Beta-blocker treatment of dilated cardiomyopathy with congestive heart failure in children: A multi-institutional experience

Background: Dilated cardiomyopathy is the primary indication for heart tran splantation in children beyond infancy. Although beta-blockers improve symp toms, ejection fraction, and survival in adults with congestive heart failu re, little is known of their effects in children. Methods: This study reviews our pediatric experience with the beta-blocker, metoprolol, at 3 institutions. We gave metoprolol to 15 children, age 8.6 +/- 1.3 years (range 2.5 to 15 years), with idiopathic dilated cardiomyopat hy (n = 9), anthracycline cardiomyopathy (n 3), and Duchenne muscular dystr ophy cardiomyopathy, post-myocarditis cardiomyopathy, and post-surgical car diomyopathy (n = 1 each). All had been treated with conventional medication s (digoxin, diuretics, and ACE inhibitors) for 22.5 +/- 9 months before sta rting metoprolol. Metoprolol was started at 0.1 to 0.2 mg/kg/dose given twi ce daily and slowly increased over a period of weeks to a dose of 1.1 +/- 0 .1 mg/kg/day (range 0.5 to 2.3 mg/kg/day). Results: Between the time point of stabilization on conventional medication s and the initiation of metoprolol therapy, there was no significant change in fractional shortening (13.1 +/- 1.2% vs 15.0 +/- 1.2%) or ejection frac tion (25.6 +/- 2.1% vs 27.0 +/- 3.4%). However, after metoprolol therapy fo r 23.2 +/- 7 months, there was a significant increase in fractional shorten ing (23.3 +/- 2.6%) and ejection fraction (41.1 +/- 4.3%) (p < 0.05). Conclusions: Metoprolol improves ventricular function in some children with dilated cardiomyopathy and congestive heart failure. Further study is warr anted to better define which children may benefit most from beta-blocker th erapy and which betablockers are most efficacious.