TIME-COURSE OF IMPAIRED CORONARY FLOW RESERVE AFTER REPERFUSION IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION

To evaluate the time course of coronary flow reserve after reperfusion , 14 patients with a first anterior wall acute myocardial infarction w ho underwent successful coronary angioplasty within 6 hours after symp tom onset were studied. After angioplasty coronary flow reserve of the left anterior descending artery was measured with a coronary Doppler guidewire and intravenous dipyridamole (0.56 mg/kg over 4 minutes). Me asurements were repeated at predischarge (16 +/- 3 days, n = 12) and a t follow-up (6 +/- 3 months, n = 9). Patients with restenosis at the t ime of repeat catheterization were excluded. An additional 13 patients with normal angiograms served as reference patients. Coronary flow re serve was 1.33 +/- 0.29 after angioplasty. It increased to 1.88 +/- 0. 36 at predischarge (9 < 0.01) and further to 2.34 +/- 0.38 at follow-u p (p < 0.01 vs offer angioplasty and at predischarge, respectively). H owever, compared with reference patients (3.15 +/- 0.48), coronary flo w reserve was significantly reduced in the infarct patients even at fo llow-up (p < 0.01). In infarct patients, the infarct region wall motio n was initially -3.86 +/- 0.67 SD/chord. It significantly improved to -2.07 +/- 1.04 SD/chord at predischarge (p < 0.01) and to -1.67 +/- 1. 43 SD/chord at follow-up (p < 0.01). However, there was no significant relation between coronary flow reserve and region wall motion after. angioplasty (r = 0.10), at predischarge (r = 0.35), and at follow-up ( r = 0.28). Thus, coronary flow reserve is severely impaired early afte r reperfusion. Coronary flow reserve improves over 2 weeks, but the im pairment persists at 6 months after acute myocardial infarction. The i mpairment of coronary flow reserve cannot be predicted by left ventric ular function. Small sample size is ct potential limitation of this st udy, and a larger study should be performed to confirm these findings. (C) 1996 by Excerpta Medica, Inc.