Efficacy of reduced-dose sirolimus-eluting stents in the human coronary artery: serial IVUS analysis of neointimal hyperplasia and luminal dimension.
OBJECTIVE
Using serial intravascular ultrasound (IVUS), the efficacy of reduced-dose sirolimus-eluting stents (SESs) in the prevention of neointimal hyperplasia (NH) and maintenance of luminal patency in human coronary arteries was evaluated.


BACKGROUND
In the animal model, a broad therapeutic window regarding sirolimus doses in suppressing NH has been reported.


METHODS
Serial cross-sectional and volumetric IVUS analyses were performed in 44 patients treated with SES that contained lower sirolimus doses (either 45% or 70%) than standard SES. For cross-sectional analysis, minimum lumen area (MLA) was measured. Percent (%) NH volumetric obstruction was calculated as 100 x NH volume/stent volume.


RESULTS
IVUS measurements were similar between the two drug-dose groups. At 12 months follow-up, only one case developed late incomplete stent apposition. Between 4 and 12 months, a slight increase of in-stent % area loss and % NH obstruction was noted (3.5% +/- 10.4% to 6.7% +/- 10.7% and 1.9% +/- 5.0% to 4.4% +/- 8.0%, respectively). The majority of studied cases, however, sustained less than a 10% volumetric (93% of studied cases) and area loss (75% of studied cases) in the stented segment up to 12 months. At 12 months, % area loss within the stented segments and 5-mm reference segments were comparable (7.0% +/- 19.6% versus 6.7% +/- 10.7%).


CONCLUSIONS
Although slight increases of NH were noted, SESs, delivering two reduced drug doses, appeared to be effective for maintaining luminal patency during 12 months follow-up.
Nakamura
Mamoo
M
Department of Medicine, University of Pittsburgh Medical Center, Pennsylvania, USA.
Abizaid
Alexandre
A
Hirohata
Atsushi
A
Honda
Yasuhiro
Y
Sousa
J Edward
JE
Fitzgerald
Peter J
PJ
D015906:Angioplasty, Balloon, Coronary / Q000295:instrumentation*; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D004305:Dose-Response Relationship, Drug; D054855:Drug-Eluting Stents; D006801:Humans; D006965:Hyperplasia; D020123:Sirolimus / Q000008:administration & dosage*; D013997:Time Factors; D016896:Treatment Outcome; D017539:Tunica Intima / Q000000981:diagnostic imaging; D018084:Ultrasonography, Interventional; D014654:Vascular Patency
D002317:Cardiovascular Agents; D020123:Sirolimus