Prognostic Importance of Novel Oxygen Desaturation Metrics in Patients With Heart Failure and Central Sleep Apnea.
BACKGROUND
Sleep-disordered breathing, particularly central sleep apnea (CSA), is highly prevalent in heart failure (HF) and an independent prognostic marker. We assessed the hypothesis that an increased hypoxemic burden during sleep may have greater prognostic value than the frequency of apneic and hypopneic episodes.


RESULTS
We prospectively conducted overnight cardiorespiratory polygraphy on consecutive HF patients referred to our hospital from 2008 to 2011. We studied CSA defined by an apnea-hypopnea index (AHI) of ≥5 events/h with >75% of all events being central in origin. We determined the AHI, proportion of the sleep time with SpO2<90% (T90%), and proportion of the recording time that 4% desaturation events occurred (4%POD). We studied 112 HF patients with either systolic or diastolic dysfunction. During a follow-up period of 37 ± 25 months, 32 patients (29%) died. Nonsurvivors had a higher 4%POD compared with survivors (11 ± 6.4% vs 19 ± 13%; P = .001), but did not differ significantly from survivors regarding AHI and T90%. An adjusted logistic regression analysis revealed that the 4%POD was the best independent predictor of mortality.


CONCLUSIONS
The 4%POD, a novel metric for the nocturnal hypoxemic burden, is an independent prognostic marker in HF patients affected by CSA.
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan. Electronic address: enwatan@fujita-hu.ac.jp.
Eiichi
E
Watanabe
Division of Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan.
Ken
K
Kiyono
Division of Bioengineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan.
Shojiro
S
Matsui
Mayo Clinic and Mayo Foundation, Rochester, Minnesota.
Virend K
VK
Somers
Department of Cardiology, Hekinan City Hospital, Hekinan, Japan.
Kan
K
Sano
Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
Junichiro
J
Hayano
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Tomohide
T
Ichikawa
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Mayumi
M
Kawai
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Masahide
M
Harada
Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
Yukio
Y
Ozaki
D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D054144:Heart Failure, Diastolic / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D054143:Heart Failure, Systolic / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010092:Oximetry / Q000379:methods; D010101:Oxygen Consumption / Q000502:physiology*; D017286:Polysomnography / Q000379:methods; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012720:Severity of Illness Index; D020182:Sleep Apnea, Central / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D013997:Time Factors
Sleep; heart failure; hypoxia and mortality