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Mitral insufficiency usually accompanies numerous aortic valve diseases. At present, concomitant pronounced mitral regurgitation remains a fairly urgent problem in the transcatheter treatment of aortic valve diseases. During the postoperative period of transcatheter aortic valve replacement, mitral insufficiency tends to decrease in majority of the patients; however, in certain patients, mitral insufficiency persists as well as progresses, highlighting the advantages of this approach over open two-valve surgery. This article presents an analysis of research devoted to functional mitral insufficiency in patients undergoing the interventional treatment of aortic valve diseases. This study included high-risk patients (according to the STS scale of operational risk ≥8%), representing an older age group with a broad spectrum of comorbid pathologies. Some cases were categorised as the New York Heart Association functional class IV, presented with pronounced systolic dysfunction of the left ventricle or were considered inoperable. Based on the systematic review of eight studies, predictors of potential mitral insufficiency progression were identified, and treatment algorithms for this category of patients were studied for the interventional treatment of aortic valve disease. The intervention aims to optimise long-term prognosis, both in open surgery and minimally invasive interventions. The results of the present study will help improve immediate and long-term postoperative outcomes of the interventional treatment of aortic valve diseases. Determining the prognostic development of mitral regurgitation will help select the best management tactics for this complex group of patients, thereby improving treatment outcomes and long-term prognosis of both open surgery and minimally invasive interventions.Received 26 June 2019. Revised 23 August 2019. Accepted 26 August 2019.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.

Construction of distributed control systems for pulp and paper production is under consideration. The complex object is interpreted through functional decomposition as a number of interconnected elementary units. Mathematical description of control objects with decentralized structure and certain mathematical production models are presented. Discussion concerns system structure characteristics and application of distributed systems in industry in terms of economy.

The bleached kraft pulping optimal control problem is discussed. It is formulated in the way of minimizing losses in the end product, energy and chemicals while taking also into account losses associated with the altered product quality properties as caused by random emergency shutdowns of the prime processing equipment. The following three subproblems are analysed - evaluation of the optimal amount of stock in buffer vessels with regard to emergency shutdowns - determination of the interconnected facilities optimal output in case one of the units fails - optimal problem for attaining preset conditions.