M. Ishihara et al., TIME-COURSE OF IMPAIRED CORONARY FLOW RESERVE AFTER REPERFUSION IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION, The American journal of cardiology, 78(10), 1996, pp. 1103-1108
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.