The third-generation resorbable magnesium scaffold showed significantly lower in-scaffold late lumen loss (LLL) than its predecessor at 6-month follow-up, and it showed “very good safety and efficacy,” according to a first-in-man study. Michael Haude, MD, PhD, of Rheinland Klinikum Neuss GmbH, Neuss, Germany, reported these findings Sunday during a Late-Breaking Trials session at Cardiovascular Research Technologies (CRT) 2023 in Washington, D.C. The CE-marked second-generation drug-eluting resorbable magnesium scaffold DREAMS 2G (commercial name Magmaris showed low target lesion failure and scaffold thrombosis rates in multiple studies. However, in-scaffold late lumen loss (LLL) was not comparable to LLL seen with older poly-l-lactic acid (PLLA) scaffolds or contemporary drug-eluting stents. The next-generation DREAMS 3G resorbable magnesium scaffold has increased durability of radial support while maintaining the 12-month resorption time of DREAMS 2G. The stent has a backbone made of a proprietary magnesium alloy with improved mechanical properties, known as BIOmag, and the BIOlute coating of sirolimus and PLLA. It also has reduced strut thickness: 99 μm for the 2.5-mm stent, 117 μm for the 3.0- and 3.5-mm stents, and 147 μm for the 4.0-mm stent. The BIOMAG-I study’s objective was to assess the angiographic, clinical and safety performance of the DREAMS 3G stent in patients with de novo coronary artery lesions. The primary endpoint was in-scaffold LLL at 6 months post-procedure. The study was sponsored by Biotronik, manufacturer of the DREAMS 2G and 3G scaffolds. To be included, patients had to have no more than two de novo lesions in two separate coronary arteries, the target reference vessel diameter (RVD) had to be between 2.5 and 4.2 mm, lesion length had to be no more than 28 mm, and stenosis had to be at least 50%. Subjects with stable or unstable angina pectoris or documented silent ischemia, or hemodynamically stable patients with non-ST-elevation myocardial infarction (NSTEMI) without angiographic evidence of thrombus at the target lesion. Exclusion criteria included evidence of ST-elevation myocardial infarction within 72 hours before the index procedure, thrombus in the target vessel and heavily calcified lesions. The study enrolled 116 patients (117 lesions). Intravascular ultrasound (IVUS) was performed on 103 lesions and optical coherence tomography (OCT) on 113. At 6-month follow-up, 115 patients were available (one missed the follow-up visit). Angiographic assessment was performed on 111 lesions, IVUS on 103 and OCT on 106. At baseline, the patients’ mean age was 61.0 ± 9.0 years, 90% were male, 74.1% had hypertension, 62.1% had hypercholesterolemia, and 64.7% had smoking history. About one-fifth (20.7%) presented with NSTEMI. A plurality of the lesions were located in the left anterior descending artery. The mean lesion length was 12.3 ± 5.1 mm, and the mean RVD was 2.7 ± 0.5 mm. Most lesions (90 [76.9%]) were American Heart Association/American College of Cardiology class B2/C, and 25 (21.4%) were bifurcation lesions. At 6 months, the mean in-scaffold LLL was 0.21 ± 0.31 mm (95% confidence interval [CI] 0.16, 0.27), which is about. The investigators conducted a post hoc superiority analysis with DREAMS 2G in the BIOSOLVE II trial. In BIOSOLVE II, the mean in-scaffold LLL at 6 months was 0.44 ± 0.36 mm (95% CI 0.37, 0.50). Under the superiority analysis, the weighted mean was 0.44, the superiority margin was 0.11, calculated power was 93.6% (p<0.0001 for superiority). A key secondary endpoint was in-segment LLL at 6 months. Mean in-segment LLL at 6 months for BIOMAG-I was 0.05 ± 0.36 mm (95% CI: -0.014, 0.12), while the same measure in BIOSOLVE-II was 0.27 ± 0.37 mm (95% CI: 0.20, 0.37). The post hoc superiority analysis showed the weighted mean was 0.44, the superiority margin was 0.0675, and the calculated power was 0.0675 (p<0.0001). The BIOMAG-I study had one target lesion failure (0.9%) at 6 months, which was a clinically driven target lesion revascularization. In this case, Haude said, the patient was asymptomatic, but at follow-up angiography had a 63% diameter stenosis by core laboratory assessment with an instantaneous wave-free ratio of 0.51. The patient was treated with an Orsiro drug-eluting stent (Biotronik). Also, there was no definite or probable scaffold thrombosis and no MI at 6 months. In addition, IVUS assessment showed preserved scaffold area through 6 months with a small neointimal area. OCT revealed that the struts were well-embedded in the vessel wall with a small proportion of malapposed struts, which were no longer visible at 6 months. Image Credit: Jason Wermers/CRTonline.org