Comparison of Immediate With Delayed Stenting Using the Minimalist Immediate Mechanical Intervention Approach in Acute ST-Segment-Elevation Myocardial Infarction: The MIMI Study

Circ Cardiovasc Interv. 2016 Mar;9(3):e003388. doi: 10.1161/CIRCINTERVENTIONS.115.003388.


Background: Delayed stent implantation after restoration of normal epicardial flow by a minimalist immediate mechanical intervention aims to decrease the rate of distal embolization and impaired myocardial reperfusion after percutaneous coronary intervention. We sought to confirm whether a delayed stenting (DS) approach (24-48 hours) improves myocardial reperfusion, versus immediate stenting, in patients with acute ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Methods and results: In the prospective, randomized, open-label minimalist immediate mechanical intervention (MIMI) trial, patients (n=140) with ST-segment-elevation myocardial infarction ≤12 hours were randomized to immediate stenting (n=73) or DS (n=67) after Thrombolysis In Myocardial Infarction 3 flow restoration by thrombus aspiration. Patients in the DS group underwent a second coronary arteriography for stent implantation a median of 36 hours (interquartile range 29-46) after randomization. The primary end point was microvascular obstruction (% left ventricular mass) on cardiac magnetic resonance imaging performed 5 days (interquartile range 4-6) after the first procedure. There was a nonsignificant trend toward lower microvascular obstruction in the immediate stenting group compared with DS group (1.88% versus 3.96%; P=0.051), which became significant after adjustment for the area at risk (P=0.049). Median infarct weight, left ventricular ejection fraction, and infarct size did not differ between groups. No difference in 6-month outcomes was apparent for the rate of major cardiovascular and cerebral events.

Conclusions: The present findings do not support a strategy of DS versus immediate stenting in patients with ST-segment-elevation infarction undergoing primary percutaneous coronary intervention and even suggested a deleterious effect of DS on microvascular obstruction size.

Clinical trial registration: URL: Unique identifier: NCT01360242.

Keywords: ST-segment–elevation myocardial infarction; infarction; myocardial infarction; percutaneous coronary intervention; stent.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Coronary Circulation
  • Female
  • France
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Microcirculation
  • Middle Aged
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / physiopathology
  • Myocardial Infarction / therapy*
  • Percutaneous Coronary Intervention / adverse effects
  • Percutaneous Coronary Intervention / instrumentation*
  • Prospective Studies
  • Recovery of Function
  • Stents*
  • Stroke Volume
  • Thrombectomy* / adverse effects
  • Time Factors
  • Time-to-Treatment*
  • Treatment Outcome
  • Ventricular Function, Left

Associated data