Abstract 3145: Mortal Interaction of Sleep Apnea with Ischemic, But Not Non-Ischemic Heart Failure
Introduction: Past studies showed that in patients with heart failure (HF), sleep apnea (SA) increases mortality risk, but these patients were not characterized on the basis of HF etiology.
Hypothesis: Since patients with ischemic HF may suffer greater adverse consequences of SA-related hypoxia and hypertension than those with non-ischemic HF, SA will increase risk of death in patients with ischemic, but not in those with non-ischemic HF.
Methods: From 1997 to 2004, consecutive HF patients with ejection fraction (EF) ≤ 45% had sleep studies and were divided into those with SA (apnea-hypopnea index ≥ 15/hr of sleep) and those without SA. They were followed prospectively to determine all-cause mortality rate.
Results: Of 218 patients enrolled, follow up data were obtained in 95%. Of these, 87 (40%) had ischemic HF. SA was found in 53% of those with ischemic HF and in 41% of those with non-ischemic HF. 14 patients with obstructive sleep apnea on CPAP therapy were excluded from the analysis. Of the remaining 193 patients, 34 (18%) died during a mean follow up of 32 months. In the non-ischemic HF group, there was no difference in mortality between those with, and those without SA (Figure⇓). In contrast, in the ischemic group, mortality was significantly higher in those with SA than those without it (18.9 vs. 4.6 deaths/100 patient-years, P = 0.003). After adjusting for age, EF, New York Heart Association class, β-blocker use, and the presence of diabetes using multivariate Cox analysis, SA remained a significant independent risk for death (HR 3.02, 95%CI 1.07– 8.59, P = 0.037).
Conclusions: These data show that ischemic etiology identifies those HF patients with SA at increased risk of death.