LEFT-VENTRICULAR VOLUME IN THROMBOLYSED PATIENTS WITH ACUTE ANTERIOR MYOCARDIAL-INFARCTION - THE EFFECT OF CAPTOPRIL AND XAMOTEROL

We measured left ventricular volume in 70 asymptomatic patients after first Q-wave anterior myocardial infarction in order to determine whet her ventricular dilatation occurs and whether there is evidence for it s attenuation or prevention by treatment with captopril or xamoterol - PRevention Of VEntricular Dilatation?: the PROVED? study. 77% of pati ents received thrombolytic treatment. Patients were randomised a mean of 11 days after infarction to receive either captopril 25 mg three ti mes daily, xamoterol 200 mg twice daily or matching placebo. After 6 m onths of treatment, 6 patients from the placebo group (n = 24), 1 from the captopril group (n = 23) and 3 from the xamoterol group (n = 23) had been withdrawn from the study because of clinical complications. L eft ventricular volume was measured using magnetic resonance imaging, before randomisation and after 6 months of treatment. Changes in left ventricular end-diastolic and end-systolic volume after 6 months of tr eatment were defined prospectively as the primary endpoints. Mean init ial end-diastolic volume index was 85 (S.D. 19) ml/m(2), mean end-syst olic volume index was 45 (S.D. 18) ml/m(2), and mean ejection fraction was 48 (S.D. 11)% for the whole group. There was no significant chang e in left ventricular volume index in the placebo or either treatment group after 6 months of treatment. Only minimal left ventricular dilat ation was evident at 11 days. No further increase in left ventricular volume occurred after six months and there was no additional benefit f rom treatment with either captopril or xamoterol. This finding is impo rtant because it shows that patients with uncomplicated anterior myoca rdial infarction who have received thrombolytic treatment may not be a t as great a risk of ventricular dilatation as previously thought, and so may not need long term treatment designed to attenuate ventricular dilatation.