The effect of RheothRx Injection on the hemorheological parameters in patients with acute myocardial infarction

This study evaluated the hemorheological effects of a nonionic block copolymer surfactant, RheothRx Injection, on the hemorheological parameters in patients with acute myocardial infarction (AMI). For the in vitro study blood from 24 patients admitted with chest pains (mean age: 49 +/- 11 yrs) was sampled after admission and in AMI cases (15 patients, mean age: 53 +/- 13 yrs) a second sample was collected 48 hours later. Different concentrations of RheothRx were added (0.25, 0.5, 1, 2 and 5 mg/ml) and the blood was tested for RBC aggregation via our computerized Myrenne Aggregometer (at Hct = 40%). Besides other routine laboratory parameters, fibrinogen levels were measured. In a substudy for CORE Trial, the hemorheological effects of RheothRx infusion was studied. Seven patients (mean age: 63 +/- 13 yrs) admitted with AMI and randomized for CORE Trial were studied. The samples were collected after admission, at 12, 24, 48 hours, and at day 8 and 35. In vitro we found a significant (p < 0.05 or better) concentration-related decrease of RBC aggregation from 0.5 mg/ml drug concentration in the admission (both groups) and in the 48 hour (AMI) samples, in AMI patients with a mean decrease of 7 and 5% at 0.5 mg/ml, 13 and 8% at 1 mg/ml, 22 and 19% at 2 mg/ml and 39 and 33% at 5 mg/ml plasma concentration of the drug. In the CORE Trial patients hemorheological parameters (plasma and whole blood viscosity, RBC aggregation and fibrinogen level) decreased during and after the administration of RheothRx, but after 2-8 days their values returned to the baseline level. These findings indicate that this agent can significantly reduce RBC aggregation and other hemorheological parameters, and thus suggest its potential usefulness in clinical states associated with increased RBC aggregation.