Mr X

A 55 year old man with multiple risk factors presented to the district hospital with acute inferior posterior STEMI. He has a history of PCI to RCA in 2012 with drug eluting stents. Thrombolysis was given as per protocol and showed successful reperfusion on ECG. He developed ventricular fibrillation post thrombolysis and was resuscitated and intubated. ECG the next day showed reinfarction with cardiogenic shock and he was transferred to our cardiac centre for emergency revascularization.  

ECG on arrival showed persistent ST segment elevation over the inferior and posterior leads. Troponin was raised and eGFR was 39. He arrived to the catherization lab with pulseless electrical activity (PEA) and femoral access was obtained while CPR was in progress.  Runs of ventricular tachycardia was also observed, requiring multiple episodes of cardioversion during procedure. 

Angiogram showed significant disease in mid left anterior descending artery (LAD) with diffuse disease in the left circumflex artery (LCX). Mid right coronary artery (RCA) was occluded with faint septal collaterals from LAD. RCA occlusion appears proximal to the previous stents on angiography. 

We proceeded with an emergency PCI to RCA with JR 4.0. We attempted with Sion Blue to RCA but our wire entered dissection plane. Using buddy wire technique, Sion black wire was wired into PLV. Lesion was predilated and using a dual lumen catheter, Sion blue wire was wired into PDA. IVUS assessment showed previous stents placed just before the bifurcation were undersized with heavy thrombus burden and in stent restenosis (ISR). Thrombus aspiration was done multiple times and TIMI 3 flow restored. ECG showed resolution of ST segment elevation. We decided to stop and relook later but patient developed multiple episodes of ventricular tachycardia right after removing the wires and angiography showed slow flow distally probably due to thrombus or plaque shift. Immediately rewired with dual lumen catheter support. RCA lesion distal to stent was prepared with Scoreflex 3.0x15 and Sapphire 3.5 x 15 non-compliant balloon was used to expand the previous undersized stents. IVUS assessment showed good lesion preparation and expansion of previous stents. A drug coated balloon (DCB) 3.0x15 was deployed at distal RCA to PLV. The previous stented segments were overlapped with a 4.0x48 drug eluting stent and post dilated accordingly. Final IVUS assessment showed excellent results. There was immediate resolution of ventricular tachycardia and ST segment elevation post PCI.

He was subsequently weaned off ventilator and inotropic support. His ejection fraction via echocardiography and renal function showed marked improvement and he was discharged well. He underwent stage PCI to LAD later on and relook to RCA stent remained well patent. Very late stent thrombosis can occur many years after DES implantation. Undersized stents are a major risk factor for late lumen loss. Coronary imaging using IVUS is an important tool to allow lesion assessment and post PCI optimization while minimizing contrast usage. In patients with impaired renal function, it is important to minimize contrast usage to prevent contrast nephropathy which ultimately leads to poorer prognosis