Comparison of the safety between first- and second-generation drug eluting stents: meta-analysis from 19 randomized trials and 16,924 patients

Background/objective: Despite the effectiveness of first generation drug eluting stent, DES-1 (Taxus and Cypher) in avoiding restenosis and the need for new revascularizations, a slightly increase in stent thrombosis, ST have been published. Second generation drug eluting stent, DES-2 has been developed to optimize the results of percutaneous coronary intervention in terms of efficacy and safety, for avoiding early and late ST. Our objective was to compare the risk of ST between DES-1 and DES-2.

Methods: We performed a meta-analysis of 19 randomized trials. Overall 16,924 patients; 7294 were allocated to DES-1 and 9630 were allocated to DES-2. The primary endpoint was to compare the risk of overall ST during the first year. Other clinical outcomes of interest were to compare the incidence of early (<1 month) and late ST (>1 month-<1 year).

Results: The incidence of overall ST was not increased in patients receiving DES-1 (1.13% DES-1 vs 0.75% DES-2, OR 0.79, 95% CI:0.45-1.40, p 0.43). There were no significant differences in the incidence of; early ST (0.85% DES-1 vs 0.53% DES-2, OR 0.68, 95% CI:0.31-1.51, p 0.35) and late ST (0.40% DES-1 vs 0.25% DES-2, OR 0.69, 95% CI:0.39-1.24, p 0.22).

Conclusions: During the first year after stent implantation, we didn't found differences in ST between DES-1 and DES-2. Most of ST was produced under appropriate anti-platelet therapy so it is possible that many other factors such as; clopidogrel resistance, procedural complications or stent malapposition were implicated. Safety after longer follow-up (>1 year) remains unclear.