Radioactive stents delay but do not prevent in-stent neointimal hyperplasia.
BACKGROUND
Restenosis after conventional stenting is almost exclusively caused by neointimal hyperplasia. Beta-particle-emitting radioactive stents decrease in-stent neointimal hyperplasia at 6-month follow-up. The purpose of this study was to evaluate the 1-year outcome of (32)P radioactive stents with an initial activity of 6 to 12 microCi using serial quantitative coronary angiography and volumetric ECG-gated 3D intravascular ultrasound (IVUS).


RESULTS
Of 40 patients undergoing initial stent implantation, 26 were event-free after the 6-month follow-up period and 22 underwent repeat catheterization and IVUS at 1 year; they comprised half of the study population. Significant luminal deterioration was observed within the stents between 6 months and 1 year, as evidenced by a decrease in the angiographic minimum lumen diameter (-0.43+/-0.56 mm; P:=0.028) and in the mean lumen diameter in the stent (-0.55+/-0. 63 mm; P:=0.001); a significant increase in in-stent neointimal hyperplasia by IVUS (18.16+/-12.59 mm(3) at 6 months to 27.75+/-11. 99 mm(3) at 1 year; P:=0.001) was also observed. Target vessel revascularization was performed in 5 patients (23%). No patient experienced late occlusion, myocardial infarction, or death. By 1 year, 21 of the initial 40 patients (65%) remained event-free.


CONCLUSIONS
Neointimal proliferation is delayed rather than prevented by radioactive stent implantation. Clinical outcome 1 year after the implantation of stents with an initial activity of 6 to 12 microCi is not favorable when compared with conventional stenting.
Kay
I P
IP
Thoraxcenter, University Hospital Rotterdam, Dijkzigt, The Netherlands.
Wardeh
A J
AJ
Kozuma
K
K
Foley
D P
DP
Knook
A H
AH
Thury
A
A
Sianos
G
G
van der Giessen
W J
WJ
Levendag
P C
PC
Serruys
P W
PW
D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000295:instrumentation; D017023:Coronary Angiography; D003327:Coronary Disease / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000175:diagnosis / Q000517:prevention & control* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D010761:Phosphorus Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D011829:Radiation Dosage; D015607:Stents; D017211:Treatment Failure; D016896:Treatment Outcome
D010761:Phosphorus Radioisotopes