A 47-year-old diabetic Bangladeshi male with prior two-vessel disease history, PCI was done abroad about 4 months prior. He came to Malaysia, working as contract labourer, with financial limitation. Patient presented with typical anginal chest pain, similar to prior event, and relieved by GTN. ECG showed ST depression at II, III, and aVF, and patient was diagnosed with NSTEMI. Exam revealed stable vitals, physical examination was unremarkable. He was admitted to ward and send for PCI urgently.

Renal profile                      : Creatinine 89 µmol/L, Urea2 mmol/L, Na 136 mmol/L, K 3.7 mmol/L, eGFR >90 mL/min/1.73m².Troponin I                            : 119 ng/L (elevated).FBC                                           : Hb 13 g/dL, Plt 235 x10⁹/L, TWC 8 x10⁹/L.Chest X-ray                           : no evidence of heart failure, No consolidation seen

The previous PCI was done abroad, no formal result or PCI notes available, patient was unsure about the exact findings. Coronary angiogram was challenging due to difficult engagement of RCA. After careful engagement, RCA showed ISR at ostial to proximal area, Mehran class III (proliferative). There was significant stent protrusion estimated around 8mm into the aorta with deformation mid stent. Left anterior descending artery (LAD) and Left circumflex artery (LCX) showed mild disease.

This PCI addressed a challenging case of significant in-stent restenosis (ISR), where the prior stent protruded into the aorta and deformed, almost completely obstructing blood flow to RCA.Through femoral access, a Judkins Right (JR) 3.5 catheter was used to engage the RCA, with navigation complicated by the previous stent’s deformation. The operator could only manage to engage to side of the previous deformed stent into the RCA. A Runthrough floppy guidewire was then carefully positioned to the posterior descending artery(PDA). High-pressure balloon dilations were used: an NC Trek (2.5 x15 mm) balloon was inflated at 20 ATM, followed by a Scoreflex (3.0 x 15 mm) balloon at 24 ATM to secure vessel expansion and stabilize the stent.The initial plan was to place a DCB, however in view of significant recoil, the team decided for placement of Xience Sierra drug-eluting stent (DES), 3.5 x 18 mm deployed at 16 ATM from proximal to ostial RCA overlapping the previous stent. Further post-dilatation done with NC Trek 3.5 x 15 mm balloon at 20 ATM, and flare at 24 ATM at the ostium, achieving optimal vessel apposition. The outcome was successful, with TIMI III flow restored and no complications such as dissection, perforation, or adverse ECG changes.This case illustrated the procedural complexity and skill needed to manage complication of severe restenosis involving a deformed stent, technical difficulty to engage and stabilize, choice of DES vs DCB usage, to prevent future ISR.

This PCI case highlights the importance of a structured approach to complex in-stent restenosis (ISR), especially when mechanical stent issues are present. Preventing similar complications in the future requires thorough pre-procedural strategy, usage of imaging such as intracoronary imaging (IVUS/OCT) whenever possible, proper usage of DCB or DES, and careful catheter navigation to avoid further stent damage is crucial. High-pressure ballooning and the use of DES remain effective in managing ISR. Each case enriches our strategies for complex ISR, ensuring even high-risk cases are managed with precision and confidence.