OSA and Depression Are Common and Independently Associated With Refractory Angina in Patients With Coronary Artery Disease

Abstract

OBJECTIVE: Refractory angina is a severe form of coronary artery disease (CAD) characterized by persistent angina despite optimal medical therapy. OSA and depression are common in patients with stable CAD and may contribute to a poor prognosis. We hypothesized that OSA and depression are more common and more severe in patients with refractory angina than in patients with stable CAD. METHODS: We used standardized questionnaires and full polysomnography to compare consecutive patients with well-established refractory angina vs consecutive patients with stable CAD evaluated for coronary artery bypass graft surgery. RESULTS: Patients with refractory angina (n = 70) compared with patients with stable CAD (n = 70) were similar in sex distribution (male, 61.5% vs 75.5%; P = .07) and BMI (29.5 +/- 4 kg/m(2) vs 28.5 +/- 4 kg/ m(2), P = .06), and were older (61 +/- 10 y vs 57 +/- 7 y, P = .013), respectively. Patients with refractory angina had significantly more symptoms of daytime sleepiness (Epworth Sleepiness Scale score, 12 +/- 6 vs 8 +/- 5; P < .001), had higher depression symptom scores (Beck Depression Inventory score, 19 +/- 8 vs 10 +/- 8; P < .001) despite greater use of antidepressants, had a higher apnea-hypopnea index (AHI) (AHI, 37 +/- 30 events/h vs 23 +/- 20 events/h; P = .001), higher proportion of oxygen saturation < 90% during sleep (8% + 13 vs 4% + 9, P = .04), and a higher proportion of severe OSA (AHI >= 30 events/h, 48% vs 27%; P = .009) than patients with stable CAD. OSA (P = .017), depression (P < .001), higher Epworth Sleepiness Scale score (P = .007), and lower sleep efficiency (P = .016) were independently associated with refractory angina in multivariate analysis. CONCLUSIONS: OSA and depression are independently associated with refractory angina and may contribute to poor cardiovascular outcome.