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Biomedical subjects

A N Samko

Publications and source records attributed to A N Samko.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Immediate and long-term results of implantation of the coronary stent "BioDiamond"].

AIM: To assess immediate and long-term outcomes after BioDiamond-stent implantation in patients with native coronary artery disease. MATERIALS AND METHODS: The BioDiamond stent was implanted in 112 patients with 132 de novo lesions. Most patients (54%) had unstable angina, 33% of the lesions were of type B2-C. RESULTS: No stent deployment failure occurred as well as acute or subacute stent thrombosis. The 6-month angiographic follow-up was obtained in 108 patients (98%) (125 lesions). The loss index was 0.40 +/- 0.27. Angiographic restenosis rate occurred in 14%. Repeat target lesion revascularization was successful in 16 patients with restenosis. CONCLUSION: The results of this study indicate a potential benefit of BioDiamond for prevention of stent thrombosis and restenosis in these relatively high-risk patients.

Adult↗
PubMed2002

[Serum level of secretory phospholipase A2 (sPLA2) as a predictor of restenosis after coronary angioplasty].

AIM: To elucidate whether secretory phospholipase A2 (sPLA2) level in the blood and catalytic activity are significant predictors of restenosis after coronary angioplasty (CAP). MATERIAL AND METHODS: Samples of venous blood were obtained from 24 patients before CAP and 1, 3, 6 days and 6 months after it. sPLA2 was measured with enzyme immunoassay, catalytic activity--using aqueous emulsion of 14C-labelled phosphatidylcholine. Control coronarography was performed in all the examinees 6 months after CAP. RESULTS: Restenosis was detected in 13 patients. In the serum of their blood sPLA2 rose significantly after CAP and persisted for 6 days after it. If restenosis was not registered, this rise was insignificant and disappeared by day 6 after CAP. Catalytic activity of sPLA2 on day 6 after CAP was significantly higher in patients who later developed restenosis. CONCLUSION: Elevated concentrations of sPLA2 in blood serum of patients after CAP may predict restenosis. Moreover, sPLA2 may not only mark inflammation but directly participate in development of restenosis.

Adult↗
PubMed2002

[Increased expression of monocytic cell adhesion molecules and formation of monocyte-thrombocyte aggregates in coronary restenosis].

AIM: To examine expression of superficial antigens by blood monocytes and granulocytes as well as the number of leukocyte-platelet complexes forming in in vitro activation in patients subjected to coronary angioplasty; to analyse changes in these parameters in coronary restenosis. MATERIAL AND METHODS: Membrane expression of leukocytic antigens and the number of leukocyte-platelet complexes after activation in the whole blood were measured by direct immunofluorescence and flow cytometry in 24 patients who have undergone stenting of coronary arteries. 14 of them had angiographically confirmed restenosis. RESULTS: The tests discovered high expression of integrins Mac-1 and VLA-4 by monocytes and elevated relative number of monocyte-platelet complexes in patients with restenosis vs those free of stenosis (1425 +/- 76 and 1195 +/- 71 r.u. for Mac-1, 87 +/- 7 and 65 +/- 6 r.u. for VLA-4, 47 +/- 4 and 29 +/- 3%, respectively, for monocyte-platelet complexes; p < 0.05 for all the indices). CONCLUSION: Coronary restenosis may result from elevated expression of adhesion molecules by monocytes manifest in activation of the cells in vitro.

Angioplasty, Balloon, Coronary↗
PubMed2002

[Prolonged pulmonary artery pressure monitoring in patients with pulmonary hypertension].

Pulmonary artery pressure (PAP) was monitored for 24-48 hours in 10 and 8 patients with primary and secondary pulmonary hypertension, respectively. The data obtained were compared with results of prolonged PAP monitoring in 2 healthy volunteers. Variability of mean PAP was 7.43-/+3.1, 5.78-/+1.64, and 3.4-/+0.63 mm Hg, coefficient of variability - 10.39-/+3.68, 13.04-/+6.01 and 22.73-/+8.03% in patients with primary and secondary pulmonary hypertension and healthy subjects, respectively. After surgery in patients with secondary pulmonary hypertension coefficient of variability rose from 13.04-/+6.01 to 16.7-/+12.8%, while variability decreased from 5.78-/+1.64 to 4.3-/+1.65 mm Hg. Level of spontaneous fluctuations of PAP was the highest in healthy subjects (71.4%) and the lowest - in patients with primary pulmonary hypertension (34.9%). Thus PAP variability is a widespread phenomenon which should be taken into consideration during right heart catheterization and acute pharmacological tests.

Adolescent↗
PubMed2002

[Invasive cardiology: focus on restenosis. Part II].

In-stent restenosis represents a pathological process which histology is different from that of restenosis after balloon angioplasty. In-stent restenosis is mainly caused by neointima proliferation. This part of review deals with technologies of prevention of in-stent restenosis including novel stent designs and coatings aimed at suppression of neointima proliferation.

Angiogenesis Inhibitors↗
PubMed2002

[Coronary angioplasty with direct stenting: assessment of primary results and some economical aspects].

UNLABELLED: Comparison of immediate angiographical and clinical results of direct coronary stenting and stenting after predilation was carried out in 68 patients. Groups of patients subjected to direct stenting and stenting with predilation had similar clinical and angiographical characteristics. Direct stenting was successful in 100%, stenting with predilation--in 97.2% of patients with residual stenosis 5.1 and 4.9%, respectively. There were no cases of stent loss, death or emergent bypass grafting during neither the procedure nor period of hospitalization. There was 1 Q-wave myocardial infarction (2.8%) and 2 non-Q wave myocardial infarctions (1 in each group). Compared with stenting with predilation procedure of direct stenting was associated with significantly shorter procedure duration (39-/+7.1 min, 60-/+12.5 min, respectively), radiation exposure time (7.9-/+6.3 and 13.5-/+8.9 min, respectively), lower workload of the laboratory (4.9-/+3.5 and 6.1-/+2.0 patients/day, respectively), decreased consumption of contrast medium (200-/+71 and 275-/+75.9 ml, respectively), and thus lower overall cost of the procedure. CONCLUSION: Direct coronary stenting is a convenient, safe and economically justified method of stent implantation.

Angioplasty, Balloon, Coronary↗
PubMed2002

[Pharmacodynamics, safety, and clinical effects of a novel glycoprotein IIb/IIIa antagonist framon during high risk coronary angioplasty].

Preparation framon [F(ab')2 fragments of the anti-glycoprotein (GP) IIb/IIIa monoclonal antibody (FRaMon)] blocks fibrinogen binding to GP IIb/IIIa and platelet aggregation. Dynamics of platelet aggregation inhibition, safety, and clinical effects of framon were studied in high-risk coronary angioplasty. Twenty seven patients underwent angioplasty with framon, 29 - with abciximab and 28 - with no GP IIb/IIIa antagonists. Framon at 0.2 mg/kg (n=16) and 0.25 mg/kg (n=11) bolus administration inhibited platelet aggregation induced by 20 mcM ADP by more than 90%, 80%, 60% and 30% in comparison with the predrug level 1, 12, 24 and 72 h after injection, respectively. Almost the same dynamics of aggregation inhibition was observed upon abciximab administration at 0.25 mg/kg bolus + 0.125 mcg/kg/min infusion for 12 h. No signs of individual intolerance and side effects including allergic reactions and bleedings were detected in patients treated with framon. Slight decrease of platelet count (15-20%) was observed on the first day after framon administration. Antibodies against framon were detected in 1 out of 22 tested patients. Free (nonbound to platelets) framon was completely removed from the circulation 12 h after injection. The number of endpoints (death, myocardial infarction and indications for repeat revascularization) within 1 year after angioplasty was approximately the same in the groups with framon and abciximab - 7 of 25 (28%) and 7 of 28 (25%), respectively, and more than 1.5 fold higher in the group without GP IIb/IIIa blockers - 12 of 27 (44,4%).

Angioplasty, Balloon, Coronary↗
PubMed2002

[Clinical and angiographical results of the use of the EPHESOS stent in patients with coronary artery atherosclerosis].

The Ephesos is a new balloon-expandable, stainless steel, tubular stent with multicellular design. This open nonrandomized study assesses the immediate and long-term clinical and angiographic outcomes after Ephesos implantation in patients with native coronary artery disease. The Ephesos was implanted in 168 patients with 198 de novo lesions. Most patients (56%) had unstable angina, and 38% of lesions were type B2-C. The mean lesion length was 12.5-/+7.2 mm, and 29% of lesions were >15 mm in length. No stent deployment failure occurred, as well as acute or subacute stent thrombosis. In-hospital non-Q-wave myocardial infarction occurred in 2 patients. The 6-month event-free survival was 83.9%. Two patients with no restenosis in the target vessel died of fatal infarction due to abrupt closure of a nontarget vessel. The 6-month angiographic follow-up was obtained in 164 patients (98%) (192 lesions). The loss index was 0.27-/+0.25. Angiographic restenosis rate was 12%. Twenty patients with restenosis had repeat target lesion revascularization. The results of this study indicate a potential benefit of EPHESOS for the prevention of stent thrombosis and restenosis in these relatively high-risk patients.

Adult↗
PubMed2001

Monocyte integrin expression and monocyte-platelet complex formation in humans with coronary restenosis.

1. In the present study, we sought to determine whether patients with restenosis after coronary stenting possess increased monocyte reactivity, as manifested by a higher level of adhesion molecule expression and an enhanced propensity to form monocyte-platelet aggregates after activation in vitro. 2. Anti-coagulated peripheral venous blood from 24 patients, 10 with and 14 without angiographically verified restenosis, was obtained. Leucocyte antigen expression and the number of leucocyte-platelet complexes were measured by flow cytometry after activation in whole blood. 3. Surface integrin Mac-1 (CD11b/CD18) and VLA-4 (CD49d/ CD29) expression on monocytes and the relative number of monocyte-platelet complexes after in vitro activation were significantly elevated in patients with restenosis compared with patients without restenosis (fluorescence intensities of 1425 +/- 76 vs 1195 +/- 71, 87 +/- 7 vs 65 +/- 6 and 47 +/- 4 vs 29 +/- 3% for for Mac-1, VLA-4 and monocyte-platelet complexes, respectively; P < 0.05 for each parameter). 4. The results suggest that restenosis is associated with increased monocyte VLA-4 and Mac-1 integrin expression and monocyte-platelet complex formation, which can be revealed after activation in vitro.

Blood Platelets↗
PubMed2001

[Myocardial microcirculation in patients with systemic lupus erythematosus].

AIM: To examine myocardial microcirculation in patients with SLE. MATERIAL AND METHODS: Examination of 21 SLE patients consisted of perfusion tomoscintigraphy of the myocardium with Tl-201 at rest and in combination with bicycle exercise. Various protocols were used. RESULTS: The majority of SLE patients had resting disorders of myocardial perfusion: 5 had macrofocal scar lesion of the myocardium, 12 had disorders typical for small-focal myocardial fibrosis. Normal distribution of the perfusion occurred in 4 cases. Tomoscintigraphy performed in combination with exercise test revealed in 11 of 15 patients transient perfusion disturbances reflecting transient myocardial ischemia. One third of the patients had changes characteristic of myocardial ischemia due to coronary atherosclerosis. CONCLUSION: SLE patients have disorders of myocardial perfusion including those characteristic of scar lesion, small-focal cardiofibrosis and transient myocardial ischemia of different genesis: due to disorders in microcirculation and atherosclerotic lesion of major coronary arteries.

Adult↗
PubMed1999

Left ventricular remodelling: common process in patients with different primary myocardial disorders.

Currently the problem of left ventricular remodelling in the early and late stages after myocardial infarction are under intense study. Studies of the role of remodelling of the left ventricle in patients with long-term arterial hypertension have been recently initiated. The purpose of this investigation was to study whether left ventricular remodelling is common for different primary myocardial disorders. The study population consisted of 212 patients with primary myocardial lesions (121 with dilated cardiomyopathy, 45 with chronic myocarditis and 46 with prolonged damage of the myocardium with alcohol; 196 male and 16 female, mean age 42.6+/-11.3 years) and 32 age matched normal subjects (24 male and eight female). Cardiac catheterization for ventriculography and coronary angiography was performed in all subjects for detection of left ventricular haemodynamics, including chamber volume and shape at end-systole and end-diastole. Worsening of heart failure was associated with a progressive enlargement of the left ventricle, with increases in end-systolic left ventricular wall stress, that lead to increases in left ventricular muscle mass, alteration of left ventricular geometry from a more ellipsoid to a more spherical shape and a progressive decrease of relative wall thickness index that reflects inadequate enlargement of the ventricular chamber in comparison with the increase in muscle mass. This process of left ventricular remodelling was common to all the primary myocardial disorders studied. Thus, regardless of the different etiological nature, most primary myocardial disorders show a similar left ventricular remodelling process suggesting common mechanisms for the development of chronic heart failure.

Adult↗
PubMed1995

[Magnetic resonance tomography of the heart and major vessels in patients with pulmonary hypertension].

Potentialities of magnetic resonance imaging (MRI) have been studied for evaluation of patients with pulmonary hypertension. For this purpose 54 patients with primary and secondary pulmonary hypertension have been studied using resistive and superconductive MRI systems. MRI proved useful for determination of the cause of pulmonary hypertension (primary, secondary), assessment of the right heart chambers. The cine-MRI enabled detection of tricuspid and pulmonary regurgitation, paradoxical movement of the interventricular septum, thrombi in the pulmonary artery. There were some correlations between MRI parameters and indexes of pulmonary hemodynamics. As a non-invasive imaging modality MRI has a great diagnostic value in characterization of the heart and great vessels in patients with pulmonary hypertension.

Adolescent↗
PubMed1994

[The results of catheterization and the x-ray angiographic assessment of cardiac contractility and volume in primary pulmonary hypertension].

To ascertain the role of invasive investigations in the diagnosis of primary pulmonary hypertension (PPH), 12 PPH patients underwent catheterization of the left and right heart compartments, contrast right and left ventriculography and oximetry. Compared to control values, the patients had high pressure in the pulmonary artery and right ventricle. Some of them exhibited elevated pressure in the right atrium. Pulmonary artery wedge pressure, left ventricular end-diastolic and systolic, diastolic pressure in the aorta did not differ significantly from those in the controls. Right and left ventriculography revealed an increase in the end-systolic and end-diastolic volumes of the right ventricle which diminished its stroke index and ejection fraction. The latter two were reduced in the left ventricle also. Because the procedure was well tolerated by the patients, it is recommended for PPH diagnosis and follow-up.

Adult↗
PubMed1993

[Decreased tonus of the epicardial coronary arteries in patients with dilated cardiomyopathy].

The tone of coronary artery (CA) was evaluated in 26 patients with dilated cardiomyopathy (DCMP) and 20 patients with atypical chest pain, intact CA, and normal left ventricular contractility served as controls. All the patients underwent selective polyviewed coronarography, left and right ventriculography. The configurations of the great CA were examined by a computer which calculated their mean diameter in diastole (Dd) and systole (Ds), their difference (d) and the elasticity index (EI) by the formula: d/Dsx 100%. Twelve patients with DCMP and 10 control patients had repeated left coronary contrasting after intracoronary injection of nitroglycerin, 150 mg, they authors calculated the baseline Dd (Dd1), Dd after nitroglycerin (Dd2), the degree of nitroglycerin-induced CA dilation. Ds was found to be greater than Dd in the two groups. The mean CA diameter was significantly more in DCMP patients who had lower D and EI. Intracoronary nitroglycerin injection caused a less marked increase ion the Dd of the anterior descending CA in DCMP patients. Thus, the computer-aided analysis of coronarograms and nitroglycerin test allowed one to quantitatively determined the decreases in CA in DCMP.

Biopsy↗
PubMed1992

[Cellular mechanisms of impaired cardiac energetics in patients with dilated cardiomyopathy: decrease in mitochondrial respiration and creatine kinase expression].

The mitochondrial functional characteristics were assessed in the biopsy specimens from patients with various Functional Classes dilated cardiomyopathy (DCMP). The assessment was made by using endomyocardial biopsy specimens weighing 2-4 mg which had been taken from 39 patients aged 19-64 years during coronary ventriculography and cardiac transplantation. The status of mitochondria and the efficiency of mitochondrial creatine kinase functioning were evaluated by recording the respiration of saponin-skinned muscular fibers. The maximum mitochondrial respiration rate calculated on a dry weight basis was not substantially different in all functional classes of DCMP, while the acceptor control index (Vmax/V0) and the level of creatine-activated respiration decreased with an increase in the functional class of DCMP. The findings show a good positive correlation between ejection fraction and creatine-stimulated respiration values and a linear negative correlation between this parameter and end-diastolic pressures. Thus, the respiratory parameters of mitochondria in the endomyocardial biopsy specimens may be used to assess the severity of cardias lesions.

Adult↗
PubMed1991

[Evaluation of the overall contractile function of the right ventricle using two-dimensional echocardiography in patients with myocardial infarction].

The paper presents two methods for calculating the contractile function of the right ventricle (RV): (1) three-plane one with the use of short- and long-axis-cut RV; (2) single-plane one which was modified to the use of long-axis RV images in the projection of 4 chambers. A total of 56 patients with first acute gross myocardial infarction were studied. A control group included 14 healthy subjects aged 25-60 years. The proposed three-plane method for estimating the volume parameters and ejection fraction of the right ventricle was shown to correlate with contrast ventriculography significantly. A high correlation was found between the stroke output of RV (as calculated for the left ventricle by the Chapman method) and that (by the three-plane method). The RV volume values in patients with anterior or inferior myocardial infarction suggest that there is a trend to suppress RV function in the patients, but it is more specific for those with inferior myocardial infarction.

Adult↗
PubMed1991

[Effects of restored blood flow on the contractile function of the right ventricle in patients with acute myocardial infarct: data of two-dimensional computerized echocardiography].

The volumes of the right and left ventricles were measured in 78 patients with first acute transmural myocardial infarction at days 1, 3, 7, 14, and 28 of the disease. Thirty four patients were diagnosed as having anterior myocardial infarction, 35 presented with inferior myocardial infarction, and 9 had a concurrent right and left ventricular inferior wall myocardial infarction. A high incidence of right ventricular dysfunction was confirmed both in anterior and inferior myocardial infarction. The most profound right ventricular contractile dysfunctions were detected in patients with proximal right coronary occlusion in the absence of reperfusion. Successful thrombolytic therapy for myocardial infarction was found to affect right ventricular function to a lesser extent than left function.

Adult↗