Case of the month

A 66 year old man was admitted to Deutsches Herzzentrum München with an acute coronary syndrome.

Two months previously he received a drug eluting stent to his right coronary artery and had been maintained on dual anti-platelet therapy.

He underwent emergency coronary angiography which revealed a thrombotic occlusion of the distal portion of his stent (Figure 1).

Figure 1
Initial Right Coronary Artery Angiography
A Catheter
B Right coronary artery
C Filling defect due to thrombotic occlusion of right coronary artery stent.

Intra-coronary optical coherence tomography (Figure 2) confirmed the presence of thrombus and demonstrated stent strut malapposition.

Figure 2
Optical Coherence Tomography (OCT) of the Right Coronary Artery.
The OCT catheter is seen in the centre of the picture.
The guidewire (G) is adjacent and casts an optical shadow.
Stent struts (S) demonstrate a characteristic bright blooming pattern with radial optical shadowing.
The vessel lumen (L) contains thrombus (T) with an irregular margin.
At two months post-implantation there is little evidence of neointimal re-growth over the stent struts however strut malapposition (SM) is seen.

Normal flow was restored following thrombus aspiration and implantation of a drug-eluting stent (Figure 3).

Figure 3
Coronary angiography post-stenting.
Contrast from the catheter (A) shows the Right Coronary Artery unobstructed from proximal (B) through to distal segment (D). Guidewire (G)

Stent malapposition due to under-deployment at initial implantation can predispose to stent thrombosis. The patient had been adherent to his therapy and platelet function testing showed no evidence of resistance to clopidogrel. The patient made a full recovery and was subsequently discharged without any change in anti-platelet therapy.