ABSTRACT

BACKGROUND/OBJECTIVES - Long term safety of DES, particularly regarding thrombosis is of concern. The hypothesized underlying mechanisms (stent under expansion, malapposition) could be prevented by IVUS guidance. Aim of this meta-analysis of randomized controlled clinical trials (RCT) and high quality observational cohort studies (HQ-OBS) is to quantify the potential clinical benefit of intravascular ultrasound (IVUS) guidance in drug-eluting stents (DES) implantation.

METHODS - We performed an extensive literature search for full-text articles published in 2003–2013. The primary outcome was the rate of major adverse cardiac events (MACE) in RCT and HQ-OBS; secondary outcomes were death, myocardial infarction (MI), revascularization, thrombosis and post-procedural minimum lumen diameter (MLD). Fixed/random effect relative risks (RRs) or standardized mean difference (SMD) and 95% confidence interval (95% CI) were computed for the meta-analysis.

RESULTS - Thirty-four articles were retrieved from 268 found; of these 3 were RCT and 9 were HQ-OBS; 18,707 patients were enrolled, 1037 in RCT and 17,670 in OBS. Median follow-up was 20 months. IVUS guidance was associated with a significantly lower rate of MACE (RR=0.80, 95% CI 0.71–0.89, p b 0.001), death (RR=0.60, 95% CI 0.48–0.74, p b 0.001), MI (RR=0.59, 95% CI 0.44–0.80, p=0.001) and thrombosis (RR=0.50, 95% CI 0.32–0.80, p=0.007) and larger MLD (SMD=0.15, 95% CI 0.03 to 0.27, p=0.014), but not of revascularization (RR=0.95, 95% CI 0.82–1.09, p=0.75).

CONCLUSIONS - In this meta-analysis, IVUS guidance in DES implantation appears to reduce MACE, mortality and MI, possibly by reducing thrombosis rather than restenosis rate. Patients at high risk for thrombosis might be identified as the best candidate for IVUS guidance.