ObjectivesWe sought to understand the clinical outcomes of dissections left untreated after sirolimus drug‐coated balloon (DCB) angioplasty.BackgroundDCB may be a valuable alternative to stents for the treatment of native coronary lesions, but the risk of having a dissection after DCB‐angioplasty is not negligible. While type A and B dissections can be safely treated conservatively, some debate exists regarding type C dissections. We previously showed the safety of dissections left untreated after second‐generation paclitaxel‐DCB. However, the fate of dissections after sirolimus‐DCB angioplasty has not been investigated so far.MethodsEASTBOURNE is a prospective, multicenter, international, investigator‐driven study aiming to explore the safety and efficacy of a novel sirolimus‐DCB. This study enrolled a consecutive, all‐comer population of coronary artery disease patients and is the largest prospective study on DCB so far. Primary endpoints of the study, target‐lesion revascularization (TLR), and other clinical endpoints at 12 months, have been presented elsewhere. This is a prespecified subgroup analysis of the patients left with not‐flow limiting dissection after DCB angioplasty, with complete 12 months follow‐up and comparison between patients left with a dissection versus patients with DCB used for de novo lesions.ResultsBetween September 2016 and November 2020, a total of 2123 patients were enrolled at 38 study centers. Seventy‐three patients were left with nonflow limiting dissections (43 type A, 27 type B, 3 type C) and underwent complete 1‐year clinical follow‐up. In the nondissection group, 1110 patients had de‐novo coronary artery disease while 900 had in‐stent restenosis. Baseline characteristics were similar between the groups, while the dissection group was associated with longer lesions (23.8 vs. 18.4 mm, p < 0.001) and more frequent use of predilation (100 vs. 91.4%, p = 0.016). At 12‐month follow‐up, no significant differences among the groups were found, with a total of 1.25% TLR in the dissection cohort versus 5.6% in the de‐novo cohort (p = 0.13), and an overall rate of major adverse cardiovascular events of 4.4% versus 10.1% (p = 0.18). Total death (1.5 vs. 2.6, p = 0.87), cardiac death, myocardial infarction (0% vs. 2.5%, p = 0.35), and bleedings did not differ significantly among the groups as well.ConclusionsIn this subgroup analysis of the EASTBOURNE study of consecutive patients treated with new‐generation sirolimus DCB, dissections left untreated after angioplasty did not lead to an increase in adverse events.