Long-term clinical, angiographic, and optical coherence tomography findings of Mg-based bioresorbable scaffold in patients with acute coronary syndrome.

Abstract

BACKGROUND\nThis study sought to evaluate the clinical outcomes of patients treated with magnesium-based bioresorbable scaffolds (MgBRS) in the context of acute coronary syndromes (ACS) at long-term follow-up (24\u2009months). The study also aims to investigate the MgBRS performance by angiography and the healing and bioresorption pattern by optical coherence tomography (OCT) at 18\u2009months.\n\n\nMETHODS\nBetween December 2016 and December 2018, a total of 90 patients admitted for ACS and treated with MgBRS (Magmaris, Biotronik AG, Bülach, Switzerland) were enrolled in a multicenter prospective study. Clinical follow-up was performed in all patients at 24\u2009months and angiographic and OCT follow-up in 51.5% of patients at 18\u2009months. Serial OCT was available in 33 patients (36.7%).\n\n\nRESULTS\nAt a 2-year follow-up, 88.8% were free of symptoms, no cardiac death was reported, and the device-oriented composite event (DOCE): consisting of cardiac death, target vessel myocardial infarction, and target lesion revascularization (TLR) was 13.3%. Stent thrombosis and TLR were observed in 2.2 and 11.1%, respectively. Binary restenosis was observed in 21.7% of cases and in-stent late lumen loss was 0.61\u2009±\u20090.75\u2009mm. By serial OCT imaging, the minimal lumen area was significantly reduced greater than 40% (from 6.12\u2009±\u20091.59 to 3.5 ±\u20091.55\u2009mm2, p <\u2009.001). At follow-up, area stenosis was 44.33\u2009±\u200923.07% and half of the patients presented indiscernible struts. The principal observed mechanism of restenosis was scaffold collapse.\n\n\nCONCLUSIONS\nAt long-term follow-up, MgBRS implantation in ACS patients showed a high rate of DOCE, mainly caused by clinically driven TLR. MgBRS restenosis was caused by scaffold collapse in most of the cases.