TTR and cardiac amyloidosis: Although patisiran, an RNA interference therapeutic agent delivered via lipid nanoparticles that targets transthyretin (TTR) messenger RNA in the liver, thereby reducing circulating TTR protein levels, is relevant to HFpEF in the context of transthyretin cardiac amyloidosis, where it can slow disease progression and improve functional status, it is not a general treatment for HFpEF [195].