Why is this study important?

• Second generation drug eluting resorbable magnesium scaffold coronary stents have in previous trials have shown low target lesion failure and scaffold thrombosis.
• However, late lumen loss (LLL) was not comparable to drug eluting stents (DES) or poly-l-lactic acid (PLLA) scaffolds.
• Improved stent design with next generation DREAMS 3G magnesium scaffold with sirolimus coating. 
  1. Increased durability of radial support while maintaining resorption time of 12 months
  2. Reduced strut thickness
  3. Improved radiopacity with stent markers
  4. Increased size portfolio of stent
• AHA/ACC Lesion Class B2/C (77%) 

Study objective

• Assessment of angiographic, clinical and safety performance of DREAMS 3G scaffold in patients with de novo coronary artery lesions  

Primary endpoint

• In-scaffold late lumen loss (LLL) at 6-month post-procedure

What did the study show?

• Significantly lower in-scaffold LLL (mean 0.21 mm, median 0.13 mm) compared to its precursor device at 6-month follow-up which is now on the level of contemporary DES.
• Very low target lesion failure (TLF) rate (0.9%) and clinically driven target lesion revascularization (TLR) rate (0.9%)
• No definite or probable scaffold thrombosis
• No myocardial infarction
• IVUS assessment showed preservation of the scaffold area from post-procedure up to six months with a low mean neointimal area
• OCT revealed that struts were well embedded in the vessel wall with a low proportion of mal-apposed struts, which were no longer discernable at six months
• In the serial Virtual Histology IVUS analysis, the white color coding (a surrogate parameter for scaffold struts) was reduced at six months compared to post-procedure, documenting device resorption

Unanswered questions:

• Duration of follow up is short at 6 months
• Lesion/vessel preparation for ACC/AHA class C lesions not stated
• Does the scaffold resorption start before the full benefit of neointimal growth suppression by the sirolimus coating?
• What is the scaffold occupancy of the coronary lumen compared to current DES platforms and PLLA scaffolds? 

All editors: S. Tanveer Rab, MD, FSCAI