Chronic inhibition of cGMP phosphodiesterase 5A improves diabetic cardiomyopathy: A randomized, controlled clinical trial using magnetic resonance imaging with myocardial tagging

Background-cGMP phosphodiesterase type 5 protein is upregulated in myocardial hypertrophy. However, it has never been ascertained whether phosphodiesterase type 5 inhibition exerts an antiremodeling effect in nonischemic heart disease in humans. We explored the cardioreparative properties of a selective phosphodiesterase type 5 inhibitor, sildenafil, in a model of diabetic cardiomyopathy. Methods and Results-Fifty-nine diabetic men (60.3±7.4 years) with cardiac magnetic resonance imaging consistent with nonischemic, nonfailing diabetic cardiomyopathy (reduced circumferential strain [σ],-12.6±3.1; increased left ventricular [LV] torsion [θ], 18.4±4.6°; and increased ratio of LV mass to volume, 2.1±0.5 g/mL) were randomized to receive sildenafil or placebo (100 mg/d). At baseline, the metabolic indices were correlated with torsion, strain, N-terminal pro-B-type natriuretic peptide, vascular endothelial growth factor, monocyte chemotactic protein-1, and blood pressure. After 3 months, sildenafil produced a significant improvement compared with placebo in LV torsion (Δθ: sildenafil,-3.89±3.11° versus placebo, 2.13±2.35°; P