Long-term Effects of Enhanced External Counterpulsation on the Structural and Functional State of Blood Vessels in Patients With Coronary Heart Disease and Chronic Heart Failure

1. Topic relevance

The dominant positions of coronary artery disease (CAD) in the structure of morbidity, disability and mortality among patients with cardiovascular diseases determine the social significance of this disease. With an increase in the incidence of cardiovascular diseases from 2.483 million cases in 2000 to 4.784 million cases in 2018 (an increase of 193%), there is also an increase in newly diagnosed cases of CAD by 47%. The mortality rate from circulatory diseases in Russia over the past 15 years has decreased from 927.5 to 587.6 per 100,000 population. Achievements of modern medicine (optimization of pharmacotherapy and an increase in the number of revascularization procedures) have contributed to an improvement in the survival rates of patients with CAD. However, with an increase in life expectancy, the economic burden of atherosclerotic diseases and the need to improve the quality of life of such patients increase.

Taking into account the insufficient effect of a conservative strategy in patients with severe stenoses in the coronary bed, a clear increase in the number of revascularization procedures has been observed over the past two decades. However, the limited duration of the effective functioning of stents and shunts, as well as the lack of proven benefits in terms of influencing the prognosis compared to conservative measures do not allow to fully rely on this strategy as well. In the population, there is an accumulation of the proportion of people with refractory angina pectoris, with insufficient effectiveness of the use of conservative and invasive strategies. The basis of this population is patients with progression of multivessel coronary atherosclerosis, microvascular disease, incomplete myocardial revascularization, stenosis or occlusion of shunts / stents, and patients who cannot undergo coronary bypass surgery or stenting, including repeated ones, for various other reasons. In addition, the course of coronary artery disease in such patients is often complicated by chronic heart failure (CHF), which further reduces the quality of life of patients and the prognosis. This determines the search for additional methods of treatment for these patients, which can enhance the effect of conservative and invasive strategies.

Enhanced external counterpulsation (EECP) is an effective non-invasive and atraumatic treatment for patients with coronary artery disease, including complicated CHF. Preference should be given to this method in patients with severe diffuse lesions of the coronary arteries, in case of impossibility or high risk of myocardial revascularization, as well as in case of complication of heart failure. The influence of this method on the contractility of the heart, exercise tolerance and quality of life of these patients has been studied quite well. However, the long-term effects of EECP on the structural and functional state of the vascular bed (the main targets of this method) in patients with coronary artery disease complicated by CHF remain little studied. 2. The novelty of the proposed topic on literary sources and patent documentation. No similarly designed studies were found in the available literature. Scientific novelty It is planned to study long-term vascular effects, the impact on exercise tolerance, quality of life, the frequency of serious adverse events, the impact on the prognosis during the treatment of EECP patients with stable CAD complicated by CHF. It is planned to expand the possible indications for EECP, optimize the treatment of EECP in patients with refractory angina and heart failure. 3. Purpose and objectives of the planned research. Purpose of the study - To study the long-term effects of treatment with EECP on the structural and functional vascular state in patients with stable CAD complicated by CHF.

Research objectives.