Lack of Association Between Neurohormonal Blockade and Survival in Transthyretin Cardiac Amyloidosis

Background Despite the belief that heart failure therapies are not effective in transthyretin cardiac amyloidosis, data are limited. We tested the association of neurohormonal blockade use with survival. Methods and Results A total of 309 consecutive patients with transthyretin cardiac amyloidosis were identified. Medication inventory was obtained at baseline and subsequent visits. Exposure included a neurohormonal blockade class (β-blocker βB, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and mineralocorticoid antagonist) at baseline and subsequent visits. βB was modeled as baseline use, time-varying use, and in an inverse probability treatment weighted model. Primary outcome was all-cause mortality analyzed with adjusted Cox proportional hazards models. Continuing compared with stopping βB during follow-up was tested. Mean age was 73.2 years, 84.1% were men, and 17.2% had atrial fibrillation/flutter at baseline. At the time of study entry, 49.8% were on βBs, 35.0% were on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and 23.9% were on mineralocorticoid antagonists. For the total cohort, there was a trend toward harm in the unadjusted model for baseline βB use, but this was neutral after adjustment. When βB use was analyzed as a time-varying exposure, there was no association with mortality. βB discontinuation was associated with decreased mortality for the total cohort. Findings were consistent in inverse probability treatment weighted models. For angiotensin-converting enzyme inhibitor/angiotensin receptor blocker or mineralocorticoid antagonist use, there was no association with mortality after adjustment for the total cohort. Conclusions There was no association of neurohormonal blockade use with survival in transthyretin cardiac amyloidosis. For the total cohort, deprescribing βB may be associated with improved survival. Additional studies are needed to confirm these findings.