Objective: The aim of the study was to assess the effects of carvedilol, a vasodilating nonselective beta-blocker, on the indexes of left ventricular remodeling after acute myocardial infarction in those with left ventricular dysfunction.
Methods and results: Forty-nine patients with predischarge left ventricular ejection fraction <45% after acute myocardial infarction were evaluated in a double-blind, randomized, placebo-controlled, parallel group study (selected from the database of the Carvedilol Heart Attack Pilot Study: CHAPS). Patients received medication after thrombolysis and continued to do so for 6 months. Two-dimensional echocardiography was performed before discharge (7 to 10 days after admission) and at 3 months after acute myocardial infarction. Analysis of variance showed that wall thickness opposite the site of infarction decreased from (mean +/- SD) 12.3 +/- 2.1 mm to 11.0 +/- 2.4 mm with carvedilol compared with 11.6 +/- 1.9 mm to 12.2 +/- 1.9 mm with placebo (P =.01). Left ventricular mass changed from 235 +/- 74 g to 217 +/- 64 g with carvedilol compared with 227 +/- 80 g to 252 +/- 85 g with placebo ( P =.02). Carvedilol prevented alteration of sphericity index (ratio of long and short axis of left ventricle) that changed from 1.65 +/- 0.29 to 1.66 +/- 20 with carvedilol compared with 1.58 +/- 0.33 to 1.39 +/- 0.19 with placebo (P =.02); alteration was also prevented of wall thickening abnormality at infarct site, which changed from 9.2 +/- 3.1 cm2 to 9.1 +/- 3.5 cm 2 with carvedilol compared with 10.3 +/- 3.3 cm2 to 13.5 +/- 4.6 cm2 with placebo (P =.002).
Conclusion: Carvedilol administered early after acute myocardial infarction results in attenuation of left ventricular remodeling in patients with persistent left ventricular dysfunction before discharge.