In pre-specified stratified analyses of the primary endpoint , biodegradable polymer sirolimus-eluting stents were associated with improved outcome compared with durable polymer everolimus-eluting stents in the subgroup of patients with ST-segment elevation myocardial infarction ( 7 [ 33 % ] vs 17 [ 87 % ] , RR 038 , 95 % CI 016-091 , p = 0024 , p for interaction = 0014 ) .