ISCHEMIA trial. The relationship between medical and interventional approach to stable ischemic heart disease treatment. Myocardial ischemia with non-obstructive coronary arteries (INOCA)
Introduction. Approaches to the stable coronary heart disease (CHD) treatment have been the subject to debate a long time. One of the first and fundamental studies in the treatment of stable coronary heart disease patients is the COURAGE trial, which showed the advantage of rational drug therapy in comparison with percutaneous intervention in such patients. However, the CHD high prevalence with medical and social significance necessitate the future consideration of the relationship between medical, that is conservative, and invasive approaches in treatment of this disease. It was particularly the focus of the recently completed multicentre ISCHEMIA trial. Another urgent problem of modern cardiology is myocardial ischemia in non-obstructive (<50% luminal occlusion) coronary arteries (INOCA) identified in approximately 70% of patients who underwent coronary angiography. Aim of the research. Analysis of the available data on the management of stable CHD patients based on the ISCHEMIA trial data and review of publications on the INOCA problem. Results. In the ISCHEMIA trial, the occurrence rate of the primary outcome (cardiovascular death, myocardial infarction (MI), resuscitated cardiac arrest, hospitalization for chronic heart failure) was 13.3% in the routine invasive strategy group and 15.5% in the conservative strategy group ( p = 0.34). The occurrence rate of the main secondary outcomes also did not differ between the groups significantly. Quality of life in the invasive group was higher only in patients who had angina at baseline. The study subanalysis demonstrated that borderline left coronary artery stenosis is associated with a poor prognosis, and an invasive strategy relieves the angina symptoms. Women who participated in the ISCHEMIA trial had a higher incidence of angina attacks, despite less extensive coronary arteries (CA) lesions and less severe ischemia manifestations than men. Among patients with stable CHD accompanied with moderate to severe ischemia and severe chronic kidney disease patients, no evidence for the benefit of the initial invasive strategy in reducing the risk of death or nonfatal myocardial infarction compared to the conservative strategy was found. As for ischemia in non-obstructive coronary arteries (INOCA), it is diagnosed in at least one in five patients who have undergone coronary angiography. This requires the search for new diagnostic methods, verification of risk factors, causes, and optimal treatment approaches. Conclusion. The ISCHEMIA trial data demonstrated the necessity for a more careful selection of patients with stable CHD for invasive treatment, taking into account the angina pectoris severity and modern antianginal therapy possibilities. Management of patients with myocardial ischemia accompanied by non-obstructive CA lesions should be carried out on the basis of the EAPCI Expert Consensus Document on Ischaemia with INOCA (2020) which discusses the genesis of angina, as well as the diagnosis and treatment of this condition.