Obesity and the magnitude of nocturnal oxygen desaturation, which is an important pathophysiological consequence of OSA, are independent risk factors for incident AF in individuals <65 years of age.

The best available evidence suggests that people with MetSyn are at increased risk of cardiovascular events. These results can help clinicians counsel patients to consider lifestyle interventions, and should fuel research of other preventive interventions.

People with obstructive sleep apnea have a peak in sudden death from cardiac causes during the sleeping hours, which contrasts strikingly with the nadir of sudden death from cardiac causes during this period in people without obstructive sleep apnea and in the general population.

Background-Obstructive sleep apnea (OSA) is associated with recurrent atrial fibrillation (AF) after electrocardioversion.OSA is highly prevalent in patients who are male, obese, and/or hypertensive, but its prevalence in patients with AF is unknown. Methods and Results-We prospectively studied consecutive patients undergoing electrocardioversion for AF (nϭ151) and consecutive patients without past or current AF referred to a general cardiology practice (nϭ312). OSA was diagnosed with the Berlin questionnaire, which is validated to identify patients with OSA. We also assessed its accuracy compared with polysomnography in a sample of the study population. Groups were compared with the 2-tailed t, Wilcoxon, and 2 tests. Logistic regression modeled the association of AF and OSA after adjustment for relevant covariates. Patients in each group had similar age, gender, body mass index, and rates of diabetes, hypertension, and congestive heart failure. The questionnaire performed with 0.86 sensitivity, 0.89 specificity, and 0.97 positive predictive value in our sample. The proportion of patients with OSA was significantly higher in the AF group than in the general cardiology group (49% versus 32%, Pϭ0.0004). The adjusted odds ratio for the association between AF and OSA was 2.19 (95% CI 1.40 to 3.42, Pϭ0.0006). Conclusions-The novel finding of this study is that a strong association exists between OSA and AF, such that OSA is strikingly more prevalent in patients with AF than in high-risk patients with multiple other cardiovascular diseases. The coinciding epidemics of obesity and AF underscore the clinical importance of these results.

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.