BACKGROUND Noninvasive assessment of the fractional flow reserve (FFR) in patients with coronary artery disease plays an important role in determining the need for revascularization. It is particularly relevant for patients with a borderline stenoses and painless myocardial ischemia. Our article describes the first clinical experience in the Russian Federation of using an automated method of noninvasive assessment of the fractional flow reserve (FFRct) with a one-dimensional (1-D) mathematical model in a patient with painless myocardial ischemia. CASE REPORT A 58-year-old male patient who underwent stent implantation in the left circumflex coronary artery (LCX) due to an acute non-ST-elevation posterior myocardial infarction had borderline stenoses of the left anterior descending artery (LAD). After stent implantation, there were no relapse angina symptoms on drug treatment, and according to our examination guideline for patients with borderline stenoses, a treadmill test was performed. The test was positive; therefore, FFR assessment was recommended, with coronary multi-slice CT being performed. The following results were obtained: FFRct LAD - 0.57; FFRct LCX - 0.88. An invasive assessment of FFR was also performed as a reference standard and revealed: FFR LAD - 0.6; FFR LCX - 0.88, and simultaneously a LAD percutaneous coronary intervention (PCI) was performed. Three months later, the patient underwent a stress test, which revealed no evidence of induced ischemia. CONCLUSIONS Our method of noninvasive assessment of FFR has shown encouraging results, but we believe that larger-scale studies are needed to establish it as common clinical practice.