Objective: We sought to assess vascular remodelling and neointima formation after implantation of bioabsorbable magnesium alloy stents (AMS).
Design: Randomised experimental study.
Interventions: AMS (n = 11), sirolimus-eluting stents (Cypher; n = 11) and bare-metal stents (BMS; n = 9) were randomly implanted in 31 porcine coronary arteries (n = 11 pigs).
Main outcome measures: Neointima formation was measured by histomorphometry at 90 days. Vascular remodelling defined as change in external elastic membrane area from index intervention to follow-up was assessed by serial intravascular ultrasound (IVUS).
Results: By histomorphometry, lumen (median (quartiles); AMS: 1.75 mm2 (1.07–3.26), Cypher 2.52 mm2 (2.22–5.01), BMS 4.55 mm2 (3.2–7.44); p = 0.013) and external elastic membrane area (AMS: 5.56 mm2 (4.09–6.95), Cypher 7.95 mm2 (6.45–10.92), BMS 9.08 mm2 (7.85–11.63); p = 0.014) were smallest after AMS implantation. By IVUS, external elastic membrane area at follow-up was smallest (AMS: 7.5 (2.8) mm2, Cypher 9.1 (2.7) mm2, BMS 9.9 (3.1) mm2; p = 0.33) and change in external elastic membrane area from index intervention to follow-up (remodelling; AMS: −1.0 (3.1) mm2, Cypher 1.0 (0.8) mm2, BMS 0.9 (1.2) mm2; p = 0.30) was greatest in the AMS group. In a dichotomised IVUS assessment of vascular remodelling, six AMS stents were remodelled (negative remodelling: n = 5; positive remodelling: n = 1) at 90-day follow-up (AMS versus Cypher + BMS: p = 0.001). Neointima formation was smallest in the AMS group (p<0.05 for both histomorphometry and IVUS).
Conclusion: Coronary implantation of absorbable magnesium stents, compared to two non-absorbable stents, was associated with the smallest lumen area at three-month follow-up because of negative vascular remodelling.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.
Competing interests: None.