Objective To investigate the effect of metoprolol on chronic heart failure and to discuss the relationship between polymorphism of ACE and the curative effect of metoprolol.

Methods 118 patients with chronic heart failure were included randomly and were divided into two groups. In control group (group A), the patients were treated with benazapril 2.5–10 mg once daily and routinely, in treatment group the patients were treated additionally with metoprolol 12.5–100 mg once daily. The period of treatment for all patients was 2 years. ACE polymorphism was detected by a PCR.

Results The patients encountered heart failure, myocardial infarction, malignant arrhythmia and sudden death in metoprolol group were lower than those of control group, the difference was significant (p<0.05). PRA was significant increased and AngII, ALD were significant lowered in two groups after treatment. The frequency of DD genotype in metoprolol effective group was 0.47 and that in metoprolol ineffective group was 0.13, the difference was significant (p<0.05). The effective rate of DD genotype was 90.9%, that of ID genotype was 76.9%, that of II genotype was 54.2%, and the effective rate of DD genotype was significantly higher than II genotype (p<0.05).

Conclusion Adding metoprolol to the treatment of chronic heart failure can improve heart function. The polymorphism of the ACE (I/D) is helpful for the diagnosis of the therapeutic efficacy of metoprolol in chronic heart failure.