No abstract available.

After coronary stent implantation, neointima formation resembles the wound healing process as it involves the sequential processes of inflammation, granulation, and remodeling. Because antiproliferative drugs and polymers of drug-eluting stents (DESs) delay vascular healing compared with bare metal stents, fibrin deposition can remain long after stent implantation, or inflammation can be excessive. Delayed vascular healing can be associated with adverse clinical outcomes including DES thrombosis or restenosis, and poor endothelization of DES neointima can accelerate neoatherosclerotic change inside the neointima, further contributing to luminal restenosis or neointimal instability. Despite the lack of correlation between pathologic and optical coherence tomography (OCT) findings, OCT assessments of neointima under various circumstances can reveal vascular responses to stent therapy. Homogeneous, heterogeneous, and layered neointima patterns can be recognized by OCT and can change with time. Homogeneous neointima might be associated with better clinical outcomes after DES implantation, whereas non-homogeneous neointima or neoatherosclerotic change can be associated with poorer clinical outcomes. However, limited data are currently available, and further studies are required to comprehensively address these questions.
Coronary Artery Disease ; Drug-Eluting Stents* ; Fibrin ; Inflammation ; Neointima* ; Phenobarbital ; Polymers ; Stents ; Thrombosis ; Tomography, Optical Coherence ; Wound Healing

BACKGROUND: The purpose of this study was to investigate the mechanism of endothelium-dependent and independent responses to endothelins (ETs) in porcine coronary artery. METHODS: The vascular rings of left anterior descending artery or left circumflex artery from 7 pigs were suspended in conventional organ chambers for the measurement of isometric force. To evaluate relaxation responses, vascular rings with endothelium were exposed to ET-1 and ET-3. To evaluate contraction responses, vascular rings with and without endothelium were exposed to ET-1 and ET-3 in the presence or absence of BQ 123 (ET(A) receptor antagonist) or TAK-044 (ET(A) and ET(B) receptor antagonist). RESULTS: Transient relaxation responses of vascular rings occurred after exposure of ET-1 and ET-3. These transient responses disappeared after preincubation with N-nitro-L arginine. There was an increased contractions of vascular rings according to increasing concentration of ET-1 and ET-3. The initial responses were enhanced in vascular rings without endothelium in ET-1 and ET-3. In vascular rings with endothelium, the contraction responses were more reduced in vascular rings with preincubation of BQ 123 than in vascular rings without BQ 123 in ET-1. In vascular rings without endothelium, the contraction responses were more reduced in vascular rings with preincubation of TAK-044 than in vascular rings without TAK-044 in ET-1. CONCLUSION: ET(B) receptor on the endothelium might mediate the transient vasodilator responses to ET-1 and ET-3 through release of nitric oxide in porcine coronary artery. ET(A) and ET(B) receptor on vascular smooth muscle cells might mediate vasoconstrictor responses to ETs.
Arginine ; Arteries ; Coronary Vessels* ; Endothelins* ; Endothelium ; Muscle, Smooth, Vascular ; Nitric Oxide ; Receptors, Endothelin ; Relaxation ; Swine

No abstract available.
Tuberculosis, Miliary*

BACKGROUND: Systemic anticoagulation therapy has been recommended to prevent subacute thrombosis after intracoronary stening. Recent data, however, suggest that antiplatelet therapy might be an effective alternative to anticoagulation therapy. We evaluated the effect of antithrombotic regimens on subacute thrombosis and short-term clinical course after successful implantation of Cordis coronary stent, which is a flexible, balloon expandable, radiopaque tantalum stent. METHOD: Two hundred and seventy-five consecutive patients with 290 lesions were treated with 356 Cordis stents implantation. According to post-stent antithrombotic regimen, patients were divided into three groups ; 165 patients with 175 lesions received aspirin 200mg/day, ticlopidine 500mg/day and warfarin for one month(Group 1), 66 patients with 69 lesions received aspirin and ticlopidine(Group 2) and 44 patients with 46 lesions received aspirin alone(Group 3) after successful Cordis stenting. RESULTS: The overall procidural success rates were 97.7% in group 1, 98.6% in group 2 and 100% in group 3. More than 65 percents of the patients were eligible for elective stenting aspirin, ticlopidine and warfarin, 0% in patients with aspirin and ticlopidine, and 6.8% in patients assigned to the treatment with aspirin alone. CONCLUSION: The Cordis coronary stent is an effective endovascular stent in various clinical indications including unstable angina and acute myocardial infarction. Antiplatelet therapy using aspirin and ticlopidine after successful Cordis coronary stenting is promising alternative to anticoagulation therapy to overcome the drawbacks of stenting. However, post-stent antithrombotic therapy with aspirin alone is associated with significant rate of stent thrombosis.
Angina, Unstable ; Aspirin ; Coronary Artery Disease ; Humans ; Korea* ; Myocardial Infarction ; Stents* ; Tantalum ; Thrombosis ; Ticlopidine ; Warfarin

Interest in the prevalence of patent foramen ovale(PFO) and its relation to embolic stroke has increased with the sophistication of methods for noninvasive cardiac assessment. The effect of foramen ovale closure on the risk for subsequent strokes is promised. A 22-year old woman was presented with sudden onset of cerebral infarct. She had a patent formen ovale, and right to left shunt during the Valsalva maneuver, which was diagnosed by transesophageal contrast echocardiography. Transcatheter closure of PFO was performed with Rashkind PDA umbrella under the guidance of transesophageal echocardiography. Transcatheter closure of PFO can be accomplised with little morbidity and may reduce the risk of embolic episode.
Echocardiography ; Echocardiography, Transesophageal* ; Female ; Foramen Ovale ; Foramen Ovale, Patent* ; Humans ; Prevalence ; Stroke* ; Valsalva Maneuver ; Young Adult

Transcatheter aortic valve implantation (TAVI) has been accepted as one of primary options for treatment of symptomatic severe aortic stenosis. Although TAVI has been predominantly used for patients at high risk or with old age who were not considered optimal candidates for surgical aortic valve replacement (SAVR), its indication is now expanding toward low risk profile and younger age. Many clinical trials are now ongoing to test the possibility of TAVI for use in patients even with uncharted indications who are not eligible for SAVR in current guidelines but may benefit from valve replacement. Current issues including periprocedural safety, long-term adverse events, hemodynamics and durability associated with TAVI should be also solved for expanding use of TAVI. The review presents current status and future directions of TAVI and discusses perspectives in Korea.
Aortic Valve ; Aortic Valve Stenosis ; Hemodynamics ; Humans ; Korea ; Transcatheter Aortic Valve Replacement

Transcatheter aortic valve implantation (TAVI) has been accepted as one of primary options for treatment of symptomatic severe aortic stenosis. Although TAVI has been predominantly used for patients at high risk or with old age who were not considered optimal candidates for surgical aortic valve replacement (SAVR), its indication is now expanding toward low risk profile and younger age. Many clinical trials are now ongoing to test the possibility of TAVI for use in patients even with uncharted indications who are not eligible for SAVR in current guidelines but may benefit from valve replacement. Current issues including periprocedural safety, long-term adverse events, hemodynamics and durability associated with TAVI should be also solved for expanding use of TAVI. The review presents current status and future directions of TAVI and discusses perspectives in Korea.

Optical coherence tomography (OCT) has been recently applied to investigate coronary artery disease in interventional cardiology. Compared to intravascular ultrasound, OCT is able to visualize various vascular structures more clearly with higher resolution. Several validation studies have shown that OCT is more accurate in evaluating neointimal tissue after coronary stent implantation than intravascular ultrasound. Novel findings on OCT evaluation include the detection of strut coverage and the characterization of neointimal tissue in an in-vivo setting. In a previous study, neointimal healing of stent strut was pathologically the most important factor associated with stent thrombosis, a fatal complication, in patients treated with drug-eluting stent (DES). Recently, OCT-defined coverage of a stent strut was proposed to be related with clinical safety in DES-treated patients. Neoatherosclerosis is an atheromatous change of neointimal tissue within the stented segment. Clinical studies using OCT revealed neoatherosclerosis contributed to late-phase luminal narrowing after stent implantation. Like de novo native coronary lesions, the clinical presentation of OCT-derived neoatherosclerosis varied from stable angina to acute coronary syndrome including late stent thrombosis. Thus, early identification of neoatherosclerosis with OCT may predict clinical deterioration in patients treated with coronary stent. Additionally, intravascular OCT evaluation provides additive information about the performance of coronary stent. In the near future, new advances in OCT technology will help reduce complications with stent therapy and accelerating in the study of interventional cardiology.
Atherosclerosis/diagnosis/pathology/ultrasonography ; Coronary Artery Disease/*diagnosis/pathology/ultrasonography ; Humans ; Postoperative Complications/diagnosis/pathology/ultrasonography ; Stents/*adverse effects ; Tomography, Optical Coherence/*methods ; Ultrasonography, Interventional

Coronary heart disease is still highly prevalent worldwide and remains a common cause of mortality. The underlying cause responsible for stable angina is chronic atherosclerotic narrowing of the coronary artery. Most patients with stable angina can be managed with medical treatment with aspirin, beta-blocker, calcium channel blocker (CCB), and nitrate. High-risk patients with previous myocardial infarction (MI), left ventricular dysfunction, and diabetes mellitus should be considered for angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARB) and aggressive statin treatment. Acute coronary syndromes (ACS) are the clinical spectrum that includes unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) and ST-segment elevation myocardial infarction (STEMI). Because the atherosclerotic plaque instability with subsequent rupture and thrombus formation is a primary mechanism of ACS, antiplatelet and antithrombotic agents are essential for the prevention of coronary events. Combination treatment with antiplatelet agents (aspirin, clopidogrel and cilostazol) and anticoagulants, such as unfractionated heparin and low-molecular-weight heparins (LMWH), provides improved efficacy for the secondary prevention of ACS. The main goal of treatment in STEMI is quick recovery of the culprit vessel patency and maintaining sufficient myocardial perfusion. It can be done by thrombolytic therapy or primary coronary angioplasty.
Acute Coronary Syndrome ; Angina, Stable ; Angina, Unstable ; Angioplasty ; Anticoagulants ; Aspirin ; Calcium Channels ; Coronary Artery Disease* ; Coronary Disease ; Coronary Vessels* ; Diabetes Mellitus ; Fibrinolytic Agents ; Heparin ; Heparin, Low-Molecular-Weight ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Mortality ; Myocardial Infarction ; Perfusion ; Plaque, Atherosclerotic ; Platelet Aggregation Inhibitors ; Rupture ; Secondary Prevention ; Thrombolytic Therapy ; Thrombosis ; Ventricular Dysfunction, Left