Early- and long-term intravascular ultrasound and angiographic findings after bioabsorbable magnesium stent implantation in human coronary arteries.
OBJECTIVE
This study aimed to evaluate the degradation rate and long-term vascular responses to the absorbable metal stent (AMS).


BACKGROUND
The AMS demonstrated feasibility and safety at 4 months in human coronary arteries.


METHODS
The PROGRESS-AMS (Clinical Performance and Angiographic Results of Coronary Stenting) was a prospective, multicenter clinical trial of 63 patients with coronary artery disease who underwent AMS implantation. Angiography and intravascular ultrasound (IVUS) were conducted immediately after AMS deployment and at 4 months. Eight patients who did not require repeat revascularization at 4 months underwent late angiographic and IVUS follow-up from 12 to 28 months.


RESULTS
The AMS was well-expanded upon deployment without immediate recoil. The major contributors for restenosis as detected by IVUS at 4 months were: decrease of external elastic membrane volume (42%), extra-stent neointima (13%), and intra-stent neointima (45%). From 4 months to late follow-up, paired IVUS analysis demonstrated complete stent degradation with durability of the 4-month IVUS indexes. The neointima was reduced by 3.6 +/- 5.2 mm(3), with an increase in the stent cross sectional area of 0.5 +/- 1.0 mm(2) (p = NS). The median in-stent minimal lumen diameter was increased from 1.87 to 2.17 mm at long-term follow-up. The median angiographic late loss was reduced from 0.62 to 0.40 mm by quantitative coronary angiography from 4 months to late follow-up.


CONCLUSIONS
Intravascular ultrasound imaging supports the safety profile of AMS with degradation at 4 months and maintains durability of the results without any early or late adverse findings. Slower degradation is warranted to provide sufficient radial force to improve long-term patency rates of the AMS.
Waksman
Ron
R
Division of Cardiology, Washington Hospital Center, Washington, DC 20010, USA. ron.waksman@medstar.net
Erbel
Raimund
R
Di Mario
Carlo
C
Bartunek
Jozef
J
de Bruyne
Bernard
B
Eberli
Franz R
FR
Erne
Paul
P
Haude
Michael
M
Horrigan
Mark
M
Ilsley
Charles
C
Böse
Dirk
D
Bonnier
Hans
H
Koolen
Jacques
J
Lüscher
Thomas F
TF
Weissman
Neil J
NJ
D020341:Absorbable Implants; D000368:Aged; D000497:Alloys; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000628:therapy*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D004219:District of Columbia; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008274:Magnesium; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D017539:Tunica Intima / Q000000981:diagnostic imaging; D018084:Ultrasonography, Interventional; D014481:United States; D014739:Victoria
D000497:Alloys; D008274:Magnesium