**4. Conclusions**

Currently, the guidelines approve the use of ECMO support in cardiogenic shock or cardiac arrest patients. There are limited data on the use of ECMO support for PCI in stable angina and NSTE-ACS patients without hemodynamic disturbances. However, the use of ECMO for PCI support has a theoretical and practical rationale and showed encouraging results in our single-center observation. Our single-center experience demonstrated that PCI supported by ECMO may be an alternative for high-risk revascularization (CABG and PCI) for both stable angina and NSTE-ACS patients. The extremely poor prognosis in high-risk patients treated with a pharmacological approach who are often refused a CABG surgery or standard PCI makes PCI + ECMO method very promising as it improves the access to revascularization.

Our experience in this study allowed us to come to the following conclusions. A detailed assessment of the viable myocardium in a group of patients with stable coronary artery disease can improve the 12-month results as a more accurate selection of patients for PCI + ECMO support will be done. A particular attention should be paid to factors that increase the probability of stent thrombosis. The role of this revascularization method for NSTE-ACS patients is more obvious. PCI + ECMO is a life-saving technique that significantly improves hospital and 12-month survival of patients who were refused a CABG surgery or standard PCI. Unfortunately, we do not know the exact indications for ECMO in the elective pre-procedural setting, therefore, we need to develop a methodology (calculator) to immediately assess the need for mechanical circulatory support devices during high-risk PCI. In the end, selection of mechanical circulatory support devices is a matter of a personalized approach and should be based on the results of upcoming large randomized comparative studies.
