1) LMCA: atherosclerosis    M/3: discrete; eccentric lesion; 40% stenosis; 2) LAD: atherosclerosis    P/3: total occlusion 3) LCX: atherosclerosis    P/3: diffuse; eccentric lesion; 70% stenosis;  4) RCA: atherosclerosis    P/3: discrete; eccentric lesion; 95% stenosis; TIMI 2 flow    M/3 to D/3: diffuse; eccentric lesion; 70% stenosis; TIMI 2 flow 5) VG to OM: patent 6) VG to DB: patent 7) VG to PDA: patent, but slow flow 8) LIMA to LAD: patent

1. The RCA ostium was engaged by SAL 1.0 guiding catheter.2. The Sion black wire was used to cross the RCA lesion and landed at distal PL.3. The Proximal RCA lesion was dilated by a 1.5X20 mm balloon. 4. Pressure wire was used to evaluate the effect of PDA graft on RCA and PL. The RFR showed 0.64 at PL, 0.68 at D/3 RCA and 0.70 at M/3 RCA.5. The RCA lesion was dilated by a 3.0X20 mm NC balloon and the proximal PL lesion was dilated by a 2.0X20 mm balloon.[IVUS] The MLA of the lesion is 3.78 mm2, circumferential calcification was noted. The plague burden was 81%.6. The RCA lesion was dilated by a 2.5X10 mm Cutting balloon to break the circumferential calcification.7. The D/3 RCA to PL lesion was stented with a 3.0X38 mm Stent and post-dilated with a 3.5X15 mm NC balloon with stenosis from 50% to 0%.8. The M/3 to D/3 RCA lesion was stented with a 3.5X48 mm Stent and post-dilated with a 3.5X15 mm NC balloon.9. The P/3 RCA lesion was stented with a 3.5X33 mm Stent and post-dilated with a 4.0X12 mm NC balloon.10. The pressure wire was used to evaluate the stent effect. However, the RFR showed 0.75 at D/3 of PL, 0.92 at P/3 of PL and 0.93 at RCA.11. The distal PL was dilated by a 2.0X20 mm Trek balloon and then stented with a 2.5X22mm Stent. Post-dilatation with a 2.5X15 mm NC balloon.12. The RFR showed 0.85 at D/3 PL and 0.97 at RCA.[IVUS] MSA is 8.81 mm2, well position and expansion were noted.13. Final angiography showed <10% residual stenosis with TIMI 3 flow.

We present a case following CABG with recurrent angina pectoris. The patient exhibited a patent vein graft but with slow blood flow in both the native RCA and the vein graft to PDA. Physiological evaluation provided valuable guidance in determining the need for intervention and identifying the lesions requiring treatment. While the utilization of resting full-cycle ratio (RFR) in bypass vein grafts lacks extensive study, this case highlighted a functionally suboptimal distal myocardial segment using RFR, prompting intervention for the physiologically significant lesions. Following stenting, the patient experienced an improvement in angina symptoms and was discharged without complications.