Anomalous Intercoronary Communication in the Setting of Chronic Left Circumflex Occlusion

ABSTRACT Intercoronary communication (ICC) is a rare coronary artery anomaly that can be mistaken for collateral flow in chronic occlusive disease, with implications for procedural planning. We report a 77‐year‐old woman with 2 h of retrosternal, burning chest pain, ischemic ST‐segment depression, negative serial high‐sensitivity troponins, and poorly controlled hypertension. Imaging showed coronary calcification and impaired left‐ventricular diastolic function. On Day 3, angiography revealed no significant left main disease, diffuse proximal–mid LAD atherosclerosis, and an occluded left circumflex artery (LCx) distal to second obtuse marginal (OM2), alongside severe mid‐right coronary artery stenosis. Contrast opacified the left system from the RCA via a large channel consistent with ICC. An antegrade strategy was prioritized while recognizing the ICC as a potential retrograde bailout. After plaque shift via OM2 predilation (1.5/2.0‐mm balloons), intravascular ultrasound (IVUS)‐guided stenting (2.75 × 26 mm) required a distal sealing stent (2.5 × 12 mm) for an edge hematoma. With microcatheter support, a Fielder XT wire crossed into the distal LCx, and true‐lumen position was confirmed; subsequent dilatation improved flow, but a distal LCx dissection was identified and confirmed by IVUS. A reverse‐crush two‐stent strategy with final kissing inflations achieved optimal expansion and thrombolysis in myocardial infarction (TIMI) 3 flow. The patient was discharged on dual antiplatelet therapy and remained symptom‐free at 1 month. This case underscores the need to differentiate ICC from collaterals and demonstrates an imaging‐guided, stepwise strategy for bifurcation lesions when wiring is difficult, and complications such as edge hematoma or dissection arise.