Impact of OSA on cardiovascular events after coronary artery bypass surgery.

BACKGROUND: The impact of OSA on new cardiovascular events in patients undergoing coronary artery bypass graft (CABG) surgery is poorly explored. METHODS: Consecutive patients referred for CABG underwent clinical evaluation and standard polysomnography in the preoperative period. CABG surgery data, including percentage of off-pump and on-pump CABG, number of grafts, and intraoperative complications, were collected. The primary end point was major adverse cardiac or cerebrovascular events (MACCEs) (combined events of all-cause death, myocardial infarction, repeated revascularization, and cerebrovascular events). Secondary end points included individual MACCEs, typical angina, and arrhythmias. Patients were evaluated at 30 days (short-term) and up to 6.1 years (long term) after CABG. RESULTS: We studied 67 patients (50 men; mean age, 58 ± 8 years; mean BMI, 28.5 ± 4.1 kg/m2). OSA (apnea-hypopnea index ≥ 15 events/h) was present in 56% of the population. The patients were followed for a mean of 4.5 years (range, 3.2-6.1 years). No differences were observed in the short-term follow-up. In contrast, MACCE (35% vs 16%, P = .02), new revascularization (19% vs 0%, P = .01), episodes of typical angina (30% vs 7%, P = .02), and atrial fibrillation (22% vs 0%, P = .0068) were more common in patients with than without OSA in the long-term follow-up. OSA was an independent factor associated with the occurrence of MACCE, repeated revascularization, typical angina, and atrial fibrillation in the multivariate analysis. CONCLUSIONS: OSA is independently associated with a higher rate of long-term cardiovascular events after CABG and may have prognostic and economic significance in CABG surgery.

OSA and depression are common and independently associated with refractory angina in patients with coronary artery disease.

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/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. CONCLUSIONS: OSA and depression are independently associated with refractory angina and may contribute to poor cardiovascular outcome.

Obstructive sleep apnea is common among patients referred for coronary artery bypass grafting and can be diagnosed by portable monitoring.

BACKGROUND: Obstructive sleep apnea (OSA) is common among patients with coronary artery disease. However, OSA remains largely under recognized. The lack of clinical suspicion and difficulties to access full polysomnography (PSG) are limiting factors. The aim of this study was to evaluate, among patients referred to coronary artery bypass grafting (CABG): (i) the prevalence of OSA, (ii) the association of OSA with clinical symptoms, (iii) the performance of overnight unattended portable monitoring (PM) as an alternative method for the diagnosis of OSA. METHODS: Consecutive patients referred for CABG were evaluated by standard physical evaluation and validated questionnaires (Berlin questionnaire and Epworth Sleepiness Scale) and underwent full PSG and PM (Stardust II). RESULTS: We studied 70 consecutive patients (76% men), age 58±7 years (mean±SD), BMI [median (interquartile range)] 27.6 kg/m (25.8-31.1). The prevalence of OSA (full PSG) using an apnea-hypopnea index of at least 5 events/h was 87%. Commonly used clinical traits for the screening of OSA such as the Epworth Sleepiness Scale and neck circumference had low sensitivities to detect OSA. In contrast, the Berlin questionnaire showed a good sensitivity (72%) to detect OSA. PM showed good sensitivity (92%) and specificity (67%) for the diagnosis of OSA. CONCLUSION: OSA is strikingly common among patients referred for CABG. The Berlin questionnaire, but not symptom of excessive daytime sleepiness is a useful tool to screen OSA. PM is useful for the diagnosis of OSA and therefore is an attractive tool for widespread use among patients with coronary artery disease.