sildenafil-citrate and Cardiomyopathy--Restrictive

We tested the hypothesis that chronic treatment with sildenafil attenuates myocardial infarction (MI)-induced heart failure. Sildenafil has potent protective effects against necrosis and apoptosis following ischemia-reperfusion in the intact heart and cardiomyocytes. ICR mice underwent MI by left anterior descending coronary artery ligation and were treated with sildenafil (0.71 mg/kg bid) or saline for 4 wk. Infarct size (IS) was measured 24 h postinfarction, and apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. Left ventricular end-diastolic diameter (LVEDD) and fractional shortening (FS) were measured by echocardiography. Sildenafil reduced IS (40.0 +/- 4.6%) compared with that in saline (69.6 +/- 4.1%, P < 0.05). NG-nitro-l-arginine methyl ester, a nitric oxide synthase (NOS) inhibitor (15 mg/kg bid), blocked the protective effect of sildenafil (IS, 60.2 +/- 1.6%, P < 0.05 vs. sildenafil). Western blot analysis revealed a significant increase in endothelial NOS/inducible NOS proteins 24 h post-MI after treatment with sildenafil versus saline. Apoptosis decreased from 2.4 +/- 0.3% with saline to 1.2 +/- 0.1% with sildenafil (P < 0.05) on day 7 and from 2.0 +/- 0.2% with saline to 1.2 +/- 0.1% with sildenafil on day 28 (P < 0.05), which was associated with an early increase in the Bcl-2-to-Bax ratio. LVEDD increased from baseline value of 3.6 +/- 0.1 to 5.2 +/- 0.2 and to 5.5 +/- 0.1 mm on days 7 and 28, respectively, with saline (P < 0.05) but was attenuated to 4.4 +/- 0.2 and 4.4 +/- 0.1 mm following sildenafil treatment on days 7 and 28, respectively (P > 0.05 vs. baseline). FS significantly improved post-MI with sildenafil. A marked decline in cardiac hypertrophy was observed with sildenafil, which paralleled a reduction in pulmonary edema. Survival rate was lower with saline (36%) compared with sildenafil (93%, P < 0.05). Sildenafil attenuates ischemic cardiomyopathy in mice by limiting necrosis and apoptosis and by preserving left ventricular function possibly through a nitric oxide-dependent pathway.

Topics: Animals; Apoptosis; Blotting, Western; Cardiomegaly; Cardiomyopathy, Restrictive; Coronary Vessels; Echocardiography, Doppler; Enzyme Inhibitors; In Situ Nick-End Labeling; Ligation; Male; Mice; Mice, Inbred ICR; Myocardial Infarction; Necrosis; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Piperazines; Pulmonary Edema; Purines; Sildenafil Citrate; Sulfones; Survival Analysis; Vasodilator Agents; Ventricular Function, Left; Ventricular Remodeling

We report successful management of a 22-month-old child with restrictive cardiomyopathy and severe pulmonary hypertension using the heterotopic heart transplant technique. Additional lessons learned from postoperative management, including the novel use of Sildenafil (Viagra, Pfizer, NY) for controlling pulmonary arterial pressure are described.

Topics: Cardiomyopathy, Restrictive; Combined Modality Therapy; Female; Heart Transplantation; Humans; Infant; Piperazines; Postoperative Care; Purines; Sildenafil Citrate; Sulfones; Transplantation, Heterotopic; Vasodilator Agents