Spontaneous delayed recovery of perfusion after thrombolyzed acute myocardial infarction: Is it predictable before discharge?

In patients with thrombolyzed acute myocardial infarction, early assessment of the final infarct size is difficult because spontaneous recovery of per fusion and function of the left ventricle may be delayed. This study was un dertaken to evaluate the ability of predischarge low-dose dobutamine echoca rdiography to predict late spontaneous recovery of perfusion assessed by si ngle-photon emission computed tomography after acute myocardial infarction. We prospectively studied 53 consecutive patients with myocardial infarctio n treated with thrombolysis. Low-dose dobutamine echocardiography and resti ng Tc-99m-sestamibi single-photon emission computed tomography (MIBI SPECT) were performed 4 +/- 2 days after infarction. A follow-up SPECT study was carried out in 45 patients after 6 months. Myocardial recovery was defined as a reduction of SPECT defect size by more than 10% at follow-up compared with the early study. in 25 of the 45 patients, the size of the left ventri cular perfusion defect decreased significantly from 42% +/- 16% to 27% +/- 10% (group 1), whereas in the remaining 20 patients it showed no significan t change (group 2). Predischarge low-dose dobutamine echocardiography showe d a significant improvement in wall motion score index compared with baseli ne in group 1, from 1.62 +/- 0.28 to 1.41 +/- 0.24, P < .001, whereas in gr oup 2 this index remained without significant change. Predischarge low-dose dobutamine echocardiography is an accurate tool for prediction of late rec overy of myocardial perfusion after acute myocardial infarction treated wit h thrombolysis.