Bitter et al performed CPAP titration on 192 patients with congestive heart failure and obstructive sleep apnea, unmasking residual central sleep apnea (so-called complex sleep apnea) in 34 (18%). Providing adaptive servoventilation (dynamic delivery of pressure support to achieve a target minute ventilation) improved AHI, NYHA class, BNP levels, ejection fraction, and other variables, at ~1 year follow-up. Authors say this is the first cohort study of patients with complex sleep apnea and CHF. Thorax 2011;66:402-407.