Left ventricular volumes, ejection fraction, and plasma proatrial natriuretic factor (1-98) after withdrawal of enalapril treatment initiated early after myocardial infarction. CONSENSUS II Multi-Echo Study Group.

OBJECTIVES

To assess whether the reduction in left ventricular dilatation after acute myocardial infarction obtained by early administration of angiotensin converting enzyme inhibitors depends on continuous treatment.

DESIGN

Prospective observational and cross sectional study of withdrawal of randomised treatment with enalapril or placebo.

PATIENTS

106 patients on 6 months trial treatment after an acute myocardial infarction.

MAIN OUTCOME MEASURES

Left ventricular volumes and ejection fraction as assessed by echocardiography and circulating proatrial natriuretic factor (1-98) before and 4-6 weeks after withdrawal of treatment.

RESULTS

There were no significant changes (mean (SD)) in left ventricular systolic (0.7 (4.7) ml/m2) and diastolic (0.4 (6.6) ml/m2) volume indices, ejection fraction (-0.9 (6)%), and proatrial natriuretic factor (172 (992) pmol/l) after withdrawal of enalapril. The significantly lower left ventricular volumes observed with 6 months of enalapril therapy after acute myocardial infarction, as compared with placebo, were maintained 6 weeks after drug withdrawal.

CONCLUSION

The results show that the benefit of 6 months of enalapril treatment initiated early after myocardial infarction is maintained for at least 6 weeks after drug withdrawal, suggesting that the treatment effect on left ventricular structure is not reversed by changes in loading conditions caused by subsequent drug withdrawal.