ROME — Antithrombotic medications successfully treated plaque erosion without stenting in a proof-of-concept study reported here. With 1 month of antithrombotic therapy after finding plaque erosion on optical coherence tomography (OCT), patients’ median thrombus volume plummeted from 3.7 mm3 to 0.2 mm3 (P<0.001). In addition, minimal flow area rose from 1.7 mm2 to 2.1 mm2 (P=0.002), according to Ik-Kyung Jang, MD, PhD, of Boston’s Massachusetts General Hospital. Minimum lumen diameter increased from 1.35 mm to 1.54 mm (P<0.001). In addition, 78.3% of patients had their thrombus volume slashed in half or more; another 36.7% had no residual thrombus on follow-up. Jang presented the results of the so-called EROSION study at the annual meeting of the European Society of Cardiology; they were also published simultaneously in the European Heart Journal. “Randomized trials will be needed to reproduce this pilot data and to further evaluate the long-term outcome of this new treatment strategy in patients with acute coronary syndrome [ACS] caused by plaque erosion,” Jang said. However, the minimum lumen diameter achieved after therapy (1.54 mm) was theoretically still flow-limiting in a non-infarcted area, session discussant Patrick W. Serruys, MD, PhD, of Erasmus University in Rotterdam, The Netherlands, pointed out. What’s more, he added, 66% of patients did not have their minimum lumen area rise above 1.95 mm2, a threshold for positive fractional flow reserve. EROSION included 60 patients (out of 405 screened) who presented with an ACS at the emergency department of a single center in China and had plaque erosion identified on OCT without plaque rupture or major stenosis. Those with the lowest left ventricular ejection fractions (less than 30%) were excluded, as well as those who could not tolerate the antithrombotics. One patient died of gastrointestinal bleeding; another had target lesion revascularization following no angiographic improvement with the antithrombotics. Before invasive imaging, patients got aspirin 300 mg, ticagrelor 180 mg, and unfractionated heparin 100 IU/kg. The antithrombotics continued after catheterization, including dual antiplatelet therapy with aspirin and ticagrelor thereafter. Most patients (83.6%) also received manual aspiration thrombectomy as part of their treatment. Serruys noted the use of the glycoprotein IIb/IIIa inhibitor tirofiban (Aggrastat) in two-thirds of participants involved — another limitation of Jang’s non-randomized, unblinded trial. Disclosures EROSION was supported by AstraZeneca. Jang declared receiving a fellowship grant from St. Jude Medical. Serruys reported relationships with Abbott, AstraZeneca, Biotronik, Cardialysis B.V., GLG Research, Medtronic, Sinomedical, Societe Europa Digital & Publishing, Stentys, Svelte, Volcano, Q3 Medical, and St. Jude Medical.