An analysis published on 12 March, 2009 in The Lancet, from the ABSORB clinical trial, demonstrated that Abbott’s bioabsorbable drug-eluting stent, currently in development, successfully treated coronary artery disease and was absorbed into the walls of treated arteries within two years.
The two-year data also demonstrated that after the bioabsorbable device was absorbed, the treated blood vessels appeared to move and function similar to unstented arteries. Preliminary findings from the 30-patient ABSORB trial were presented in October 2008 at the Transcatheter Cardiovascular Therapeutics annual meeting in Washington, DC, USA.
“Abbott’s bioabsorbable drug-eluting stent leaves behind a vessel that expands and contracts in a manner similar to a vessel that has never been stented, which could be an advantage over permanent metal-based stent implants,” said Dr Patrick W Serruys, Thoraxcentre, Erasmus University Hospital, Rotterdam, The Netherlands, lead author of The Lancet publication; and co-principal investigator of the first phase of the ABSORB trial. “This bioabsorbable device has the potential to provide optimal vessel scaffolding and drug delivery capability over the crucial first several months after a stenting procedure while avoiding the long-term restrictions of metallic stents.”
As published in The Lancet, the first phase of the ABSORB trial demonstrated the following key results:
- A zero percent rate of stent thrombosis for all patients out to two years of follow up;
- No new major adverse cardiac events (any event that resulted in re-treatment of the treated artery lesion, heart attack or cardiac death) between six months and two years. At two years, the bioabsorbable device demonstrated a major adverse cardiac events rate of 3.6% (one patient);
- Bioabsorption of the stent at two years after implantation, as confirmed by an assessment of the stent struts using optical coherence tomography;
- Restoration of vasomotion was observed at two years, with the drug acetylcholine used in nine patients showing vasodilation in the previously stented area, and the drug methergin used in seven patients showing vasoconstriction in the previously stented area;
- Reduction in plaque area in treated arteries, corresponding to an increase in blood flow between six months and two years, as confirmed by intravascular ultrasound and virtual histology.
Abbott will begin enrolling patients in the second phase of its international ABSORB clinical trial in the first half of 2009.