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.
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.
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/m2 vs 28.5 ± 4 kg/m2, 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.
OSA and depression are independently associated with refractory angina and may contribute to poor cardiovascular outcome.