Recovery of myocardial perfusion in acute myocardial infarction after successful balloon angioplasty and stent placement in the infarct-related coronary artery.
OBJECTIVE
This study sought to investigate changes in myocardial perfusion after direct percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (MI).


BACKGROUND
After initially successful recanalization of the infarct-related artery, coronary perfusion may deteriorate as a result of reocclusion, distal embolization of platelet aggregates formed at the dilated plaque or microvascular reperfusion injury. This change could offset the benefit from early intervention.


METHODS
The study included 19 patients in whom the infarct-related artery was successfully recanalized by PTCA with Palmaz-Schatz stent placement within 24 h after the onset of pain. Basal and papaverine-induced coronary blood flow were assessed by Doppler flow velocity measurements and quantitative coronary angiography. In addition, basal and adenosine-induced myocardial blood flow were measured by nitrogen-13 ammonia positron emission tomography (PET).


RESULTS
Immediately after completion of the intervention, the average coronary flow reserve (CR) in the recanalized vessel was 1.56 +/- 0.51; it increased to 2.04 +/- 0.65 at 1 h (p = 0.013) and to 2.66 +/- 0.72 at 2 weeks after reperfusion (p = 0.008, n = 16). PET studies in 12 patients revealed that perfusion defect size and CR in the infarct region (2.19 +/- 0.89 vs. 2.33 +/- 0.86) did not change significantly between day 2 after recanalization and 2 weeks. However, we found significant (p < 0.03) increases in basal (by 26%) and adenosine-induced (by 40%) blood flow in the infarct region.


CONCLUSIONS
Despite the persistence of a perfusion defect after successful recanalization of the occluded artery in acute MI, CR of the infarct region improves in most patients within 1 h and further improves within 2 weeks.
Neumann
F J
FJ
Deutsches Herzzentrum und 1. Medizinische Klinik and the Nuklearmedizinische Klinik der Technischen Universität München, Munich, Germany. neumann@dhm.mhn.de
Kósa
I
I
Dickfeld
T
T
Blasini
R
R
Gawaz
M
M
Hausleiter
J
J
Schwaiger
M
M
Schömig
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary; D001783:Blood Flow Velocity; D003251:Constriction, Pathologic; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D012008:Recurrence; D012039:Regional Blood Flow; D015607:Stents; D014055:Tomography, Emission-Computed