Comparative effects of cilazapril, carvedilol and their combination in preventing from left ventricular remodeling after acute myocardial infarction in rats

Purpose: To compare the effects of cilazapril, carvedilol and their combination in preventing from left ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in rats. Methods: Twenty-four hours after ligating left coronary artery, 100 surviving AMT female SID rats were randomly assigned to: (1) AMI control (n=25), (2) cilazapril (Cila, 1mg/kg.d) (n=25); (3) carvedilol (Car, 1mg/kg.d) (n=25), and (4) cilazapril (1mg/kg.d)+ carvedilol (1mg/kg.d) (Combination) (n=25) groups. Sham-operated group (n=17) were selected randomly as non-infarction control. After 4 weeks of therapy with the drugs gastric gavage, hemodynamic studies were performed, then the rat hearts were fixed and pathologically analyzed. Exclusive of the rats with MI size < 35% or > 55%, complete data were obtained in 64 rats, which were comprised of AMI control (n=13), Cila(n=12), Car (n=12), Combination (n=14), and sham-operated (n=13) groups. Results: There were no significant differences in MI size among the four AMI groups (45.2 similar to 46.7%, P >0.05). Compared with sham-operated group, Left ventricular (LV) 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 left ventricular pressure maximal rate of rise and fall (+/- dp/dt) were significantly decreased (all P <0.001). In comparison with AMI group, LVEDP, LVV, LVW, STh and RVW were all significantly decreased, while +/- dp/dt were significantly increased in Cila, Car, and tile combination groups, with LVEDP and STh decreasing more in the combination group than in the two monotherapy group (P <0.05 similar to0.01), but there were no significant differences in other variables among the three therapy groups. Conclusions: Cilazapril, carvedilol and their combination are all effective in preventing from LVRM after AMI in rats, and improving hemodynamics and LV function, with the combination therapy superior.