MCI-154, a Ca2+ sensitizer, increases survival in cardiomyopathic hamsters

To assess the long-term efficacy of a Ca2+ sensitizer MCI-154, 6-[4-(4'-pyr idylamino)phenyl]-4,5-dihydro-3(2 H)-pyridazinone hydrochloride trihydrate, on chronic heart failure, we studied the effects of the agent on the life span of cardiomyopathic hamsters of the BIO-14.6 strain. At approximately 1 50 days of age, 210 male hamsters were randomly divided into three groups: MCI-154 0.1 mg kg(-1) day(-1) (MCI-154-low), MCI-154 0.1 mg kg(-1) day(-1) (MCI-154-high), and control group. The median survival time in control, MCI -154-low and MCI-154-high groups was 227, 243 and 260 days after the start of treatment, respectively. Final survival rate at 284 days in control, MCI -154-low and MCI-154-high groups was 0, 17.1 and 38.6%, respectively. The c umulative survival times in the two MCI-154 treated groups were significant ly prolonged in comparison with that in the control group (P < 0.0001). Thu s, the present study clearly showed that MCI-154 prolonged the life span of cardiomyopathic hamsters, suggesting that long-term therapy with MCI-154 w ould be promising in the treatment of congestive heart failure. (C) 1999 El sevier Science B.V. All rights reserved.