A comparative assessment by optical coherence tomography of the performance of the first and second generation of the everolimus-eluting bioresorbable vascular scaffolds.
OBJECTIVE
The first generation of the everolimus-eluting bioresorbable vascular scaffold (BVS 1.0) showed an angiographic late loss higher than the metallic everolimus-eluting stent Xience V due to scaffold shrinkage. The new generation (BVS 1.1) presents a different design and manufacturing process than the BVS 1.0. This study sought to evaluate the differences in late shrinkage, neointimal response, and bioresorption process between these two scaffold generations using optical coherence tomography (OCT).


RESULTS
A total of 12 lesions treated with the BVS 1.0 and 12 selected lesions treated with the revised BVS 1.1 were imaged at baseline and 6-month follow-up with OCT. Late shrinkage and neointimal area (NIA) were derived from OCT area measurements. Neointimal thickness was measured in each strut. Strut appearance has been classified as previously described. Baseline clinical, angiographic, and OCT characteristics were mainly similar in the two groups. At 6 months, absolute and relative shrinkages were significantly larger for the BVS 1.0 than for the BVS 1.1 (0.98 vs. 0.07 mm² and 13.0 vs. 1.0%, respectively; P = 0.01). Neointimal area was significantly higher in the BVS 1.0 than in the BVS 1.1 (in-scaffold area obstruction of 23.6 vs. 12.3%; P < 0.01). Neointimal thickness was also larger in the BVS 1.0 than in the BVS 1.1 (166.0 vs. 76.4 µm; P < 0.01). Consequently, OCT, intravascular ultrasound, and angiographic luminal losses were higher with the BVS 1.0 than with the BVS 1.1. At 6 months, strut appearance was preserved in only 2.9% of the BVS 1.0 struts, but remained unchanged with the BVS 1.1 indicating different state of strut microstucture and/or their reflectivity.


CONCLUSIONS
The BVS 1.1 has less late shrinkage and less neointimal growth at 6-month follow-up compared with the BVS 1.0. A difference in polymer degradation leading to changes in microstructure and reflectivity is the most plausible explanation for this finding.
Department of Interventional Cardiology, Thoraxcenter, Erasmus MC,'s-Gravendijkwal 230, 3015 CE Rotterdam, The Netherlands.
Josep
J
Gomez-Lara
Salvatore
S
Brugaletta
Roberto
R
Diletti
Scot
S
Garg
Yoshinobu
Y
Onuma
Bill D
BD
Gogas
Robert Jan
RJ
van Geuns
Cécile
C
Dorange
Susan
S
Veldhof
Richard
R
Rapoza
Robert
R
Whitbourn
Stephan
S
Windecker
Hector M
HM
Garcia-Garcia
Evelyn
E
Regar
Patrick W
PW
Serruys
D000368:Aged; D001672:Biocompatible Materials / Q000592:standards; D001807:Blood Vessel Prosthesis / Q000592:standards; D017023:Coronary Angiography / Q000379:methods; D054855:Drug-Eluting Stents / Q000592:standards*; D000068338:Everolimus; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000628:therapy; D011474:Prosthesis Design; D011475:Prosthesis Failure; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives*; D054457:Tissue Scaffolds; D041623:Tomography, Optical Coherence / Q000379:methods*; D018084:Ultrasonography, Interventional
D001672:Biocompatible Materials; D007166:Immunosuppressive Agents; D000068338:Everolimus; D020123:Sirolimus