Time dependence of left ventricular recovery after delayed recanalization of an occluded infarct-related coronary artery: findings of a pilot study

J Am Coll Cardiol. 1998 Jul;32(1):97-102. doi: 10.1016/s0735-1097(98)00188-0.


Objectives: We sought to test the hypothesis that late recanalization of infarct-related coronary arteries (IRAs) improves long-term left ventricular (LV) function.

Background: Reperfusion within 24 h of an acute myocardial infarction (MI) has been shown to improve myocardial healing and to reduce infarct expansion. Uncontrolled data suggest that there may be a time window of several weeks for such an effect.

Methods: Sixteen asymptomatic patients 10 +/- 4 days after a first Q wave anterior wall MI with persistent left anterior descending coronary artery occlusion and infarct-zone akinesia were randomized to immediate (2 weeks) or delayed (3 months) angioplasty. Repeat catheterization and cardiac magnetic resonance imaging (MRI) were performed after 3 and 12 months.

Results: Angiography 3 months after MI revealed that LV ejection fraction (LVEF) had increased ([mean +/- SD] 54.4 +/- 4.3% vs. 63.9 +/- 7.4%, p < 0.01) as a result of improved regional function (p < 0.01) and LV end-systolic volume had decreased (p < 0.002), whereas LV end-diastolic volume remained unchanged. With delayed angioplasty, LVEF, infarct zone wall motion and LV volumes did not improve. Cardiac MRI at baseline and at 3 and 12 months confirmed these findings and extended them up to 1 year, indicating that delayed angioplasty could no longer improve LV function because of marked LV dilation (p < 0.01). Immediate angioplasty had a high success rate, but restenosis (50%) was accompanied by new severe angina as a clinical indicator of salvaged myocardium, which did not occur after delayed angioplasty.

Conclusions: This pilot study in selected patients supports the hypothesis that myocardial viability persists ("hibernation") for 2 to 3 weeks but not for 3 months after MI, during which time it may be worthwhile to restore blood flow to a large myocardial territory, even in asymptomatic patients, to improve long-term LV function.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cardiac Catheterization
  • Coronary Circulation / physiology
  • Female
  • Follow-Up Studies
  • Hemodynamics / physiology
  • Humans
  • Magnetic Resonance Angiography
  • Male
  • Middle Aged
  • Myocardial Infarction / physiopathology
  • Myocardial Infarction / therapy*
  • Myocardial Reperfusion Injury / diagnosis*
  • Myocardial Reperfusion Injury / physiopathology
  • Myocardial Stunning / diagnosis*
  • Myocardial Stunning / physiopathology
  • Pilot Projects
  • Time Factors
  • Ventricular Function, Left / physiology*