Publications by authors named "Young-Guk Ko"
Background: The pathophysiology underlying very late drug-eluting stent (DES) thrombosis is not sufficiently understood. Using optical coherence tomography, we investigated characteristics of very late stent thrombosis (VLST) according to different onset times.
Methods And Results: A total of 98 patients from 10 South Korean hospitals who underwent optical coherence tomography for evaluation of very late DES thrombosis were retrospectively included in analyses.
Objective: Stent graft-induced new entry (SINE) has been increasingly observed after thoracic endovascular aortic repair (TEVAR) for Stanford type B aortic dissection. SINE is often life threatening, and reintervention is required. This study investigated risk factors for SINE after TEVAR.
View Article and Find Full Text PDFBackground: We evaluated whether vessel diameters measured by preprocedural computed tomography angiography (CTA) affects the immediate and late outcomes of endovascular therapy for iliac artery diseases.
Methods and results: A total of 254 patients who underwent endovascular treatment for iliac artery diseases were retrospectively evaluated. Minimum vessel diameters were measured on preprocedural CTA images at target lesions, common iliac arteries, and external iliac arteries (EIA).
Purpose: To evaluate the effects of sex and anthropometry on clinical outcomes in patients who underwent percutaneous coronary intervention (PCI).
Materials And Methods: From three randomized trials (REal Safety and Efficacy of 3-month dual antiplatelet Therapy following Endeavor zotarolimus-eluting stent implantation, Impact of intraVascular UltraSound guidance on outcomes of Xience Prime stents in Long lesions, Chronic Total Occlusion InterVention with drUg-eluting Stents), we compared 333 pairs of men and women matched by propensity scores, all of whom underwent intravascular ultrasound (IVUS)-guided PCI for complex lesions.
Results: For 12 months, the incidence of adverse cardiac events, defined as the composite of cardiac death, target lesion-related myocardial infarction, and target lesion revascularization, was not different between women and men (2.
Purpose: To compare the 1-year outcomes of a durable polymer Zotarolimus-eluting stent (ZES) versus a biodegradable polymer Biolimus-eluting stent (BES) in patients undergoing percutaneous coronary intervention.
Materials And Methods: A total of 2083 patients from 2 different registries, 1125 treated with BES in NOBORI registry and 858 received ZES in CONSTANT registry were included in this study. Clinical outcomes were compared with the use of propensity score matching (PSM).
Purpose: To investigate safety and efficacy of hybrid treatment for infected aortic and iliac aneurysms.
Materials And Methods: Between July 2007 and May 2011, hybrid treatment was performed in 6 male patients (mean age, 67.7 y; range, 57-76 y).
This study aimed to develop a new biodegradable stent for peripheral artery disease (PAD) that could provide sufficient radial force to maintain long-term patency and flexibility. All self-expandable hybrid biodegradable stents were designed by using a knitting structure composed of poly-L-lactic acid (PLLA) and nitinol. Four different types of stents were implanted in 20 iliac arteries in 10 mini pigs as follows: a bare-metal stent (BMS) (group 1, = 5), a drug-free hybrid stent (group 2, = 5), a 50% (50 : 100, /) paclitaxel (PTX)/poly-lactide--glycolic acid (PLGA; fast PTX-releasing form) hybrid stent (group 3, = 5), and a 30% (30 : 100, /) PTX/PLGA (slow PTX-releasing form) hybrid stent (group 4, = 5).
View Article and Find Full Text PDFBackground: Although intensive statin therapy is recommended for high risk patients, evidence of its benefit in patients with stable coronary artery disease (CAD) and very low low-density lipoprotein-cholesterol (LDL-C) has been very rare. In this study, we investigated whether higher statin intensity reduces cardiovascular risks in this population.
Methods: In this retrospective study, a total of 5234 patients with stable CAD were screened at three tertiary hospitals in Korea; 449 patients (mean age: 65 years, male: 69%) with LDL-C <80 mg/dL were finally analyzed.
Background: There is general agreement that the optimal duration of dual antiplatelet therapy (DAPT) in patients treated with drug-eluting stents should be individualized. We hypothesized that the extent of coronary artery disease may affect the clinical outcomes of DAPT.
Methods And Results: We pooled patient-level data from 5 large, randomized trials comparing short-term DAPT with prolonged therapy.
Introduction And Objectives: There are limited data on the usefulness of intravascular ultrasound (IVUS) for long coronary lesions treated with second-generation drug-eluting stents. We evaluated IVUS predictors of major adverse cardiovascular events (MACE) 12 months after implantation of everolimus-eluting stents for long coronary lesions.
Methods: A total of 804 patients who underwent both postintervention IVUS examination and long everolimus-eluting stent (≥ 28mm in length) implantation were included from 2 randomized trials.
Objective: Tibial artery calcification (TAC) is associated with increased risk of amputation and mortality in peripheral artery disease. We sought to investigate whether the severity of TAC based on semiquantitative analysis of computed tomography angiography (CTA) can predict outcomes of endovascular therapy in patients with critical limb ischemia.
Methods: We reviewed medical records of 124 patients who underwent lower extremity CTA before intervention.
Objectives: The aim of this study was to evaluate the clinical usefulness of intravascular ultrasound (IVUS)-guided new-generation drug-eluting stent (DES) implantation using a meta-analysis of individual patient-level data from randomized trials.
Background: Published randomized trials that compare IVUS-guided versus angiography-guided new-generation DES implantation are scarce.
Methods: Searches of the MEDLINE, Embase, and Cochrane databases were performed to find randomized trials that compared IVUS-guided versus angiography-guided new-generation DES implantation.
Aims: At present no proven standard treatment for drug-eluting stent (DES) restenosis is available, and the efficacy and safety of everolimus-eluting stent (EES) and zotarolimus-eluting stent (ZES) for DES restenosis are limited. The purpose of this prospective, randomized 9-month intracoronary ultrasound (IVUS) and 3-year clinical follow-up study was to compare the effects of EESs and ZESs on neointima volume and major adverse cardiovascular events (MACEs) such as death, myocardial infarction (MI), target lesion revascularization (TLR) and stent thrombosis in DES restenosis patients.
Methods And Results: Patients were eligible for this study if they were between 40 and 75 years old with in-stent restenosis >50% by quantitative coronary angiographic analysis in DES or within 5 mm of the stent edges with signs of ischaemia.
Background: The optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation has not been established yet. The objectives of this study were to evaluate the optimal duration of DAPT after the DES implantation.
Methods: From three randomized controlled trials investigating DAPT duration after coronary stent implantation, we evaluated the clinical outcomes of short-term (6 months or less) DAPT compared with prolonged DAPT (12 months or more) in 1661 DES-treated pairs matched by propensity scores.
Purpose: Magnetocardiography (MCG) has been proposed as a noninvasive, diagnostic tool for risk-stratifying patients with acute myocardial infarction (AMI). This study evaluated whether MCG predicts long-term prognosis in AMI.
Materials And Methods: In 124 AMI patients (95 males, mean age 60±11 years), including 39 with ST-elevation myocardial infarction, a 64-channel MCG was performed within 2 days after AMI.
Background: Intravascular optical coherence tomography (OCT) imaging provides limited information on the functional assessment of coronary stenosis. We evaluated a new approach to OCT image-based computation modeling, which can be used to estimate the fractional flow reserve (FFR) in patients with intermediate coronary stenosis.
Methods And Results: Ninety-two patients with intermediate diameter stenosis in the left anterior descending artery underwent both FFR measurement with pressure wires and OCT examination.
Purpose: Appropriate animal models of atherosclerotic plaque are crucial to investigating the pathophysiology of atherosclerosis, as well as for the evaluation of the efficacy and safety of vascular devices. We aimed to develop a novel animal model that would be suitable for the study of advanced atherosclerotic lesions in vivo.
Materials And Methods: Atherosclerotic plaque was induced in 24 iliac arteries from 12 rabbits by combining a high cholesterol diet, endothelial denudation, and injection into the vessel wall with either saline (n=5), olive oil (n=6), or inflammatory proteins [n=13, high-mobility group protein B1 (HMGB1) n=8 and tumor necrosis factor (TNF)-α n=5] using a Cricket™ Micro-infusion catheter.
Purpose: The effects of short-term intensive lipid-lowering treatment on coronary plaque composition have not yet been sufficiently evaluated. We investigated the influence of short-term intensive lipid-lowering treatment on quantitative and qualitative changes in plaque components of non-culprit lesions in patients with acute coronary syndrome.
Materials And Methods: This was a prospective, randomized, open-label, single-center trial.
Purpose: To evaluate the ability of coronary computed tomographic angiography (CCTA) to predict the need of coronary revascularization in symptomatic patients with stable angina who were referred to a cardiac catheterization laboratory for coronary revascularization.
Materials And Methods: Pre-angiography CCTA findings were analyzed in 1846 consecutive symptomatic patients with stable angina, who were referred to a cardiac catheterization laboratory at six hospitals and were potential candidates for coronary revascularization between July 2011 and December 2013. The number of patients requiring revascularization was determined based on the severity of coronary stenosis as assessed by CCTA.
Background: The self-expandable COMPLETE™ stent (Medtronic) has greater elasticity, allowing it to regain its shape after the compression force reduces, and has higher trackability, thus is easier to maneuver through tortuous vessels, whereas the balloon-expandable SCUBA™ stent (Medtronic) has higher radial stiffness and can afford more accurate placement without geographic miss, which is important in aortoiliac bifurcation lesions. To date, there have been no randomized control trials comparing efficacy and safety between the self-expanding stent and balloon-expandable stent in advanced atherosclerotic iliac artery disease.
Methods/design: The purpose of our study is to examine primary patency (efficacy) and incidence of stent fracture and geographic miss (safety) between two different major representative stents, the self-expanding nitinol stent (COMPLETE-SE™) and the balloon-expanding cobalt-chromium stent (SCUBA™), in stenotic or occlusive iliac arterial lesions.
We reported a patient with Buerger's disease who presented with critical limb ischemiawith prior recurrent occlusions after multiple surgical and endovascular treatments. Total occlusion of the whole native femoropopliteal and infrapopliteal arteries was observed. The femoropopliteal bypass graft, as well as a stent that was implanted in the mid-popliteal artery, were also occluded.
View Article and Find Full Text PDFObjectives: The aim of this study was to investigate whether a 6-month dual-antiplatelet therapy (DAPT) duration was comparable with a 12-month duration in patients who underwent everolimus-eluting stent implantation.
Background: Well-designed studies that determine optimal DAPT strategies after everolimus-eluting stent implantation are limited.
Methods: A total of 1,400 patients (implanted mean total stent length >45 mm) were randomly assigned to receive 6-month (n = 699) or 12-month (n = 701) DAPT between October 2010 and July 2014 at 20 centers in Korea.
Background: Atrial fibrillation (AF) is considered to be associated with poor clinical outcomes in patients with acute myocardial infarction (AMI). However, it remains uncertain whether transient new-onset AF (NOAF) during AMI has a subsequent increased risk of poor clinical outcomes.
Methods and results: Transient NOAF was defined as AF that developed during AMI without a prior history and not documented for 1 month after discharge.
Although intraprocedural coronary computed tomographic angiography (CCTA) allows for scanning during intervention without relocation of the patient, studies have yet to report on its use during chronic total occlusion (CTO) intervention. Therefore, we investigated the role of CCTA during CTO intervention, particularly whether CCTA could be used to evaluate the location of guidewires. A total of 61 patients scheduled for elective CTO intervention were consecutively enrolled and underwent CCTA and on-site analyses during intervention.
View Article and Find Full Text PDFBackground/aims: Although transient changes in the electrocardiogram (ECG) of patients with stress-induced cardiomyopathy (SCMP) are common, there are little data about ECG changes in patients with SCMP and the clinical implications of these variations.
Methods: We investigated a total of 128 patients (age, 63.2 ± 15.