A Transthoracic Echocardiographic Follow-Up Study After Catheter Ablation of Atrial Fibrillation: Can We Detect Pulmonary Vein Stenosis by Transthoracic Echocardiography?

BACKGROUND AND OBJECTIVES: While pulmonary vein isolation (PVI) is an effective curative procedure for patients with atrial fibrillation (AF), pulmonary vein (PV) stenosis is a potential complication which may lead to symptoms that are often unrecognized. The aim of this study was to compare differences between ablation sites in pulmonary venous flow (PVF) measured by transthoracic Doppler echocardiography (TTE) before and after PVI. SUBJECTS AND METHODS: One hundred five patients (M : F=64 : 41; mean age 56+/-10 years) with paroxysmal AF (n=78) or chronic, persistent AF (n=27) were enrolled. PVI strategies consisted of ostial ablation (n=75; OA group) and antral ablation using an electroanatomic mapping system (n=30; AA group). The ostial diameter was estimated by magnetic resonance imaging (MRI) in patients with PVF > or =110 cm/sec by TTE after PVI. RESULTS: No patient complained of PV stenosis-related symptoms. Changes in mean peak right PV systolic (-6.7+/-28.1 vs. 10.9+/-25.9 cm/sec, p=0.038) and diastolic (-4.1+/-17.0 vs. 9.9+/-25.9 cm/sec, p=0.021) flow velocities were lower in the AA group than in the OA group. Although the change in mean peak systolic flow velocity of the left PV before and after PVI in the AA group was significantly lower than the change in the OA group (-13.4+/-25.1 vs. 9.2+/-22.3 cm/sec, p=0.016), there was no difference in peak diastolic flow velocity. Two patients in the OA group had high PVF velocities (118 cm/sec and 133 cm/sec) on TTE, and their maximum PV stenoses measured by MRI were 62.5% and 50.0%, respectively. CONCLUSION: PV stenosis after PVI could be detected by TTE, and PVI by antral ablation using an electroanatomic mapping system might be safer and more useful for the prevention of PV stenosis.

The Effect of Cilostazol on Stent Thrombosis After Drug-Eluting Stent Implantation

BACKGROUND AND OBJECTIVES: Placement of drug-eluting stents (DES) can be complicated by stent thrombosis; prophylactic antiplatelet therapy has been used to prevent such events. We evaluated the efficacy of cilostazol with regard to stent thrombosis as adjunctive antiplatelet therapy. SUBJECTS AND METHODS: A total of 1,315 patients (846 males, 469 females) were prospectively enrolled and analyzed for the frequency of stent thrombosis. Patients with known risk factors for stent thrombosis, except diabetes and acute coronary syndrome, were excluded from the study. All patients maintained antiplatelet therapy for at least six months. To evaluate the effects of cilostazol as another option for antiplatelet therapy, triple antiplatelet therapy (aspirin+clopidogrel+cilostazol, n=502) was compared to dual antiplatelet therapy (aspirin+clopidogrel, n=813). Six months after stent placement, all patients received only two antiplatelet drugs: treatment either with cilostazol+aspirin (cilostazol group) or clopidogrel+aspirin (clopidogrel group). There were 1,033 patients (396 in cilostazol group and 637 in clopidogrel group) that maintained antiplatelet therapy for at least 12 months and were included in this study. Stent thrombosis was defined and classified according to the definition reported by the Academic Research Consortium (ARC). RESULTS: defined and classified according to the definition reported by the Academic Research Consortium (ARC). RESULTS: During follow-up (561.7+/-251.4 days), 15 patients (1.14%) developed stent thrombosis between day 1 to day 657. Stent thrombosis occurred in seven patients (1.39%) on triple antiplatelet therapy and four patients (0.49%) on dual antiplatelet therapy (p=NS) within the first six months after stenting. Six months and later, after stent implantation, one patient (0.25%) developed stent thrombosis in the cilostazol group, and three (0.47%) in the clopidogrel group (p=NS). CONCLUSION: During the first six months after DES triple antiplatelet therapy may be more effective than dual antiplatelet therapy for the prevention of stent thrombosis. However, after the first six months, dual antiplatelet treatment, with aspirin and cilostazol, may have a better cost benefit ratio for the prevention of stent thrombosis.

Aortic Valve Sclerosis on Echocardiography is a Good Predictor of Coronary Artery Disease in Patients With an Inconclusive Treadmill Exercise Test

BACKGROUND AND OBJECTIVES: The treadmill exercise test (TMT) is used as a first-line test for diagnosing coronary artery disease (CAD). However, the findings of a TMT can be inconclusive, such as incomplete or equivocal results. Aortic valve sclerosis (AVS) is known to be a good predictor of CAD. We determined the usefulness of assessing AVS on 2-dimensional (2D) echocardiography for making the diagnosis of CAD in patients with inconclusive results on a TMT. SUBJECTS AND METHODS: This prospective study involved 165 consecutive patients who underwent a TMT that resulted in inconclusive findings, 2D echocardiography to detect AVS, and coronary angiography to detect CAD. Following echocardiography, AVS was classified as none, mild, or severe. CAD was defined as > or =70% narrowing of the luminal diameter on coronary angiography. RESULTS: CAD was more common in patients with AVS than in patients without AVS (75% vs. 47%, respectively, p<0.01). Multiple logistic regression analysis showed that AVS was the only independent predictor of CAD {odds ratio=8.576; 95% confidence interval (CI), 3.739-19.672}. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the presence of AVS for predicting CAD in a patient with an inconclusive TMT were 62%, 67%, 64%, 75%, and 53%, respectively. During a 1-year clinical follow-up, patients with and without AVS were similar in terms of event-free survival rates. CONCLUSION: If the results of TMT for patients with chest pain on exertion are inconclusive, the presence of AVS on echocardiography is a good predictor of CAD.

A Case of Hemodynamically Unstable Bradycardia after Risperidone Overdose

Risperidone is an atypical antipsychotic medication commonly used to treat psychotic illness, such as schizophrenia. It has strong serotonin and dopamine receptor antagonism and antagonist activity at alpha-adrenergic receptors and histamine receptors. An overdose of risperidone can cause tachycardia, hypertension, hypotension, prolonged QT interval, and bradycardia. Risperidone overdose is rare,but life-threatening. Here, we present the rare case of a 33- year-old woman who ingested risperidone overdose for the purposes of suicide, developing hemodynamically unstable bradycardia with trifascicular block, leading to fatality. Lessons from our case report are of urgent consideration for temporary pacemaker insertion, and use of alpha-1 agonist, such as phenylephrine in cases of hemodynamically unstable bradycardia by risperidone overdose. Prompt and appropriate identification and interventions are essential for the successful management of risperidone overdose.

Effect of Cardiac Nerve Growth Factor in Acute Myocardial Infarction in Human

BACKGROUND AND OBJECTIVES: It has been demonstrated that the concentration of plasma nerve growth factor (NGF) effects nerve sprouting. In addition, the relationship between plasma NGF concentration and the occurrence of ventricular tachyarrhythmia (VT) has been reported in animal models of myocardial infarction (MI). However, the causal relationship between NGF and VT remains unclear in humans. The aim of the current study was to determine whether NGF is increased in patients with MI. In addition, the relationship between the concentration of plasma NGF and the inducibility of VT was evaluated. SUBJECTS AND METHODS: We studied 15 patients with stable angina pectoris (SA) and 30 patients with an acute MI (AMI). The patients in the AMI group were divided into VT occurrence (n=14) and non-VT occurrence groups (n=16). Thirty-four patients suspected to have VT underwent programmed electrical stimulation (PES) and were divided into an idiopathic VT group (n=24) and an induced VT with PES {healthy control (C) group; n=10}. Plasma NGF concentrations were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The plasma concentrations of the AMI group were significantly increased compared to the C group {median (interquartile range), 18.9 (8.7) vs. 10.3 (12.5) pg/mL, p<0.05} and the patients with SA {18.9 (8.7) vs. 15.1 (6.7) pg/mL, p<0.05}, but not significantly different from those in the idiopathic VT group {median (interquartile range), 18.9 (8.7) vs. 18.7 (8.5) pg/mL, p=0.89}. There was no significant difference in the plasma NGF concentrations between the C and SA groups {10.3 (12.5) vs. 15.1 (6.7) pg/mL, p=0.18}. In the AMI patients, there was no significant difference in the plasma NGF concentrations between patients with VT and those without VT {18.5 (6.7) vs. 21.2 (10.2) pg/mL, p=0.25}. CONCLUSION: The plasma NGF concentrations were increased in patients with an AMI compared to patients with SA and Cs.

Effect of High Dose External Irradiation on the Matrix Metalloprotease-2 Expression in a Rat Carotid Artery Injury Model

BACKGROUND AND OBJECTIVES: Remodeling of the injured arterial wall is dependent on the action of several extracellular proteases, including matrix metalloprotease-2 (MMP-2), and this protein is associated with the migration of vascular smooth muscle cells. The effect of a high dose of external irradiation (20 Gy) on the MMP-2 expression in neointimal hyperplasia is not known. MATERIALS AND METHODS: Sprague-Dawley rats were subjected to balloon injury to the common carotid artery. At 24 hours after injury, 20 Gy external irradiation was done for the irradiated group (n=25) and this was not done for the control group (n=25). The percent area stenosis, the maximal intimal thickness, the intima/media area ratio on H-E staining and the MMP-2 positivity on the immunohistochemical staining were measured. Western blotting and a gelatin zymogram for determining the MMP-2 protein expression were also performed after the injury. RESULTS: The parameters of neointimal hyperplasia such as the percent area stenosis, the maximal intimal thickness and the intima/media area ratio were 40.2+/-12.1%, 0.30+/-0.12 mm and 1.27+/-0.32, respectively, at 14 days after injury, and these parameters were maintained as a hyperplastic state at 28 days after injury in the control group. There was undetectable neointimal hyperplasia in the irradiated group compared with the control group (p<0.01). Western blotting demonstrated an increase in the MMP-2 protein level beginning 2 to 4 days after injury in the control group, but there was only a transient increase in the MMP-2 level at day 2 after injury in the irradiated group. The gelatin zymogram and immunohistochemical staining also showed the expression of MMP-2 in the control group, but not in the irradiated group. CONCLUSION: These findings suggest the suppressed expression of MMP-2 is associated with reduced neointimal hyperplasia in the balloon injury-rat model.

Takayasu's Arteritis Treated by Percutaneous Transluminal Angioplasty with Stenting in the Descending Aorta

A 17-yr-old young woman was referred to our hospital with a 2-yr history of claudication of the lower extremities and severe arterial hypertension. Physical examination revealed significantly different blood pressures between both arms (160/92 and 180/95 mmHg) and legs (92/61 and 82/57 mmHg). The hematological and biochemical values were within their normal ranges, except for the increased erythrocyte sedimentation rate (83 mm/hr) and C-reactive protein (6.19 mg/L). On 3- dimensional computed tomographic angiography, the ascending aorta, the aortic arch and its branches, and the thoracic and, descending aorta, but not the renal artery, were shown to be stenotic. The diagnosis of type IIb Takayasu's arteritis was made according to the new angiographic classification of Takayasu's arteritis, Takyasu conference 1994. Percutaneous transluminal angioplasty with stenting was performed on the thoracic and abdominal aorta. After the interventional procedures, the upper extremity blood pressure improved from 162/101 mmHg to 132/85 mmHg, respectively. She has been free of claudication and there have been no cardiac events during 2-yr of clinical follow-up.

Elevated Troponin I after Implantation of Drug-Eluting Stents: Incidence, Predictors, and Prognostic Value

BACKGROUND AND OBJECTIVES: The presence of elevated troponin after percutaneous coronary intervention (PCI) is considered to reflect irreversible myocardial injury. However, its prognostic value remains unclear. The purpose of this study was to investigate the incidence, risk factors, and clinical outcomes of troponin I (TnI) elevation after the implantation of drug-eluting stent (DES). SUBJECTS AND METHODS: We performed a retrospective analysis of 335 patients who had undergone PCI with DES. Patients who had acute coronary syndrome with elevated TnI levels before PCI were excluded. TnI levels were measured 6 and 24 hours after PCI. RESULTS: Baseline clinical characteristics were similar in the elevated TnI and normal TnI groups. Elevated postprocedural TnI (>1.5 ng/mL) occurred in 52 patients (15.5%). Univariate analysis revealed that the clinically significant variables were multi-vessel disease (p<0.001), multiple stent implantation (p=0.003), total stent length (p=0.001), side-branch occlusion (p<0.001), and bifurcation lesion (p=0.003). Multivariate analysis indicated that the independent predictors of elevated TnI after DES implantation were multi-vessel disease (p=0.019), side-branch occlusion (p=0.001), and bifurcation (p=0.011). There were no significant differences in major adverse cardiovascular events between the elevated TnI and normal TnI groups (p=0.461). CONCLUSION: Multi-vessel disease, side-branch occlusion, and bifurcation were independent predictors of elevated TnI following DES implantation. The elevation of TnI after successful PCI with DES was not associated with worse 400-day clinical outcomes.

Effect of Adult Bone Marrow Stem Cells on Myocardial Regeneration in Doxorubicin-Induced Mouse Cardiomyopathy

BACKGROUND AND OBJECTIVES: Bone marrow cells have been shown to differentiate into various cell lineages, including cardiomyocytes, in recent studies. This study evaluates the hypothesis that intravenous injection of bone marrow mononuclear cells (BMNCs) into rats with doxorubicin-induced cardiomyopathy can induce myocardial regeneration and improve myocardial contractility. MATERIALS AND METHODS: Adult male Sprague-Dawley rats were induced to develop cardiomyopathy by treatment with doxorubicin (2.5 mg/kg, 6 times, 2-week period). Stem cell enriched BMNCs were injected into the tail vein of the rats after cessation of the doxorubicin injections. One week after the injection of PKH-67-labeled BMNCs, the localization of transplanted cells was evaluated. Immunohistochemical studies and Western blots were performed two weeks after BMNCs injection. RESULTS: Cell-treated animals showed significant improvement in left ventricular fractional shortening as compared to untreated (control) rats (cell treated group vs. control group 47.2+/-4.9% vs. 34.4+/-3.6%, p<0.01). Histological analyses showed that in the cell-treated animals there was an increase in ventricular interstitial collagen deposition and the cell-treated animals had an improved number of capillary endothelial cells as compared with the control rats. PKH-67-labeled BMNCs and cell proliferation by BrdU was noted in the cell-treated hearts. Cardiac CXCR4 protein expression increased at day 7 and 14 in the cell-treated rats, but only at day 14 in the control animals. CONCLUSION: These results suggest that intravenous injection of BMNCs effectively induce engraftment of BMNCs into the myocardium and attenuation of fibrosis. Intravenous injection of BMNCs also improved myocardial contractility in doxorubicininduced cardiomyopathy.

Association between the JNC 7 Classification of the Stages of Systolic Hypertension and Inflammatory Cardiovascular Risk Factors

BACKGROUND AND OBJECTIVES: It is well known that the higher the blood pressure, the greater the chance of cardiovascular disease, but the factors that are responsible for this association remain largely unknown. We sought to determine whether blood pressure, in a dose-dependent way, is associated with systemic inflammation, which is a known risk factor for cardiovascular events. SUBJECTS AND METHODS: We analyzed the data from 5,626 participants, aged 40-65 years, of the Third National Health and Nutrition Examination Survey (NHANES III). We quantified the blood pressure by dividing the participants into the normal, pre-, stage 1 and stage 2 hypertension groups based on the Joint National Committee 7 (JNC) classification. We used multiple linear and logistic regression models to determine the relationship between blood pressure and the levels of inflammatory markers. RESULTS: After adjustments were made for various co-morbidities, participants with stage 2 systolic hypertension had higher circulating leukocyte levels [840/microliter (95% confidence interval [CI], 374 to 939/microliter)] and fibrinogen levels [24.5 mg/dL (95% CI, 8.9 to 31.9 mg/dL)] than those participants with normal blood pressure. They also showed higher circulating C-reactive protein levels (C-reactive protein>10.0 mg/L: p for trend=0.001). There was a dose-dependent increase for the circulating levels of the risk factors across the different levels of systolic blood pressure, but not for diastolic blood pressure. CONCLUSION: These findings demonstrate that an elevated systolic blood pressure is an independent risk factor for systemic inflammation and this may explain why systolic hypertension is a risk factor for atherosclerosis and cardiovascular events.

Intracoronary Stent Deployment without Antiplatelet Agents in a Patient with Idiopathic Thrombocytopenic Purpura

Deciding on the appropriate antiplatelet therapy is a challenge when treating patients with idiopathic thrombocytopenic purpura (ITP) and who are undergoing percutaneous coronary intervention (PCI). We describe here a case of PCI in a patient with chronic, refractory ITP. A 61-year-old woman presented with exertional chest pain and a low platelet count (4 x 109/L) at admission. Coronary angiography revealed 99% stenosis of the mid left anterior descending artery and 95% stenosis of the mid left circumflex artery. Antiplatelet agents couldn't be administered because of the risk of bleeding. After transfusion of platelets and administering intravenous immunoglobulin, we deployed baremetal stents in both lesions without administering any antiplatelet agents. Although focal in-stent restenosis developed 5 months later, there was no episode of stent thrombosis despite not using antiplatelet agents. The present case suggests that the rate of stent thrombosis may be lower was previously thought and antiplatelet therapy may be considered on a case by case for patient suffering with thrombocytopenia.

Clinical features and prognostic factors in Korean patients hospitalized for coronary artery disease (Catholic Heart Care Network Study) / 대한내과학회지

BACKGROUND: Coronary artery disease (CAD) has recently become one of the major causes of mortality and morbidity in Korea. However, not much epidemiologic and demographic data has yet been reported. The purpose of this study was to investigate the clinical features as well as the prognostic factors of patients with CAD. METHODS: We prospectively enrolled 1,665 consecutive patients with CAD who had been admitted to the Catholic University Hospitals from December 1999 to April 2003. RESULTS: Acute myocardial infarction (AMI) was the most common cause of admission (n=715, 42.9%). Dyslipidemia, hypertension and smoking were the most common risk factors. More than 70% of the patients who underwent percutaneous coronary intervention (PCI) received stent implantation. A total of 965 (612 males) patients were followed at least for 6 months (the mean follow-up duration was 23.8+/-12.2 months). The incidence rates of major adverse cardiac events (MACE: cardiac death, acute myocardial infarction, target vessel revascularization) and cardiac death were 15.1% (n=146) and 2.2% (n=21), respectively. There was no difference in overall survival between the patients treated with medical therapy and those treated with PCI. By Cox regression analysis, the independent prognostic factors for MACE were PCI (95% CI: 1.75-4.85; p<0.01) and multivessel disease (95% CI: 1.03-2.04; p<0.05), and the independent prognostic factors for cardiac death were medical therapy (95% CI: 1.08-14.41; p<0.05) and old age (95% CI: 1.13-16.13; p<0.05). CONCLUSIONS: There was no difference in overall survival between the patients treated with medical therapy and those treated with PCI. However, PCI was superior to medical therapy for preventing death of the patients with acute coronary syndrome.

Arrhythmogenic Gene Change and Nerve Sprouting after Acute Myocardial Infarction in Mice

BACKGROUND AND OBJECTIVES: Myocardial infarction (MI) elicits nerve sprouting. However, the time course and spatial distribution of this nerve sprouting and its relationship to the expression of neurotrophic factors is unclear. The aim of this study was to identify the association of nerve sprouting with the expression of neurotrophic factors. MATERIALS AND METHODS: We induced MI in FVB mice by ligating the left coronary artery. The hearts were removed at 3 hours to 13 months after MI for growth associated protein 43 (GAP-43) immunostaining. The nerve density (micrometer2/mm2) was determined by ImagePro software. In another group of mice, their myocardial tissues were processed and analyzed with using an Affymetrix RG U74V2 array. RESULTS: The density of the nerve fibers that were immunopositive for GAP-43 was the highest 3 hours after MI in both the peri-infarct areas and the remote areas. The outer loop of the ventricle had a higher nerve density than that in the inner loop of the ventricle. The differences were at a peak 3 hours after MI, but they persisted for 2 months afterwards. The expressions of nerve growth factor, insulin-like growth factor, leukemia inhibitory factor, transforming growth factor-beta3 and interleukin-1alpha were increased for up to 2 months after MI as compared to the normal control. qRT PCR analyses showed increased mRNA for tyrosine hydroxylase, synaptophysin, nerve growth factor and leukemia inhibiting factor in the peri-infarct areas for up to 2 months after MI, but this occurred only for roughly 3 days after MI in the remote areas. CONCLUSION: We conclude that MI resulted in immediate upregulation of nerve growth factor, insulin-like growth factor, leukemia inhibitory factor, transforming growth factor-beta3 and interleukin-1alpha in the peri-infarct areas and this all occurred to a lesser extent in the remote areas. These changes persisted for at least 2 months, and they were associated with increased nerve sprouting activity, which was most active in the outer loop of the heart.

The Association between Coronary Artery Calcification on MDCT and Angiographic Coronary Artery Stenosis

BACKGROUND AND OBJECTIVES: The assessment of CT-derived coronary artery calcification (CAC) has been used as a surrogate measurement for coronary atherosclerosis. However, the blooming artifact caused by CAC on MDCT is the potential limitation when evaluating the coronary artery stenosis. The aim of this study was to classify the morphologic characteristics of CAC on MDCT and to test whether this new classification predicts the stenotic severity on coronary angiography. SUBJECTS AND METHODS: A total of 73 CAC lesions were observed on 64 slice MDCT in the 56 enrolled patients (M:F=33:23, mean age: 66+/-9.3 years) who underwent coronary angiography. The morphologic types of CAC on 64-slice MDCT were classified into four groups [degree of stenosis (S), shape of the calcification (M), length of the calcification (L) and the number of calcified vessels (N)] with using a scoring system, and this morphologic classification was compared with the angiographic severity of coronary stenosis. RESULTS: Diffuse (L3), elongated (M2) and multi-vessel (N2) calcified lesions were significantly associated with angiographic coronary artery stenosis (p=0.03, p=0.019 and p=0.002, respectively) On the multivariate regression analysis, multivessel CAC was the only independent predictor for significant coronary artery stenosis [p=0.019, beta=3.77, CI: 1.23-11.5 (95%)]. The type of stenosis (luminal narrowing > or =50%) accompanying CAC on MDCT was not correlated with the angiographically determined stenosis (p=0.13). A total morphologic score less than 4 had a negative predictive value of 78% for predicting significant coronary artery stenosis. CONCLUSION: Our results suggest that the diffuse and multi-vessel CAC on MDCT can predict the coronary artery stenosis; however, the stenosis severity of the lesion accompanying CAC on MDCT might not coincide with the angiographic severity. Therefore, the morphologic classification with this scoring system should be considered for use when evaluating lesion with CAC on MDCT.

The Relationship Between the Acute Changes of the Systolic Blood Pressure and the Brachial-Ankle Pulse Wave Velocity

BACKGROUND: The brachial-ankle pulse wave velocity (baPWV) is a useful parameter to assess arterial stiffness. However, it is difficult to evaluate arterial stiffness in hypertensive patients because the baPWV is affected by the blood pressure itself. This study was designed to estimate the relationship between the change of the blood pressure parameters and the baPWV (delta baPWV) when hypertensive patients were subjected to an acute reduction of blood pressure. METHODS: Thirty patients with essential hypertension and whose blood pressure was higher than 140/90 mmHg were enrolled. In all the patients, the blood pressure and baPWV were measured using an automatic waveform analyzer with the patients at a resting state. When the reduction of blood pressure was more than 10 mmHg after sublingual administration of nifedipine 10 mg, then the blood pressure and baPWV were measured again in the same manner and then they were compared with the baseline values. Spearman's correlation and multiple linear regression tests were performed to estimate the relationship between the change of the blood pressure parameters (delta SBP, delta DBP, delta MAP and delta PP) and the delta baPWV. RESULTS: The baPWV was significantly decreased shortly after the administration of nifedipine (1903.6+/-305.2 cm/sec vs. 1716+/-252.0 cm/sec, respectively, p<0.01). The delta baPWV was correlated with the delta SBP (r=0.550, p<0.01), delta DBP (r=0.386, p<0.05), delta MAP (r=0.441, p<0.05), and delta PP (r=0.442. p<0.05). On the multiple regression analysis, the delta SBP was the only significant variable for predicting the delta baPWV, and the linear equation was delta baPWV=8.7 x SBP-48. CONCLUSIONS: The baPWV is affected by the systolic blood pressure level to a large degree and careful attention must be paid to the blood pressure level when evaluating arterial stiffness with using the baPWV.

Inhibition of Neointima Formation by Anti-Vascular Endothelial Growth Factor and Receptor-1 Peptides in a Balloon-Injured Rat Carotid Artery

BACKGROUND AND OBJECTIVES: Vascular endothelial growth factor (VEGF) is a potent endothelial cell-specific mitogen. This study was undertaken to test the hypothesis that the neointima hyperplasia induced by a balloon injury is inhibited by blocking VEGF and VEGF receptor-1 (VEGFR-1) with anti-VEGF peptides. Materials and Methods: Anti-VEGF RRKRRR peptide (dRK6) and anti-VEGFR-1 peptide (anti-flt-1) were synthesized at Pohang University of Science and Technology, Korea. Male Sprague-Dawley rats, weighing 300-350 g, were subcutaneously injected 0.5 mg/kg of dRK6 or 0.5 mg/kg of anti-flt-1, dissolved in phosphate buffer solution, 2 days before induction of a carotid balloon-injury, and then daily in the same manner post carotid balloon injury for 2 weeks. RESULTS: Neointima formation was suppressed in both the dRK6 and anti-flt-1 groups compared to that in the untreated controls at 2 weeks post carotid balloon-injury (neointimal area; control group 0.44+/-0.09 mm2, dRK6 group 0.25+/-0.05 mm2, anti-flt-1 group 0.19+/-0.05 mm2, p<0.01). Anti-flt-1 peptide and dRK6 reduced the numbers of proliferative bromodeoxyuridine-labeled cells in the neointima (control group 16.4+/-10.6%, dRK6 group 3.7+/-2.1%, anti-flt-1 group 5.9+/-3.4%, p<0.05). In addition, an inflammatory response, as determined by monocyte chemoattractant protein-1 and interleukin-6 upregulation, which was evident in the controls, was inhibited by both dRK6 and anti-flt-1. CONCLUSION: This study suggests anti-vascular endothelial growth factor peptides can reduce the inflammation and neointima formation in balloon injured rat carotid arteries.

Coronary artery aneurysm at the site of stent fracture / 대한내과학회지

No abstract available.

Coronary artery aneurysm at the site of stent fracture / 대한내과학회지

No abstract available.

Clinical Implication of Natriuretic Peptides and Left Atrial Volume for the Screening Methods of Advanced Diastolic Dysfunction in the Community

BACKGROUND: Recently, B-natriuretic peptide (BNP) level and left atrial volume index (LAVi) were known to correlate with indices of LV diastolic function. As a screening method, we tried to evaluate the efficacy to BNP, ANP, and LAVi to predict the advanced diastolic dysfunction that means myocardial relaxation abnormality and elevated LV filling pressure. METHODS: In 100 patients who referred for echocardiography, Doppler recording of the mitral inflow and tissue Doppler imaging of the mitral annulus were obtained and classified into 4 diastolic function grades (normal, impaired relaxation, pseudonormal, and restrictive). Advanced diastolic dysfunction was defined as pseudonormal and restrictive physiology. LAVi was measured by modified Simpson's method in apical 4-chamber view at end-systole. Plasma levels of BNP and ANP were measured on the same day as echocardiogram was done. RESULTS: BNP and ANP levels were increased as diastolic function grade was worsening (BNP : 60+/-92, 108+/-204, 778+/-1,023 and 1,426+/-1,421 pg/ml, p<0.001; ANP: 22+/-30, 23+/-26, 94+/-92, 96+/-61 pg/ml, p<0.001). LAVi was also increased as diastolic dysfunction was advanced: 24+/-7 ml/m2, 27+/-9 ml/m2, 37+/-12 ml/m2, 45+/-12 ml/m2, p<0.001. The areas under the curve of receiver-operator characteristic curve for BNP, ANP and LAVi to detect the advanced diastolic dysfunction were 0.91, 0.88 and 0.84, respectively. BNP of 137 pg/ml, ANP of 34 pg/ml, and LAVi of 30 ml/m2 were the best values of sensitivity and specificity, respectively. CONCLUSION: These data suggest that BNP, ANP and LAVi provide meaningful sensitivity and specificity for the detection of advanced diastolic dysfunction, respectively. Among these, BNP is better than ANP or LAVi for the screening method to predict the advanced diastolic dysfunction.

A Case of Acute and Severe Mitral Regurgitation Presented as Acute Perfusion Failure and Treated by Emergency Mitral Valve Replacement

The majority of patients who was presented as severe mitral regurgitation can be managed with medical treatment. However, some cases of severe and acute mitral regurgitation need to rapid surgical intervention like as primary angioplasty for acute myocardial infarction. In this case, a patient with acute and severe mitral regurgitation presented as accelerating shortness of breath and impending multi-organ perfusion failure was dramatically recovered by rapid echocardiographic diagnosis and emergency valve replacement operation.