Obstructive Sleep Apnea and the Risk of Sudden Cardiac Death

Abstract

Objective To identify the risk of sudden cardiac death (SCD) associated with obstructive sleep apnea (OSA). Background Risk stratification for SCD, a major cause of mortality, is difficult. OSA is linked to cardiovascular disease and arrhythmias, and has been shown to increase the risk of nocturnal SCD. It is unknown if OSA independently increases the risk of SCD. Methods We included 10,701 consecutive adults undergoing their first diagnostic polysomnogram between 7/1987 and 7/2003. During follow-up up to 15 years, we assessed incident resuscitated or fatal SCD in relationship to the presence of OSA, physiological data including the apnea-hypopnea index (AHI) and nocturnal oxygen saturation (O2sat) parameters, and relevant comorbidities. Results During an average follow-up of 5.3 years, 142 patients had resuscitated or fatal SCD (annual rate 0.27%). In multivariate analysis, independent risk factors for SCD were age, hypertension, coronary artery disease, cardiomyopathy or heart failure, ventricular ectopy or nonsustained ventricular tachycardia, and lowest nocturnal O2sat (per -10%, HR 1.14, P=0.029). SCD was best predicted by age >60 years (HR 5.53), AHI >20 (HR 1.60), mean nocturnal O2sat <93% (HR 2.93), and lowest nocturnal O2sat <78% (HR 2.60, all P<0.0001). Conclusions In a population of 10,701 adults referred for polysomnography, OSA predicted incident SCD, and the magnitude of risk was predicted by multiple parameters characterizing OSA severity. Nocturnal hypoxemia, an important pathophysiological feature of OSA, strongly predicted SCD independently of well-established risk factors. These findings implicate OSA, a prevalent condition, as a novel risk factor for SCD.

Nocturnal Hypoxemia Due to Obstructive Sleep Apnea Is an Independent Predictor of Poor Prognosis After Myocardial Infarction

“…Clinically, nocturnal oxygen desaturation is independently associated with prevalence of cardiovascular diseases,13 correlates well with severity of coronary atherosclerosis using invasive coronary angiography,14 and may be an independent predictor of mortality 15. Previous large‐scale studies found that decreases in nocturnal oxygen saturation16 and lowest (nadir) nocturnal oxygen saturation (minSaO 2 ) <78%,5 but not AHI, were independently associated with an increased risk of incident atrial fibrillation and sudden cardiac death, respectively. In a study of MI patients, we reported that minSaO 2 , but not AHI, was independently associated with impaired endothelial function,7 a marker of cardiovascular risk 17…”

“…Although seldom recognized by clinicians, the prevalence of OSA in patients hospitalized for myocardial infarction (MI) is >60% using an apnea‐hypopnea index (AHI) ≥5 events/h,2 and >40% for an AHI ≥15 events/h 2, 3. OSA has been reported as an independent risk factor for the development of MI and for sudden cardiac death 4, 5…”

Obstructive sleep apnea syndrome among obese individuals: A cross-sectional study

“…OSAS is a progressive chronic disease that directly influences quality of life, given that sleep is a brain function that is essential to life and aids in relieving human stress. 1,7,8,[12][13][14] While obesity is one of the major risk factors for developing OSAS, it is the only one that is reversible. According to the World Health Organization (WHO), an individual is considered obese when he or she has an abnormal or excessive energy reserve in the form of fat.…”

rAAV8-733-Mediated Gene Transfer of CHIP/Stub-1 Prevents Hippocampal Neuronal Death in Experimental Brain Ischemia

“…1 Cerebral hypoxic and ischemic injuries are involved in many CNS diseases that can be acute, as promoted by occlusion of large arteries 2 and intrapartum, 3 or chronic, as promoted by sleep apnea 4 and rare vascular conditions like Moyamoya disease. 5 In addition, silent chronic brain infarction, which exhibits no apparent symptoms, is directly associated to increased morbidity and mortality in aged populations.…”