PCI to the ostial RCA was performed. Multiple 6F guides were used including JR4 with side hole, AL0.75 with side hole, AR1 with side hole, XBRCA with side hole, and JR3.5 with side hole. Finally, a JR5 guide successfully engaged the RCA. Wiring the ostial RCA was difficult but was eventually done with a Fielder wire (Fig. 5.2a, Videos 5.3 and 5.4). Although the initial strategy was to perform rotational atherectomy, the lesion could not be crossed with a Finecross microcatheter due to the severe calcific stenosis and lack of guide support (Fig. 5.2b). Predilation with 1.0 and 1.5 mm semi-compliant balloons had to be performed before a Finecross catheter could cross the lesion (Fig. 5.3a, b). The Fielder wire was then exchanged out for a Rota extra-support wire. The rotational atherectomy was then successfully performed with a 1.25 mm burr (Fig. 5.4, Video 5.5). Once rotational atherectomy was performed, the lesion was further modified with a 2.5 × 10 mm AngioSculpt scoring balloon at high pressures (Figs. 5.5 and 5.6). Video 5.6 shows the RCA after predilatation with semi-compliant and scoring balloons (Video 5.6). After that, 2.5 and 3.0 mm DES were then implanted and post-dilated with 2.75 and 3.5 mm non-compliant balloons with excellent final angiographic results (Fig. 5.7, Videos 5.7 and 5.8).