Failure of nafazatrom to reduce infarct size and arrhythmias in a porcine model of acute coronary occlusion.

The effects of nafazatrom (10 mg/kg, b.i.d., orally for 2 days preoperatively; 10 mg/kg, intraduodenally, 30 min before coronary occlusion) on hemodynamics and arrhythmias were assessed in a group of drug-treated anesthetized pigs and compared with the effects in animals that received the drug vehicle and were treated identically. Infarct size (triphenyl-tetrazolium method) of the left anterior descending coronary artery was 24.4 +/- 2.4% of the left ventricle in nafazatrom-treated hearts after 2 h of occlusion and 26.2 +/- 3.2% in control hearts. Blood pressure, heart rate, left ventricular systolic and end-diastolic pressure, cardiac output and stroke volume were not different between the groups during cardiac insult. There were no differences in the number of premature ventricular contractions, arrhythmia and tachycardia, and ventricular fibrillation. It is concluded that short-term administration of the 5-lipoxygenase inhibitor nafazatrom had no effect on infarction, hemodynamics or arrhythmias in the acutely ischemic porcine myocardium.