Abstract 2442: Carvedilol Improves the Ventricular Function of Patients with Dilated Cardiomyopathy Secondary to Muscular Dystrophy
Background: By 20 yrs of age, almost all patients (pts) with Duchenne’s or Becker’s muscular dystrophy (MD) develop dilated cardiomyopathy (DCM), a condition that contributes significantly to the morbidity and mortality of these pts. Although carvedilol has been found to be an effective therapy for pts with other forms of DCM, its use has not been studied in pts with MD.
Purpose: To evaluate the safety and efficacy of carvedilol in pts with DCM secondary to MD.
Methods: In this prospective, single arm, open label trial, 22 MD pts age 14 – 46 (median 18.5) yrs, with DCM and ejection fraction (EF)<50%, underwent baseline cardiac MRI, echocardiography, and 24 hr Holter monitoring. Carvedilol was then initiated, uptitrated over 6 wks, and administered at maximum or highest tolerated dose for 6 mos. Baseline studies were then repeated. Student’s paired t-test was used to compare pre and post treatment values.
Results: Carvedilol therapy was associated with a modest, but statistically significant improvement in MRI-derived EF. EF increased in 14 pts and declined in 6 (pre and post treatment studies could not be obtained in 2 pts). Carvedilol was also associated with statistically significant improvements in the Tei index and the mean dP/dt during isovolumetric contraction. Significant improvements were not observed in the shortening fraction (SF), E/E’ ratio and isovolumetric relaxation time (IRT). Two pts had runs of non-sustained ventricular tachycardia (VT)>140 bpm prior to carvedilol administration. VT>140 bpm was not observed following carvedilol therapy. Carvedilol was well tolerated by all pts. Two pts were successfully treated for pneumonia during the study. No other serious adverse events were identified. No pt required permanent increases in ventilatory support.
Conclusion: Pts with DCM secondary to MD tolerate carvedilol therapy without signifcant adverse effects and demonstrate modest improvements in both systolic and diastolic function.