The Clinical Significance of Elevated Troponin in Patients with Acute Coronary Syndrome with Normal Electrocardiogram

BACKGROUND AND OBJECTIVES: The level of cardiac specific troponin (cTn) may be important in patients with acute coronary syndrome (ACS), but with normal electrocardiography (ECG). SUBJECTS AND METHODS: Three hundred and nineteen patients (61+/-11 years, M:F=212:107), with ACS and normal ECG, who underwent a diagnostic coronary angiogram (CAG), between July 2000 and June 2001, were analyzed according to their cTn level. The clinical characteristics, initial CAG findings and major adverse cardiac events (MACE), during a one-year clinical follow-up, were compared between positive and negative cTn groups. RESULTS: Of the enrolled patients, 191 had a negative cTn (group A, 61+/-10 years, M:F=131:60), and 128 a positive cTn (group B, 60+/-11 years, M:F=81:47), and 176 (55.2%) were shown to have significant coronary artery stenosis on CAG. There were no significant differences in risk factors between the two groups. The mean left ventricular ejection fraction was 64+/-9%, and was lower in group B than in group A (59+/-10% vs. 67+/-7%, p<0.05). cTn positivity was associated with the percentage of significant coronary artery stenosis present (88% vs. 32%, p<0.05), a smaller minimal luminal diameter (1.09+/-0.44 mm vs. 2.68+/-0.33 mm, p<0.05) and a larger diameter of stenosis (68+/-6% vs. 44+/-6%, p<0.05). A multi-vessel lesion was more common in group B than in group A (58.3% vs. 30.3%, p<0.05). During the one-year follow-up period, 36 patients developed MACE, resulting in 3 deaths, 7 acute myocardial infarctions and 34 patients with restenosis. MACE was observed in 9 patients of group A and in 27 of group B (4.7% vs. 21.1%, p<0.05). CONCLUSION: The troponin levels are valuable for the early diagnosis, and prediction of the long-term prognosis, in patients with ACS and a normal ECG.

The Inhibitory Effects of Platelet Glycoprotein IIb/IIIa Receptor Blocker-Coated Stent on Neointima Formation and Inflammatory Response in Porcine Coronary Stent Restenosis

BACKGROUND AND OBJECTIVES: Previously, we reported that Abciximab (ReoPro(r))-coated stent inhibited in-stent neointimal hyperplasia. ReoPro(r) is known to suppress vascular inflammation through CD 11b/18 (macrophage-1 receptor). We observed inhibitory effects of neointima formation and inflammatory reaction after stenting in a porcine model. MATERIALS AND METHODS: The surface of the stent was coated with ReoPro(r) by means of plasma polymerization followed by chemical grafting. Stent overdilation injury was performed with control bare stent (Group I, n=13) and ReoPro(r)-coated stents (Group II, n=13) in 26 porcine coronary arteries. Follow-up coronary angiogram and the histopathologic assessments of stented porcine coronary were performed on day 14 (Group I:n=6, Group II:n=6) and day 28 (Group I:n=7, Group II:n=7) after stenting. RESULTS: Pathologic area stenosis was 19.7+/-5.3% in Group I and 15.9+/-3.3% in Group II at day 14, and 33.6+/-27.7% and 22.6+/-6.6%, respectively, at day 28 (p<0.05 at day 28). The ratio of inflammatory cells out of the number of total cells in the neointima was 21.8+/-6.5% in Group I and 22.5+/-11.6% in Group II at day 14, and 27.3+/-18.3% in Group I and 28.6+/-10.7% in Group II at day 28 post stenting (p=NS). And those of the media were 2.89+/-1.13% in Group I and 1.36+/-1.27% in Group II at day 14, and 6.61+/-5.61% and 6.26+/-4.51% at day 28 (p=NS). Fibrinoid materials associated with inflammatory reaction were observed in both groups at days 14 and 28. CONCLUSION: An inflammatory reaction was not suppressed with the use of ReoPro(r)-coated stenting in a porcine stent restenosis model.

Long-Term Clinical Follow-up after Rotational Atherectomy and Plain Old Balloon Angioplasty for the Treatment of Coronary Stent Restenosis

BACKGROUND AND OBJECTIVES: Since 1987, coronary stents have changed the pattern of practice of interventional cardiology, by reducing the complications and improving the clinical outcomes. However, coronary stent restenosis still remains a significant clinical problem in the field of interventional cardiology. The aim of this trial was to compare the clinical efficacy of a rotational atherectomy (ROTA), with that of a plain old balloon angioplasty (POBA), in patients with coronary stent restenosis. SUBJECTS AND METHODS: One hundred and three patients (men 80, 58.4+/-10.3 years of age), diagnosed with coronary stent restenosis, at Chonnam National University Hospital, between January 1999 and December 2000, were analyzed. The clinical end-points were the occurrence of major adverse cardiac events (MACE): death, myocardial infarction and target lesion revascularization (TLR) during the one-year clinical follow-up. RESULTS: The baseline clinical and angiographic characteristics were similar between the two groups. Before the percutaneous coronary intervention (PCI), the diameter of stenosis of the POBA and ROTA groups were 81.9+/-14.0 and 82.9+/-10.0%, respectively, which decreased to 25.5+/-15 and 22.7+/-12% after treatment. At the one-year clinical follow-up, the TLR rates were 7.0 and 6.3% in the POBA and ROTA groups, respectively. The MACE results were not different between the two groups (7.0 and 9.4% in the POBA and ROTA groups, respectively). CONCLUSION: There was no significant long-term clinical benefit of a rotational atherectomy prior to a POBA, compared with a POBA alone, for the treatment of coronary stent restenosis.

A Successful Management for Acute Thrombotic Myocardial Infarction with Abciximab in a Nephrotic Syndrome

A 28-year old male presented with chest pain of two hours duration. He had histories of 10 years smoking and 2 years of nephrotic syndrome, due to minimal change disease. His EKG showed marked ST segment elevations in the V3-6, I, II, III and aVF leads. The levels of cardiac enzymes were increased (CK: 481 U/l, CK-MB: 96 U/l and Troponin I: 4.8 ng/mL). The prothrombin and activated partial promboplastin times were normal. Accelerated tissue type plasminogen activator (100 mg) was administered at the emergency room, but his chest pain continued, with persistent ST segment elevations. An urgent coronary angiograph revealed huge multiple filling defects, suggestive of thrombi in the proximal left anterior descending artery (LAD), with thrombolysis in the myocardial infarction (TIMI) flow. A rescue percutaneous coronary intervention was performed using repeated angioplasties with a 3.0 mm balloon. However, the filling defects and distal LAD flow did not improve. We administered Abciximab (ReoPro(r)), and the LAD flow improved to a TIMI III flow, with resolution of the thrombus in the LAD. His clinical course was uneventful after discharge, and a left coronary angiogram, at the 6-month follow-up, showed no filling defects, with the TIMI III flow maintained.

The Role of Extracellular Matrix within the Neointima in A Porcine Coronary Stent Restenosis Model

BACKGROUND AND OBJECTIVES: Coronary stent restenosis remains a major limitation to percutaneous coronary intervention. The most important mechanism of coronary stent restenosis is neointimal hyperplasia (NIH). In addition to neointimal cell proliferation, extracellular matrix (ECM) synthesis may be important in the induction of NIH. We sought to observe the degree of this in a porcine model. SUBJECTS AND METHODS: Twenty-one coronary stents were placed in 15 pigs, and the pigs were sacrificed at 14 (Group I), 28 (Group II) and 56 (Group III) days following stenting. The twenty-one coronary stents were classified into three groups, followed by histopathological analyses of 7 stented arteries. Each specimen was analyzed by H&E, modified Movat and Masson-Trichrome staining methods. Immunocytochemistry was performed for type I collagen, smooth muscle a-actin and proliferating cell nuclear antigen (PCNA). A Visus 2000 Visual Image Analysis System was used. RESULTS: There were no differences in the injury scores of the stented porcine coronary arteries between the three groups. The areas of neointima in Groups I, II and III were 0.75+/-0.32, 1.45+/-0.78 and 1.62+/-0.51 mm2, respectively (Group I vs. II and Group I vs. III ; p=0.08, p=0.03). The pathological area stenoses were 18.8+/-7.4, 34.2+/-0.2 and 43.1+/-28.4% in Groups I, II and III, respectively (Group I vs. II and Group I vs. III ; p=0.35, p=0.02). The PCNA indices of neointima were 16.5+/-14.4, 0.5+/-0.74 and 0.83+/-0.68% in Groups I, II and III, respectively (Group I vs. II and Group I vs. III ; p=0.01). The collagen content ratios within the neointima were 23.5+/-4.7, 27.7+/-5.0 and 36.6+/-10.5% in Groups I, II and III, respectively (Group I vs. II and Group I vs. III ; p=0.52, p=0.01). Proteoglycans were abundant in Groups I and II, and alpha-actin was positive in the neointima cells. CONCLUSION: The role of cell proliferation and proteoglycans are important in the early period, but collagen plays a major role in the late period, following coronary stenting, in a porcine model.

The Long-Term Clinical Effects of Heparin-Coated Coronary Stent

BACKGROUND AND OBJECTIVES: A heparin-coated stent has been reported to be effective in the prevention of restenosis in a porcine model. The aim of this study was to compare the long term effects of heparin-coated and bare stents in patients who underwent percutaneous coronary intervention (PCI), with regard to the clinical and angiographic outcomes. SUBJECTS AND METHODS: Thirty patients who underwent PCI at Chonnam National University Hospital between July 1999 and December 2000 were randomly assigned into two groups; Group I had control bare stents (n=15, 15 lesions, 59+/-12 years, 13 males) and Group II heparin coated stents (n=15, 15 lesions, 59+/-11 years, 14 males). Six months following stenting, follow-up coronary angiograms were performed in 24 (80%) patients. The average follow-up period was 22+/-6 months. RESULTS: The initial clinical and angiographic characteristics were no different between the two groups. The reference diameters (Group I; 2.84+/-0.57 mm, II; 3.34+/-0.57 mm), minimal luminal (Group I; 2.37+/-0.60 mm, II; 2.60+/-0.59 mm) and diameter stenosis (Group I; 16.8+/-8.8%, II; 22.6+/-8.6%) following stenting, were no different between the two groups. Subacute stent thrombosis was observed in 1 patient (6.7%) of Group I. On follow-up coronary angiograms, the reference (group I; 2.46+/-0.34 mm, group II; 2.70+/-0.43 mm), minimal luminal diameters (group I; 1.47+/-0.59 mm, group II; 1.64+/-0.80 mm) and diameter stenosis (group I; 39.4+/-25.1%, group II; 40.8+/-26.1%) diameters were also no different, and restenosis was observed in 3 (25%) patients of each group. One cardiac death and 3 target vessel revascularizations were observed in each group during follow-up. CONCLUSION: The heparin-coated coronary stents were not effective in the prevention of coronary stent restenosis.

A Huge Left Ventricular Pseudoaneurysm after Acute Inferior Myocardial Infarction

No abstract available.

The Effect of Gender on Short- and Long-term Clinical Outcomes of Percutaneous Coronary Intervention in Korean Octogenarians

BACKGROUND AND OBJECTIVES: Previous studies examining the gender differences in patients undergoing percutaneous coronary intervention (PCI) have reported that women have a higher in-hospital mortality rate, and are at an increased risk for adverse outcomes compared to men. The aim of this study was to determine whether or not Korean women undergoing contemporary PCI have a higher risk than men. SUBJECTS AND METHODS:Seventy eight elderly patients with 105 lesions, including 33 women (47 lesions, 81.9+/-1.97 year-old) and 45 men (58 lesions, 81.6+/-1.74 year-old) who underwent PCI from Jan 1996 to Apr 2001 were enrolled in this study. The demographics, angiographic findings and the clinical outcomes of each gender were compared. RESULTS: Clinical diagnosis and risk factors for atherosclerosis for males and females were similar with the exception of their smoking status (36.7% vs. 14.8%, p=0.002) and stroke history (9.1% vs. 0%, p=0.038). There were no differences in the major in-hospital complications including cardiac death (12.1% vs 15.6%, p=0.75), acute myocardial infarction (AMI:3% vs. 0%, p=0.42), rescue PCI (3% vs. 0%, p=0.42) and emergent coronary artery bypass grafts (CABG:6.1% vs. 11.1%. p=0.44) between the two groups. A twelve-month clinical follow-up showed that the major adverse cardiac events including cardiac death (17.8% vs 28.9%, p=0.27), AMI (0% vs. 5.3%, p=0.5) and repeated revascularization (20.7% vs. 15.8%, p=0.6) in males and females were also similar. CONCLUSION: PCI in Korean female patients older than 80 years can be performed with a comparable procedural success rate and clinical outcomes to those of elderly male patients.

A Case of Successful Brachytherapy Using Local Delivery of 99mTc-HMPAO for the Recurrent Coronary Stent Restenosis

A percutaneous coronary intervention (PCI) is known to be one of the effective methods for the treatment of coronary artery disease. However, restenosis remains a major limitation of PCI. Recently vascular brachytherapy has been introduced for the prevention of recurrent restenosis following PCI, especially after stenting.We report a case of a 64-year-old man suffering from an acute myocardial infarction due to total occlusion of the proximal right coronary artery (RCA) and critical stenosis in the proximal left circumflex artery (LCX). After successful PCI for RCA occlusion and LCX stenosis, restenosis developed in both arteries on follow-up coronary angiogram. Simple balloon dilation for the proximal RCA edge restenosis, and cutting balloon angioplasty for the instent restenosis, were performed. The follow-up angiogram revealed no restenosis in the RCA or second instent restenosis in the LCX. A vascular brachytherapy using local delivery of 99mTc-HMPAO was performed for this recurrent lesion. A one-year follow-up angiogram, after local radioisotope delivery, revealed a patent stent without restenosis in the LCX.

Effects of Antiplatelet Agents in the Prevention of Ventricular Tachyarrhythmias during Acute Myocardial Ischemia in the Rats

BACKGROUND: Aspirin, one of the antiplatelet agents, improves the survival rate after myocardial infarction. This beneficial effect is known to be obtained in part by the antiarrhythmic action of aspirin. It is not known whether other antiplatelet agents have such effects. This study was performed to compare the effects of aspirin, ticlopidine, and abciximab (platelet glycoprotein IIb/IIIa receptor antagonist) on the ischemia-induced arrhythmias with a rat model of cardiac regional ischemia. METHODS: Experiments were performed in 4 groups of rats. The 4 groups were as follows : control, n=10:aspirin-pretreated, 300 mg/kg po for 1 week:ticlopidine-pretreated, 200 mg/kg po for 1 wk:abciximab-pretreated, 2 mg/kg iv 10-20 minutes before experiment. The electrocardiogram and blood pressure were recorded during 20 minutes. The time to the onset of ST-segment elevation and ventricular tachyarrhythmias, frequency and incidence of ventricular tachyarrhythmias, and death rate were assessed during acute myocardial ischemia induced by ligation of proximal left anterior descending coronary artery in anesthetized rats. RESULTS: Platelet aggregations to ADP were significantly lower in aspirin (42.8%), ticlopidine (43.8%), and abciximab group (34.0%) than in control group (66.4%). The frequencies of sustained ventricular tachycardia (VT) were 6.8+/-3.6 in control, 3.6+/-3.8 aspirin, 4.7+/-3.7 ticlopidine, and 1.4+/-2.5 abciximab group. The frequency of sustained VT in the abciximab group was significantly lower than in control group. The incidences of ventricular arrhythmias for 20 min were 10/10 for VT and 8/10 for ventricular fibrillation (VF) in control group, 7/10 for VT and 3/10 for VF in aspirin group, 10/10 for VT and 3/10 for VF in ticlopidine group, and 5/10 for VT and 4/10 for VF in abciximab group. The incidences of cardiac death during 20 min were 8/10 in control group, 4/10 in aspirin group, 2/10 in ticlopidine group and 5/10 in abciximab group. The incidence of VT in the abciximab group was significantly lower than in control group, incidences of VF in the aspirin and ticlopidine groups were significantly lower than in control group, and death rate in ticlopidine group was significantly lower than in control group. CONCLUSION: The present study suggested that aspirin, ticlopidine, and abciximab could prevent ventricular tachycardia or ventricular fibrillation in a rat model of cardiac regional ischemia and their antiarrhythmic effects improve the survival rate.

Effects of Antiplatelet Agents in the Prevention of Ventricular Tachyarrhythmias during Acute Myocardial Ischemia in the Rats

BACKGROUND: Aspirin, one of the antiplatelet agents, improves the survival rate after myocardial infarction. This beneficial effect is known to be obtained in part by the antiarrhythmic action of aspirin. It is not known whether other antiplatelet agents have such effects. This study was performed to compare the effects of aspirin, ticlopidine, and abciximab (platelet glycoprotein IIb/IIIa receptor antagonist) on the ischemia-induced arrhythmias with a rat model of cardiac regional ischemia. METHODS: Experiments were performed in 4 groups of rats. The 4 groups were as follows : control, n=10:aspirin-pretreated, 300 mg/kg po for 1 week:ticlopidine-pretreated, 200 mg/kg po for 1 wk:abciximab-pretreated, 2 mg/kg iv 10-20 minutes before experiment. The electrocardiogram and blood pressure were recorded during 20 minutes. The time to the onset of ST-segment elevation and ventricular tachyarrhythmias, frequency and incidence of ventricular tachyarrhythmias, and death rate were assessed during acute myocardial ischemia induced by ligation of proximal left anterior descending coronary artery in anesthetized rats. RESULTS: Platelet aggregations to ADP were significantly lower in aspirin (42.8%), ticlopidine (43.8%), and abciximab group (34.0%) than in control group (66.4%). The frequencies of sustained ventricular tachycardia (VT) were 6.8+/-3.6 in control, 3.6+/-3.8 aspirin, 4.7+/-3.7 ticlopidine, and 1.4+/-2.5 abciximab group. The frequency of sustained VT in the abciximab group was significantly lower than in control group. The incidences of ventricular arrhythmias for 20 min were 10/10 for VT and 8/10 for ventricular fibrillation (VF) in control group, 7/10 for VT and 3/10 for VF in aspirin group, 10/10 for VT and 3/10 for VF in ticlopidine group, and 5/10 for VT and 4/10 for VF in abciximab group. The incidences of cardiac death during 20 min were 8/10 in control group, 4/10 in aspirin group, 2/10 in ticlopidine group and 5/10 in abciximab group. The incidence of VT in the abciximab group was significantly lower than in control group, incidences of VF in the aspirin and ticlopidine groups were significantly lower than in control group, and death rate in ticlopidine group was significantly lower than in control group. CONCLUSION: The present study suggested that aspirin, ticlopidine, and abciximab could prevent ventricular tachycardia or ventricular fibrillation in a rat model of cardiac regional ischemia and their antiarrhythmic effects improve the survival rate.

The Effects of Oral Nitric Oxide Donor (Molsidomine) in Patients with Variant Angina Unresponsive to Conventional Anti-Anginal Drugs

BACKGROUND: We observed the changes of clinical characteristics after oral Molsidomine, a nitric oxide donor, in patients who have documented coronary artery spasm by ergonovine coronary angiogram and refractory to conventional anti-anginal therapy. METHOD: Molsidomine, oral nitric oxide donor, was administrated over 12 weeks in 20 patients (6 male, 14 female, 54+/-11.5 years) in order to observe the clinical effects in patients with coronary artery spasm unresponsive to nitrate and calcium channel blockers. Changes in the frequency of pain and sublingual nitroglycerin use, blood pressure, heart rate, side effects, electrocardiogram, and laboratory findings were evaluated before and after Molsidomine therapy. RESULTS: The frequencies of pain and sublingual nitroglycerin use were 3.9+/-0.9/week before treatment and decreased to 2.9+/-0.9/week at 4th week after the additional Molsidomine treatment (pre-treatment vs. 4th week; p<0.001), to 1.0+/-0.8/week at 8th week (4th week vs. 8th week; p<0.001), and to 0.7+/-0.8/week at 12th week. Systolic blood pressure decreased after treatment, but there were no significant changes in diastolic blood pressure, heart rate, resting electrocardiogram and laboratory findings. Molsidomine was discontinued in one patient because of headache. CONCLUSIONS: Molsidomine is an effective and well tolerated anti-ischemic agent in patients with variant angina refractory to conventional anti-anginal therapy.