Implications of revised AASM rules on scoring apneic and hypopneic respiratory events in patients with heart failure with nocturnal Cheyne-Stokes respiration.

Study Objectives: This study investigated the implications of the revised scoring rules of the American Academy of Sleep Medicine (AASM) in patients with heart failure (HF) with Cheyne-Stokes respiration (CSR).

Methods: Ninety-one patients (NYHA ≥II, LVEF ≤45 %; age 73.6 ± 11.3 years old; 81 male subjects) with documented CSR underwent 8 h of cardiorespiratory polygraphy recordings. Those were analyzed by a single scorer strictly applying the 2007 recommended, 2007 alternative, and the 2012 scoring rules.

Results: Compared with the AASM 2007 recommended rules, apnea-hypopnea index (AHI) and hypopnea index (HI) increased significantly when the 2007 alternative and 2012 rules were applied (AHI 34.1 ± 13.5/h vs 37.6 ± 13.2/h vs 38.3 ± 13.2/h, respectively; HI 10.2 ± 9.4/h vs 13.7 ± 10.7/h vs 14.4 ± 11.0/h, respectively; all p < 0.001). Duration of CSR increased significantly with the alternate versus recommended 2007 rules (182.2 ± 117.0 vs 170.1 ± 115.0 min; p ≤ 0.001); there was a significant decrease in CSR duration for the 2012 versus 2007 alternative rules (182.2 ± 117.0 vs 166.7 ± 115.4 min; p ≤ 0.001).

Conclusion: AHI was higher using the AASM 2012 scoring rules due to a less strict definition of hypopnea. Data on the prognostic effects of CSR in patients with HF and the benefits of treatment are mostly based on the AASM 2007 recommended rules, so differences between these and the newer version need to be taken into account.