Acute Stent Thrombosis: Severe In-Stent Malapposition and Insufficient Platelet Inhibition as Partners in Crime!

J INVASIVE CARDIOL 2021;33(5):E400.

Key words: acute stent thrombosis, stent malapposition, optical coherence tomography, insufficient platelet inhibition, morphine

A 65-year-old man underwent primary angioplasty and stent implantation on the proximal left anterior descending (LAD) coronary artery. Morphine 10 mg, heparin, and ticagrelor loading dose were administered during the procedure. However, 6 hours post procedure, the patient experienced cardiac arrest due to ventricular fibrillation. We repeated an urgent coronary angiography (Figure 1A), which showed an acute stent thrombosis (ST). Since the P2Y₁₂ reactivity unit (PRU) value was 212 (corresponding to 12% platelet inhibition) as assessed by VerifyNow assay (Accumetrix) after cardiac arrest, we administered tirofiban. We were not able to overcome the acute ST of the LAD with workhorse wires, and instead performed a rapid step-up to a Fielder XT-A (Asahi Intecc) supported by a FineCross microcatheter (Terumo). We quickly gained the distal LAD (Figure 1B and Video 1). After manual thrombectomy, we performed optical coherence tomography (OCT), which revealed a severe in-stent malapposition (Figure 1C). After additional manual thrombectomy, 1 drug-eluting stent was implanted at the proximal edge of the previous stent to cover the residual disease. The final angiographic result was good (Figure 1D).

Acute ST is a rare event, but procedure- and patient-related factors need to be assessed. First, only with a chronic total occlusion derived technique, wiring was successful demonstrating indirectly a stent-related problem. OCT showed a remarkable in-stent malapposition. Another important factor that contributed to acute ST was the insufficient platelet inhibition because morphine negatively affected ticagrelor absorption and onset of action. When acute ST occurs, multiple partners in crime should be investigated.

From the Clinical and Interventional Cardiology, Sassari University Hospital, Sassari, Italy.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript accepted April 29, 2020.

The authors report that patient consent was provided for publication of the images used herein.

Address for correspondence: Giuseppe Talanas, MD, Clinical and Interventional Cardiology, Sassari University Hospital, Sassari Italy, Via Enrico De Nicola 14, 07100 Sassari, Italy. Email: giuseppe.talanas@aousassari.it