Adenosine as an adjunct to thrombolytic therapy for acute myocardial infarction - Results of a multicenter, randomized, placebo-controlled trial: TheAcute Myocardial Infarction STudy of ADenosine (AMISTAD) Trial

OBJECTIVES The Acute Myocardial Infarction STudy of ADenosine (AMISTAD) tri al was designed to lest the hypothesis that adenosine as an adjunct to thro mbolysis would reduce myocardial infarct size. BACKGROUND Reperfusion therapy for acute myocardial infarction (MI) has bee n shown to reduce mortality, but reperfusion itself also may have deleterio us effects. METHODS The AMISTAD trial was a prospective, open-label trial of thrombolys is with randomization to adenosine or placebo in 236 patients within 6 h of infarction onset. The primary end point was infarct size as determined by Tc-99 m sestamibi single-photon emission computed tomography (SPECT) imagin g 6 +/- 1 days after enrollment based on multivariable regression modeling to adjust for covariates. Secondary end points were myocardial salvage inde x and a composite of in-hospital clinical outcomes (death, reinfarction, sh ock, congestive heart failure or stroke). RESULTS In all, 236 patients were enrolled. Final infarct size was assessed in 197 (83%) patients. There was a 33% relative reduction in infarct size (p = 0.03) with adenosine. There was a 67% relative reduction in infarct si ze in patients with anterior infarction (15% in the adenosine group vs. 45. 5% in the placebo group) but no reduction in patients with infarcts located elsewhere (11.5% for both groups). Patients randomized to adenosine tended to reach the composite clinical end point more often than those assigned t o placebo (22% vs. 16% odds ratio, 1.43; 95% confidence interval, 0.71 to 2 .89). CONCLUSIONS Many agents thought to attenuate reperfusion injury have been u nsuccessful in clinical investigation. In this study, adenosine resulted in a significant reduction in infarct size. These data support the need for a large clinical outcome trial. (C) 1999 by the American College of Cardiolo gy.