Sirolimus-Eluting Iron Bioresorbable Scaffolds vs Everolimus-Eluting Stents for Percutaneous Coronary Intervention: A Randomized Trial (IRONMAN II).
The novel thin-strut sirolimus-eluting iron bioresorbable scaffold (IBS) demonstrated safety and efficacy in a nonrandomized first-in-human study.
The objective of this study was to compare the IBS with contemporary metallic cobalt chromium everolimus-eluting stents (CoCr-EES) in patients with coronary artery disease.
IRONMAN-II was a prospective, multicenter, single-blinded, noninferiority randomized trial across 36 centers in China. Eligible patients had myocardial ischemia and 1 or 2 de novo target lesions. Patients were randomly assigned (1:1) to IBS or CoCr-EES, with allocation masked. Optical coherence tomography (OCT) was performed in the first 25 participant pairs. Clinical follow-up was scheduled at 1, 6, and 12 months, and annually to 5 years, with angiographic and OCT follow-up at 2 years. The primary endpoint was 2-year angiographic in-segment late lumen loss (LLL). Powered secondary endpoints included target vessel quantitative flow ratio (QFR) and OCT-derived cross-sectional mean flow area. Other secondary endpoints included target lesion failure (cardiac death, target vessel myocardial infarction [MI], or ischemia-driven target vessel revascularization), the patient-oriented composite endpoint (all-cause death, MI, or any revascularization), their individual components, and device thrombosis.
Between March 10 and December 13, 2022, 518 patients were randomized to IBS (n = 259) or CoCr-EES (n = 259). At 2 years, lesion-level in-segment LLL was 0.28 (0.52) mm with IBS and 0.23 (0.43) mm with CoCr-EES (difference: 0.08 mm; 95% CI: -0.02 to 0.18; Pnoninferiority = 0.03). Mean QFR was 0.90 (0.13) with IBS and 0.92 (0.09) with CoCr-EES (difference: -0.02; 95% CI: -0.04 to 0; Pnoninferiority = 0.05). Mean OCT flow area was 6.92 (3.48) mm2 with IBS and 6.64 (2.44) mm2 with CoCr-EES (difference: 0.27; 95% CI: -0.09 to 0.63; Pnoninferiority < 0.0001). Two-year target lesion failure occurred in 7.4% of IBS patients and 5.4% of CoCr-EES patients (HR: 1.37; 95% CI: 0.69-2.73; P = 0.37). No significant between-group differences in the rates of patient-oriented composite endpoint, death, or MI were present between the 2 groups. No scaffold thromboses occurred in the IBS group, whereas 1 stent thrombosis occurred with CoCr-EES. Binary restenosis and revascularization rates were higher with IBS, however, most such events were non-ischemia-driven.
In IRONMAN-II, the sirolimus-eluting IBS was noninferior to CoCr-EES for 2-year in-segment LLL, QFR, and OCT-derived flow area. Clinical event rates were also comparable between groups although non-ischemia-driven revascularization rates were higher after IBS. Longer-term follow-up is necessary to demonstrate whether late benefits are realized after complete IBS resorption. (A Clinical Investigation to Evaluate the Safety and Efficacy of IBS in Patients With Coronary Artery Disease; NCT05206084).
The objective of this study was to compare the IBS with contemporary metallic cobalt chromium everolimus-eluting stents (CoCr-EES) in patients with coronary artery disease.
IRONMAN-II was a prospective, multicenter, single-blinded, noninferiority randomized trial across 36 centers in China. Eligible patients had myocardial ischemia and 1 or 2 de novo target lesions. Patients were randomly assigned (1:1) to IBS or CoCr-EES, with allocation masked. Optical coherence tomography (OCT) was performed in the first 25 participant pairs. Clinical follow-up was scheduled at 1, 6, and 12 months, and annually to 5 years, with angiographic and OCT follow-up at 2 years. The primary endpoint was 2-year angiographic in-segment late lumen loss (LLL). Powered secondary endpoints included target vessel quantitative flow ratio (QFR) and OCT-derived cross-sectional mean flow area. Other secondary endpoints included target lesion failure (cardiac death, target vessel myocardial infarction [MI], or ischemia-driven target vessel revascularization), the patient-oriented composite endpoint (all-cause death, MI, or any revascularization), their individual components, and device thrombosis.
Between March 10 and December 13, 2022, 518 patients were randomized to IBS (n = 259) or CoCr-EES (n = 259). At 2 years, lesion-level in-segment LLL was 0.28 (0.52) mm with IBS and 0.23 (0.43) mm with CoCr-EES (difference: 0.08 mm; 95% CI: -0.02 to 0.18; Pnoninferiority = 0.03). Mean QFR was 0.90 (0.13) with IBS and 0.92 (0.09) with CoCr-EES (difference: -0.02; 95% CI: -0.04 to 0; Pnoninferiority = 0.05). Mean OCT flow area was 6.92 (3.48) mm2 with IBS and 6.64 (2.44) mm2 with CoCr-EES (difference: 0.27; 95% CI: -0.09 to 0.63; Pnoninferiority < 0.0001). Two-year target lesion failure occurred in 7.4% of IBS patients and 5.4% of CoCr-EES patients (HR: 1.37; 95% CI: 0.69-2.73; P = 0.37). No significant between-group differences in the rates of patient-oriented composite endpoint, death, or MI were present between the 2 groups. No scaffold thromboses occurred in the IBS group, whereas 1 stent thrombosis occurred with CoCr-EES. Binary restenosis and revascularization rates were higher with IBS, however, most such events were non-ischemia-driven.
In IRONMAN-II, the sirolimus-eluting IBS was noninferior to CoCr-EES for 2-year in-segment LLL, QFR, and OCT-derived flow area. Clinical event rates were also comparable between groups although non-ischemia-driven revascularization rates were higher after IBS. Longer-term follow-up is necessary to demonstrate whether late benefits are realized after complete IBS resorption. (A Clinical Investigation to Evaluate the Safety and Efficacy of IBS in Patients With Coronary Artery Disease; NCT05206084).
Authors
Gao Gao, Song Song, Fu Fu, Guan Guan, Li Li, Jia Jia, He He, Chen Chen, Qi Qi, Yu Yu, Yang Yang, Zhang Zhang, Zhang Zhang, He He, Chen Chen, Ma Ma, Zhou Zhou, Wang Wang, Zhao Zhao, Qian Qian, Guo Guo, Sun Sun, Huang Huang, Li Li, Wang Wang, Ge Ge, Han Han, Stone Stone,
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