PAP therapy may cause unexpected hypotension especially in patients with low baseline BP as seen in HF patients treated according to current guidelines. Whether these hypotensive effects sustain, cause any harm to the patients and/or is responsible for non-acceptance or non-adherence of PAP therapy needs to be determined.

We found that PTT- and OM-based BP results are closely correlated while applying CPAP over a period of 40 min. With higher CPAP level, bias between both methods increased.

Background: Manifestation of central sleep apnea (CSA) with Cheyne-Stokes respiration is of major prognostic impact in chronic heart failure (CHF). Inflammatory processes have been linked to a progression of cardiovascular diseases, including heart failure. While an association of C-reactive protein (CRP) levels to obstructive sleep apnea has been documented before, there is a lack of information regarding variation of CRP levels in patients with CSA. Objectives: The objective of this study was to investigate a potential association of CRP levels to CSA severity in CHF patients. Methods: High sensitivity CRP levels were analyzed in 966 patients with CHF (BMI 26.3 ± 4.6, New York Heart Association class 2.6 ± 0.5, left ventricular ejection fraction 29.4 ± 7.9%, N-terminal pro-brain natriuretic peptide, NT-proBNP, level 2,209 ± 3,315 pg/ml) without sleep-disordered breathing (SDB; Apnea-Hypopnea Index, AHI, <5/h) or various degrees of CSA, documented by in-hospital cardiorespiratory polygraphy or polysomnography. Results: The CRP concentration in CHF patients was 0.550 ± 0.794 mg/dl in patients without SDB (AHI 0-4/h, n = 403) versus 0.488 ± 0.708 mg/dl in patients with mild CSA (AHI 5-14/h, n = 123, p = n.s.) and 0.660 ± 0.963 mg/dl in patients with moderate CSA (AHI 15-29/h, n = 160, p = n.s.). In patients with severe CSA (AHI ≥30/h, n = 280), significantly higher CRP concentrations were documented (0.893 ± 1.384 mg/dl, p < 0.05). Stepwise regression analysis revealed AHI, NT-proBNP and heart rate to be independently associated with elevated CRP levels. Conclusion: Severe CSA in CHF patients is associated with elevated levels of CRP, a systemic marker of inflammation and cardiovascular risk. This might explain in part the negative prognostic impact of CSA in these patients.