10-Year Outcomes of Deferred or Conventional Stent Implantation in Patients With STEMI (DANAMI-3-DEFER).

Background: Primary percutaneous coronary intervention (PCI) with stenting is recommended in ST-segment-elevation myocardial infarction. Immediate stenting may cause distal embolization, microvascular damage, and flow disturbances, leading to adverse outcomes. We report the 10-year clinical outcomes of deferred stenting versus conventional PCI in patients with ST-segment-elevation myocardial infarction.

Methods: We conducted a 10-year follow-up study of the open-label, randomized DANAMI-3-DEFER trial (Third Danish Study of Optimal Acute Treatment of Patients With STEMI - Deferred Stent Implantation Versus Conventional Treatment), conducted in 4 PCI centers in Denmark. Patients with ST-segment-elevation myocardial infarction and acute chest pain <12 hours were randomized to deferred stenting >24 hours after the index procedure or conventional PCI with immediate stenting. In the deferred group, immediate stable Thrombolysis in Myocardial Infarction flow II to III was established, and intravenous administration of either a glycoprotein IIb/IIIa antagonist or bivalirudin for >4 hours after the index procedure was recommended. The primary outcome was a composite of hospitalization for heart failure or all-cause mortality. Key secondary outcomes included individual components of the primary outcome and target vessel revascularization.

Results: Of 1215 patients, 603 were randomized to deferred stenting and 612 to conventional PCI. After 10 years, deferred stenting did not significantly reduce the primary composite outcome (hazard ratio, 0.82 [95% CI, 0.67-1.02]; =0.08). In the deferred group, 124 (24%) died versus 150 (25%) in the conventional PCI group (hazard ratio, 0.95 [95% CI, 0.75-1.19]). Hospitalization for heart failure was lower in patients treated with deferred stenting compared with conventional PCI (odds ratio, 0.58 [95% CI, 0.39-0.88]). Target vessel revascularization was similar in both groups (odds ratio, 1.20 [95% CI, 0.81-1.79]).

Conclusions: Deferred stenting did not reduce all-cause mortality or the composite primary outcome after 10 years but reduced hospitalization for heart failure compared with conventional PCI.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01435408.