TTR and polyneuropathy: Although the initial phase-3 trials of TTR gene silencers were conducted in patients with ATTRv polyneuropathy and were not powered to assess the benefit in patients with cardiac symptoms, subgroup analyses of these studies in patients with markers suggestive of cardiomyopathy showed improvements in measures such as echocardiographic parameters, 6-minute walk test distances, and NT-proBNP levels.45, 46, 47