Early changes in myocardial perfusion patterns after myocardial infarction: Relation with contractile reserve and functional recovery

Objectives. The purpose of this study was to assess early temporal changes in myocardial perfusion pattern by myocardial contrast echocardiography (MC E) and their relation to myocardial viability in patients with reperfused a cute myocardial infarction (AMI). Background. Myocardial contrast echocardiography no-reflow is associated wi th poor contractile recovery after AMI. However, little is known regarding early reversibility of microvascular dysfunction and its relation to myocar dial viability. Methods. Intracoronary MCE was performed immediately after reflow and 9 day s later in 28 patients with a first AMI and successful coronary recanalizat ion (Thrombolysis in Myocardial Infarction trial grade 3 flow). Semiquantit ative contrast score and wall motion score (WMS) mere assessed in each init ially asynergic segment at initial and repeat MCE study. Low dose dobutamin e echocardiography (DE) was performed at day 10, and follow up (FU) rest ec hocardiography was performed 6 weeks later. Results. Among 200 initially asynergic segments, 49% exhibited no or hetero geneous contrast enhancement at initial MCE versus 24% at restudy (p < 0.00 1). Three groups of segments were defined according to early changes in con trast pattern: group A, "sustained no-reflow" (n = 17); group B, improved c ontrast score (n = 68), and group C, "sustained reflow" (n = 112). Group A segments showed no improvement in WMS at FU. In contrast, group B segments showed significant improvement in WMS at FU (p < 0.0001), and exhibited mor e frequently contractile reserve at DE (36% vs. 6%, p = 0.02) and contracti le recovery at FU (34% vs. 7%, p = 0.03) than group A segments. Group C seg ments exhibited contractile reserve and contractile recovery in 47% and 51% of segments respectively. Conclusions. Improvement in MCE perfusion pattern may occur after initial n o-refloow in the days following reperfused AMI and is associated with prese rvation of contractile reserve and gradual regional functional recovery. (J Am Coil Cardiol 1998;32:2011-7) (C) 1998 by the American College of Cardio logy.