Early vascular responses to ultrathin biodegradable polymer sirolimus-eluting stent for the treatment of st-elevation myocardial infarction

Background Recent clinical study suggests newer-generation drug-eluting stents (DES) that combine ultrathin strut and nano-coating with biodegradable polymers sirolimus-eluting stent (BP-SES) could improve long-term clinical outcomes in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) over current generation DES. However, safety profiles in very early phase have not been systematically addressed. Objective and method We exploratory investigate early vascular response following BP-SES implantation in patients with STEMI to reveal mechanism of the favorable clinical outcomes in recent studies using frequency domain-optical coherence tomography (FD-OCT). Consecutive twenty patients with STEMI who underwent FD-OCT immediately after primary PCI and were eligible for follow-up FD-OCT at 2 weeks after implantation were enrolled between June 2018 and November 2019. Results Twenty patients (age 62.7±11.3 years, male 85.0%) were enrolled with frequencies of hypertension (45.0%), diabetes mellitus (35.0%), dyslipidemia (55.0%) and smoking (80.0%). Aspiration catheter were used in all patients, and 1.13±0.34 stents were used. Only one patient (5.0%) received chronic antiplatelet therapy with aspirin prior to the onset of STEMI. All patients started to receive prasugrel as thienopyridine from this event and continued dual antiplatelet therapy for 2 weeks. The percentage of uncovered struts significantly decreased from post-procedure to 2W follow-up (69±18% post-procedure versus 30±11% at 2W follow up, p<0.0001). Malapposed struts also decreased (5.6±5.7% post-procedure versus0.9±1.2% at 2W follow up, p<0.0001).The average protrusion area of athero-thrombotic burden numerically decreased (0.37±0.19 at post-procedure versus 0.34±0.14 mm2 at 2W follow up, p=0.19) and its volume showed similar tendency (10.60±6.40 at post-procedure versus 9.36±5.14 mm3 at 2W follow up, p=0.19). Conclusion(s) This study firstly elucidated very early vascular responses following ultrathin strut BP-SES implantation in STEMI patients, showing early progression of strut coverage and resolution of athero-thrombotic materials. This technology may have a potential to overcome the current generation DESs in this clinical setting. Thrombus, uncovered and malapposed struts Funding Acknowledgement Type of funding source: None