Abstract

Background The impact of incomplete stent apposition (ISA) after drug-eluting stent implantation determined by intravascular ultrasound (IVUS) on late clinical events is not well defined. We sought to evaluate the clinical impact of ISA after sirolimus-eluting stent (SES) placement during a follow-up period of four years.

Design Pooled analysis from the RAVEL, the SIRIUS and E-SIRIUS trials, three randomized, multicenter studies comparing SES and BMS.

Methods IVUS at angiographic follow-up [at 6 months in RAVEL patients and 8 months in SIRIUS and E-SIRIUS patients] was available in 325 patients (SES: n=180, BMS: n=145). IVUS images were reviewed for the presence of ISA defined as iÝ1 unapposed stent strut. Clinical follow-up was available for a 4-year period in all patients. Frequency, predictors and clinical sequel of ISA at follow-up after SES and BMS implantation were determined.

Results ISA at follow-up was more frequent after SES (n=45 [25%]) than after BMS (n= 12 [8.3%], p<0.001). (Canadian Cardiology Society) CCS class III or IV angina at stent implantation (OR=4.69, 95%CI= 2.15-10.23, p<0.001) and absence of diabetes (OR=3.42, 95%CI=1.05-11.1, p=0.041) were predictors of ISA at follow-up after SES placement. Rate of myocardial infarction tended to be slightly higher with ISA compared to non-ISA patients. Considering only SES patients, major adverse cardiac event free survival at four years was identical for those with and without ISA at follow-up (11.1% vs 16.3%, P=0.48).

Conclusions ISA at follow-up is more frequent after SES implantation than after BMS implantation. Considering the current very sensitive IVUS definition, ISA appears to be an IVUS finding without significant impact on frequency of major adverse cardiac events even during long-term follow-up.