Sirolimus-Eluting Balloon vs Repeat Drug-Eluting Stent or Balloon Angioplasty for Coronary In-Stent Restenosis

BACKGROUND: Drug-eluting stents (DESs) are recommended treatment for coronary in-stent restenosis (ISR) but are not used in >20% of cases. OBJECTIVES: The aim of the SELUTION4ISR (SELUTION SLR 014 In-stent Restenosis) trial was to assess the safety and effectiveness of a novel sirolimus drug-eluting balloon (DEB). METHODS: After successful lesion predilation, patients with ISR were randomly assigned to the SELUTION Sustained Limus Release (MedAlliance) DEB or a control strategy of usual care, including any approved DES or balloon angioplasty (BA) on the basis of operator selection prerandomization. Randomization to selected BA control treatment was limited to 20% of patients. The primary outcome was target lesion failure (TLF) (cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization) assessed at 1 year in the per protocol group (all treated eligible patients with complete primary endpoint follow-up). Noninferiority was established if the upper limit of the 2-sided 95% credible interval was smaller than 10%. A sequential secondary hypothesis test was performed comparing DEB with DES in patients with single-layer ISR. RESULTS: From July 2020 to July 2024, 418 patients were randomly assigned to the DEB group (n = 210) or the control group (n = 208), with 390 patients per protocol (DEB, 197; control, 193 [154 DES; 39 BA]). TLF occurred in 32 (16.2%) of 197 patients in the DEB group and in 28 (14.5%) of 193 patients in the control group (difference: 1.7%; 95% credible interval: -5.5% to 8.9%; posterior probability of noninferiority: 98.80%). In the secondary hypothesis test, TLF occurred in 22 (14.2%) of 155 patients in the DEB group and in 9 (6.5%) of 138 patients in the DES control group (difference: 7.7%; 95% credible interval: 0.6%-14.6%, posterior probability for noninferiority: 76.07%). TLF according to operator selected control was higher for DEB compared with DES (15.3% vs 7.1%; difference: 8.1%; 95% credible interval: 1.4%-15.0%) and lower for DEB compared with BA (23.6% vs 43.6%; difference: 23.7%; 95% credible interval: -41.4% to -1.5%; P_{forinteraction} = 0.0026). CONCLUSIONS: The sirolimus DEB was noninferior to a usual care control strategy including 80% repeat DES but not noninferior to DES for single-layer ISR for TLF at 12 months. There was significant interaction on the basis of operator selection of DES vs BA. (SELUTION SLR 014 In-stent Restenosis [SELUTION4ISR]; NCT04280029).