 Prerequisites for TRI were a sufficiently pulsating radial artery and presence of an ulnar pulse with a sufficient palmar arch, as evidenced by the absence of digital ischemia according to the Allens test. Exclusion criteria for the current study included planned use of a cutting balloon, rotational atherectomy, directional coronary atherectomy, and intravascular ultrasound, which were not compatible with 4-Fr catheter. 