A favorable neointimal proliferation healing process of large drug-eluting stent malapposition

Case summary A male patient, 64 years old, was admitted to our hospital because of anterior ST-segment elevation myocardial infarction. Coronary angiography showed a subocclusion of mid-left anterior descending coronary artery (LAD) and a moderate stenosis of proximal LAD. Primary percutaneous coronary intervention was performed and after manual thrombus-aspiration, a zotarolimus drug-eluting stent (DES, resolute integrity 3.0× 38 mm, 12 atm) was implanted in mid LAD. A proximal optimization technique with a semi-compliant balloon (3.5× 12 mm, 14 atm) and a final kissing balloon of LAD-first diagonal bifurcation with semi-compliant balloons (3.0× 20 and 2.0× 20 mm, respectively, 10 atm) were also performed. After 7 days, a repeated coronary angiography and an optical coherence tomography (OCT) were performed to evaluate LAD proximal stenosis. The OCT identified the presence of no obstructive plaque in the proximal tract of LAD and a stent malapposition with a stent–vessel distance of 900 μm located at the proximal stent edge (Fig. 1). In the malapposed area, the OCT also showed a minimal atherotherombotic plaque prolapse through stent strut. We decided not to perform additional procedures and the patient was discharged in double antiplatelet therapy. After 17 months, the patient was readmitted to our hospital because of ischemia silent STsegment depression of 1.5 mm during the exercise stress test. A new coronary angiography was performed, which showed a moderate stenosis of proximal LAD and a patent DES. OCT analysis confirmed the presence of no obstructive plaque of proximal LAD and a complete resolution of stent malapposition (Fig. 2). The OCT showed a complete stent endothelialization and a neointimal proliferation that had ‘filled in’ the space between the stent strut and the vessel wall in the malapposed stent area. In this tract, the minimal lumen area of the stent was the same, measured after 7 days of stent implantation, underlying the favorable role of neointimal proliferation in stent malapposition healing.