Sildenafil não melhora a cardiopatia em pacientes com Duchenne/Becker
USA – estudos experimentais demonstraram que o sildenafil, indicado para disfunção erétil pode causar melhora da função cardíaca e muscular na distrofia de Duchenne/ Becker. Neste estudo com 15 pacientes os resultados sugeriam uma piora da função cardíaca e a pesquisa foi interrompida. Apesar do número pequeno de pessoas neste estudo o resultado com o uso de sildenafil foi negativo.
O resumo em inglês pode ser lido abaixo:
Objective: Duchenne and Becker muscular dystrophy (DBMD) are allelic disorders caused by mutations in dystrophin. Adults with DBMD develop life-threatening cardiomyopathy. Inhibition of phosphodiesterase 5 (PDE5) improves cardiac function in mouse models of DBMD. To determine if the PDE5-inhibitor sildenafil benefits human dystrophinopathy, we conducted a randomized, double-blind, placebo-controlled trial (ClinicalTrials.gov, number NCT01168908).
Methods: Adults with DBMD and cardiomyopathy (ejection fraction ≤50%) were randomized to receive sildenafil (20mg three times daily) or placebo for 6 months. All subjects received an additional 6 months of open-label sildenafil. The primary endpoint was change in left ventricular end-systolic volume (LVESV) on cardiac MRI. Secondary cardiac endpoints, skeletal muscle function, and quality of life were also assessed.
Results: An interim analysis (performed after 15 subjects completed the blinded phase) revealed that 29% (4/14) of subjects had a ≥10% increase in LVESV after 6 months of sildenafil compared to 13% (1/8) of subjects receiving placebo. Subjects with LVESV >120ml at baseline were more likely to worsen at 12 months regardless of treatment assignment (p=0.035). Due to the higher number of subjects worsening on sildenafil, the Data and Safety Monitoring Board recommended early termination of the study. There were no statistically significant differences in outcome measures between treatment arms.
Interpretation: Due to the small sample size, comparisons between groups must be interpreted with caution. However, this trial suggests that sildenafil is unlikely to improve cardiac function in adults with DBMD.
