Validity and Predictive Value of a Portable Two-Channel Sleep-Screening Tool in the Identification of Sleep Apnea in Patients With Heart Failure

Abstract Background Sleep apnea is an important comorbidity in heart failure (HF) and is associated with an adverse outcome. Diagnosing sleep apnea is difficult, and polysomnography, considered to be the criterion standard, is not widely available. We assessed the validity of a portable 2-channel sleep-screening tool for the identification of sleep apnea in patients with HF. Methods and Results One hundred patients with stable HF had simultaneous recordings of home-based polysomnography and the screening tool (Apnealink). To compare the apnea-hypopnea index of the screening tool with polysomnography, intraclass correlation (ICC), sensitivity, and specificity were calculated, and a Bland-Altman plot and receiver operating characteristic (ROC) curves were constructed. Ninety valid measurements with the screening tool were obtained (mean age 65.5 ± 11.0 y, 72% male, mean left ventricular ejection fraction 34.6 ± 11.0%). Agreement between the screening tool and polysomnography was high (ICC 0.85). The optimal cutoff value was apnea-hypopnea index ≥15/h (area under the ROC curve 0.94). Sensitivity and specificity were 92.9% and 91.9%, respectively. Conclusions The screening tool is useful in excluding the presence of sleep apnea in HF patients to refer only high-risk patients for more extensive polysomnography. This method may potentially reduce the need for the more expensive polysomnography.