Although most research has concentrated on the link between sleep apnea and atrial fibrillation, obstructive sleep apnea (OSA) is also associated with ventricular arrhythmias. These cardiac arrhythmias can be triggered by repeated episodes of hypoxemia, hypercapnia, acidosis, intrathoracic pressure fluctuations, reoxygenation, and other mechanisms that occur during apnea and hypopnea. Studies show that OSA reduces the effectiveness of arrhythmia treatments, such as antiarrhythmic medications and radiofrequency current ablation. Several non-randomized studies indicate that treating sleep apnea syndrome with continuous positive airway pressure (CPAP) may help maintain sinus rhythm following electrical cardioversion and increase the success rates of catheter ablation. This review aims to thoroughly examine the role of OSA in the development of cardiac arrhythmias. Screening for OSA and arrhythmias in patients with OSA provides vital information on the need for additional interventions, such as CPAP therapy, anticoagulation, antiarrhythmic drug therapy, catheter ablation for specific arrhythmias, or device therapy. New therapies for OSA treatment have the potential to significantly influence arrhythmia development in patients with sleep-disordered breathing. However, further research is required to validate these findings and formulate comprehensive treatment protocols.

Background: Obstructive sleep apnea (OSA) is a prevalent but frequently underdiagnosed comorbidity in patients undergoing cardiac surgery, including coronary artery bypass grafting (CABG), aortic valve replacement (AVR), and mitral valve repair or replacement (MVR). This systematic review and meta-analytic synthesis investigates the relationship between OSA and postoperative morbidity and mortality, with particular attention to the predictive utility of established screening instruments. Methods: A systematic search of the PubMed database was conducted (April 2025), identifying 724 articles published in the last ten years. Seventeen primary studies met the inclusion criteria for qualitative synthesis, and four additional studies were included in the meta-analyses. Outcomes assessed included atrial fibrillation, major adverse cardiac and cerebrovascular events (MACCE), acute kidney injury (AKI), respiratory complications, pneumonia, hospital length of stay (LOS), and mortality. Risk of bias was assessed qualitatively based on study design and reporting limitations. This review was registered in the PROSPERO database under registration number CRD420251049574. Results: Meta-analyses demonstrated significantly elevated odds of atrial fibrillation (OR = 2.44, 95% CI: 1.46–4.07), major adverse cardiac and cerebrovascular events (OR = 2.06, 95% CI: 1.61–2.63), acute kidney injury (OR = 2.24, 95% CI: 1.67–3.01), and respiratory complications (OR = 1.15, 95% CI: 1.05–1.25) among patients with OSA. Additionally, OSA was associated with a significantly prolonged hospital length of stay (standardized mean difference [SMD] = 0.62, 95% CI: 0.46–0.78) and a marginal increase in pneumonia risk (OR = 1.07, 95% CI: 1.00–1.15). Evidence regarding stroke, intensive care unit (ICU) stay, and mortality was inconsistent or underpowered. Conclusions: Across core outcomes, findings were consistent across multiple studies involving a large patient population. Obstructive sleep apnea is a clinically consequential risk factor in cardiac surgery, associated with increased perioperative complications and prolonged hospitalization. These findings support the integration of routine OSA screening into preoperative risk assessment protocols. Further prospective, multicenter trials are warranted to assess the efficacy of perioperative management strategies, including continuous positive airway pressure (CPAP) therapy, in improving surgical outcomes.

Background: Obstructive sleep apnea (OSA) has been associated with adverse cardiometabolic profiles, but its relationship with cholesterol target attainment in patients receiving lipid-lowering therapy remains incompletely characterized. We investigated the association between severe OSA and non-attainment of predefined cholesterol thresholds in patients undergoing elective cardiac surgery. Methods: This secondary analysis included 142 adults from a prospectively assembled observational cohort. Participants underwent in-hospital preoperative Type III cardiorespiratory polygraphy, fasting lipid assessment, and documentation of lipid-lowering therapy. Severe OSA was defined as an apnea–hypopnea index ≥30 events/h. The primary outcome was non-high-density lipoprotein cholesterol (non-HDL-C) ≥ 100 mg/dL. Multivariable models were adjusted for age, sex, body mass index, diabetes mellitus, high-intensity statin therapy, and non-statin lipid-lowering therapy. Results: Severe OSA was associated with higher odds of non-HDL-C ≥ 100 mg/dL (adjusted odds ratio [OR] 3.49, 95% confidence interval [CI] 1.56–7.78; p = 0.002), LDL-C ≥ 55 mg/dL (OR 2.93, 95% CI 1.18–7.29; p = 0.021), and LDL-C ≥ 70 mg/dL (OR 2.30, 95% CI 1.03–5.12; p = 0.041). In contrast, associations with continuous LDL-C (p = 0.113) and non-HDL-C (p = 0.100) concentrations were not statistically significant. No significant associations were observed for triglyceride-related or lipid-derived outcomes. The primary association with non-HDL-C ≥ 100 mg/dL remained significant in the analysis restricted to statin-treated patients. Conclusions: Severe OSA was associated with non-attainment of predefined cholesterol thresholds in this cardiac surgical cohort, with the strongest and most consistent association observed for non-HDL-C ≥ 100 mg/dL. These findings identify an association with categorical cholesterol target non-attainment but do not establish treatment failure, causality, or a generalized increase in cholesterol concentrations.

Background: Postoperative respiratory dysfunction remains a frequent complication after cardiac surgery, yet the influence of preoperative pulmonary reserve on postoperative respiratory recovery remains incompletely understood. We investigated whether preoperative spirometric phenotype was associated with postoperative ventilatory burden following cardiac surgery. Methods: We performed a secondary analysis of a prospective cohort of adults undergoing elective cardiac surgery with cardiopulmonary bypass. Preoperative spirometry was used to classify patients as having normal spirometry, a restrictive spirometric pattern, or an obstructive spirometric pattern according to ERS/ATS recommendations. The primary endpoint was VBI, a study-specific, unweighted composite defined as the cumulative duration of IPPV, SIMV, invasive CPAP, and post-extubation CPAP/AIRVO support. Univariable and multivariable linear regression analyses were performed to evaluate variables associated with postoperative VBI. Results: A total of 129 patients were included. Preoperative spirometry was normal in 82 patients (63.6%), demonstrated a restrictive spirometric pattern in 20 (15.5%), and an obstructive spirometric pattern in 25 (19.4%). VBI did not differ significantly among spirometric phenotypes (p = 0.443). In the multivariable analysis, preoperative spirometric phenotype was not significantly associated with VBI. Older age was associated with higher VBI (β = 0.0095, p = 0.015), whereas higher left ventricular ejection fraction was associated with lower VBI (β = −0.0161, p = 0.032). Exploratory analyses demonstrated a numerical tendency toward longer invasive respiratory-support duration among patients with a moderate restrictive spirometric pattern. Conclusions: Broad preoperative spirometric phenotype was not significantly associated with cumulative postoperative respiratory-support burden. Exploratory findings should be regarded as hypothesis-generating. Larger prospective studies are needed to determine whether restrictive spirometric abnormalities are associated with delayed liberation from invasive mechanical ventilation.