Impact of technological developments in drug-eluting stents on patient-focused outcomes: a pooled direct and indirect comparison of randomised trials comparing first- and second-generation drug-eluting stents.

AIMS: To establish whether technological improvements in drug-eluting stent (DES) technology introduced in second-generation (G2) DES have contributed to improving patient-focused outcomes. METHODS AND
RESULTS: We performed a systematic review of randomised clinical trials (RCT) comparing first-generation (G1) and G2 DES with a>9-month clinical follow-up. The primary endpoint for efficacy was ischaemia-driven target lesion revascularisation (ID-TLR); safety endpoints were all-cause death, myocardial infarction (MI) and stent thrombosis (ST). Sixteen RCTs involving 25,427 patients met eligibility criteria (17 comparisons). In these trials, paclitaxel (PES) and sirolimus (SES) were compared with everolimus (EES), zotarolimus (ZES) or biolimus A9 (BES) DES. G2 varied in metal alloy, strut thickness and type of drug-eluting matrix. Overall, G2 DES were associated with a 26% relative risk reduction (RRR) of MI (relative risk [RR]=0.74, 95% CI: 0.61-0.90, p=0.003) and ST (RR=0.70, 95% CI: 0.55-0.89, p=0.004), while no significant benefit was observed for ID-TLR and death. Use of 2G DES was associated with a significant reduction in the risk of ID-TLR (RR=0.66, 95% CI: 0.51-0.85, p=0.002), MI (RR=0.60, 95% CI: 0.49-0.72, p<0.001) and ST (RR=0.41, 95% CI: 0.26-0.65, p=0.001) when compared with PES. Strut thickness ≤91 µm in G2 DES was associated with a significantly lower risk of MI (RR=0.54, 95% CI: 0.51-0.86, p=0.002).
CONCLUSIONS: The introduction of thinner stent struts and other technological improvements made in G2 DES technology have translated into better patient outcomes. Overall, the net benefit of G2 DES over G1 DES is expressed in terms of ID-TLR and ST risk reduction but it could be masked by heterogeneities in the use of G1 comparators and the use of non-inferiority study designs in RCTs.