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Postoperative Outcomes in Obstructive Sleep Apnea Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis of Comparative Studies

Nagappa, Mahesh MD*; Ho, George BSc; Patra, Jayadeep PhD; Wong, Jean FRCPC; Singh, Mandeep FRCPC; Kaw, Roop MD‡§; Cheng, Davy FRCPC∥¶; Chung, Frances MD, FRCPC

doi: 10.1213/ANE.0000000000002558
Respiration and Sleep Medicine: Meta-Analysis

BACKGROUND: Obstructive sleep apnea (OSA) is a common comorbidity in patients undergoing cardiac surgery and may predispose patients to postoperative complications. The purpose of this meta-analysis is to determine the evidence of postoperative complications associated with OSA patients undergoing cardiac surgery.

METHODS: A literature search of Cochrane Database of Systematic Reviews, Medline, Medline In-process, Web of Science, Scopus, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL until October 2016 was performed. The search was constrained to studies in adult cardiac surgical patients with diagnosed or suspected OSA. All included studies must report at least 1 postoperative complication. The primary outcome is major adverse cardiac or cerebrovascular events (MACCEs) up to 30 days after surgery, which includes death from all-cause mortality, myocardial infarction, myocardial injury, nonfatal cardiac arrest, revascularization process, pulmonary embolism, deep venous thrombosis, newly documented postoperative atrial fibrillation (POAF), stroke, and congestive heart failure. Secondary outcome is newly documented POAF. The other exploratory outcomes include the following: (1) postoperative tracheal intubation and mechanical ventilation; (2) infection and/or sepsis; (3) unplanned intensive care unit (ICU) admission; and (4) duration of stay in hospital and ICU. Meta-analysis and meta- regression were conducted using Cochrane Review Manager 5.3 (Cochrane, London, UK) and OpenBUGS v3.0, respectively.

RESULTS: Eleven comparative studies were included (n = 1801 patients; OSA versus non-OSA: 688 vs 1113, respectively). MACCEs were 33.3% higher odds in OSA versus non-OSA patients (OSA versus non-OSA: 31% vs 10.6%; odds ratio [OR], 2.4; 95% confidence interval [CI], 1.38–4.2; P = .002). The odds of newly documented POAF (OSA versus non-OSA: 31% vs 21%; OR, 1.94; 95% CI, 1.13–3.33; P = .02) was higher in OSA compared to non-OSA. Even though the postoperative tracheal intubation and mechanical ventilation (OSA versus non-OSA: 13% vs 5.4%; OR, 2.67; 95% CI, 1.03–6.89; P = .04) were significantly higher in OSA patients, the length of ICU stay and hospital stay were not significantly prolonged in patients with OSA compared to non-OSA. The majority of OSA patients were not treated with continuous positive airway pressure therapy. Meta-regression and sensitivity analysis of the subgroups did not impact the OR of postoperative complications for OSA versus non-OSA groups.

CONCLUSIONS: Our meta-analysis demonstrates that after cardiac surgery, MACCEs and newly documented POAF were 33.3% and 18.1% higher odds in OSA versus non-OSA patients, respectively.

From the *Department of Anesthesia and Perioperative Medicine, London Health Sciences Centre and St Joseph Health Care, Western University, London, Ontario, Canada; Department of Anesthesiology and Pain Medicine, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada; Departments of Hospital Medicine and §Outcomes Research (Anesthesiology), Cleveland Clinic, Cleveland, Ohio; Centre for Medical Evidence, Decision Integrity and Clinical Impact (MEDICI), Western University, London, ON, Canada; and Department of Anesthesia & Perioperative Medicine, Western University, London, ON, Canada.

Accepted for publication August 16, 2017.

Funding: The STOP-Bang tool is proprietary to University Health Network. This study is supported by University Health Network Foundation, and Department of Anesthesiology, University Health Network, University of Toronto.

Conflicts of Interest: See Disclosures at the end of the article.

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Address correspondence to Frances Chung, MD, FRCPC, Department of Anesthesiology and Pain Medicine, Toronto Western Hospital, University Health Network, 399 Bathurst St, Toronto, Ontario, M5T 2S8, Canada. Address e-mail to

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© 2017 International Anesthesia Research Society