Renal Dysfunction in Korean Acute Heart Failure Patients

김장영 대한심장학회 2017 Korean Circulation Journal Vol.47 No.5

돼지 관상동맥 스텐트 재협착 모델에서 Cobalt Alloy와 Stainless Stainless Steel Core® Stent의 비교

김장영,윤정한,정일형,왕희성,안민수,이경훈,유병수,이승환,최경훈,장양수,안재모,류용선 대한심장학회 2005 Korean Circulation Journal Vol.35 No.7

The stent material and thickness may influence the rate of restenosis following coronaryartery stenting. A thin strut cobalt-alloy stent has been developed in an attempt to reduce the restenosisrate, while maintaining the radiopacity and radial strength. The purpose of this study was to compare a stainlesssteel Core?? stent (thickness: 90 μm/HUMED Co. Ltd, Korea) with that of a cobalt alloy Core?? stent (thickness:60 μm/HUMED Co. Ltd, Korea) in a porcine coronary stent restenosis model. Materials and Methods:The cobaltalloy (Co-alloy) and stainless steel (SS) stents were implanted in 24 porcine coronary arteries. Four weeks afterstenting, the pigs were sacrificed after quantitative coronary angiography (QCA). The coronary arteries were perfusion-fixed and stained, and a pathological examination performed by computer-aided histomorphometry. Results:The minimal luminal diameter at 4 weeks was larger in the Co-alloy than the SS group according to the QCA(1.8±0.8 mm vs. 2.7±0.8 mm, p=0.019). The neointimal area was significantly smaller in the Co-alloy thanthe SS group (1.96±0.68 mm2 vs. 0.89±0.27 mm2, p<0.001). The intima/media area ratio was significant lowerin the Co-alloy than the SS group (1.33±0.46 vs. 0.69±0.21, p=0.003). Conclusion:The thin strut cobalt alloyCore?? stent significantly reduces the neointimal formation compared to the stainless steel Core?? stent in a porcinecoronary stent injury model. 기존의 연구에 의하면 스텐트의 재협착의 중요한 요소 중 하나는 스텐트의 구성 물질(material composition), 두께(thickness)이다. Cobalt alloy 소재는 스텐트의 두께를 줄이면서radial force를 유지할 수 있어 스텐트의 내막 증식에 의한재협착을 줄일 수 있을 것으로 생각된다. 연구의 목적은 국내에서 개발된 60 μm두께의 cobalt alloy Core?? 스텐트와 90μm두께의 316 L stainless steel Core?? 스텐트가 돼지 관상동맥의 스텐트 재협착 모델에서 내막증식 억제 효과를 비교하고자 하였다.방 법:스텐트를 각각 12개씩 돼지 관상동맥 혈관(좌전 하행 지 및우 관상동맥)에 스텐트를 삽입하였다. 관상동맥 손상 4주 후에 추적 관상동맥 조영술을 시행하고, 돼지를 희생시킨 후 관상동맥 표본의 조직 병리학적인 특징을 관찰하였다. 결 과: 24개의 스텐트를 성공적으로 삽입하였고, 4주 후의 추적 관찰에서 사망한 돼지는 없었다. 4주 후 희생 전 관상동맥 조영술에서의 최소 혈관 내경은 Co-alloy군이 1.8±0.8 mm와 SS군이 2.7±0.8 mm로 유의한 차이가 있었다(p=0.019). Injury score는 Co-alloy군은 1.14±0.14이고 SS군은 1.19±0.31로 양군의 혈관 손상의 차이는 없었다(p=0.688). 내막 면적은 Co-alloy군 0.89±0.25 mm2, SS stent군 1.96±0.68 mm2로 Co-alloy군이 유의하게 적었다(p<0.001). Intima to media ratio는 Co-alloy군 0.69±0.29, SS군 1.33±0.46로 Co-alloy군이 유의하게 적었다(p=0.003). 결 론:돼지 관상동맥 스텐트 재협착 모델을 이용한 실험에서 60μm두께의 cobalt alloy Core?? 스텐트가 기존의 316L stainless steel Core?? 스텐트보다 유의한 내막의 증식의 억제효과를 보였다.

Announcement: New Deputy Editors of the Journal of Cardiovascular Imaging

김장영 한국심초음파학회 2018 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.26 No.2

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Announcement of New Associate Editors

김장영 한국심초음파학회 2018 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.26 No.3

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Aspirin and Clopidogrel Resistance in Drug Eluting Stent Era

김장영,윤정한 대한심장학회 2007 Korean Circulation Journal Vol.37 No.4

Platelets play a central role in the pathogenesis of atherothrombosis. Dual antiplatelet therapy with clopidogrel plusaspirin has been shown to reduce ischemic events in patients undergoing percutaneous coronary intervention(PCI) and stenting. Although dual antiplatelet therapy reduces the risk of cardiovascular episodes after PCIs, a substantialnumber of incidents continue to occur. Many cardiologists have focused their attention to the relationshipsbetween the interindividual variability of platelet inhibition after aspirin or clopidogrel administration and majorcardiac adverse events such as stent thrombosis. Recent evidence has suggested that “aspirin or clopidogrel resistance”is associated with poor health outcomes (recurrent atherothrombotic events and stent thrombosis) after drugeluting stent (DES) implantation. However, the current clinical guidelines do not support routine screenings for antiplateletresistance because standardized objective screening has not yet been established. Thus, this review describesthe antiplatelet therapy used in PCI and it outlines the mechanism, laboratory tests, clinical impact and treatmentoptions for aspirin and clopidogrel resistance in the DES era. (Korean Circulation J 2007;37:135-147)

Strategy for the Treatment of Clopidogrel Low Responsiveness in Diabetes Mellitus and Stent Implantation

김장영 대한심장학회 2009 Korean Circulation Journal Vol.39 No.11

Platelets play a central role in the pathogenesis of atherothrombosis. 1) Thus, achieving platelet inhibition is an important part of managing patients that have experienced an atherothrombotic event. Dual antiplatelet therapy with clopidogrel plus aspirin has been shown to markedly reduce ischemic events in patients undergoing percutaneous coronary intervention (PCI) and stenting.2) Despite its proven benefit of dual antiplatelet therapy, diabetic patients remain at increased risk of recurrent ischemic events when compared to non-diabetic patients. Recent evidence suggests that diabetic patients are resistant or partially responsive to treatments with a dual antiplatelet effect (especially clopidogrel) which is related to poor clinical outcomes such as stent thrombosis and recurrent atherothrombotic events.3)4) Yang et al.5) previously reported that triple antiplatelet therapy (dual antiplatelet plus cilostazol) results in more potent inhibition of adenosine diphosphase (ADP) induced platelet aggregation than dual antiplatelet therapy in patients with diabetes and drug-eluting stent (DES) implantation. These results suggest that triple antiplatelet therapy is a treatment option for amelioration of low responsiveness to clopidogrel in diabetes mellitus (DM). No treatments of clopidogrel low responsiveness in DM have been reported to date. An initial approach to clopidogrel low responsiveness was considered to be a correctable cause of resistance, including hyperglycemia, noncompliance, insulin resistance (metabolic syndrome) and drug interaction. Currently, practical strategies to overcome clopidogrel low responsiveness include 1) addition of cilostazol, 2) increasing the dose of antiplatelet agents, and 3) the use of new drugs, such as prasugrel or ticagrelor. Adding Cilostazol Cilostazol is a potent oral antiplatelet agent with a rapid onset of action that selectively inhibits phosphodiesterase III and increases cyclic adenosine mono phosphate (cAMP) levels in platelets. The increase in cAMP blocks all activating pathways in platelets, including ADP-induced platelet activations.6) An OPTIMUS-2 study7) of randomized crossover platelet function study in patients with type 2 DM and coronary artery disease following dual antiplatelet therapy revealed that the reduced platelet inhibition of P2Y12 signaling can be enhanced by adjunctive treatment with cilostazol when compared with dual antiplatelet therapy. Thus, cilostazol led to significantly increased P2Y12 platelet inhibition, as measured by flow cytometry and light transmission aggregometry. These findings were similar to the results of a study conducted by Yang et al. Several clinical studies have shown that triple antiplatelet therapy has better clinical outcomes than dual antiplatelet therapy in patients undergoing PCI and coronary stenting. Lee et al.8) compared the clinical benefit undergoing PCI between dual antiplatelet therapy (aspirin plus clopidogrel or ticlopidine, group I, n=1,597) and triple antiplatelet therapy (aspirin plus clopidogrel or ticlopidine plus cilostazol, group II, n=1,415) groups. They found that stent thrombosis within 30 days was significantly lower in group II (0.1%) than in group I (0.5%; p=0.024). Additionally, the independent predictors of stent thrombosis were found to be primary stenting {hazard ratio (HR) 7.9, 95% confidence interval (CI) 2.0 to 30.8, p= ○ cc This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Refer to the page 462-466 460·Clopidogrel Low Responsiveness in DM and DES 0.003} and triple therapy (HR 0.12, 95% CI 0.015 to 0.98, p=0.048). They concluded that triple antiplatelet therapy more effectively prevented thrombotic complications after stenting without an increased risk o... Platelets play a central role in the pathogenesis of atherothrombosis. 1) Thus, achieving platelet inhibition is an important part of managing patients that have experienced an atherothrombotic event. Dual antiplatelet therapy with clopidogrel plus aspirin has been shown to markedly reduce ischemic events in patients undergoing percutaneous coronary intervention (PCI) and stenting.2) Despite its proven benefit of dual antiplatelet therapy, diabetic patients remain at increased risk of recurrent ischemic events when compared to non-diabetic patients. Recent evidence suggests that diabetic patients are resistant or partially responsive to treatments with a dual antiplatelet effect (especially clopidogrel) which is related to poor clinical outcomes such as stent thrombosis and recurrent atherothrombotic events.3)4) Yang et al.5) previously reported that triple antiplatelet therapy (dual antiplatelet plus cilostazol) results in more potent inhibition of adenosine diphosphase (ADP) induced platelet aggregation than dual antiplatelet therapy in patients with diabetes and drug-eluting stent (DES) implantation. These results suggest that triple antiplatelet therapy is a treatment option for amelioration of low responsiveness to clopidogrel in diabetes mellitus (DM). No treatments of clopidogrel low responsiveness in DM have been reported to date. An initial approach to clopidogrel low responsiveness was considered to be a correctable cause of resistance, including hyperglycemia, noncompliance, insulin resistance (metabolic syndrome) and drug interaction. Currently, practical strategies to overcome clopidogrel low responsiveness include 1) addition of cilostazol, 2) increasing the dose of antiplatelet agents, and 3) the use of new drugs, such as prasugrel or ticagrelor. Adding Cilostazol Cilostazol is a potent oral antiplatelet agent with a rapid onset of action that selectively inhibits phosphodiesterase III and increases cyclic adenosine mono phosphate (cAMP) levels in platelets. The increase in cAMP blocks all activating pathways in platelets, including ADP-induced platelet activations.6) An OPTIMUS-2 study7) of randomized crossover platelet function study in patients with type 2 DM and coronary artery disease following dual antiplatelet therapy revealed that the reduced platelet inhibition of P2Y12 signaling can be enhanced by adjunctive treatment with cilostazol when compared with dual antiplatelet therapy. Thus, cilostazol led to significantly increased P2Y12 platelet inhibition, as measured by flow cytometry and light transmission aggregometry. These findings were similar to the results of a study conducted by Yang et al. Several clinical studies have shown that triple antiplatelet therapy has better clinical outcomes than dual antiplatelet therapy in patients undergoing PCI and coronary stenting. Lee et al.8) compared the clinical benefit undergoing PCI between dual antiplatelet therapy (aspirin plus clopidogrel or ticlopidine, group I, n=1,597) and triple antiplatelet therapy (aspirin plus clopidogrel or ticlopidine plus cilostazol, group II, n=1,415) groups. They found that stent thrombosis within 30 days was significantly lower in group II (0.1%) than in group I (0.5%; p=0.024). Additionally, the independent predictors of stent thrombosis were found to be primary stenting {hazard ratio (HR) 7.9, 95% confidence interval (CI) 2.0 to 30.8, p= ○ cc This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Refer to the page 462-466 460·Clopidogrel Low Responsiveness in DM and DES 0.003} and triple therapy (HR 0.12, 95% CI 0.015 to 0.98, p=0.048). They concluded that triple antiplatelet therapy more effectively prevented thrombotic complications after stenting without an increased risk of side effects when compared to dual antiplatelet. These bench and clin...

Transradial Coronary Intervention: Comparison of the Left and Right Radial Artery Approach

김장영,윤정한,정일형,왕희승,정현숙,유병수,이승환,최경훈 대한심장학회 2006 Korean Circulation Journal Vol.36 No.12

Background and Objectives:We evaluated the efficacy and safety of the left transradial approach as comparedto the right radial approach when performing transradial coronary intervention. Subjects and Methods:Weperformed the transradial coronary intervention in 711 cases via the left approach (Lt. group) and in 614 casesvia the right approach (Rt. group) for patients with a normal Allen’s test of both arms. We evaluated the proceduralsuccess rate, the crossover rate, the puncture time, the total procedural duration, the fluoroscopy time, theamount of contrast agent used and the local vascular complications of both groups. Results:The baseline clinicaland angiographic profiles were comparable between both groups. The puncture time, the amount of contrast agentused, choice of the guide catheter and local vascular complications were similar for the two groups. There was nodifference in the procedural success rate (Rt. group; 96.4% vs. Lt. group; 96.2%, p=NS). However, there was tendencyfor a higher success rate via radial access for the Lt. group than for the Rt. group (Rt. group; 91.9% vs. Lt.group; 93.5%, p=0.056). The crossover rate was lower for the Lt. group than for the Rt. group (2.7 % vs. 4.6%,respectively; p=0.04). The total procedural time (32.3±15.4. vs. 30.7±17.6 min, respectively; p=0.03) and fluoroscopytime (16.9±12.6 vs. 13.9±7.9 min, respectively; p<0.01) were shorter in the Lt. group. The number ofguide catheters used was higher in the Rt. group compared to the Lt. group (1.21±0.48 vs. 1.08±0.33, respectively;p=0.04). Conclusion:The left radial approach may provide increased procedural efficacy for transradial PCIcompared to the right radial approach along with similar complications. (Korean Circulation J 2006;36:780-785)

고등학교 과학 교실의 건축 계획에 관한 연구

김장영 中央大學校 建設大學院 1994 建設論叢 Vol.7 No.1

심전도와 심근 효소가 정상인 급성 관동맥 증후군에서Ischemia Modified Albumin 측정의 진단적 의의

김장영,최경훈,윤정한,정일형,왕희성,최훈,정현숙,김현,유병수,이승환,어영,황성오 대한심장학회 2005 Korean Circulation Journal Vol.35 No.12

Background and Objectives:In the early phase of acute chest pain, the diagnosis of acute coronary syndrome(ACS) is often difficult to achieve in an emergency department (ED) due to the non-diagnostic ECG and cardiacmarkers. Ischemia modified albumin (IMA) has recently been shown to be a sensitive early biochemical markerof ischemia. The aim of this study was to evaluate the diagnostic value of IMA for the patients with suspectedACS and who have normal ECG/cardiac markers. Subjects and Methods:We enrolled 142 consecutive patientswho presented to the ED due to suspected ACS, and they had a normal EKG and troponin-I/CK-MB within 5hours after the onset of their chest pain. The diagnosis of ACS was based upon the clinical findings, the resultsof serial ECG/troponin and the coronary angiography. The ideal cutoff value of IMA for ACS was calculated bythe receiver operator characteristic (ROC) curve analysis. Results:The ACS was diagnosed in 80/142 (56%).The ROC curve area for the IMA test was 0.77 (CI; 0.70-0.85, p<0.01). At a cutoff value of 98.5 U/mL, thesensitivity, specificity and negative predictive values for ACS were 73%, 75% and 75%, respectively. At a cutoffvalue of 85 U/mL, the sensitivity and specificity and negative predictive values for ACS were 92%, 35% and95%, respectively. Conclusion:IMA might be a useful diagnostic marker of ACS for those patients with normalECG/cardiac markers and who present within 5 hours after the onset of chest pain. 배경 및 목적:급성 흉통으로 조기에 응급실에 내원한 환자에서 심전도 및CK-MB/troponin-I가 정상인 경우 관동맥 증후군을 진단하기 어려운 경우가 흔하다. 최근 소개된 혈청 내 ischemiamodified albumin은 민감한 심근 허혈의 검사법으로 알려지고 있다. 본 연구의 목적은 급성 흉통환자에서 심전도 및CK-MB/troponin-I가 정상이며 급성 관동맥 증후군이 의심되는 환자에서 IMA 측정의 진단적 의의를 알아보고자 하였다방 법:대상환자는 연속적인 급성 흉통 후 5시간 안에 응급실에내원한 환자 중 troponin-I와 CK-MB가 정상이면서 심전도상 허혈의 증거가 없는 142명(평균나이: 58±14세, 남성;56%)을 포함시켰다. 관동맥 증후군의 진단은 내원하여 검사한 연속적인 생화학적 표식자 및 침습적/비침습적 심혈관검사에 의해 전향적으로 분석하였다. ROC커브를 통해 진단적 의의를 조사하였다. 결 과: 대상환자에서 관동맥 증후군은 80예(56%)였다. ROC커브상 IMA의 area under the curve는 0.77(confidence interval,0.70~0.85)이며 통계적으로 유의하였다(p<0.01).IMA치가 98.5 units/mL에서 관동맥 증후군의 민감도, 특이도, 음성 예측도는 각각 73%, 75%, 75였다. IMA치가 85units/mL에서 관동맥 증후군의 민감도, 특이도, 음성 예측도는 각각 92%, 35%, 95%였다. 결 론: 급성 흉통으로 조기에 내원하여 심전도와 CK-MB와 troponin-I이 정상인 환자에서, IMA의 측정은 관동맥 증후군을 예측할 수 있는 유용한 검사임을 시사하였다.

An Efficient Algorithm for Big Data Prediction of Pipelining, Concurrency (PCP) and Parallelism based on TSK Fuzzy Model

김장영,Kim, Jang-Young The Korea Institute of Information and Commucation 2015 한국정보통신학회논문지 Vol.19 No.10

The time to address the exabytes of data has come as the information age accelerates. Big data transfer technology is essential for processing large amounts of data. This paper posits to transfer big data in the optimal conditions by the proposed algorithm for predicting the optimal combination of Pipelining, Concurrency, and Parallelism (PCP), which are major functions of GridFTP. In addition, the author introduced a simple design process of Takagi-Sugeno-Kang (TSK) fuzzy model and designed a model for predicting transfer throughput with optimal combination of Pipelining, Concurrency and Parallelism. Hence, the author evaluated the model of the proposed algorithm and the TSK model to prove the superiority. 정보가 급증함에 따라 큰 용량의 데이터를 전송해야 할 경우가 있다. 빅 데이터 전송 기술은 큰 용량의 데이터를 전송할 때 필요하다. 본 논문은 빅 데이터를 최적화된 속도로 전송하기 위해 GridFTP의 주된 기능인 PCP를 사용하며 또한 PCP 값을 예측하는 알고리즘을 개발한다. 또한, TSK 퍼지 모델을 적용하여 PCP에 따른 최적화된 전송률을 측정하는데 사용된다. 따라서, 제안된 TSK모델을 이용한 PCP 예측 알고리즘은 본 논문의 우수성을 입증한다.