Patient case (clinical description): An 8-year-old boy is brought to the clinic by his parents because of weakness and difficulty of standing up from a sitting position. The mother is healthy but had a brother who died in his 20th after being disabled and using wheelchairs in the last few years of his life. Physical examination shows 3/5 lower extremity muscle strength and enlarged calf muscles. The other physical examination and vital signs are unremarkable. Muscle biopsy showed absence of dystrophin protein. The patient is diagnosed with DMD.

Patient's own account: I brought my  8-year-old son to the doctor's clinic. He was struggling to stand up from a chair for the past few days. My wife is healthy but she was pretty worried since his brother died in his 20s after being disabled and using a wheelchair for the last years of his life. The doctor did an exam which highlighted weakness in the leg muscles and unusually large calf muscles. The rest of the exam was fine, and his vitals were normal. My son did a muscle biopsy, and it showed that the protein important for muscle strength and function is missing. The doctor diagnosed him with Duchenne muscular dystrophy.

Clinical trial: Revatio for Heart Disease in Duchenne Muscular Dystrophy and Becker Muscular Dystrophy

Eligibility criteria:
Inclusion Criteria:

          1. DBMD as determined by either a skeletal muscle biopsy demonstrating absence or lack of
             dystrophin, and/or genetic testing showing a mutation in the dystrophin gene
             predictive of DBMD, as well as a consistent physical examination

          2. Male gender

          3. Age greater than or equal to 18 years

          4. Cardiac dysfunction with ejection fraction less than or equal to 50% as determined by
             echocardiogram, cardiac MRI, or multi-gated acquisition (MUGA) scan

          5. On a stable dose of ACE-inhibitor or angiotensin receptor blocker (ARB) for at least 3
             months; beta-adrenergic receptor blockers and glucocorticosteroids are not required
             but if used, a stable dose for at least 3 months is required.

          6. Ability of the subject or legal guardian to provide informed consent

          7. Ability to adhere with study follow-up

          8. Willingness to abstain from food and alcohol for 8 hours prior to FMD

        Exclusion Criteria:

          1. Use of nitrates or alpha-adrenergic receptor blockers

          2. Known intolerance or allergy to sildenafil, or a history of any severe allergic or
             anaphylactic reactions

          3. Any medical or psychosocial condition, which, in the view of the study investigator,
             makes study participation inadvisable

          4. Known hereditary retinal disorder such as retinitis pigmentosa

          5. History of priapism or conditions that may predispose to priapism such as sickle cell
             anemia, multiple myeloma, or leukemia

          6. Bleeding disorders

          7. Active tobacco use

          8. Chronic atrial fibrillation or frequent arrhythmia that would result in an irregular
             pulse

          9. Factors that would preclude obtaining an MRI study - (e.g. implantable pacemaker or
             cardioverter-defibrillator; body habitus cannot fit into scanner)

         10. Systolic blood pressure (SBP) less than 85 mmHg at baseline evaluation

         11. Chronic kidney disease stages 4 and 5: GFR< 30 mL/min/1.73 m2 as determined by serum
             cystatin C level and the equation eGFRcys = 76.7 x (serum cystatin C-1.18)

         12. Current use of sildenafil.
Male
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.
Subject must be at most 50 Years

Eligibility (NLI label): Contradiction