Efficacy of Carvedilol in Patients with Dilated Cardiomyopathy due to
Beta-thalassemia major; a Double-blind Randomized Controlled Trial.
Author(s): Ajami GH, Amoozgar H, Borzouee M, Karimi M, Piravian F, Ashrafi A, Kheirandish Z.
Affiliation(s): Division of Pediatric Cardiology, Department of Pediatrics, Shiraz University of
Medical Sciences, IR Iran.
Publication date & source: 2010, Iran J Pediatr. , 20(3):277-83
OBJECTIVE: Dilated cardiomyopathy is the end result of chronic iron overload in
patients with beta thalassemia major. The objective of the present study was to
evaluate the safety and efficacy of Carvedilol in patients with beta thalassemia
major and dilated cardiomyopathy.
METHODS: During a six-month period, fourteen patients with beta-thalassemia major
and heart failure without diabetes mellitus referred to pediatric cardiology
clinic enrolled in this double blind, randomly assigned study. All patients were
on anti failure therapy with Digoxin, Captopril and Furosemide. Carvedilol was
started at a dosage of 3.12 mg bid and for patients who had a systolic blood
pressure >100 mmHg, heart rate >60/min and no signs of low cardiac output the
dosage was increased every two weeks to a maximum of 25 mg bid. Clinical signs
and symptoms, systolic and diastolic echocardiographic indexes and Tissue Doppler
Imaging (TDI) data were collected from each patient.
FINDINGS: Eight patients received Carvedilol (Group 1) and six received placebo
(Group 2). The mean age of patients in Group1 and 2 were 16±0.7 years and 17±3
years respectively. Only one patent in Group 1 tolerated increasing Carvedilol
dosage to more than 6.25 mg bid. Changes in New York Heart Association (NYHA)
classification, Ejection fraction, End diastolic dimension changes, TDI
systolic(S), early (Ea) and late (Aa) diastolic waves were not statistically
significant in these two Groups (P>0.05). Pulse Doppler E/A wave ratio of mitral
valve in Group1 and Group 2 changed from 1.1±0.37 m/s to 1.8±0.40 m/s and from
1.34±0.30 m/s to 2.6±0.23m/s respectively (P=0.04).
CONCLUSION: Patients with thalassemia and dilated cardiomyopathy have poor
tolerance to increasing Carvedilol dosage and develop decreased systolic blood
pressure during advancement of the drug dosage. Carvedilol can be effective in
prevention of progression of diastolic dysfunction in these patients.
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