We thank Dr Jaffuel and colleagues for their stimulating discussion of the heterogeneous effects of positive airway pressure on breathing disturbances and cardiovascular parameters. They hypothesized that higher levels of CPAP or expiratory positive airway pressure may impair hemodynamics, increase the ventilatory loop gain, and, thus, aggravate Cheyne-Stokes respiration. Our study1 confirmed previous findings, showing a 50% reduction of central sleep apnea under CPAP, whereas auto-servoventilation (ASV) normalized both obstructive and central disturbances. To address the idea of Jaffuel et al, we analyzed responders and nonresponders irrespective of their treatment mode. We asked whether a reduction of the apnea-hypopnea index to ≤10/h and by ≥50% was associated with different CPAP/expiratory positive airway pressure levels. The mean pressures differed significantly between responders (9.2 ± 1.7 cm H2O; n = 32) and nonresponders (10.3 ± 2.2; n = 19; P =.045). However, the absolute difference was mild and even smaller than the pressure difference between the complete CPAP and ASV groups. Most importantly, this difference was related almost exclusively to ASV responders (Table 1), whereas no pressure difference in CPAP responders vs nonresponders was found. These findings are not surprising because we aimed to apply a homogenous CPAP level of 10 cm H2O. Thus, the data do not support the idea that higher pressures are responsible for differences in efficacy. The heterogeneous response is associated with a homogeneous pressure profile.