Introduction.When evaluating angiographically marginal coronary stenoses (i.e. 40-70% reduction of the diameter of the arterial lumen) it is under certain conditions difficult to decide on their actual functional impact. Assessment of the fractional flow reserve (FFR) is a simple method based on assessment of intracoronary pressures during pharmacologically induced hyperaemia. For the severity of stenosis according to previous studies the liminal values is FFR lower than 0.75; furthermore it was proved that intervention of angiographically marginal stenoses with FFR values of 0.75 or more can be safely postponed. Objective: Test the safety of FFR examination and take in a group of patients with marginally severe stenosis further steps according to results of FFR assessment. Material and methods: During the period from January to Juky 2000 FFR asses- sments were made in a total of 34 patients (11 women, 23 men, mean age 62 ± 12 years) who suffered from marginal stenosis of some coronary vessel. The FFR examination took place under pharmacologically induced hyperaemia after intracoronary adenosine administration. Results. Measurements were made in a total of 41 stenoses. Only in two a value lower than 0.75 was found. In these patients coronary intervention was implemented; intervention was also made in two patients on account of technical problems and inconsistent results of FFR measurements. A FFR value of 0.75 or less was found in 37 stenoses (90 %) and intervention was therefore postponed. Examination and the immediate subsequent course were without complications. Conclusion. Ac- cording to initial experience FFR examination is a safe, simple and easily reproducible method. Based on the results of assessment and knowledge of the accomplished studies in the group of marginally significant stenoses in a great proportion of patients coronary intervention was po- stponed.

        Key words: Coronary angioplasty - Myocardial fractional flow reserve - Ischaemic heart disease