Hi, Thank you for your query. I can understand your concerns. Diffuse forms of hyperpigmentation,as your skin is turning grayish along with loss of muscle mass/loss of weight points towards the possibility of Addisons disease,which may be unrelated to your heart disease, presumably multivessel coronary artery disease requiring several stent placement. You may undergo morning plasma cortisol levels ( sometimes used as a screening test for adrenal insufficiency).Plasma cortisol peaks at approximately 8 a.m., making this the best time to evaluate the hypothalamic-pituitary-adrenal axis. If the morning plasma cortisol level is below 8 to 10 µg per deciliter ,you may undergo further confirmatory tests for adrenal insufficiency. Second possibility is diffuse hyperpigmentation due to deposits of the drug in the dermis.Administration of amiodarone,often prescribed in cardiac patients can result in slate-gray to violaceous discoloration of sun-exposed skin. Regards Dr. T.K. Biswas M.D. Mumbai