Inclusion Criteria:

• 18 years or older.
• Diagnosed with hATTR amyloidosis with polyneuropathy, with a documented V122I or T60A mutation.
• PND score of I-IIIB at the baseline visit.
• Naive to patisiran treatment at the time of enrollment with intention to initiate treatment with Patisiran.
• Willing and able to comply with the study requirements and to provide written informed consent.

Exclusion Criteria:

Disease-specific Conditions or History

• New York Heart Association (NYHA) heart failure classification ≥ 3 at the baseline visit.
• Have a Karnofsky Performance Status (KPS) of < 60% at the baseline visit.
• Unstable congestive heart failure (CHF), including patients who require additional diuretics at the baseline visit to achieve optimal treatment of CHF, or patients with a heart failure related hospitalization in the 8 weeks prior to the baseline visit.
• Any condition that in the opinion of the Investigator would interfere with the patient’s participation and completion of the study assessments in the 12-month duration of the study. This includes significant active and poorly controlled (unstable) cardiovascular disorders and untreated hypo- or hyperthyroidism.
• Known primary amyloidosis (AL) or leptomeningeal amyloidosis.
• Prior major organ transplant.
• Planned major surgery, including orthotopic liver transplantation (OLT) during the study period.
• Had a malignancy within 5 years, except for basal or squamous cell carcinoma of the skin or carcinoma in situ of the cervix that has been successfully treated.

Prior Medication Use

• Has previously received patisiran prior to enrollment in this study.
• Has received treatment with a TTR silencing therapy in the past 6 months.
• Participated in a clinical trial for any investigational agent in the past 6 months.