Excessive ventilatory responses elicited by metaboreflex activation inversely correlated with physical function and peak VO2, suggesting that metaboreflex over-activation may contribute to exercise intolerance by causing hyperventilation and early onset of dyspnea in CA-TTR patients, as previously shown in chronic heart failure (Alam and Smirk, 1937; Aimo et al., 2021; Gama et al., 2021). Here, TTR is linked to congestive heart failure.