This 54 y/o man was a case of LICAS, HTN, T2DM, and dyslipidemia. He was an ex-smoker. He also had a family history of CAD. The patient complained of intermittent chest tightness since 6 months ago. He denied exertional dyspnea, exertional chest pain, palpitation, syncope, and productive cough recently. He received a thallium scan at the local medical department, and suspected ischemia was told. Previous CXR showed borderline cardiomegaly. The physical exam showed clear BS, RHB with no murmur.

The baseline 12-lead ECG showed SR with LVH and suspected old inferior MI. The treadmill exercise reported ST-changes reaching criteria for positive results. Echocardiography showed normal LV systolic function with no regional wall motion abnormalities.

LM: patentLAD: proximal stenosis 80%, ostial stenosis 80%, D1 aneurysmal change at the ostium, D1 chronic total occlusion, fistulas between dLAD and LVLCX: patent, with collateral to to PLARCA: proximal chronic total occlusion, with ipsilateral collateral to PDA

1. Tried to wire D1 CTO with RT Floppy under the support of Mizuki micro-catheter and wired RT Hypercoat to dLAD.2. Checked D1 with IVUS, which showed calcified plaque with critical stenosis, though with a lumen size of at least 3.0 mm.3. Dilated D1 with balloon 2.5 x 15 mm up to 6 atm.4. IVUS was performed at LAD and it showed diffuse calcified plaque from LAD ostium to pLAD. The minimal luminal area of pLAD was 8.15 mm². The MLA of LAD was acceptable. 5. Advanced balloon 2.5 x 15 to the dLAD for successfully examining the effectiveness of plugging the fistula from LAD to LV.6. Advanced pressure wire to the dLAD and performed FFR in order to check if the fistulas were physiologically significant. Pd/Pa was 0.79 after administration of 800 mcg adenosine.7. Dilated LAD ostium-pLAD with NC 5.0 x 12 mm up to 10 atm.8. Deployed DES  5.0 x 12mm with stent balloon up to 12 atm for 15 secs.9. IVUS was performed and it showed good apposition and expansion of the stent.10. FFR was performed again at LAD and Pd/Pa turned out to be 0.91 after administration of 800 mcg adenosine. Therefore, we didn't perform any intervention for those fistulas.11. IVUS was passed in order to check if the LCx was jailed by the DES, and it showed that the LCx ostium was fully covered by the stent with adequate flow (IVUS was passed easily through the LCx ostium as well).12. The final flow of LAD and LCx reached TIMI 3 flow.

1. The MLA (8.15 mm²) of p-LAD in this patient far exceeds the determined cut-off value of IVUS-derived MLA (> 5~6mm²).2. Although the MLA is enough, the result of FFR is positive.3. The reverse visual-functional mismatch may be due to insufficient blood supply in the setting of concomitant coronary artery disease(CAD) and coronary artery fistula(CAF).4. In concomitant CAD and CAF, additional functional coronary assessment, rather than only anatomical, can enhance clinical reasoning and help guide management.5. IVUS and anatomical evaluations cannot replace FFR for deciding on revascularization and should be used to optimize stenting outcomes.