Mr AA

70-year-old man with background history of diabetes mellitus, hypertension, dyslipidaemia and chronic kidney disease had percutaneous coronary intervention (PCI) to left anterior descending artery (LAD) 2 years ago. He was referred to our centre for non ST-elevation acute coronary syndrome (NSTE-ACS). He presented with chest pain for 3 days prior to presentation. His blood pressure was 130/70 mmHg with heart rate 70 beat per minute.

Electrocardiogram showed T wave inversion in the anterior leads. Ejection fraction from echocardiography was 50%. Troponin T was elevated at 259 pg/ml (normal <14).  His creatinine level was 170 umol/l (normal <100). The rest of blood parameters were unremarkable.

Coronary angiogram revealed mild left main artery (LM) disease. Left anterior descending artery (LAD) was heavily calcified with severe peri-stent stenosis, under expanded stent and in-stent restenosis (ISR). Left circumflex artery (LCX) had chronic total occlusion at ostial level while right coronary artery (RCA) showed severe calcified stenosis from mid to distal with calcium nodules.

1. Intravascular Lithotripsy (IVL) LAD with Intravascular Ultrasound (IVUS) IVUS revealed diameter at distal LAD 2.6 mm, proximal LAD 4.1 mm, circumferential calcium ring at proximal LAD causing stent under expansion and ISR, Minimal Luminal Area (MLA) 2.55 mm² at tightest point. Pre-dilated distal ISR with Scoreflex 2.75 x 15 mm up to 16 atmosphere (atm) and proximal LAD, however lesions inadequately prepared. Decided to use IVL at proximal LAD 3.5 x 12 mm, shockwave at 4 - 6 atm for 50 pulses. Further prepared with non-compliant (NC) balloon 3.5 x 15 mm up 20 atm. Drug Coated Balloon (DCB) Sequent Please was then delivered to distal stent ISR : 2.75 x 20 mm. Stent Onyx 3.5 x 22 mm was deployed at proximal LAD, overlapped. Post-dilated with 4.0 x 12 mm NC Trek at 18 - 20 atm. IVUS showed well expanded and apposed stent. Mean Stent Area (MSA) 8.15mm² at tightest point.
2. Orbital Atherectomy (OA) Right Coronary Artery with Optical Coherence Tomography (OCT) OA to RCA was a staged procedure and was done 3 days after IVL to LAD.Temporary pacemaker was used as back up. OCT showed distal diameter 3.5 mm, calcium nodules, proximal reference 4.5 mm.
Micro catheter Teleport was used to exchange to Viper wireOA 80,000 - 120,000 rpm for 8 runs at the distal lesion, while 10 runs to the more proximal lesion. The lesions were optimized further with NC baloons.Stent Xience Sierra 3.5 x 33 mm deployed at distal, while at proximal Xience Sierra 4.0 x 33 mm. Post-dilated with NC Trek 4.0 x 15mm at 12 - 24 atm. 

Coronary artery calcification complicates stent delivery and stent expansion. Stent under expansion is a strong predictor of restenosis and stent thrombosis, therefore appropriate plaque modification prior to stent implantation is essential in order to allow adequate device deployment. At present, there are limited options to treat refractory stent under expansion. In this case, the IVL system proven be a safe and effective strategy.  In the same patient we demonstrated another approach, using OA for the other vessel with heavily calcified lesion and calcium nodule. For native heavily calcified coronary vessel, OA provided good lesion preparation with high technical success.