A randomized, double-blinded, placebo-controlled multicenter trial of adenosine as an adjunct to reperfusion in the treatment of acute myocardial infarction (AMISTAD-II).
OBJECTIVE
The purpose of this research was to determine the effect of intravenous adenosine on clinical outcomes and infarct size in ST-segment elevation myocardial infarction (STEMI) patients undergoing reperfusion therapy.


BACKGROUND
Previous small studies suggest that adenosine may reduce the size of an evolving infarction.


METHODS
Patients (n = 2,118) with evolving anterior STEMI receiving thrombolysis or primary angioplasty were randomized to a 3-h infusion of either adenosine 50 or 70 microg/kg/min or of placebo. The primary end point was new congestive heart failure (CHF) beginning >24 h after randomization, or the first re-hospitalization for CHF, or death from any cause within six months. Infarct size was measured in a subset of 243 patients by technetium-99m sestamibi tomography.


RESULTS
There was no difference in the primary end point between placebo (17.9%) and either the pooled adenosine dose groups (16.3%) or, separately, the 50-microg/kg/min dose and 70-microg/kg/min groups (16.5% vs. 16.1%, respectively, p = 0.43). The pooled adenosine group trended toward a smaller median infarct size compared with the placebo group, 17% versus 27% (p = 0.074). A dose-response relationship with final median infarct size was seen: 11% at the high dose (p = 0.023 vs. placebo) and 23% at the low dose (p = NS vs. placebo). Infarct size and occurrence of a primary end point were significantly related (p < 0.001).


CONCLUSIONS
Clinical outcomes in patients with STEMI undergoing reperfusion therapy were not significantly improved with adenosine, although infarct size was reduced with the 70-microg/kg/min adenosine infusion, a finding that correlated with fewer adverse clinical events. A larger study limited to the 70-microg/kg/min dose is, therefore, warranted.
Ross
Allan M
AM
Department of Medicine, George Washington University, Washington, DC, USA.
Gibbons
Raymond J
RJ
Stone
Gregg W
GW
Kloner
Robert A
RA
Alexander
R Wayne
RW
D000241:Adenosine / Q000627:therapeutic use*; D015906:Angioplasty, Balloon, Coronary; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006333:Heart Failure / Q000517:prevention & control; D006760:Hospitalization; D006801:Humans; D009203:Myocardial Infarction / Q000628:therapy*; D015912:Thrombolytic Therapy; D014665:Vasodilator Agents / Q000627:therapeutic use*
D014665:Vasodilator Agents; D000241:Adenosine