Excerpt

An 80-year-old man with a history of pacemaker implantation due to atrioventricular block and bare-metal stent implantation at mid-left anterior descending artery (LAD) due to angina pectoris was admitted to our hospital because of silent myocardial ischemia. On admission, his electrocardiogram showed normal sinus rhythm with wide QRS waveform under ventricular pacing, and echocardiogram showed no left ventricular wall motion abnormalities. Coronary angiography demonstrated 75% in-stent restenosis at the mid-LAD (Fig. 1a). Fractional flow reserve (FFR) at the distal LAD revealed low FFR value of 0.63. FFR pullback from distal LAD significantly increased to 0.98 at the proximal LAD, which showed 25% stenosis on coronary angiography; there was no significant pressure gradient at the mid-LAD, which had 75% in-stent restenosis (Fig. 1a, b). To assess the decrease of FFR value at the proximal LAD, we performed optical frequency domain imaging (OFDI), which revealed an intracoronary wall partition that divided the lumen into two chambers (Fig. 1c). Subsequently, high-vision coronary angioscopy (Forwardlooking^®, OVALIS, Osaka, Japan) was performed. Coronary angioscopy clearly demonstrated fibrous wall partition with a red thrombus that was similar to the finding on OFDI (Fig. 1d).

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