Comparative effects of carvedilol,losartan and cilazapril on preventing left ventricular remodeling after acute myocardial infarction in rats

Objective To compare the effects of the third generation β blocker carvedilol with losartan and cilazapril in preventing left ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in rats Methods Twenty four hours after ligating left coronary artery, 100 surviving AMI female Sprague Dawley rats were randomly divided into 4 groups: (1)AMI control( n =25), (2) carvedilol 1 mg·kg -1 ·d -1 (C1, n =25); (3) cilazapril 1 mg·kg -1 ·d -1 (C2, n =25), and (4) losartan 3 mg·kg -1 ·d -1 (L3, n =25) Sham operated group ( n =17) were selected randomly as non infarction control After 4 weeks of drug therapy by gavage, hemodynamic studies were performed, then the rat hearts were fixed and pathologically analyzed The rats with MI size 35% or 55% were excluded The complete data were obtained in 63 rats with 13 in AMI control, 12 in C1, 12 in C2, 13 in L3, and 13 sham operated groups Results There were no significant differences in MI size among the four AMI groups [(45 8～46 7)%, all P 0 05] Compared with sham operated group, left ventricular end diastolic pressure (LVEDP),volume (LVV), weight (LVW), septal thickness (STh )and right ventricular weight (RVW)were all significantly increased (all P 0 001)in AMI group, while the maximal rate of left ventricular pressure rise and fall (±dp/dt)was significantly decreased (both P 0 001) In comparison with AMI control group, LVEDP, LVV, LVW, STh and RVW were all significantly decreased( P 0 01～0 001) in C1, C2 and L3 groups, while ±dp/dt were significantly increased ( P 0 05～0 001); LVEDP decreased more in L3 group than in C1 group ( P 0 05), but there were no significant differences in other variables among the three therapeutic groups (all P 0 05) Conclusion Carvedilol has a similar effect as cilazapril and losartan on preventing LVRM after AMI in rats, which is worth studying further