Background: Myocardial perfusion associates with clinical syndromes and prognosis. Adenosine could improve myocardial perfusion of acute myocardial infarction within 6 hours, but few data are available on late perfusion of myocardial infarction (MI). This study aimed at quantitatively evaluating the value of intracoronary adenosine improving myocardial perfusion in late reperfused MI with myocardial contrast echocardiography (MCE).
Methods: Twenty-six patients with anterior wall infarcts were divided randomly into 2 groups: adenosine group (n = 12) and normal saline group (n = 14). Their history of myocardial infarction was about 3 - 12 weeks. Adenosine or normal saline was given when the guiding wire crossed the lesion through percutaneous coronary intervention (PCI), then the balloon was dilated and stent (Cypher/Cypher select) was implanted at the lesion. Contrast pulse sequencing MCE with Sonovue contrast via the coronary route was done before PCI and 30 minutes after PCI. Video densitometry and contrast filled-blank area were calculated with the CUSQ off-line software. Heart function and cardiac events were followed up within 30 days.
Results: Perfusion in the segments of the criminal occlusive coronary artery in the adenosine group was better than that in the saline group (5.71 +/- 0.29 vs 4.95 +/- 1.22, P < 0.05). Ischemic myocardial segment was deminished significantly after PCI, but the meliorated area was bigger in the adenosine group than in the saline group ((1.56 +/- 0.60) cm(2) vs (1.02 +/- 0.56) cm(2), P < 0.05). The video densitometry in critical segments was also improved significantly in the adenosine group (5.53 +/- 0.36 vs 5.26 +/- 0.35, P < 0.05). Left ventricular ejection fraction (LVEF) was improved in all patients after PCI, but EF was not significant between the two groups ((67 +/- 6)% vs (62 +/- 7)%, P > 0.05). There was no in-hospital or 30-day major adverse cardiac event (MACE) in the adenosine group but 3 MACE in the saline group in 30 days after PCI.
Conclusions: Adenosine could improve myocardial microvascular perfusion in the late reopening of an occluded infarct related artery (3 to 12 weeks after AMI) and clinical outcome in the follow-up period, and myocardial microvascular perfusion is a powerful predictor of clinical events.