Despite obvious progress of cardiac surgery, a low left ventricular ejection fraction is an important independent predictor of a high rate of complications and increased in-hospital lethality in open surgical interventions. On this ground, promising seems to be a method of endovascular myocardial revascularization, which is associated with a minimal number of intraoperative and postoperative complications. However, by means of transcutaneous coronary intervention (TCI) it is not always possible to perform complete anatomical myocardial revascularization. The subject concerning the necessity of complete myocardial revascularization, changes of anatomy and physiology of the heart, clinical state of patients with a low left ventricular ejection fraction after endovascular intervention has not been sufficiently explored. In order to clear up these problems we carried out a prospective single-centre study including a total of 151 patients suffering from ischaemic heart diseases with a left ventricular ejection fraction of less than 35%, who were subjected to endovascular myocardial revascularization. The patients were divided into two groups: with complete (n=87) and incomplete (n=64) revascularization. All patients before and 6 months after the intervention underwent echocardiographic examination with the measurement of the left ventricular ejection fraction, stroke volume, end-diastolic volume and assessment of the functional class of angina pectoris. The obtained findings are indicative of efficacy of both complete and incomplete endovascular myocardial revascularization in patients with a low left ventricular fraction. No statistically significant difference by the examined parameters between the patients of both groups was revealed.