In a previous study,2 using level II, comprehensive, unattended sleep studies within 4 days of admission to the coronary care unit (CCU) in a group of patients who had experienced a first AMI and were comparable to the group studied by Lee et al1 in terms of age, body mass index, gender distribution, and timing of sleep studies, we reported an OSA prevalence of 52% using AHI prevalence cutoffs of 10 events per hour, and 36% at an AHI of > 20 events per hour. In our view, the high prevalence of OSA in the study by Lee et al1 can be partially attributed to a number of factors. The authors did not exclude conditions that may increase the prevalence of sleep-disordered breathing in patients who are in the acute phase of an AMI, such as those patients receiving sedation or narcotics, those with a decreased level of consciousness, alcoholic patients, patients with COPD, and those patients with neurologic disorders such as stroke. Additionally, as sleep position was not monitored, the effect of sleep position on AHI cannot be excluded. Patients are more likely to lie in the supine position in the ICU setting compared with their own home, which may in turn increase the AHI.