Background and Aims The aims of this study were to assess prescription patterns, dosages, discontinuation rates and association with prognosis of conventional heart failure (HF) medications in patients with transthyretin cardiac amyloidosis (ATTR-CA). Methods A retrospective analysis of all consecutive patients diagnosed with ATTR-CA at the National Amyloidosis Centre between 2000-2022 identified 2371 patients with ATTR-CA. Results Prescription of HF medications was greater among patients with a more severe cardiac phenotype, comprising beta-blockers in 55.4%, angiotensin-converting enzyme inhibitors (ACEi)/angiotensin-II receptor blockers (ARB) in 57.4%, and mineralocorticoid receptor antagonists (MRAs) in 39.0% of cases. During a median follow-up of 27.8 months (IQR 10.6-51.3), 21.7% had beta-blockers discontinued, and 32.9% had ACEi/ARB discontinued. In contrast, only 7.5% had MRAs discontinued. Propensity score-matched analysis demonstrated that treatment with MRAs was independently associated with a reduced risk of mortality in the overall population (HR 0.77 [95% CI 0.66-0.89], P40% (HR 0.75 [95% CI 0.63-0.90], P=0.002); and treatment with low-dose beta-blockers was independently associated with a reduced risk of mortality in a pre-specified subgroup of patients with a LVEF ≤40% (HR 0.61 [95% CI 0.45-0.83], P=0.002). No convincing differences were found for treatment with ACEi/ARBs. Conclusions Conventional HF medications are currently not widely prescribed in ATTR-CA, and those that received medication had more severe cardiac disease. Beta-blockers and ACEi/ARBs were often discontinued, but low-dose beta-blockers were associated with reduced risk of mortality in patients with a LVEF ≤40%. In contrast, MRAs were rarely discontinued and were associated with reduced risk of mortality in the overall population; but these findings require confirmation in prospective randomized controlled trials.