The influence of timing of polysomnography on diagnosis of obstructive sleep apnea in patients presenting with acute myocardial infarction and stable coronary artery disease

BackgroundWe aimed to determine if timing of polysomnography (PSG) influences the diagnosis of obstructive sleep apnea (OSA) in acute myocardial infarction (AMI) or stable coronary artery disease (CAD).MethodsA total of 160 patients admitted with AMI or stable CAD were consecutively recruited for either in-hospital (n = 80) or postdischarge (n = 80) PSG.ResultsThe median time from admission to PSG for the in-hospital and postdischarge groups was 1 day and 17 days, respectively (P < .001). Overall, 59 patients (36.9%) were diagnosed with OSA (apnea–hypopnea index [AHI] ⩾15), and they were more likely to have diabetes mellitus (DM), hypertension, hyperlipidemia, chronic renal failure, and a greater body mass index (BMI) (P < .05 for all). The diagnosis of OSA was significantly higher (P = .037) in patients who had a PSG performed as an inpatient than those who had a PSG as an outpatient. There was a significant interaction between clinical presentation and the effect of PSG timing on the diagnosis of OSA (P = .003). For the patients presenting with AMI but not those with stable CAD, in-hospital PSG was an independent predictor of OSA (adjusted odds ratio, 3.84 [95% confidence interval, 1.42–10.41]; P = .008).ConclusionThe timing of PSG influenced the diagnosis of OSA in patients who presented with AMI but not in those who presented with stable CAD.