Comparing Stent Thrombosis associated with Zotarolimus Eluting Stents versus Everolimus Eluting Stents at 1 year follow up: a systematic review and meta-analysis of 6 randomized controlled trials

BACKGROUND: Two thousand fifteen has been a winning year for Drug Eluting Stents (DES). Increase in the number of patients with cardiovascular diseases treated by Percutaneous Coronary Intervention (PCI) has resulted to a high demand for second generation DES. This current analysis aimed to compare the different types of Stent Thrombosis (ST) associated with Zotarolimus Eluting Stents (ZES) versus Everolimus Eluting Stents (EES) at 1 year follow up. METHODS: Electronic databases were searched for studies comparing ZES with EES. Different types of ST reported at 1 year follow up were considered as the primary endpoints in this analysis. Odds Ratios (OR) with 95% Confidence Intervals (CIs) were used as the statistical parameters and the pooled analyses were carried out by the RevMan 5 · 3 software. RESULTS: A total number of 10,512 patients were included in this analysis. No significant difference in any definite ST, acute definite ST, subacute definite ST, and late definite ST were observed between ZES and EES, at 1 year follow up with OR: 1.70, 95% CI: 0.92 – 3.16; P = 0.09, OR: 3.44, 95% CI: 0.82 – 14.43; P = 0.09, OR: 1.13, 95% CI: 0.43 – 2.95; P = 0.80 and OR: 2.39, 95% CI: 0.83 – 6.85; P = 0.11 respectively. Moreover, any definite or probable ST and definite/probable/possible ST were also not significantly different with OR: 1.39, 95% CI: 0.89 – 2.17; P = 0.15 and OR: 1.19, 95% CI: 0.84 – 1.70; P = 0.33 respectively. In addition, any probable ST, acute probable ST, late probable ST and possible ST were also not significantly different at 1 year follow up with OR: 1.11, 95% CI: 0.60 – 2.05; P = 0.75, OR: 0.53, 95% CI: 0.12 – 2.40; P = 0.41, OR: 1.67, 95% CI: 0.35 – 7.86; P = 0.52 and OR: 1.08, 95% CI: 0.64 – 1.82; P = 0.78 respectively. CONCLUSION: At 1 year follow up, ZES were not associated with significantly lower or higher definite and probable ST compared to EES. In addition, no significant difference was observed in acute, subacute and late definite or probable ST. However, further trials are recommended to assess the effects of these second-generation DES during the long-term.