Abstract Aims Central apnoea (CA) and obstructive apnoea (OA) are highly prevalent in patients with chronic heart failure (HF), and transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized HF aetiology. This study aims to investigate the prevalence and impact of CA and OA in patients with ATTR-CA. Methods and results Consecutive patients with ATTR-CA who underwent 24 h ambulatory cardiorespiratory monitoring were enlisted for an evaluation of the prevalence and severity of breathing disorders. The severity of these disorders was quantified using the apnoea–hypopnoea index (AHI). Accordingly, the patients were categorized as having normal breathing (NB, AHI <5 events/h), OA (AHI ≥5 events/h with >50% being obstructive), or CA (AHI >5 events/h with ≥50% being central). The primary endpoint at follow-up was all-cause mortality. Out of 142 patients enrolled (n = 142, aged 77 ± 7 years, 91% males, 96% wild-type ATTR-CA), considering the 24 h monitoring, 20% had NB (39% at daytime and 8% at nighttime), 35% had CA (45% at daytime and 39% at nighttime), and 45% had OA (25% at daytime and 54% at nighttime). After a median 2.3-year (1.4–3.3 years) follow-up, 24 h, daytime, and nighttime AHIs were higher in non-survivors vs. survivors (all P < 0.05), independently of the prevalent apnoea type (P = 0.64). At multivariable regression analysis (adjusted for the possible clinical, echocardiographic, and biohumoral confounders), nighttime AHI ≥30 events/h {hazard ratio 2.37 [95% confidence interval (CI) 1.07–5.23], P = 0.033} and high-sensitivity troponin T [hazard ratio 2.43 (95% CI 1.42–4.17), P = 0.001] were predictors of mortality. Conclusion Both CA and OA are highly prevalent, both at daytime and nighttime, in patients with ATTR-CA and are associated with higher mortality.
Read full abstract