INTRAVENOUS ADENOSINE AND LIDOCAINE IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION

Objectives A pilot study was designed to assess the safety of combined intravenous adenosine and lidocaine in patients with acute myocardial infarction and to estimate the likelihood of a beneficial effect on f inal infarct size. Background Adenosine plus lidocaine reduces infarct size in animals, but the safety and efficacy in human beings is unkno wn. Methods and Results Adenosine (70 mu g/kg per minute intravenous i nfusion) plus lidocaine (1 mg/kg intravenous bolus injection and 2 mg/ kg per minute infusion) was given to 45 patients with acute myocardial infarction. Patients underwent immediate balloon angioplasty without preceding thrombolytic therapy. Myocardial perfusion defects were meas ured with serial technetium 99m sestamibi studies. One patient develop ed persisting hypotension in conjunction with a large inferolateral my ocardial infarction. Transient hypotension in three other patients res olved with a reduction in adenosine. Advanced atrioventricular block w as never observed. Other adverse events (including atrial fibrillation , ventricular tachyarrhythmia, bradycardia, and respiratory distress) occurred at low frequencies, as expected for patients with acute myoca rdial infarction. An initial median perfusion defect of 45% of the lef t ventricle (60% for anterior infarction, 17% for nonanterior infarcti on) was observed. At hospital discharge (mean +/- SD = 4.3 +/- 2.1 day s) the median value was 12%, and at 8 +/- 4 weeks it was 3% (7% for an terior infarction, 0% for nonanterior infarction); 14 patients had no measurable follow-up. Compared with historical control patients, preho spital discharge measurements were not different but late perfusion de fects were improved. Conclusions Treatment with intravenous adenosine and lidocaine during acute myocardial infarction has sufficient safety and potential for improved myocardial salvage. Randomized studies are justified.