All-cause mortality and frequency of cardiovascular hospitalization were analyzed using Finkelstein-Schoenfeld method. The method combines all-cause mortality and frequency of CV-related hospitalizations in a hierarchical fashion using all-cause mortality first. The method compares every participant with every other participant within strata, assigning a +1 to the "better" participant and a -1 to the "worse" participant and 0 if they are "tied". Participants who discontinued for transplantation (heart transplantation and combined heart and liver transplantation) or for implantation of a cardiac mechanical assist device, were handled in the same manner as death. 'Win' represents a participant doing better based on hierarchical comparison. The reported unit is the total "wins" for each treatment group from performing such a hierarchical comparison across all 4 strata in the study.

ITT analysis set:participants in safety population(randomized participants who received at least 1 dose of double-blind medication)having at least 1 post baseline efficacy.Pre-specified intent of study was to compare results between tafamidis with placebo,irrespective of tafamidis doses. Analysis based on pooled dose groups,as per study protocol.

Number of deaths due to any cause was analyzed. Participants who discontinued for transplantation (heart transplantation and combined heart and liver transplantation) or for implantation of a cardiac mechanical assist device were handled in the same manner as death.

ITT analysis set: all participants in the safety population who had at least 1 post baseline efficacy evaluation. The pre-specified intent of this study was to compare the results between tafamidis with placebo, irrespective of the tafamidis doses. Therefore, this analysis was based on the pooled dose groups, as per the study protocol.

CV related hospitalizations per year is calculated as participant's number of CV related hospitalizations upon duration on study in years.

ITT analysis set: all participants in the safety population who had at least 1 post baseline efficacy evaluation. The pre-specified intent of this study was to compare the results between tafamidis with placebo, irrespective of the tafamidis doses. Therefore, this analysis was based on the pooled dose groups, as per the study protocol.

6MWT is the total distance that a participant could walk in 6 minutes. Participants were asked to perform the test at a pace that was comfortable to them, with as many breaks as they needed.

Analysis performed on ITT analysis set. The pre-specified intent of this study was to compare the results between tafamidis with placebo, irrespective of the tafamidis doses. This analysis was based on the pooled dose groups, as per the study protocol. Here, 'number analyzed' = participants evaluable for this outcome at specified time points.

KCCQ is a 23-item participant-completed questionnaire that assesses health status and health-related quality of life in participants with heart failure. Eight domain scores were calculated for the KCCQ: Physical limitation, Social limitation, Quality of life, Self-efficacy, Symptom stability, Symptom frequency, Symptom burden, and Total symptoms (calculated as the mean of Symptom frequency and Symptom burden scores). Two summary scores were also calculated: Clinical Summary (calculated as mean of Physical limitation and Total symptom scores) and Overall Summary (calculated as mean of Physical limitation, Social limitation, Total symptoms, and Quality of life scores). Domain and summary scores were scaled to range from 0 (minimum) to 100 (maximum); higher scores represent better health status.

Analysis performed on ITT analysis set. The pre-specified intent of this study was to compare the results between tafamidis with placebo, irrespective of the tafamidis doses. This analysis was based on the pooled dose groups, as per the study protocol. Here, 'number analyzed' = participants evaluable for this outcome at specified time points.

Deaths adjudicated as CV-related and indeterminate are reported. Participants who discontinued for transplantation (heart transplantation and combined heart and liver transplantation) or for implantation of a cardiac mechanical assist device, were handled in the same manner as death.

ITT analysis set: all participants in the safety population who had at least 1 post baseline efficacy evaluation. The pre-specified intent of this study was to compare the results between tafamidis with placebo, irrespective of the tafamidis doses. Therefore, this analysis was based on the pooled dose groups, as per the study protocol.

TTR stabilization is a measure of the degree of stabilization afforded the TTR molecule by tafamidis.

Analysis performed on ITT analysis set. The pre-specified intent of this study was to compare the results between tafamidis with placebo, irrespective of the tafamidis doses. This analysis was based on the pooled dose groups, as per the study protocol. Here, 'number of participants analyzed' = participants evaluable for this outcome.