Using an Artificial Neural Network to Predict Coronary Microvascular Obstruction (No-Reflow Phenomenon) during Percutaneous Coronary Interventions in Patients with Myocardial Infarction.

The aim of the study was to develop, evaluate, and validate an artificial neural network to predict coronary microvascular obstruction (CMVO) during percutaneous coronary interventions (PCI) in patients with myocardial infarctions (MI) based on the parameters, which are routinely available in an operating room when choosing a surgical approach. Materials and Methods: 5621 patients with MI and emergency PCI were retrospectively selected from the database of the City Clinical Hospital No.13 (Nizhny Novgorod, Russia); among them, there were 3935 men (70%) and 1686 women (30%), their mean age was 61.5±10.8 years. CMVO was recorded in 201 (4%) patients (the blood flow in the infarction-related artery after PCI was less than 3 points according to TIMI flow grade). The following input parameters were assessed: age, gender, past history of coronary artery disease, previous revascularization, presence of ST-segment elevation, a class of acute heart failure, a fact of systemic thrombolytic therapy administration and its effectiveness, symptom-to-balloon time, severity of coronary thrombosis and atherosclerosis, the number of stents and the number of operated coronary arteries. The sampling was divided into a training group (n=4060), a testing group (n=717), and an independent validation group (n=844). Results: We developed an artificial neural network by a fully connected multilayer perception with forward signal propagation and two hidden layers (the area under the ROC curve - 0.69) to predict CMVO based on the subsampling for training and testing. The network model was tested on an independent subsampling (the area under the ROC curve - 0.64, negative predictive value - 97.4%, positive predictive value - 14.6%). Conclusion: The developed artificial neural network enables to use the parameters routinely available in an operating room when choosing a surgical approach and predict CMVO development during PCI in MI patients with accuracy sufficient for practical use.

[Endothelial dysfunction in patients with combined coronary heart disease and chronic obstructive pulmonary disease].

The aim of this work was to evaluate functional incompetence of endothelium in patients with chronic coronary heart disease (CHD, stable angina) combined with chronic obstructive pulmonary disease and to choose the most informative method for the diagnosis of endothelial dysfunction. A total of 103 patients aged 36-66 (mean 57.2 +/- 7.6) years were examined. Group 1 comprised 38 patients with CHD and concomitant chronic obstructive pulmonary disease (COPD). Group 2 included 36 patients with stable angina alone, group 3 consisted of 29 patients with COPD without CHD. Attention is focused on the characteristic of endothelial function by instrumental and laboratory methods. Comparative analysis of the severity of endothelial dysfunction in patients of the three groups revealed different mechanisms of plasma nitrogen oxide dynamics in patients with CHD and/or COPD. CHD and COPD caused mutual aggravation (potentiation) of pathological reactions leading to the development of the disease. Blood levels of nitrogen oxide metabolites in patients with cardiovascular problems or with COPD alone did not reflect the actual amount of "vasodilatory" NO. Reactive hyperemia test is believed to be the most informative method for the assessment of endothelial function in patients with CHD and COPD.

[Effects of beta 1-adrenoblocker bisoprolol on endothelial dysfunction in patients with stable angina pectoris in combination with chronic obstructive pulmonary disease].

AIM: To study effects of a cardioselective beta-adrenoblocker bisoprolol on vascular wall endothelium and external respiration function in stable angina of effort combined with chronic obstructive pulmonary disease (COPD). MATERIAL AND METHODS: Endothelial function and external respiration were studied before and after 4-week treatment with bisoprolol in 36 patients with stable angina and COPD using assessment of endothelium-dependent vasodilatation (EDVD) and concentrations of nitric oxide metabolites. RESULTS: Significant improvement of endothelial function was achieved due to bisoprolol 4-week treatment which did not affect external respiration function. CONCLUSION: Bisoprolol is effective and safe drug in the treatment of stable angina combined with COPD. It can noticeably improve endothelial function.

[A 2-stage method for the surgical correction of calcified aortic stenosis in patients with an extreme degree of risk for an operation]. / Dvukhétapnyi metod khirurgicheskoi korrektsii kal'tsinirovannogo aortal'nogo stenoza u bol'nykh s krainei stepen'iu riska operatsii.

During the period of 1992-1998 the authors dealt with treatment of 32 patients with aortic stenosis under extreme risk of operation. All the patients were considered to be inoperable because of the severity of their state. At the first stage of operation the catheter balloon valvuloplasty (CBV) was performed for decompression of the left ventricle since it was the only possible variant at this stage of surgical treatment. Good results of CBV were obtained in 22 patients which led to the possibility to perform the prosthetizing of the aortic valve in 13 patients within two months at an average. There were no lethal outcomes. Long-term results followed-up during 6 years were estimated as satisfactory.