Impact of intravascular ultrasound guidance in stent deployment on 6-month restenosis rate: a multicenter, randomized study comparing two strategies--with and without intravascular ultrasound guidance. RESIST Study Group. REStenosis after Ivus guided STenting.
OBJECTIVE
We aimed to investigate the impact of intravascular ultrasound (IVUS)-guided stent implantation on the 6-month restenosis rate, which has not yet been fully established in randomized trials.


BACKGROUND
The 6-month angiographic restenosis rate was compared in patients with symptomatic ischemic heart disease who were randomly allocated to angioplasty and stent deployment, with versus without IVUS guidance.


METHODS
After successful stent implantation, patients were randomized into two groups: Group A had no further dilation, and Group B had additional balloon dilation until achievement of IVUS criterion for stent expansion. The study group consisted of 164 patients, assuming a 50% reduction of the restenosis rate in Group B (15% vs. 30%) (alpha = 10%, beta = 20%).


RESULTS
We enrolled 155 patients. Overdilation was carried out in 31 (39%) of 79 Group B patients, with the IVUS criterion being achieved in 63 (80%) of 79. No significant difference was observed in the minimal luminal diameter (MLD), but the stent lumen cross-sectional area (CSA) was significantly larger in Group B (mean +/- SD) (7.16 +/- 2.48 vs. 7.95 +/- 2.21 mm2, p = 0.04). At 6 months, there was no significant difference in the restenosis rate, (28.8% [21 of 73] in Group A vs. 22.5% [16 of 71] in Group B, p = 0.25), but according to the observed difference in the restenosis rate, the power of the study was only 40%. The difference in MLD was also nonsignificant (1.60 +/- 0.65 mm in Group A vs. 1.70 +/- 0.64 mm in Group B, p = 0.20), whereas the lumen CSA was 20% larger in the IVUS-guided group (4.47 +/- 2.59 vs. 5.36 +/- 2.81 mm2, p = 0.03). Lumen CSA was the only predictor of restenosis by multivariate logistic regression analysis.


CONCLUSIONS
A nonsignificant 6.3% absolute reduction in the restenosis rate and a nonsignificant difference in MLD were observed in this study. Nonetheless, we still cannot rule out a beneficial effect of IVUS guidance, although this may have gone undetected owing to a lack of statistical power. A significant increase was observed in immediate and 6-month lumen size, as detected by IVUS, indicating that ultrasound guidance in stent deployment may be beneficial.
Schiele
F
F
Hôpital Universitaire Saint Jacques, Service de Cardiologie, Besançon, France.
Meneveau
N
N
Vuillemenot
A
A
Zhang
D D
DD
Gupta
S
S
Mercier
M
M
Danchin
N
N
Bertrand
B
B
Bassand
J P
JP
D015906:Angioplasty, Balloon, Coronary; D002404:Catheterization; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D003331:Coronary Vessels / Q000473:pathology; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017202:Myocardial Ischemia / Q000628:therapy; D012008:Recurrence; D015607:Stents; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional