Left Coronary Ostium Research Articles

Time course of transcardiac interleukin-6 release after coronary stenting for stable angina

Cytokines are known to play a critical role in the atherosclerotic process.1 The cytokine interleukin-6 (IL-6) is involved in a variety of physiological functions ultimately leading to macrophage activation, platelet aggregation, and stimulation of matrix degrading enzymes. An increase in circulating concentrations of IL-6 and of its hepatic byproduct C reactive protein (CRP) has been reported in unstable angina2 and after percutaneous coronary intervention (PCI); high concentrations of IL-6 and CRP are considered to be markers of poor prognosis, probably related to the intensity of plaque inflammation. The present study was designed specifically to evaluate whether transmyocardial production of IL-6 could be measured immediately and within two hours of a successful elective PCI and stent implantation in stable patients. The study involved 11 patients with stable angina, admitted for an elective PCI of the proximal segment of the left anterior descending coronary artery. All patients received standard medical treatment consisting of intravenous heparin (70 U/kg body weight), acetylsalicylic acid, and nitrates. No glycoprotein IIb/IIIa inhibitors were given. A six French Cournand catheter was introduced through the right femoral vein in the coronary sinus and the left coronary ostium was catheterised through the right femoral artery. Coronary sinus and arterial blood samples were taken simultaneously …

Calcium scoring of the coronary artery by electron beam CT: how to apply an individual attenuation threshold.

Our aim was to assess the inter- and intraindividual variability of the attenuation threshold used to identify coronary artery calcification on electron beam CT and to illustrate a new threshold method. We measured the soft-tissue attenuation of regions surrounding the coronary arteries at the level of the left main coronary artery ostium (high level) and at the bottom of the heart (low level) in 48 consecutive patients (22 men, 26 women). Mean +/- 2 standard deviations (SD) of soft-tissue attenuation and variance of soft-tissue density and SDs were calculated at each level for every patient. It was assumed that setting an attenuation threshold greater than or equal to 3 SDs above that of soft tissue at each myocardial level would eliminate 99.5% of all scatter artifacts, allowing precise identification of calcific deposits. For the entire patient cohort, the average soft-tissue attenuation was 41 H and 35 H at the high and low levels, respectively (p < 0.01), indicating a large intraindividual variability. The SDs of soft-tissue attenuation measured by the computer software at the high and low levels were not different (26 H at the high level and 28 H at the low level; p = not significant). However, the calculated SD of the individual mean soft-tissue attenuation was 5 H at the high level and 8 H at the low level, again indicating a large intraindividual variability (p < 0.01). The addition of 3 measured SDs above the mean individual soft-tissue attenuation predicted a mean threshold of 120 and 121 H at the high and low levels, respectively, but with a wide interindividual variability (83-193 H at the high level and 79-242 H at the low level). There was a strong correlation between body weight and SD of soft-tissue attenuation at the low level (r = 0.75, p < 0.001) and a weaker but statistically significant correlation between weight and SD of soft-tissue attenuation at the high level (r = 0.51, p < 0.001). For the patients in this study, a threshold of 120 H for the detection of coronary calcification by electron beam CT seemed more appropriate than a threshold of 130 H, which is currently in use. However, given the great inter- and intraindividual variability, a biologic threshold tailored to the individual patient and to each individual imaging level should be used instead of a fixed threshold.

Direct ostioplasty of the left main coronary artery using the right internal thoracic artery as patch material

Three female patients underwent operations for nonatherosclerotic isolated left main coronary artery stenosis. Transaortic patch angioplasty was performed via an anterior approach using the most proximal segment of the right internal thoracic artery as patch material. Six months after surgery coronary angiography revealed good results in all three cases. The internal thoracic artery can be used to enlarge the left coronary ostium safely, if heavy calcification is not present.

In vivo myocardial gene transfer: optimization and evaluation of intracoronary gene delivery in vivo.

Clinical reports suggest that intracoronary delivery of adenoviruses encoding angiogenic growth factors, or their transactivators, has a therapeutic benefit. However there has not been a systematic assessment of the transfection efficiency of this technique in vivo. In rabbits we investigated the efficiency of myocardial gene transfer following intracoronary infusion of 1 x 10(-10) -1 x 10(12) p.f.u. of adenovirus in combination with interventions to enhance transfection. In five standard short axis sections, we were barely able to detect reporter gene expression following unmodified intracoronary infusion. Efficiency was not enhanced by the exclusion of blood and the increase of intracoronary dwell time through occlusive engagement of the left coronary ostium enabled by oxygenated perfluorocarbon emulsion as viral diluent. Of the interventions and pretreatments designed to increase vascular permeability, VEGF, calcium-free viral diluent and adenosine, only the latter tended to increase efficiency. However an intervention designed to increase the myocardial transcapillary gradient, by increasing venular pressure with pulmonary artery occlusion and arteriolar pressure with occlusion of the aorta above the coronary ostia, increased transfection efficiency by two orders of magnitude. Unfortunately the clinical utility of this technique may be limited by accompanying cardiac dilation and marked elevations in intracardiac pressure.

Magnesium causes nitric oxide independent coronary artery vasodilation in humans

OBJECTIVETo determine how magnesium affects human coronary arteries and whether endothelium derived nitric oxide (EDNO) is involved in the coronary arterial response to magnesium.DESIGNQuantitative coronary angiography and Doppler flow velocity measurements were used to determine the effects of the nitric oxide synthase inhibitorNG-monomethyl-L-arginine (L-NMMA) on magnesium induced dilation of the epicardial and resistance coronary arteries.SETTINGHiroshima University Hospital a tertiary cardiology centre.PATIENTS17 patients with angiographically normal coronary arteries.INTERVENTIONSMagnesium sulfate (MgSO4) (0.02 mmol/min and 0.2 mmol/min) was infused for two minutes into the left coronary ostium before and after intracoronary infusion of L-NMMA.MAIN OUTCOME MEASURESDiameter of the proximal and distal segments of the epicardial coronary arteries and coronary blood flow.RESULTSAt a dose of 0.02 mmol/min, MgSO4 did not affect the coronary arteries. At a dose of 0.2 mmol/min, MgSO4 caused coronary artery dilation (mean (SEM) proximal diameter 3.00 (0.09) to 3.11 (0.09) mm; distal 1.64 (0.06) to 1.77 (0.07) mm) and increased coronary blood flow (79.3 (7.5) to 101.4 (9.9) ml/min, p &lt; 0.001 vbaseline for all). MgSO4 increased the changes in these parameters after the infusion of L-NMMA (p &lt; 0.001v baseline).CONCLUSIONSMagnesium dilates both the epicardial and resistance coronary arteries in humans. Furthermore, the coronary arterial response to magnesium is dose dependent and independent of EDNO.

Relationship between intracoronary and peripheral expression of soluble cell adhesion molecules

Background: Elevated levels of soluble cell adhesion molecules (sCAMs) have been reported in various coronary artery disease processes. The principle stimulus for expression of sCAMs is believed to be an inflamed atherosclerotic plaque within the coronary vessel. The relationship between levels of sCAMs in the coronary circulation and the peripheral circulation has not been defined. The primary aim of this study was to define the relationship between levels of sCAMs sampled from the systemic circulation and from the coronary circulation. We also set out to document the acute expression of soluble CAMs following coronary angioplasty with or without stent implantation. Methods: The coronary sinus was cannulated in patients undergoing LAD angioplasty. Samples were drawn from left coronary ostium (LCO) and coronary sinus (CS) and femoral vein simultaneously before, immediately after and 4 h after the PTCA procedure. Levels of sICAM-1, sVCAM-1, sE-selectin and sP-selectin were measured using ELISA technique. Results: 10 patients (7 male/3 female, 61±11 y) entered the study. There was no significant difference in the levels of sICAM-1, sVCAM-1, sE-selectin and sPselectin whether sampled from left coronary ostium, coronary sinus or femoral vein at all time points. There was no significant change in the acute expression of sICAM-1, sVCAM-1 and sE-selectin following coronary angioplasty. Levels of sP-selectin fell significantly during the PTCA procedure (142±7 ng/ml to 64±6 ng/ml, P<0.001) but then rose again after 4 h and returned toward baseline levels at 24 h. Conclusion: Levels of soluble CAMs sampled in the systemic circulation directly reflect levels in the coronary circulation. Coronary angioplasty results in rapid fall in levels of sP-selectin which returns to normal within 24 h following the procedure.

A Case of Isolated Left Main Coronary Ostial Stenosis due to Acute Angle Takeoff

Isolated and severe left main coronary ostial stenosis is a rare condition. In the majority of these patients, ostial stenosis has been associated with any of the conditions known to involve the coronary ostia. These conditions include syphilitic aortitis, Takayasu’s aortitis, familial hypercholesterolemia, and aortic valve disease. A 34-year old female patient was presented with exertional and stabbing anterior chest pain. There was no history of syphilis, diabetes mellitus, hypertension, hyperlipidemia or smoking. Coronary angiogram showed isolated left main coronary ostial stenosis. Transesophageal echocardiography (TEE) showed acute angle takeoff of the left main coronary artery. The patient underwent surgical angioplasty of the coronary ostia with a patch of the autologous pericardium. Following angioplasty, TEE showed dilatation of the left main coronary ostium and the clinical symptoms improved. (Korean Circulation J 2001;31(4):442-446)

The effect of myocardial bridging of the coronary artery on vasoactive agents and atherosclerosis localization.

The relationship between alterations in the immunohistochemical expression of three vasoactive agents [endothelial nitric oxide synthase (eNOS), endothelin-1 (ET-1), and angiotensin-converting enzyme (ACE)] and the occurrence human atherosclerosis was investigated in relation to the myocardial bridge (MB) of the left anterior descending coronary artery (LAD), an anatomical site that experiences increased shear stress. Five millimetre cross-sections of LADs with MB from 22 autopsied cases were taken from the left coronary ostium to the cardiac apex and were immunohistochemically stained with antibodies against eNOS, ET-1, and ACE. The extent of atherosclerosis in each section was calculated using the atherosclerosis ratio (intimal cross-sectional area/medial cross-sectional area) determined by histomorphometry. The results were analysed according to their anatomical location relative to the MB, either proximal, beneath, or distal. The extent of atherosclerosis was significantly lower beneath the MB, compared with proximal and distal segments. The expression of eNOS, ET-1, and ACE was also significantly lower beneath the MB. The expression of these agents correlated significantly with the extent of atherosclerosis. Because nitric oxide, after its production by eNOS, is believed to be degraded by superoxide radicals, the effect of eNOS expression on atherosclerosis remains controversial. However, the present findings clearly indicate that the expression of ET-1 and ACE is directly related to the development of human coronary atherosclerosis in vivo through shear stress.

Long-Term Clinical Follow-up in A Case of Takayasu's Arteritis Involving the Ostium of Left Coronary Artery after Ostioplasty

A 25-year-old woman presented with effort-induced chest pain. Physical examination revealed different blood pressures, 180/100 mmHg in right arm and 100/60 mmHg in left arm. Resting electrocardiogram was normal, but down-slope depression of ST segment more than 3 mm in V3-6, II, III, aVF developed at the stage 1 of treadmill exercise test. Stress Thallium-201 scan showed severe ischemia in the anteroseptal and lateral wall of left ventricle. Diagnostic coronary angiogram showed critical stenosis in the ostium of left main coronary artery. The left subclavian artery was occluded totally with well-developed collateral circulation. The patient underwent ostioplasty of left coronary ostium using pericardial patch, and her symptom improved after surgery. Follow-up coronary angiogram one year after surgery showed patent coronary artery ostium with good flow and myocardial perfusion improved on follow-up Thallium-201 SPECT. She has no major cardiac events during 7-year clinical follow-up. (Korean Circulation J 2001;31(2):246-250)

Plastia cirúrgica de óstio coronariano esquerdo com estenose não aterosclerótica

A clinical case of a 38 year old male, with heart failure grade IV (NYHA) and angina at rest related to severe aortic regurgitation, right coronary ostial occlusion, and a sub-total occlusion of the left coronary ostium owing to syphilitic infection in the past is reported and discussed. Treatment was established implanting a mechanical aortic prosthesis and a direct left main angioplasty suturing a patch made of safenous vein. Follow up has been excellent and the patient is today having a normal life, free of symptoms.

Occlusion of left coronary artery ostium by an aortic valve cusp

Congenital anomalies of the aortic valve can be associated with other cardiac anomalies. In this report, we present a patient with an aortic valve anomaly associated with occlusion of left coronary ostia. In addition, we reviewed the literature and found 10 similar cases. Although compatible with life, this anomaly can lead to significant symptoms. Preoperative diagnosis as well as proper therapeutic planning should be tailored to correct valvular competence and restore coronary blood flow.

Distal embolization: A threat to the coronary artery?

A67-year-old man with a history of hypertension and hypercholesterolemia was scheduled for elective direct stent implantation for a severe proximal left descending artery stenosis. Using the femoral approach, a 7-French Judkins left guiding catheter was placed in the left coronary ostium. To keep the activated clotting time …

A Case of Anomalous Origin of Left Coronary Artery from the Pulmonary Artery with Severe Mitral Regurgitation

We report a case of an anomalous origin of left coronary artery from the pulmonary artery with severe mitral regurgitation. A 20-year-old female was admitted to hospital for recurrent syncope and dyspnea on exertion. Cardiac ausculatation revealed systolic murmur radiating to left axilla and blood pressure was 90/70 mmHg. Electrocardiography showed a nonspecific ST-T wave change on V1, V2, V6, I, & aVL leads. Holter monitering showed no significant abnormality except occasional premature ventricular complexes. Chest radiography showed mild cardiomegaly with mitral valvular heart configuration and no pulmonary abnormality. Echocardiog- raphy showed normal left ventricular dimension and systolic function with markedly dilated left atrium, severe mitral regurgitation, & severe resting pulmonary hypertension. Aortogram didn't show left coronary artery ostium. Right coronary angiogram showed normal right coronary artery which supplied major left epicardial coronary arteries via good collaterals (Rentrop grade III. Pulmonary angiogram showed anomalous origin of left coronary artery from main pulmonary trunk. She underwent mitral valvuloplasty and coronary artery bypass graft. ( ( ( (Korean Circulation J 2000;30( ( ( (10 :1323-1327

Intermittent Left Coronary Occlusion Caused by Native Aortic Valve Thrombosis in a Patient with Protein S Deficiency

A 77-year-old woman presented with chest pain and cardiogenic shock. Transesophageal echocardiography showed a mobile mass occluding intermittently the left coronary ostium. The mass was surgically resected, and histologic examination revealed an organized thrombus. Coagulation study demonstrated a protein S deficiency. This is the first case of aortic thrombosis associated with protein S deficiency, and it is the first time that transesophageal echocardiography provided definite evidence that a mass can cause intermittent left ostium coronary obstruction. (J Am Soc Echocardiogr 1999;12:1114-6.)

Effect of CABG on coronary flow reserve in atresia of the left coronary ostium

We evaluated the change of coronary flow reserve using a Doppler guidewire before and after coronary artery bypass grafting to assess the coronary hemodynamic effect of surgical revascularization in a 13-year-old boy with congenital atresia of the left coronary ostium, which is one of the rarest of the congenital coronary anomalies. Coronary flow reserve in the right coronary artery and left anterior descending artery increased significantly after coronary revascularization, and a microvascular bed developed in the left anterior descending artery.

Management of Aortic Dissection That Involves the Right Coronary Artery

A report on the follow-up of 11 patients who suffered from aortic dissection involving the right coronary artery and who underwent surgical treatment is reported. In two patients, the left coronary ostia was also affected. In seven patients, the dissection was acute and in four, chronic. The ascending aorta was substituted by a Dacron graft in all patients, and right coronary artery saphenous vein bypass or Gore-Tex graft to the coronary ostia or right coronary artery was performed in nine, and reimplantation of both dissected coronary in two. There were three early postoperative deaths (27.3%) caused by low-output syndrome and myocardial infarction. There were two late deaths. The six surviving patients were followed-up from 78 to 96 months (mean 83 months). This experience suggests that although carrying a high risk, the involvement of the coronary ostia in aortic dissection can be successfully managed if made before irreversible complications arise.

Management of aortic dissection that involves the right coronary artery

A report on the follow-up of 11 patients who suffered from aortic dissection involving the right coronary artery and who underwent surgical treatment is reported. In two patients, the left coronary ostia was also affected. In seven patients, the dissection was acute and in four, chronic. The ascending aorta was substituted by a Dacron graft in all patients, and right coronary artery saphenous vein bypass or Gore-Tex graft to the coronary ostia or right coronary artery was performed in nine, and reimplantation of both dissected coronary in two. There were three early postoperative deaths (27.3%) caused by low-output syndrome and myocardial infarction. There were two late deaths. The six surviving patients were followed-up from 78 to 96 months (mean 83 months). This experience suggests that although carrying a high risk, the involvement of the coronary ostia in aortic dissection can be successfully managed if made before irreversible complications arise.

The role of nitric oxide in bradykinin-induced dilation of coronary resistance vessels in patients with hypercholesterolemia.

In hypercholesterolemic patients, acetylcholine- and substance P-mediated endothelium-dependent dilation of the coronary resistance vessels is impaired due to decreased nitric oxide production. However, it is not clear if bradykinin-induced coronary vasodilation is impaired in these patients. We investigated whether the endothelium-dependent dilation of coronary resistance vessels mediated by bradykinin is impaired in patients with hypercholesterolemia and, if so, whether this impairment is caused by a decreased production of nitric oxide. We examined the coronary vascular responses to acetylcholine and bradykinin. The vascular responses to bradykinin were also assessed after N(G)-monomethyl-L-arginine was infused to inhibit nitric oxide production. Drugs were infused into the left coronary ostium and coronary blood flow (CBF) and coronary vascular resistance were evaluated by quantitative angiography and Doppler flow velocity measurements. Twelve hypercholesterolemic patients and 11 control patients with angiographically normal coronary arteries were studied. The vasodilator responses to acetylcholine and bradykinin were reduced in hypercholesterolemic patients compared with control patients (p<0.005 and p<0.04, respectively, by two-way analysis of variance (ANOVA)). The CBF responses to acetylcholine and bradykinin were significantly correlated (r=0.56; p<0.01). Bradykinin-induced dilation was similar in hypercholesterolemic patients and control patients after inhibition of nitric oxide. These results suggest that the bradykinin-mediated endothelium-dependent dilation of coronary resistance vessels may be impaired due to depressed nitric oxide production in patients with hypercholesterolemia.

Aortico–right ventricular tunnel

A successful operation on an infant with a tunnel through which the aorta communicated with the right ventricle is reported. The diagnosis was suspected preoperatively on the basis of two-dimensional Doppler color echocardiography and confirmed by cardiac catheterization. The aortico–right ventricular tunnel originated independently from the left coronary ostium and above the sinus of Valsalva. Patch closure from inside the tunnel under deep hypothermia was successfully performed. Follow-up is satisfactory 5 years later.

Severe Congenital Stenosis of the Left Coronary Artery Ostium and Its Possible Pathogenesis According to Current Knowledge on Coronary Artery Development

We report a 72-year-old woman with severe congenital stenosis of the left coronary artery orifice and clinically significant atherosclerotic changes in both the right and left coronary arteries. The stenotic ostium was located at the point at which the left and posterior aortic valve leaflets joined to form the left commissure, just at the distal vertex of the left interleaflet triangle, between the left and posterior aortic sinuses. The right coronary artery was more developed in size than usual, whereas the left coronary artery consisted of a short left main coronary trunk that bifurcated into left anterior descending and left circumflex arteries. The left coronary artery system was filled retrogradely through two vessels proceeding from the right coronary artery, namely, the conal artery and a well-developed branch that ran across the interventricular septum. This abnormal arrangement of the coronary arteries showed striking functional similarities with atresia of the left main coronary artery. Current knowledge on the morphogenesis of the coronary arteries suggests that the present anomalous coronary artery pattern resulted from the penetration of the anticipated left coronary artery system into the aorta at a totally erroneus site. This hindered the normal development of the ostium, which subsisted as a punctiform, practically nonfunctional opening.