Vascular response to sirolimus-eluting stents delivered with a nonaggressive implantation technique: comparison of intravascular ultrasound results from the multicenter, randomized E-SIRIUS, and SIRIUS trials.
BACKGROUND
The effectiveness of SES to reduce the risk of restenosis was initially demonstrated in short lesions using stent implantation with routine pre-dilatation and post-dilatation. This intravascular ultrasound (IVUS) substudy of the E-SIRIUS trial sought to evaluate local arterial responses to sirolimus-eluting stents (SES) delivered with a stent implantation technique allowing direct stenting and only selectively applying high-pressure post-dilatation.


RESULTS
IVUS was performed immediately after intervention and at 8-month follow-up in 51 patients randomised to either bare-metal stents (BMS; Bx-Velocitytrade mark; N=20) or SES (Cyphertrade mark N=31). Direct stenting was allowed (24%) and post-dilation was performed only selectively (32%). Lumen dimensions, intimal hyperplasia and vessel remodeling were compared between SES and BMS. Subsequently, results of SES in the E-SIRIUS IVUS substudy (N=31) were compared to those of SES in the IVUS substudy of the SIRIUS trial (N=137). SES in SIRIUS IVUS substudy were delivered with 100% pre-dilatation and 77% post-dilatation. Baseline stent and reference segment measurements were similar between BMS and SES in E-SIRIUS IVUS patients. Using SES there was a 96% reduction in intimal hyperplasia volume within the stented segment (1.8+/-4.9 vs 50.6+/-39.7 mm3, P<0.001) and a significantly larger minimal lumen cross sectional area at 8-month follow-up (4.5+/-1.1 vs 2.3+/-0.9 mm2, P<0.001). No vessel remodeling was observed with the use of SES. The applied stent implantation technique resulted in a minimal stent/reference vessel area ratio of 0.75+/-0.17 in E-SIRIUS SES as compared to 0.84+/-0.23 in SIRIUS SES (P=0.046). Mean intimal hyperplasia cross-sectional area at follow-up was 0.1+/-0.2 mm2 in the SES group of E-SIRIUS and 0.5+/-0.8 mm2 in the SES group of SIRIUS (P=0.003).


CONCLUSIONS
An implantation technique of SES which includes direct stenting and minimizes the use of high-pressure post-dilatation results in less optimal stent expansion. However, follow-up results compare very favourable to those of BMS and are characterised by even less intimal hyperplasia than after a more forceful implantation of SES.
Hoffmann
Rainer
R
Medical Clinic I, University Hospital Aachen, Aachen, Germany. RHoffmann@UKAACHEN.de
Guagliumi
Giulio
G
Musumeci
Giuseppe
G
Reimers
Bernhard
B
Petronio
Anna S
AS
Disco
Clemens
C
Amoroso
Giovanni
G
Moses
Jeffrey W
JW
Fitzgerald
Peter J
PJ
Schofer
Joachim
J
Leon
Martin B
MB
Breithardt
Günther
G
D000368:Aged; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible; D023903:Coronary Restenosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia / Q000000981:diagnostic imaging; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D020123:Sirolimus / Q000494:pharmacology*; D015607:Stents; D016896:Treatment Outcome; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D018084:Ultrasonography, Interventional
D020099:Coated Materials, Biocompatible; D007166:Immunosuppressive Agents; D020123:Sirolimus