Impact of Beta-blockers on Physical Function in HFpEF

"The intervention is a two-arm crossover withdrawal/ reversal design (On \[A\] vs Off \[B\]) with up to 4 periods, each period lasting up to 6 weeks. During the On period (A), subjects will be on their beta blocker. During the Off period (B), their beta blockers will be down titrated and subsequently discontinued.~Subjects will be randomized into either ABAB or BABA sequences."