischemic stroke occurred in 328/8,328 (3.9%) patients with HCM and 443/16,656 (2.7%) controls. Among individuals who developed ischemic stroke, the proportion of AF concomitantly detected accounted for 26.5% (87/328) and 5.8% (26/443) in the HCM and control groups, respectively. The overall incidence of ischemic stroke was 0.716/100 person-years in the HCM group, which was significantly higher than that in the control group (0.44/100 person-years) (HR 1.643; 95% CI, 1.424–1.895; P<0.001, Figure 1). The subgroup analysis according to age, sex, and comorbidities (chronic heart failure, hypertension, dyslipidemia, and vascular disease) consistently demonstrated a higher risk of ischemic stroke in the HCM group (P for interaction >0.05). In the HCM group, age ≥65 years (adjusted hazard ratio [HR] 2.741; 95% confidence interval [CI], 2.156–3.486; P<0.001) and chronic heart failure (adjusted HR 1.748; 95% CI, 1.101–2.745; P=0.018) were independent risk factors for ischemic stroke. Overall incidence was 1.360/100 in patients with HCM aged ≥65 and 2.315/100 person-years years in those with chronic heart failure, respectively. Also, compared to controls aged <65 years and without CHF, adjusted HR for ischemic stroke was 4.756 (95% CI 3.807–5.867) in patients with HCM aged ≥65 years and 2.539 (95% CI 1.638–3.936) in those with CHF, respectively (Figure 2).

Conclusions

Patients with HCM without documented AF are at a higher risk of ischemic stroke than the propensity score-matched general population. Age ≥65 years and chronic heart failure are two strong independent risk factors for ischemic stroke in this population.

Funding Acknowledgement

Type of funding sources: None.

Impact of atrial fibrillation on the progression and outcomes of isolated mild functional tricuspid regurgitation

Background

Atrial fibrillation (AF) is increasingly recognized as a cause of tricuspid regurgitation (TR) in the structurally normal tricuspid valve. However, there are limited data regarding the impact of AF on TR progression and its long-term cardiovascular outcomes.

Purpose

We aimed to investigate the association of AF with the significant TR progression and its impact on clinical outcomes among patients with isolated mild functional TR.

Methods

We studied 834 patients with mild function TR identified on the echocardiography between 2007 and 2019, whose follow-up echocardiography beyond 1-year was available. Major exclusion criteria were the overt causes of primary and secondary TR (i.e., concomitant left-sided heart disease). Primary endpoint was the significant TR progression to more than a moderate degree on the follow-up echocardiography. Composite cardiac event was defined as cardiovascular death, TR surgery, and heart failure admission due to TR.

Results

Of 834 patients with isolated mild functional TR (mean age 65.6 years, 41% men), 292 (35.0%) patients had AF at the baseline. Patients with AF were older and had larger left atrium compared to those without. During the median of 4.55 years follow-up (interquartile interval 2.56–7.24 years), 36 patients developed a significant TR ≥ moderate degree. The cumulative rate of TR progression was significantly higher in patients with AF than those without (11.3% versus 0.6%, P<0.001) (Figure 1). Multivariable Cox analyses showed that AF was associated with a 3-fold higher risk of TR progression (adjusted hazard ratio 3.50, 95% confidence interval 1.42–8.65). Regarding the cardiovascular outcomes, patients who developed significant TR had a higher rate of composite cardiac events compared to those who did not (cardiac events: 38.9% versus 6.3% P<0.001) (Figure 2).

Conclusions

AF is a strong risk factor for TR progression among patients with isolated mild functional TR. In addition, the development of significant TR is associated with worse cardiovascular outcomes. These findings highlight the important pathophysiology of AF on TR development and its clinical consequences.

Funding Acknowledgement

Type of funding sources: None.

Pharmacokinetics of 2-phenoxyethanol and its major metabolite, phenoxyacetic acid, after dermal and inhaled routes of exposure: application to development PBPK model in rats

2-Phenoxyethanol (PE), ethylene glycol monophenyl ether, is widely used as a preservative in cosmetic products as well as in non-cosmetics. Since PE has been used in many types of products, it can be absorbed via dermal or inhaled route for systemic exposures. In this study, the pharmacokinetic (PK) studies of PE and its major metabolite, phenoxyacetic acid (PAA), after dermal (30 mg and 100 mg) and inhaled administration (77 mg) of PE in rats were performed. PE was administered daily for 4 days and blood samples were collected at day 1 and day 4 for PK analysis. PE was rapidly absorbed and extensively metabolized to form PAA. After multiple dosing, the exposures of PE and PAA were decreased presumably due to the induction of metabolizing enzymes of PE and PAA. In dermal mass balance study using [¹⁴C]-phenoxyethanol ([¹⁴C]PE) as a microtracer, most of the PE and its derivatives were excreted in urine (73.03%) and rarely found in feces (0.66%). Based on these PK results, a whole-body physiologically-based pharmacokinetic (PBPK) model of PE and PAA after dermal application and inhalation in rats was successfully developed. Most of parameters were obtained from the literatures and experiments, and intrinsic clearance at steady-state (CL_int,ss) were optimized based on the observed multiple PK data. With the developed model, systemic exposures of PE and PAA after dermal application and inhalation were simulated following no-observed-adverse-effect level (NOAEL) of 500 mg/kg/day for dermal application and that of 12.7 mg/kg/day for inhalation provided by the Environmental Protection Agency. The area under the concentration-time curve at steady state (AUC_ss) in kidney and liver (and lung for inhalations), which are known target organs of exhibiting toxicity of PE, as well as AUC_ss in plasma of PE and PAA were obtained from the model.

Tooth Loss Predicts Myocardial Infarction, Heart Failure, Stroke, and Death

We investigated whether oral health, represented by missing teeth, was associated with an increased risk of cardiovascular disease, including myocardial infarction (MI), heart failure (HF), stroke, and all-cause mortality. Subjects who underwent routine dental examinations and health checkups provided by the Korean National Health Insurance from 2007 to 2008 ( n = 4,440,970) were followed up for incident MI, HF, stroke, and death until 2016. During follow-up of 7.56 y, 68,063 (1.5%) subjects died, and 31,868 (0.7%) were admitted for MI, 22,637 (0.5%) for HF, and 30,941 (0.7%) for stroke. Cardiovascular events and mortality increased in proportion to tooth loss. Tooth loss was an independent risk factor for cardiovascular events after multivariable analysis adjusted for cardiovascular risk, behavioral, and income factors. Each missing tooth was associated with an approximately 1% increase in MI (HR, 1.010; 95% CI, 1.007 to 1.014), 1.5% increase in HF (HR, 1.016; 95% CI, 1.013 to 1.019) and stroke (HR, 1.015; 95% CI, 1.012 to 1.018), and 2% increase in mortality (HR, 1.022; 95% CI, 1.020 to 1.023). Having ≥5 missing teeth substantially increased risk for cardiovascular outcomes, and even a small number of missing teeth (1 to 4) was associated with an increased risk for MI, stroke, and death. This association was consistent in subgroup analyses and especially strong among the younger subjects (age <65 y) and those with periodontitis. In this large Korean nationwide cohort study, we found that tooth loss showed a dose-dependent association with incident MI, HF, ischemic stroke, and all-cause death and was a good predictor of cardiovascular outcome. In clinical practice, the number of missing teeth can aid physicians in discriminating patients with a higher cardiovascular risk.

P1274 Early surgery versus watchful waiting in patients with moderate aortic stenosis and left ventricular systolic dysfunction

Background

Aortic stenosis (AS) induces significant pressure overload to the left ventricle (LV) and its burden may increase if there is concomitant LV systolic dysfunction. Severe AS with LV systolic dysfunction is a class I indication for aortic valve replacement (AVR) irrespective of symptoms, however, this recommendation is not well established in those with moderate AS and LV systolic dysfunction. In this study, we sought to investigate the clinical impact of surgical AVR among patients with moderate AS and LV systolic dysfunction.

Methods

From 2001 to 2017, we retrospectively but consecutively identified patients with moderate AS and LV systolic dysfunction from a single tertiary hospital. Moderate AS was defined as aortic valve area between 1.0 and 1.5cm2 and LV systolic dysfunction as LV ejection fraction less than 50%. The primary outcome was all-cause death and we additionally analyzed cardiac death as a secondary endpoint. The outcomes were compared between those who underwent early surgical AVR at the stage of moderate AS versus those who were followed without AVR at the outpatient clinic.

Results

Among a total of 257 patients with moderate AS and concomitant LV systolic dysfunction (70.0 ± 11.3 years, 63.4% of male), 34 patients received early AVR. Patients in the AVR group was younger than the observation group (64.2 ± 8.1 vs. 70.9 ± 11.5, respectively), and had a lower prevalence of hypertension and chronic kidney disease. During a mean of 3-year follow up, 112 patients (47.5%) died and the overall death rate was 15.367 per 100 person-year (PY). The AVR group showed a significantly lower rate of all-cause death than the observation group (5.241PY vs. 18.160PY, p-value = 0.002). After multivariable Cox proportional hazard regression adjusting for age, sex, comorbidities and laboratory data, early AVR at the stage of moderate AS significantly reduced the risk of all-cause death (hazard ratio [HR] 0.340, 95% confidence interval [CI] 0.117 - 0.985, p-value = 0.047). However, there was no risk reduction of cardiac death (HR 0.578 95% CI 0.150 - 2.231, p-value = 0.426).

Conclusions

In patients with moderate AS and LV systolic dysfunction, AVR reduces the risk of all-cause death. A prospective design study is warranted to confirm our findings in the near future.

Abstract P1274 Figure. Kaplan-Meier curves for deaths

P1603 Changes of cardiac function in cirrhotic patients after liver transplantation

Funding Acknowledgements

This study was supported by the grant of CJ healthcare 2016 research fund.

Background

Liver cirrhosis (LC) has been known to affect cardiovascular performance. Limited study have evaluated the alteration of myocardial function in patients with LC after liver transplantation (LT).

Purpose

The aim of study was to evaluate changes of cardiac function in patients with cirrhosis following LT using conventional and speckle-tracking echocardiography and late gadolinium enhancement (LGE) of cardiac magnetic resonance (MR).

Methods

Thirty-five patients with cirrhosis (mean age, 57.1 ± 9.0; male, 75%) who were listed for LT were prospectively enrolled. Patients underwent conventional, speckle-tracking echocardiography, and cardiac MR imaging with LGE. Echocardiography and cardiac MR were performed at pre and 1 year after LT. Cirrhotic patients were compared with normal control (n = 20, mean age, 65.0 ± 14.8; men, 11(55%)) and echocardiographic and cardiac MR data were compared pre and post LT.

Results

Conventional and speckle-tracking echocardiography and Cardiac MR imaging demonstrated hyperdynamic left ventricular (LV) function in patients with cirrhosis (LV ejection fraction (EF) with cardiac MR 67.8 ± 7.0% in LC vs. 63.4 ± 6.4% in control, P = 0.028; global longitudinal strain (GLS) -24.3 ± 2.6% in LC vs. -18.6 ± 2.2% in control, P &lt; 0.001). There were no LGE in patients with cirrhosis and no significant differences in LV size, LV wall thickness, LV mass index, and diastolic function between cirrhotic patients and control group (all P &gt; 0.1). Corrected QT interval (QTc) in electrocardiogram was prolonged in LC patients (P &lt; 0.001). One-year after LT, LV end-diastolic diameter and LV end-diastolic volume significantly decreased (P = 0.016 and 0.022, respectively). Although LVEF showed no significant changes 1 year post-LT (P = 0.362), LV-GLS (from -24.7 ± 1.8% to -20.8 ± 3.4%, P &lt; 0.001) significantly decreased. QTc interval also decreased 1 year after LT (from 470.4 ± 29.6msec to 428.2 ± 31.6msec, P = 0.001).

Conclusions

The present study demonstrated that cirrhotic patients showed hyperdynamic circulation and prolonged QTc interval compared with normal controls. After 1 year LT, LV size reduced and augmented LV function was normalized. Given that no LGE in cardiac MR and normalized GLS and QTc after LT, cardiac dysfunction in LC patients could be reversed by LT.

P1368 Effect of angiotensin receptor blocker in patients with moderate or severe aortic stenosis: a randomized controlled trial

Funding Acknowledgements

This study was supported by grants from Boryung Pharmacy Research Fund.

Background/Introduction: Pathophysiology of aortic stenosis (AS) and several previous studies suggested the potential role of angiotensin receptor blocker (ARB) in patients with AS.

Purpose

We aimed to investigate the effects of Fimasartan, an ARB, on exercise capacity and progression of AS in patients with moderate to severe AS.

Methods

We conducted a prospective, randomized, double-blind, placebo-controlled trial in 32 normotensive or controlled-hypertensive patients with moderate or severe AS. Study participants were randomized to Fimasartan 30 mg to 60 mg daily (n = 14) or placebo (n = 18) for 1 year, and underwent cardiopulmonary exercise test, 6-minute walk test, and echocardiography at 0, 6, and 12 months, with follow-up data available in 29 subjects.

Results

Significant reductions in blood pressures were observed in the Fimasartan group but not in the placebo group. Two of the 14 patients in the Fimasartan group withdrew the study due to mild symptoms probably related with the decreased blood pressure, and one patient decline the study protocol. After the 12-month treatment, the peak oxygen consumption (VO2; the primary outcome) in the Fimasartan group was significantly decreased (from 28.3 ± 5.9 to 25.4 ± 3.8 mL/min/kg, P = 0.021) but not in the placebo group (P for interaction = 0.046) (Figure 1A). The severity of AS showed a gradual progression in both groups, without inter-group differences (mean transaortic pressure; Fimasartan group, +4.0 ± 3.8 mmHg/year; placebo group, +5.3 ± 6.2 mmHg/year; P for interaction = 0.429) (Figure 1B). Parameters of left ventricular systolic and diastolic function did not change in both groups.

Conclusions

The use of ARB impaired exercise capacity in patients with moderate or severe AS, and did not prevent the progression of AS. However, due to the small number of participants, further studies are required to confirm these findings.

Abstract P1368 Figure.

P785 Left ventricular geometry and myocardial contractility modulate impact of statins on prognosis in patients with acute heart failure

Funding Acknowledgements

N/A

Background/Introduction: The benefit of statins in patients with heart failure (HF) remains controversial and the mechanism of action is largely speculative. We investigated whether survival benefit with statins differs according to left ventricular (LV) geometry and myocardial contractility in acute HF patients.

Methods

We enrolled 1792 acute HF patients receiving statins and 2296 patients not receiving statins admitted from 2009 to 2016. The LV and right ventricular (RV) global longitudinal strain (GLS) was assessed as a measure of myocardial contractility. Patients were classified into 2 groups based on ischemic etiology of HF and further divided into 4 subgroups according to the median values of LV-GLS or RV-GLS. The primary outcome was 5-year all-cause mortality. The study protocol was approved by the ethics committee at each institute and complied with the Declaration of Helsinki. The need for written informed consent was waived.

Results

During the 5-year follow-up, 1740 (40.4%) patients died and they had more unfavorable baseline characteristics. Statin therapy was significantly associated with improved survival in overall patients and in both groups with and without ischemic etiology (all p &lt;0.001). Patients with concentric remodeling/hypertrophy and eccentric hypertrophy demonstrated survival benefit with statin therapy (P = 0.033, 0.004, and 0.008, respectively), while those with normal geometry did not (p = 0.123). In the non-ischemic HF group, survival benefit with statin therapy was confined to patients with low LV-GLS (p = 0.045) or those with low RV-GLS p = 0.003). On the contrary, in ischemic HF group, survival benefit with statin therapy was observed in all patients regardless of the values of LV-GLS or RV-GLS. Significant interactions were present between statin use and diabetes mellitus and IHD (p for interaction = 0.027 and 0.003, respectively) regarding mortality.

Conclusions

LV geometry and myocardial contractility may modulate the effects of statins in patients with acute HF. These echocardiographic measures can provide prognostic information to guide tailored statin treatment in this population. Our findings may also help to develop more well-designed prospective studies, in terms of a more homogenous study population, to confirm survival benefit with statin therapy.

Abstract P785 Figure. Multivariate Cox survival curves

P3429A novel prediction model for mortality after cardiac surgery using institutional case volume

Purpose

A number of risk prediction models have been developed to identify short term mortality after cardiovascular surgery. Most models include patient characteristics, laboratory data, and type of surgery, but no consideration for the amount of surgical experience. With numerous reports on the impact of case volume on patient outcome after high risk procedures, we attempted to develop a risk prediction models for in-hospital and 1-year mortality that takes institutional case volume into account.

Methods

We identified adult patients who underwent cardiac surgery from January 2008 to December 2017 from the National Health Insurance Service (NHIS) database by searching for patients with procedure codes of coronary artery bypass grafting, valve surgery, and surgery on thoracic aorta during the hospitalization. Study subjects were randomly assigned to either the derivation cohort or the validation cohort. In-hospital mortality and 1-year mortality data were collected using the NHIS database. Risk prediction models were developed from the derivation cohort using Cox proportional hazards regression. The prediction performances of models were evaluated in the validation cohort.

Results

The models developed in this study demonstrated fair discrimination for derivation cohort (N=22,004, c-statistics, 0.75 for in-hospital mortality; 0.73 for 1-year mortality) and acceptable calibration in the validation cohort. (N=22,003, Hosmer-Lemeshow χ2-test, P=0.08 and 0.16, respectively). Case volume was the key factor of mortality prediction models after cardiac surgery. (50≤ x <100 case per year. 100≤ x <200 case per year, ≥200 case per year are correlated with OR 3.29, 2.49, 1.85 in in-hospital mortality, 2.76, 1.99, 1.69 in 1-year mortality respectively, P value <0.001.)

Annual case volume as risk factor Variables In-hospital mortality 1-year mortality OR (95% CI) p-value OR (95% CI) p-value Annual case-volume (reference: ≥200) – – 100–200 1.69 (1.48, 1.93) <0.001 1.85 (1.58, 2.18) <0.001 50–100 1.99 (1.75, 2.25) <0.001 2.49 (2.15, 2.89) <0.001 <50 2.76 (2.44, 3.11) <0.001 3.29 (2.85, 3.79) <0.001 OR: Odds ratio; CI: confidence interval; Ref: Reference.

Discrimination and calibration

Conclusion

We developed and validated new risk prediction models for in-hospital and 1-year mortality after cardiac surgery using the NHIS database. These models may provide useful guides to predict mortality risks of patients with basic information and without laboratory findings.

Clinical Impact of a Protocolized Kidney Donor Follow-up System

BACKGROUND

Adequate kidney donor management after donation is increasingly emphasized due to concerns of renal function impairment after nephrectomy with increasing life expectancy. In this study, the clinical impact of a protocolized kidney donor follow-up system by nephrologists was evaluated.

METHODS

A total of 427 living kidney donors underwent nephrectomy from January 2010 to December 2014 and were followed for at least 2 years at the Samsung Medical Center. Donors were followed-up by nephrologists after the establishment of a donor clinic with systemized protocols in January 2013. The primary outcomes were incidence of post-donation low estimated glomerular filtration rate (eGFR) and renal function adaptability. Secondary outcomes were changes in compliance and incidence of hyperuricemia and microalbuminuria.

RESULTS

The patients were divided into 2 groups according to the time of nephrectomy: the pre-donor clinic period (n = 182) and the donor clinic period (n = 172). Preoperative eGFR in patients in the pre-donor clinic period was higher than that in patients in the donor clinic period. After donation, poor renal adaptation was less frequent in the donor clinic period compared to the pre-donor clinic period. Low eGFR tended to be less common during the donor clinic period. Shorter mean outpatient clinic visit intervals with more visits within 6 months after donation and earlier detection of de novo hyperuricemia were found during the donor clinic period.

CONCLUSION

A protocolized donor clinic run by nephrologists may improve post-nephrectomy renal outcomes and compliance and facilitate better management of potential risk factors of chronic kidney disease in donors.

Comparison of traffic collision victims between older and younger drivers in South Korea: Epidemiologic characteristics, risk factors and types of collisions

Objective

This study aimed to show the epidemiological characteristics and the difference in the risk factors and types of collision between older and younger drivers in Korea.

Methods

We collected data from the Emergency Department-based Injury In-depth Surveillance retrieved by the Korea Centers for Disease Control and Prevention from 2011 to 2015. We included injured drivers aged ≥ 18 years who were registered in the database, who were limited to drivers of four-wheeled vehicles. The enrolled patients were divided according to age into older (≥ 65 years) and younger (< 65 years) drivers. The total number of enrolled drivers was 37,511; 2,361 (6.3%) of them were older drivers. The epidemiological characteristics (e.g., age, sex, fatality rate) of traffic collision victims for 5 years were determined, and the risk factors (e.g., seat belt use) and types of collision (single- vs. multi-vehicle) between the two groups were compared.

Results

The median age and interquartile range (IQR; 25^th and 75^th percentiles) of all drivers were 41.0 (IQR, 32.0–52.0), and 24,544 (65.4%) of them were men. The median age increased from 40.0 (IQR, 31.0–50.0) to 43.0 (IQR, 33.0–54.0) between 2010 and 2015 (P < 0.001). The proportion of older drivers increased from 5.0% to 8.4% annually during the study period (P < 0.001). Between 2010 and 2015, the fatality rate decreased from 3.1% to 1.2% (P = 0.287) for older drivers and from 0.9% to 0.5% (P = 0.009) for younger drivers. The proportion of single-vehicle collision (25.9% vs. 20.3%) was higher in older than in younger drivers (P < 0.001). Older drivers had a lower rate of seat-belt use than younger drivers (79.0% vs. 83.0%, P < 0.001).

Conclusions

The proportion of older drivers increased annually during the study period, and older drivers experienced more single-vehicle collision and used seat belt less frequently than younger drivers. A national policy support to reduce traffic collision in older drivers and public relation activities to enhance their seat belt use should be strengthened in the future.

Transfer printing of vertical-type microscale light-emitting diode array onto flexible substrate using biomimetic stamp

We report the transfer printing of GaN-based microscale vertical-type light-emitting diodes (μ-VLEDs) using a functional layer and a biomimetic stamp. An oxide-based functional layer is inserted onto the structure of a μ-VLED and used to separate the chip from the μ-VLED wafer by absorbing the pulse of a UV pulse laser during pick-up of the transfer printing process. Polydimethylsiloxane (PDMS)-based biomimetic stamps have been fabricated to mimic the gecko lizard cilia for improved adhesion and repeatability. The biomimetic stamp has an adhesion force of 25.6 N/cm², which is 12 times the adhesion of a flat stamp; an adhesion force of 10 N/cm² or more was maintained after 100,000 repeated adhesion tests. A flexible 10 × 10 prototype array on a polyimide substrate was fabricated, and its bending test results indicated that the strain effect on the forward voltage and the output power was less than 1%. The stable bending test results of the prototype indicate that μ-VLEDs using biomimetic stamps allow the necessary stability for practical transfer printing.

Differences in the oral health status and oral hygiene practices according to the extent of post-stroke sequelae

Oral health and hygiene are crucial parameters in stroke patients. However, few studies have evaluated the oral health status and oral hygiene practices according to the level of function in stroke patients. The aim of this study was to evaluate the oral health status and oral hygiene practices according to ambulation and personal hygiene levels in patients with stroke. Data from the fifth (2010-2012) and sixth (2013-2015) editions of the Korea National Health and Nutrition Examination Survey (KNHANES) for 6 years were combined. A total of 700 stroke patients were enrolled in our study. Subjective oral health was significantly poorer in patients who experienced a moderate problem with walking (adjusted OR [AOR], 1.68; 95% CI, 1.21-2.33) and bed-bound patients (AOR, 2.92; 95% CI, 1.01-8.44) than in patients who could walk without difficulty. Patients who were unable to bathe or dress independently exhibited a significantly higher risk of dental caries than did those who could perform the same activities unassisted. The probability of brushing teeth ≥2 times daily was 69% lower in bed-bound patients (AOR, 0.31; 95% CI, 0.11-0.87) than in patients who could walk without difficulty and 76% lower in patients who were unable to bathe or dress independently (AOR, 0.24; 95% CI, 0.09-0.62) than in those who could perform the same activities without difficulty. There were differences in oral health status and oral hygiene practices, according to ambulation level and functional independence, in the stroke patient group. These results indicate the need for oral care for stroke patients who exhibit ambulatory and functional limitations.

Hydro-nanofibrous mesh deep cell penetration: a strategy based on peeling of electrospun coaxial nanofibers

A two-step strategy for coaxial electrospinning and postelectrospinning is an effective method for fabricating superfine nanofibers composed of highly swellable hydrogels. Alginate and poly(ε-caprolactone) [PCL] were coelectrospun via fibrous meshes with a coaxial nozzle; alginate at the core was subsequently cross-linked in calcium chloride solution. The PCL sheath was removed from the meshes by repeated organic-phase washing. The peeling process was monitored by scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry, and the complete removal of the PCL outer layers was confirmed by the thinning of the fiber volume. The obtained alginate hydronanofiber showed extreme water-swellability and mass erosion depending on the degree of cross-linking. We also measured the nanoscale and macroscale mechanical properties of a single nanofiber and of the whole mesh by atomic force microscopy and rheometry. Quantitative analysis of nanomechanical properties indicated that the hydronanofiber with higher cross-linking density had higher stiffness and Derjaguin-Müller-Toporov modulus. Cells laid on the mesh and the vertical infiltration distance were visualized and quantified by confocal laser scanning microscopy. Cells on the mesh with higher cross-linking density infiltrated deeply to the bottom of the mesh. Thus, hydrogel-like nanofibrous meshes are versatile matrices allowing for deep infiltration of cells throughout the mesh via manipulation of the mechanical properties of the nanofiber.

Effect of Changes in Body Mass Index on Cardiovascular Outcomes in Kidney Transplant Recipients

BACKGROUND

A higher body mass index (BMI) before kidney transplantation (KT) is associated with increased mortality and allograft loss in kidney transplant recipients (KTRs). However, the effect of changes in BMI after KT on these outcomes remains uncertain. The aim of this study was to investigate the effect of baseline BMI and changes in BMI on clinical outcomes in KTRs.

METHODS

A total of 869 KTRs were enrolled from a multicenter observational cohort study from 2012 to 2015. Patients were divided into low and high BMI groups before KT based on a BMI cutoff point of 23 kg/m². Differences in acute rejection and cardiovascular disease (CVD) between the 2 groups were analyzed. In addition, clinical outcomes across the 4 BMI groups divided by BMI change 1 year after KT were compared. Associations between BMI change and laboratory findings were also evaluated.

RESULTS

Patients with a higher BMI before KT showed significantly increased CVD after KT (P = .027) compared with patients with a lower BMI. However, among the KTRs with a higher baseline BMI, only persistently higher BMI was associated with increased CVD during the follow-up period (P = .003). Patients with persistently higher BMI had significantly decreased high-density lipoprotein cholesterol and increased hemoglobin, triglyceride, and hemoglobin A1c levels. Baseline BMI and post-transplantation change in BMI were not related to acute rejection in KTRs.

CONCLUSIONS

BMI in the 1st year after KT as well as baseline BMI were associated with CVD in KTRs. More careful monitoring of obese KTRs who do not undergo a reduction in BMI after KT is required.

Differential Expression Patterns of Irf3 and Irf7 in Pediatric Lymphoid Disorders

Interferon regulatory factors (IRFs) are multifunctional transcriptional factors. To define the role of IRFs in lymphoid disorders, we determined the expression patterns of IRF3 and IRF7 by immunohistochemistry in 5 normal lymph nodes, 12 reactive hyperplastic lymph nodes, and 27 pediatric lymphomas. IRF3 was prominently expressed in the nuclei of the histiocytes, and was expressed very weakly in the cytoplasm of most of the lymphocytes of the normal lymph nodes. However, IRF7 was expressed strongly in the nuclei of over 50% of the lymphocytes throughout the normal lymph nodes, but the histiocytes and fibroblasts were spared. In the reactive hyperplastic lymph nodes, the number of IRF3- and IRF7-positive cells in the nuclei was elevated. In the lymphomas, the number of IRF3-positive cells in the nucleus appeared to have decreased, and the cells were scattered throughout the lymphoma tissue in no specific pattern. However, in most cases the number of IRF7-positive cells was elevated.

These results suggested that IRF3 was activated principally in the histiocytes and T cells under inflammatory conditions, but IRF3 activation was attenuated in cases of lymphoma. However, the number of IRF7-positive cells was found to be elevated in the reactive hyperplastic lymph nodes and pediatric lymphoma.

Simultaneous Subtotal Pancreatectomy and Streptozotocin Injection for Diabetes Modeling in Cynomolgus Monkeys

BACKGROUND

In an experimental animal model of islet transplantation, stable induction of insulin-dependent diabetes mellitus (IDDM) and islet isolation from donor pancreas are essential. Total pancreatectomy for IDDM induction and islet procurement in nonhuman primates leads to unwanted loss of exocrine function and may lead to morbidities associated with IDDM.

METHODS

IDDM induction with streptozotocin (STZ) is associated with drug toxicity of STZ and necessitates the killing of another animal for islet procurement. In this study, we performed a subtotal pancreatectomy combined with reduced STZ injection to induce IDDM and procure islets in a nonhuman primate model.

RESULTS

Twelve cynomolgus monkeys received low-dose STZ injections (60 mg/kg) simultaneously with subtotal pancreatectomy. All monkeys recovered from the procedure without complications. IDDM was induced in the animals. 57,691 ± 16,050 islets were isolated from the resected pancreas and transplanted into other monkeys.

CONCLUSIONS

Simultaneous subtotal pancreatectomy and low-dose STZ injection represent an effective and safe method to create an animal model of insulin dependence diabetes, while at the same time providing sufficient amounts of fresh islet cells for allotransplantation without requiring killing of additional animals.

Predictive Factors of Renal Adaptation After Nephrectomy in Kidney Donors

BACKGROUND

Despite compensatory hyperfiltration in remaining nephrons following donor nephrectomy, some donors show impaired renal adaptation and low estimated glomerular filtration rate (eGFR). We investigated the factors predicting early renal adaptation after nephrectomy and identified kidney donors at risk of inadequate renal adaptation.

METHODS

A total of 265 living kidney donors from 2010 to 2013 were retrospectively analyzed. Renal function was serially followed for 6 months after the operation. Regression analyses were performed to identify the independent predictors of low eGFR (eGFR <60 mL/min/1.73 m²) and impaired renal adaptation (%Modification of Diet in Renal Disease [MDRD] <66% of baseline eGFR).

RESULTS

A total of 148 donors belonged to the low eGFR group, and changes in eGFR (ΔeGFR) at postoperative (PO) 1 day and 1 month were identified as independent predictors of low eGFR. Impaired renal adaptation was related to age, ΔeGFR PO 2-3 days, and ΔeGFR PO 1 month. Early renal adaptation was associated with age, male gender, and residual kidney computerized tomography angiography (CTA) volume. The best sensitivity and specificity were obtained with a cutoff value of ΔeGFR 31 at PO 1 day and 1 month for predicting low eGFR and with a value of ΔeGFR 27 at PO 2-3 days and 1 month for predicting impaired renal adaptation.

CONCLUSIONS

Our study showed that the degree of early renal adaptation determines subsequent renal function in kidney donors. Closer monitoring and management may be required in old or male donors with small residual CTA kidney volume as well as donors with persistent ΔeGFR >27 within 1 month of nephrectomy.

Descending necrotizing mediastinitis after a trigger point injection

Descending necrotizing mediastinitis (DNM) is a rare form of mediastinal infection. Most cases are associated with esophageal rupture. DNM after a trigger point injection in the upper trapezius has not been described previously. We present a case of DNM after a trigger point injection in the upper trapezius. A 70-year-old man visited the emergency department with chest discomfort and fever after a trigger point injection in the left upper trapezius. Chest computed tomography showed evidence of DNM, and antibiotic therapy was immediately administered intravenously. Because of the risk of sudden death, poor prognosis due to underlying disease, and his age, he declined surgical treatment and died of septic shock. Although trigger point injections are generally considered safe, caution should be used in patients with an underlying disease or in the elderly. Early diagnosis, broad-spectrum antibiotics, and aggressive surgical management are essential to improve the prognosis.

Major Histocompatibilty Complex-Restricted Adaptive Immune Responses to CT26 Colon Cancer Cell Line in Mixed Allogeneic Chimera

BACKGROUND

Although the induction of mixed allogeneic chimera shows promising clinical tolerance results in organ transplantation, its clinical relevance as an anti-cancer therapy is yet unknown. We introduced a mixed allogenic chimera setting with the use of a murine colon cancer cell line, CT26, by performing double bone marrow transplantation.

METHODS

We analyzed donor- and recipient-restricted anti-cancer T-cell responses, and phenotypes of subpopulations of T cells. The protocol involves challenging 1 × 10⁵ cells of CT26 cells intra-hepatically on day 50 after bone marrow transplantation, and, by use of CT26 lysates and an H-2L^d-restricted AH1 pentamer, flow cytometric analysis was performed to detect the generation of cancer-specific CD4⁺ and CD8⁺ T cells at various time points.

RESULTS

We found that immunocompetence against tumors depends heavily on cancer-specific CD8⁺ T-cell responses in a major histocompatibility complex-restricted manner; the evidence was further supported by the increase of interferon-γ-secreting CD4⁺ T cells. Moreover, we demonstrated that during the effector immune response to CT26 cancer challenge, there was a presence of central memory cells (CD62L^hiCCR7⁺) as well as effector memory cells (CD62L^loCCR7^-). Moreover, mixed allogeneic chimeras (BALB/c to C56BL/6 or vice versa) showed similar or heightened immune responses to CT26 cells compared with that of wild-type mice.

CONCLUSIONS

Our results suggest that the responses of primary immunocompetency and of pre-existing memory T cells against allogeneic cancer are sustained and preserved long-term in a mixed allogeneic chimeric environment.

Anakinra Protects Against Serum Deprivation-Induced Inflammation and Functional Derangement in Islets Isolated From Nonhuman Primates

We investigated whether serum deprivation induces islet amyloid polypeptide (IAPP) oligomer accumulation and/or a proinflammatory response and, if so, whether the addition of interleukin (IL)-1 receptor antagonist to the culture medium can relieve the proinflammatory response during serum-deprived culture of nonhuman primate (NHP) islets. After culture in medium with and without Ana under serum-deprived culture conditions, IAPP oligomer/amyloid accumulation, in vitro viability, islet function, cytokine secretion, and posttransplantation outcome in streptozotocin-induced diabetic nude mice were determined in islets isolated from heterozygote human IAPP transgenic (hIAPP^+/- ) mice and/or NHP islets. Serum deprivation induced accumulation of IAPP oligomer, but not amyloid, in NHP islets. Anakinra (Ana) protected islets from the serum deprivation-induced impairment of in vitro viability and glucose-stimulated insulin secretion and attenuated serum deprivation-induced caspase-1 activation, transcription, and secretion of IL-1β, IL-6, and tumor necrosis factor-α in hIAPP^+/- mice and NHP islets. Supplementation of medium with Ana during serum-deprived culture also improved posttransplantation in vivo outcomes of NHP islets. In conclusion, serum deprivation induced accumulation of IAPP oligomers and proinflammatory responses in cultured isolated islets. Supplementation of the culture medium with Ana attenuated the functional impairment and proinflammatory responses induced by serum deprivation in ex vivo culture of NHP islets.

Health-Related Quality of Life of Kidney Transplantation Patients: Results from the KoreaN Cohort Study for Outcome in Patients With Kidney Transplantation (KNOW-KT) Study

BACKGROUND

As patient and graft survival rates have been improving after kidney transplantation, health-related quality of life (HR-QOL) has become an important indicator of effective treatment. This study aimed to evaluate changes in HR-QOL after kidney transplantation.

MATERIALS AND METHODS

The KoreaN cohort study for Outcome in patients With Kidney Transplantation (KNOW-KT) is a multicenter, observational, 9-year, cohort study. The HR-QOL of patients in the KNOW-KT study was assessed before transplantation and 2 years after transplantation using the Kidney Disease Quality of Life Short Form (KDQOL-SF) including chronic kidney disease targeted area and the Medical Outcome Study 36-item Short Form Health Survey (SF-36). Multivariate linear regression was used to identify significant factors associated with follow-up QOL scores.

RESULTS

A total of 175 patients from 8 centers were analyzed. All QOL scores including the total QOL score, chronic kidney disease targeted score, and SF-36 at the 2-year follow-up were significantly increased compared to baseline values. Both physical and mental scale scores were improved after transplantation.

CONCLUSION

The QOL scores for both the mental and physical scales were improved at 2 years after kidney transplantation. High glomerular filtration rate at 2 years, high baseline QOL score, and low body mass index were associated with good follow-up QOL scores. Kidney transplantation for an Asian population with end-stage renal disease can result in better QOL as well as better patient and graft survival.

Short-Term Outcomes of ABO-Incompatible Living Donor Kidney Transplantation With Uniform Protocol: Significance of Baseline Anti-ABO Titer

Antibody-mediated rejection (AMR) is one of the major causes of poor outcomes in ABO-incompatible kidney transplantation (ABOi KT). Studies investigating AMR risk factors found that anti-ABO titer is a major issue. However, the significance of antibody titer has been debated. This retrospective study analyzed AMR risk factors in 59 patients who underwent ABOi KT between August 2010 and January 2015. We also analyzed AMR risk factors in recipients with high anti-ABO baseline titers (≥1:64 on dithiothreitol at 37°C phase or ≥1:256 on antihuman globulin phase). The 2-year patient survival rate was 95.8%, and the 2-year graft survival rate was 94.9%. Nine patients (15.3%) experienced clinical (6 of 59 [10.2%]) or subclinical (3 of 59 [5.1%]) AMR. One patient experienced graft loss from hyperacute rejection. AMR risk factor analysis revealed that baseline antibody titer was associated with incidence of AMR. In patients with high baseline titers, low doses of rituximab (200-mg single-dose), an antibody against CD20, was predictive for AMR. Six patients who received pretransplant intravenous immunoglobulin did not experience AMR even when they had high baseline antibody titers. Our results indicate that a high baseline antibody titer affected the incidence of AMR. ABOi KT candidates with high baseline titers need to undergo an intensified preconditioning protocol, including high-dose rituximab (375 mg/m(2)) and intravenous immunoglobulin.

Volume of hospital is important for the prognosis of high-risk patients with nonvariceal upper gastrointestinal bleeding (NVUGIB)

BACKGROUND AND AIM

Nonvariceal upper gastrointestinal bleeding (NVUGIB) is a potentially life-threatening hospital emergency requiring hemodynamic stabilization and resuscitation. This study is carried out to determine whether hospital volume can influence outcome in patients with NVUGIB.

METHOD

This is a retrospective study with a prospective cohort database (KCT 0000514. cris.nih.go.kr). Eight teaching hospitals were divided into two different groups: high-volume centers (HVC, ≥60 NVUGIB patients/year, four clinics) and low-volume centers (LVC, <60 NVUGIB patients/year, four clinics). Baseline characteristics of patients, risk stratification, and outcomes between hospitals of different volumes were compared. From February 2011 to December 2013, a total of 1584 NVUGIB patients enrolled in eight clinics were retrospectively reviewed. The main outcome measurements consisted of continuous bleeding after treatment, re-bleeding, necessity for surgical/other retreatments, and death within 30 days.

RESULTS

Similar baseline characters for patients were observed in both groups. There was a significant difference in the incidence of poor outcome between the HVC and LVC groups (9.06 vs. 13.69%, P = 0.014). The incidence rate of poor outcome in high-risk patients (Rockall score ≥8) in HVC was lower than that in high-risk patients in LVC (16.07 vs. 26.92%, P = 0.048); however, there was no significant difference in poor outcome in the lower-risk patients in either group (8.72 vs. 10.42%, P = 0.370).

CONCLUSIONS

Significant correlation between hospital volume and outcome in NVUGIB patients was observed. Referral to HVC for the management of high-risk NVUGIB patients should be considered in clinical practice.

Analysis on sports and recreation activity-related eye injuries presenting to the Emergency Department

AIM

To investigate the incidence and general characteristics of sports-related eye injuries in patients visiting the Emergency Department.

METHODS

A cross-sectional, multi-center, observational study. Patients with an injured eye who visited the Emergency Department at one of nine hospitals in Korea were enrolled. All data were prospectively collected between March and September 2010 using a questionnaire. Eye injuries that occurred during risky sports were examined by gender and age. Additionally, the rate of open globe injuries that occurred with and without protective eyewear was examined for each activity. Continuous variables were compared using Student's t-test and categorical variables were compared using Chi-square test.

RESULTS

A total of 446 patients had sports-related eye injuries. Teenagers (10-19 years old) and young adults (20-29 years old) had the most eye injuries. Eye injuries accounted for 0.2% of Emergency Department patients. Baseball was the most common cause of sports-related eye injuries, followed by soccer and hiking. Protective gear was worn by 9.4% of all patients. Patients that were 30-39 years of age had the highest rate of protective gear use, followed by patients that were 40-49 years of age. The proportion of sports-related eye injuries that were open-globe injuries was highest for soccer and hiking.

CONCLUSION

Although injuries were most common in patients below the age of 10 years, these patients had the lowest rate of protective eyewear use. Injuries in adults over 40 years of age most commonly occurred during hiking, but the rate of protective eyewear use was low. Young athletes should be educated on and provided with protective eyewear and policies protective gear use should be established. For older adults, eye protection should be encouraged, especially during hiking.

Application of physiologically based pharmacokinetic modeling in predicting drug-drug interactions for sarpogrelate hydrochloride in humans

Background

Evaluating the potential risk of metabolic drug–drug interactions (DDIs) is clinically important.

Objective

To develop a physiologically based pharmacokinetic (PBPK) model for sarpogrelate hydrochloride and its active metabolite, (R,S)-1-{2-[2-(3-methoxyphenyl)ethyl]-phenoxy}-3-(dimethylamino)-2-propanol (M-1), in order to predict DDIs between sarpogrelate and the clinically relevant cytochrome P450 (CYP) 2D6 substrates, metoprolol, desipramine, dextromethorphan, imipramine, and tolterodine.

Methods

The PBPK model was developed, incorporating the physicochemical and pharmacokinetic properties of sarpogrelate hydrochloride, and M-1 based on the findings from in vitro and in vivo studies. Subsequently, the model was verified by comparing the predicted concentration-time profiles and pharmacokinetic parameters of sarpogrelate and M-1 to the observed clinical data. Finally, the verified model was used to simulate clinical DDIs between sarpogrelate hydrochloride and sensitive CYP2D6 substrates. The predictive performance of the model was assessed by comparing predicted results to observed data after coadministering sarpogrelate hydrochloride and metoprolol.

Results

The developed PBPK model accurately predicted sarpogrelate and M-1 plasma concentration profiles after single or multiple doses of sarpogrelate hydrochloride. The simulated ratios of area under the curve and maximum plasma concentration of metoprolol in the presence of sarpogrelate hydrochloride to baseline were in good agreement with the observed ratios. The predicted fold-increases in the area under the curve ratios of metoprolol, desipramine, imipramine, dextromethorphan, and tolterodine following single and multiple sarpogrelate hydrochloride oral doses were within the range of ≥1.25, but <2-fold, indicating that sarpogrelate hydrochloride is a weak inhibitor of CYP2D6 in vivo. Collectively, the predicted low DDIs suggest that sarpogrelate hydrochloride has limited potential for causing significant DDIs associated with CYP2D6 inhibition.

Conclusion

This study demonstrated the feasibility of applying the PBPK approach to predicting the DDI potential between sarpogrelate hydrochloride and drugs metabolized by CYP2D6. Therefore, it would be beneficial in designing and optimizing clinical DDI studies using sarpogrelate as an in vivo CYP2D6 inhibitor.

The Introduction of Human Heme Oxygenase-1 and Soluble Tumor Necrosis Factor-α Receptor Type I With Human IgG1 Fc in Porcine Islets Prolongs Islet Xenograft Survival in Humanized Mice

Apoptosis during engraftment and inflammation induce poor islet xenograft survival. We aimed to determine whether overexpression of human heme oxygenase-1 (HO-1) or soluble tumor necrosis factor-α receptor type I with human IgG1 Fc (sTNF-αR-Fc) in porcine islets could improve islet xenograft survival. Adult porcine islets were transduced with adenovirus containing human HO-1, sTNF-αR-Fc, sTNF-αR-Fc/HO-1 or green fluorescent protein (control). Humanized mice were generated by injecting human cord blood-derived CD34(+) stem cells into NOD-scid-IL-2Rγ(null) mice. Both HO-1 and sTNF-αR-Fc reduced islet apoptosis under in vitro hypoxia or cytokine stimuli and suppressed RANTES induction without compromising insulin secretion. Introduction of either gene into islets prolonged islet xenograft survival in pig-to-humanized mice transplantation. The sTNF-αR-Fc/HO-1 group showed the best glucose tolerance. Target genes were successfully expressed in islet xenografts. Perigraft infiltration of macrophages and T cells was suppressed with decreased expression of RANTES, tumor necrosis factor-α and IL-6 in treatment groups; however, frequency of pig-specific interferon-γ-producing T cells was not decreased, and humoral response was not significant in any group. Early apoptosis of islet cells was suppressed in the treatment groups. In conclusion, overexpression of HO-1 or sTNF-αR-Fc in porcine islets improved islet xenograft survival by suppressing both apoptosis and inflammation. HO-1 or sTNF-αR-Fc transgenic pigs have potential for islet xenotransplantation.

A single center, open-label, randomized pilot study to evaluate the safety and efficacy of tacrolimus modified release, Advagraf, versus tacrolimus twice daily, Prograf, in stable renal recipients (single)

BACKGROUND

Compliance with immunosuppressive regimens may affect clinical outcomes in renal transplant recipients. The aim of this study was to assess the safety and efficacy of standard-dose tacrolimus modified-release (TAC-MR) once daily versus tacrolimus (TAC) twice daily in stable renal transplant recipients.

METHODS

Ninety-nine stable renal transplant recipients were randomized to receive standard-dose tacrolimus twice daily or standard-dose modified-release tacrolimus once daily on a 1:1 (mg:mg) basis. The primary end point was the incidence of adverse events (AEs) in both groups. Secondary end points included biopsy-proven acute rejection, graft survival, patient survival, clinical indicators, and change in score of questionnaire.

RESULTS

The incidence of AEs was not different between the TAC and TAC-MR groups (56.0% vs 53.1%, P > .05). There were no significant differences in mean calculated glomerular filtration rate, blood pressure, glycosylated hemoglobulin (HbA1c), blood concentration of tacrolimus, and drug compliance. The scores of all items in the 36-item short form health survey (SF-36) were not different between groups, except for vitality. With respect to the subject questionnaire, there was no difference in question scores between the two treatment groups.

CONCLUSION

A regimen of TAC-MR once daily can be considered as an effective and safe alternative formulation of tacrolimus in stable renal transplant patients.

Improved oral absorption of cilostazol via sulfonate salt formation with mesylate and besylate

Objective

Cilostazol is a Biopharmaceutical Classification System class II drug with low solubility and high permeability, so its oral absorption is variable and incomplete. The aim of this study was to prepare two sulfonate salts of cilostazol to increase the dissolution and hence the oral bioavailability of cilostazol.

Methods

Cilostazol mesylate and cilostazol besylate were synthesized from cilostazol by acid addition reaction with methane sulfonic acid and benzene sulfonic acid, respectively. The salt preparations were characterized by nuclear magnetic resonance spectroscopy. The water contents, hygroscopicity, stress stability, and photostability of the two cilostazol salts were also determined. The dissolution profiles in various pH conditions and pharmacokinetic studies in rats were compared with those of cilostazol-free base.

Results

The two cilostazol salts exhibited good physicochemical properties, such as nonhygroscopicity, stress stability, and photostability, which make it suitable for the preparation of pharmaceutical formulations. Both cilostazol mesylate and cilostazol besylate showed significantly improved dissolution rate and extent of drug release in the pH range 1.2–6.8 compared to the cilostazol-free base. In addition, after oral administration to rats, cilostazol mesylate and cilostazol besylate showed increases in C_max and AUC_t of approximately 3.65- and 2.87-fold and 3.88- and 2.94-fold, respectively, compared to cilostazol-free base.

Conclusion

This study showed that two novel salts of cilostazol, such as cilostazol mesylate and cilostazol besylate, could be used to enhance its oral absorption. The findings warrant further preclinical and clinical studies on cilostazol mesylate and cilostazol besylate at doses lower than the usually recommended dosage, so that it can be established as an alternative to the marketed cilostazol tablet.

Pharmacokinetic properties of trifolirhizin, (-)-maackiain, (-)-sophoranone and 2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran after intravenous and oral administration of Sophora tonkinensis extract in rats

1. SKI3301, a standardized dried 50% ethanolic extracts of Sophora tonkinensis, contains four marker compounds (trifolirhizin, TF; (-)-maackiain, Maack; (-)-sophoranone, SPN, and (2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran, ABF), is being developed as an herbal medicine for the treatment of asthma in Korea. This study investigates the pharmacokinetic properties of SKI3301 extract in rats. 2. The dose-proportional AUCs suggest linear pharmacokinetics of TF, Maack, SPN and ABF in the SKI3301 extract intravenous dose range of 5-20 mg/kg. After the oral administration of 200-1000 mg/kg of the extract, TF and Maack exhibited non-linearity due to the saturation of gastrointestinal absorption. However, linear pharmacokinetics of SPN and ABF were observed. 3. The absorptions of TF, Maack, SPN and ABF in the extract were increased relative to those of the respective pure forms due to the increased solubility and/or the decreased metabolism by other components in the SKI3301 extract. 4. No accumulation was observed after multiple dosing, and the steady-state pharmacokinetics of TF, Maack, SPN and ABF were not significantly different from those after a single oral administration of the extract. 5. The pharmacokinetics of TF, SPN and ABF were not significantly different between male and female rats after oral administration of the extract, but a significant gender difference in the pharmacokinetics of Maack in rats was observed. 6. Our findings may help to comprehensively elucidate the pharmacokinetic characteristics of TF, Maack, SPN and ABF and provide useful information for the clinical application of SKI3301 extract.

Development and validation of a liquid chromatography with tandem mass spectrometry method for the quantification of vitisin B in rat plasma and urine

A new, rapid, and sensitive liquid chromatography with tandem mass spectrometry method was developed for the determination of vitisin B and validated in rat plasma and urine using carbamazepine as an internal standard. The plasma (0.05 mL) or urine (0.2 mL) samples were extracted by liquid-liquid extraction with ethyl acetate and separated on an Eclipse Plus C18 column (100 × 4.6 mm, 3.5 μm) with a mobile phase consisting of acetonitrile and 0.1% formic acid water (60:40, v/v) at a flow rate of 0.7 mL/min. Detection and quantification were performed by mass spectrometry in selected reaction-monitoring mode with positive electrospray ionization. The calibration curves were recovered over the concentration ranges of 10-5000 ng/mL (correlation coefficients, r≥0.9833) in plasma and 5-2500 ng/mL (r≥0.9977) in urine, respectively. All validation data, including the specificity, precision, accuracy, recovery, and stability, conformed to the acceptance requirements. No matrix effects were observed. The developed method was successfully applied to pharmacokinetic studies of vitisin B following intravenous administration of 0.5 and 1 mg/kg and intraperitoneal injection of 5, 10, and 25 mg/kg to rats. This is the first report on the pharmacokinetic properties of vitisin B. The results provide a meaningful basis to evaluate preclinical or clinical applications of vitisin B.

Adult porcine islet isolation using a ductal preservation method and purification with a density gradient composed of histidine-tryptophan-ketoglutarate solution and iodixanol

BACKGROUND

Given the fragility of adult porcine islets, reduction of shearing stress in islet purification using histidine-tryptophan-ketoglutarate (HTK) solution and iodixanol could be an effective strategy. We examined the effect of ductal preservation with HTK solution and an islet purification protocol that utilizes HTK solution and iodixanol in adult porcine islet isolation.

METHODS

Islets were isolated with a modified Ricordi method using adult Prestige World Genetics (PWG) and Yucatan pigs. The discontinuous density gradient was composed of either HTK solution/iodixanol (n = 23, iodixanol group) or Hank's balanced salt solution (HBSS)/Ficoll (n = 17, Ficoll group). In the iodixanol group, ductal injection of HTK solution was performed before purification.

RESULTS

In PWG pigs, significantly higher islet yield after purification (3480 ± 214.2 islet equivalent [IEQ]/g, P = .003) and higher recovery rate (85.45% ± 3.49%, P = .0043) were obtained from the HTK/iodixanol group as compared to the HBSS/Ficoll group (1905 ± 323.2 IEQ/g, and 67.22% ± 4.77%, respectively). Similar results were obtained in Yucatan pigs with greater body weight.

CONCLUSION

Ductal preservation and iodixanol-based islet purification using HTK solution improved the yield of adult porcine islet isolation compared to the conventional method using HBSS and Ficoll. The results of this study support the feasibility of an adult porcine islet isolation protocol using HTK solution and iodixanol, which have the favorable physical properties.

Expanded criteria for liver transplantation in patients with hepatocellular carcinoma

Liver transplantation (LT) is one of the few effective treatment options for hepatocellular carcinoma (HCC). Our aim in this study was to evaluate the risk factors for HCC recurrence and propose new criteria for LT based on pretransplantation findings. One hundred eighty patients who underwent LT for HCC between 2002 and 2008 were reviewed retrospectively. Outcome measures included maximal tumor size and number of tumors revealed by radiological studies before transplantation, demographics, and tumor recurrence. Maximal tumor size >6 cm, >7 tumors, and alpha-fetoprotein (AFP) levels >1000 ng/mL were identified as independent prognostic factors of HCC recurrence in univariate and multivariate analysis. Disease-free survival rate in patients with a maximal tumor size ≤6 cm, ≤7 tumors, and/or AFP levels ≤1000 ng/mL at 1, 3, and 5 years was 97.9%, 91.5%, and 90.0%, respectively, but the 1-, 3-, and 5-year disease-free survival rate of patients who had a maximal tumor size >6 cm, >7 tumors, and/or AFP levels >1000 ng/mL was 61.9%, 47.6%, and 47.6%, respectively (P < .001). In conclusion, LT can improve the survival of patients with advanced HCC if they have a maximal tumor size ≤6 cm, tumor number ≤7, and/or AFP levels ≤1000 ng/mL.

Effect of the potent CYP2D6 inhibitor sarpogrelate on the pharmacokinetics and pharmacodynamics of metoprolol in healthy male Korean volunteers

1. Recently, we demonstrated that sarpogrelate is a potent and selective CYP2D6 inhibitor in vitro. Here, we evaluated the effect of sarpogrelate on the pharmacokinetics and pharmacodynamics of metoprolol in healthy subjects. 2. Nine healthy male subjects genotyped for CYP2D6*1/*1 or *1/*2 were included in an open-label, randomized, three treatment-period and crossover study. A single oral dose of metoprolol (100 mg) was administered with water (treatment A) and sarpogrelate (100 mg bid.; a total dose of 200 mg and treatment B), or after pretreatment of sarpogrelate for three days (100 mg tid.; treatment C). Plasma levels of metoprolol and α-hydroxymetoprolol were determined using a validated LC-MS/MS method. Changes in heart rate and blood pressure were monitored as pharmacodynamic responses to metoprolol. 3. Metoprolol was well tolerated in the three treatment groups. In treatment B and C groups, the AUCt of metoprolol increased by 53% (GMR, 1.53; 90% CI, 1.17-2.31) and by 51% (1.51; 1.17-2.31), respectively. Similar patterns were observed for the increase in Cmax of metoprolol by sarpogrelate. However, the pharmacodynamics of metoprolol did not differ significantly among the three treatment groups. 4. Greater systemic exposure to metoprolol after co-administration or pretreatment with sarpogrelate did not result in clinically relevant effects. Co-administration of both agents is well tolerated and can be employed without the need for dose adjustments.

Outcome and current status of therapeutic hypothermia after out-of-hospital cardiac arrest in Korea using data from the Korea Hypothermia Network registry

Objective

Therapeutic hypothermia (TH) has become the standard strategy for reducing brain damage in the postresuscitation period. The aim of this study was to investigate current TH performance and outcomes in out-of-hospital cardiac arrest (OHCA) survivors using data from the Korean Hypothermia Network (KORHN) registry.

Methods

We used the KORHN registry, a web-based multicenter registry that includes 24 participating hospitals throughout the Republic of Korea. Adult comatose OHCA survivors treated with TH between 2007 and 2012 were included. The primary outcomes were neurological outcome at hospital discharge and in-hospital mortality. The secondary outcomes were TH performance and adverse events during TH.

Results

A total of 930 patients were included, of whom 556 (59.8%) survived to discharge and 249 (26.8%) were discharged with good neurologic outcomes. The median time from return of spontaneous circulation (ROSC) to the start of TH was 101 minutes (interquartile range [IQR], 46 to 200 minutes). The induction, maintenance, and rewarming durations were 150 minutes (IQR, 80 to 267 minutes), 1,440 minutes (IQR, 1,290 to 1,440 minutes), and 708 minutes (IQR, 420 to 900 minutes), respectively. The time from the ROSC to coronary angiography was 1,045 hours (IQR, 121 to 12,051 hours). Hyperglycemia (46.3%) was the most frequent adverse event.

Conclusion

More than one-quarter of the OHCA survivors (26.8%) were discharged with good neurologic outcomes. TH performance was appropriately managed in terms of the factors related to its timing, including cooling start time and rewarming duration.

Importance of donor-recipient age gradient to the prediction of graft outcome after living donor liver transplantation

PURPOSE

Advanced donor age is a well-known risk factor for poor graft function after living donor liver transplantation (LDLT). In addition, advanced recipient age has a significant impact because of the high prevalence of comorbidities. We investigated the relationship between donor-recipient age gradient (DRAG) and the posttransplant outcomes in LDLT.

METHODS

We included 821 consecutive adult recipients who underwent LDLT from June 1997 to May 2011. According to the value of DRAG, they were divided into 2 groups: Negative years (the donor was younger than the recipient) and positive years (the donor was older than the recipient). These groups were further divided into subgroups (≤-21, -20 to -1, 0 to 20, and ≥21 years). We collected retrospectively patient characteristics, laboratory results, medical and surgical complications, and graft loss.

RESULTS

The positive DRAG group had higher level of posttransplant alkaline phosphatase, but a lower incidence of biliary complications. The negative DRAG group, particularly DRAG ≤ -21 years was associated with the superior 1-, 3-, 5-, and 10-year graft survivals. Recipients with DRAG ≥ 21 showed persistently inferior graft survival during the observation period. In cases of young donors, transplants utilizing lower DRAG seen between young donors and older recipients showed more favorable graft survival than that of young-to-young transplants.

CONCLUSION

This study demonstrated that DRAG and a fixed donor age limit could be significant factors to predict graft survival after LDLT. Patients should carefully consider the worse graft survival if the donor is older than the recipient by ≥20.