## 3 Magnesium-Based Devices
### Sirolimus DRug-Eluting Absorbable Metal Scaffold (DREAMS 2 nd Generation--2G)  
Magmaris (DREAMS 2G--Biotronik AG, Bulach, Switzerland) was a balloon expanded sirolimus-eluting poly-L-lactide acid (PLLA) coated resorbable magnesium scaffold (RMS) with 6 crowns and 2 links mounted over a rapid-exchange monorail semi-compliant balloon. In this platform, the strut thickness/width was 150/150 \(\upmu\)m; 3.0 and 3.5 mm in diameter; and 15, 20, or 25 mm in length. Also, the anti-proliferative eluting-drug and polymeric coating were substituted for sirolimus (drug density of 1.4 \(\upmu\)g/mm\({}^{2}\)) and PLLA (7 \(\upmu\)m). In this second-generation platform, 2 non-resorbable tantalum radiopaque markers were added in the proximal and distal crowns (Table 1) [38].  
In First-In-Man Biosolve-II (NCT01960504),123 patients (123 lesions) were included in this single-arm, prospective, multi-center study [38]. At 6 and 12 months, the in-segment LLL was 0.37 \(\pm\) 0.25 mm and 0.39 \(\pm\) 0.27 mm, respectively [38; 39]. Post-procedure mean scaffold area by IVUS was 6.24 \(\pm\) 1.15 mm\({}^{2}\) and 6.21 \(\pm\) 1.22 mm\({}^{2}\) at 6 months with neointimal area of 0.08 \(\pm\) 0.09 mm\({}^{2}\)[38]. There was no significant change in minimum lumen area (MLA) of 4.80 and 4.69 mm\({}^{2}\) between 6 and 12 months, respectively (\(p\) = 0.700) [39]. In-scaffold EEM, plaque area did not vary over 12 months follow-up [13]. OCT assessment at baseline, 6, and 12 months showed a significant decrease of MLA from 6.32 mm\({}^{2}\) to 4.53 mm\({}^{2}\) and 4.81 mm\({}^{2}\) (\(p\) = 0.032), respectively and no intraluminal masses were observed (Figure 2) [13; 38; 39]. In the proximal and distal edge vascular response (EVR) assessment, there was no meaningful changes in grayscale IVUS, virtual histology IVUS, and OCT except for a Fibrous plaque area reduction of 0.5 mm\({}^{2}\) (\(p\) = 0.017) in the proximal segment of the device at 12 months (Figure 3) [14].  
Magmaris vasomotion testing at 6 and 12 months in Biosolve-II trial was positive in 80% (20/25) and 79% (11/14) of the patients [38]. TLF rate at 6 and 24 months was 3% (4/123) and 6% (7/116) of the patients [38; 40], and of these 7 events, 2 were cardiac deaths, 1 MI, and 4 clinically-driven target lesion revascularizations (TLR) [40]. There were no definite or probable ST cases at 24 months [38; 39; 40].  
A patient-level pooled multivariate analysis assessing the TLF rate of Magmaris (Biosolve-II and -III trials) versus Orsiro (Bioflow II trial) showed no significant difference in the unadjusted nor in the adjusted data [41; 42]. Still, there is no randomized study comparing Magmaris and a 2 nd Generation Metallic DES.  
Figure 3: Magmaris edge vascular response segment and frame level analysis panel. Intravascular Ultrasound (**A**); and Optical Coherence Tomography (**B**), (Reproduced from: [PERSON] et al. _Cardiovasc Revasc Med._ 2019 May, 20(5), 392–398.) [14].  
Figure 2: Optical coherence tomography of DREAMS 2G. At the top, 3 spread out panels showing the attenuation maximum values. Post-PCI, the attenuation values that correspond to the scaffold struts are very high (yellow). The scaffold design can be recognized. Those very high values subsided over time, corresponding to the bioresorption process of the struts. In the middle row, 3 OCT frames are depicted. Post-PCI, the struts are shown with very high attenuation values, which disappeared over time. At the bottom, post-PCI struts are bright structures with shadowing behind. In the corresponding frames at 6 and 12 months (please note the calcium marked by *), a remnant of struts is present at 5 o’ clock (arrow), (Reproduced from: [PERSON] et al. _[PERSON]_ 2018 Mar 15, 255, 22–28.) [13].  
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