Forty-five patients with OSA and heart failure with reduced ejection fraction ( left ventricular ejection fraction @ % -LSB- meanSD -RSB- ) were evaluated with the use of echocardiography and @C-acetate and @C-hydroxyephedrine positron emission tomography before and @ to @ weeks after randomization to receive short-term CPAP ( n = @ ) or no CPAP ( n = @ ) .