Five-year clinical follow-up from the MISSION! Intervention Study: sirolimus-eluting stent versus bare metal stent implantation in patients with ST-segment elevation myocardial infarction, a randomised controlled trial.

Aims: To evaluate the clinical outcomes of sirolimus-eluting stent (SES) versus bare metal stent (BMS) implantation in patients with ST-segment elevation myocardial infarction (STEMI) at long-term follow-up.

Methods And Results: After five years, 310 STEMI patients randomly assigned to implantation of either SES or BMS, were compared. Survival rates were comparable between groups (SES 94.3% vs. BMS 92.8%, p=0.57), as were the rates of reinfarction (10.6% vs. 13.7%, p=0.40), freedom of death/re-MI (84.4% vs. 79.8%, p=0.29) and target vessel failure (14.9% vs. 21.7%, p=0.11). Likewise, rates of overall stent thrombosis (ST) (5.4% vs. 2.7%, p=0.28) and very late ST (4.1% vs. 0.7%, p=0.07) did not significantly differ between the SES- and BMS-group. In 184 patients with IVUS data, definite and definite/probable VLST was more common in those with late stent malapposition versus those without late stent malapposition (4.3% and 6.6% vs. no events [p=0.018 and p=0.004], respectively). The cumulative incidences of target vessel and target lesion revascularisation (TVR and TLR) were not significantly lower in the SES-group (11.2% vs. 17.9%, p=0.09 and 7.2% vs. 12.9%, p=0.08), as was the rate of clinically driven TLR (6.6% vs. 9.5%, p=0.30).

Conclusions: SES implantation was neither associated with increased rates of major adverse cardiac events, nor with a reduction in re-intervention, compared to implantation of a BMS in patients with STEMI after five years. However, a trend of more very late stent thrombosis was observed after SES implantation (ISRCTN62825862).