The patient, a 60-year-old non-smoker man with a history of hypertension, dyslipidemia, and PCI on the left anterior descending (LAD) artery 3 years ago was admitted to our hospital with severe chest pain, dyspnea, and diaphoresis. In electrocardiography, sinus rhythm and ST depression (4 mm) were seen in inferior leads (II, III, and aVF). Troponin I level was elevated to twenty times of normal reference value.

He was diagnosed with Non-ST-Segment Elevation Myocardial Infarction (NSTEMI) and underwent coronary angiography via the right radial artery, which revealed significant lesions in the LCX and OM arteries, moderate stenosis (50-60%) in the distal edge of the LAD stent (Figure 1, Movie 1), as well as a thrombotic lesion in the proximal to mid part of the RCA (Figure 2, Movie 2). PCI was performed on the RCA using Xience Alpine 3.5*33 mm stent, followed by sufficient postdilation by NC Saphaire and Vecchio 3.5*18 mm balloons (Figure 3, Movie 3).

Staged PCI for LCX-OM was scheduled two weeks later regarding borderline renal function (Cr=1.3 mg/dl) and after hydration and renal support. Notably, the patient complied well with treatment and received aspirin and clopidogrel as standard strategy. PCI was successfully performed for LCX by Xience Alpine 3.5*15 mm stent and OM by Supraflex 2.75*28 mm stent.

We evaluated the previously implanted stent in RCA, but we were suddenly surprised by the thrombotic lesion in the middle of the stent (Figure 4, Movie 4), and now it was time to seek help from the savior IVUS. IVUS showed a semi-fresh thrombus in the middle of the RCA stent with remarkable stent underexpansion (Figure 5, Movie 5). Therefore, we performed thrombosuction by Capturer thrombus extraction catheter and postdilation by NC TREK 4*15 mm balloon.

During the final control injection, a mobile clot was detected in the proximal part of RCA (Figure 6, Movie 6), necessitating another round of thrombosuction. However, subsequent angiography and IVUS study revealed TIMI grade 3flow in the RCA and demonstrated complete expansion and apposition of the stent struts (Figure7, Movie 7). As a result, the patient was discharged two days later in a stable condition. This case highlights the importance of IVUS in evaluating procedural success, especially for assessing stent expansion and apposition.