Background: This prospective placebo-controlled trial was designed to determine whether intravenous immune globulin (IVIG) improves left ventricular ejection fraction (LVEF) in adults with recent onset of idiopathic dilated cardiomyopathy or myocarditis.
Methods and results: Sixty-two patients (37 men, 25 women; mean age +/-SD 43.0+/-12.3 years) with recent onset (</=6 months of symptoms) of dilated cardiomyopathy and LVEF </=0.40 were randomized to 2 g/kg IVIG or placebo. All underwent an endomyocardial biopsy before randomization, which revealed cellular inflammation in 16%. The primary outcome was change in LVEF at 6 and 12 months after randomiz. Overall, LVEF improved from 0.25+/-0.08 to 0.41+/-0.17 at 6 months (P<0.001) and 0.42+/-0.14 (P<0.001 versus baseline) at 12 months. The increase was virtually identical in patients receiving IVIG and those given placebo (6 months: IVIG 0.14+/-0.12, placebo 0.14+/-0.14; 12 months: IVIG 0.16+/-0.12, placebo 0.15+/-0.16). Overall, 31 (56%) of 55 patients at 1 year had an increase in LVEF >/=0.10 from study entry, and 20 (36%) of 56 normalized their ejection fraction (>/=0.50). The transplant-free survival rate was 92% at 1 year and 88% at 2 years.
Conclusions: These results suggest that for patients with recent-onset dilated cardiomyopathy, IVIG does not augment the improvement in LVEF. However, in this overall cohort, LVEF improved significantly during follow-up, and the short-term prognosis remains favorable.