Abstract 3436: Long-term Clinical and Intravascular Ultrasound Findings Post-Absorbable Metal Stent Implantation in Human Coronary Arteries
Background: Absorbable metal stents (AMS) implanted in human coronary arteries in the PROGRESS I study demonstrated safety at 4 months with ischemic driven TLR of 23.8%. This study evaluates the clinical safety and efficacy of the AMS at 12 months and the late effects of AMS on in-stent neointima formation and vascular remodeling by serial intravascular ultrasound (IVUS).
Methods: Clinical follow-up was obtained on 60 patients at 12 months by clinical visit or telephone contact. IVUS was conducted immediately post-AMS implantation, at 4 months and in 8 patients at different time points from 12 to 28 months. Using computerized planimetry, the external elastic membrane, stent, and lumen were measured every mm within the stent. Neointima was calculated as stent minus lumen measures and volumes were calculated using Simpson’s rule.
Results: There were no death, MI or stent thrombosis in any of the patients. Ischemic driven TLR was reported in 2 patients from 4 to 12 months. In pair analysis of the 8 patients who underwent late IVUS studies, the stent struts were completely absorbed with no evidence of stent malapposition, excess of calcification or any other adverse findings. From 4 months to late follow-up the IVUS paired analysis demonstrated stability of the outcome with reduction of the neointima in 3.04 ± 4.89 mm3, increase in the CSA in 0.28 ± 0.88 mm2 and in stent volume 4.12 ± 8.91 mm2 , (p=NS).
Conclusions: AMS implantation in human coronaries was safe and associated with long-term clinical safety profile. The late IVUS results demonstrate complete absorption of the stent with no significant changes in stent volume and neointima and durability of the IVUS results after 4 months.