This is an unblinded NIH Stage I of Behavioral Intervention Development trial, using a Crossover Intervention model. The study team will enroll 16 subjects using a two-arm crossover titration/reversal design (On [A] vs. Off [B]) with up to 4 periods. Subjects will begin the study in the OFF (B) period. They will follow a pre-determined sequence: off beta-blocker, on beta-blocker, off beta-blocker, on beta-blocker. Each period will last up to 6 weeks, allowing for sufficient time for up-titration of beta-blocker and onset of drug action, and down-titration and washout. Each subject will have the option to participate in up to 4 periods, depending on whether they need additional information to make an informed decision about continuing or discontinuing their beta-blocker at the end of the trial. The intervention drug will be beta-blockers, previously prescribed to the subjects by their physician. The study team has developed a titration algorithm, where the participant's dose of each beta-blocker will be reduced by 50% every week.
In this study, the investigators will test the feasibility of N-of-1 trials for deprescribing beta-blockers in patients with Cardiac Amyloidosis. To achieve this objective, 16 N-of-1 trials (on vs. off) will be conducted and subsequently interview participants to better understand feasibility and pragmatism. Each subject can participate in a total of up to 4 periods lasting between 2-6 weeks each based on each patients' health profile. The N-of-1 trials will be iteratively refined in real-time based on feedback.