Obesity as an Effect Modifier in Sleep-Disordered Breathing and Postcardiac Surgery Atrial Fibrillation

Association between obstructive sleep apnea and atrial fibrillation and delirium after cardiac surgery. Sub-analysis of DECADE trial

BACKGROUND

Atrial fibrillation and delirium are common complications after cardiac surgery. Both are associated with increased Intensive Care Unit (ICU) and hospital length of stay, functional decline, 30-day mortality and increase in health care costs. Obstructive Sleep Apnea (OSA) induces deleterious effects in the cardiovascular and nervous systems. We hypothesized that adult patients with preoperative OSA have a higher incidence of postoperative atrial fibrillation and delirium than patients without OSA, after cardiac surgery.

METHODS

Sub-analysis of the DECADE trial at Cleveland Clinic hospitals. Our exposure was OSA, defined by STOP-BANG questionnaire score higher than 5 and/or a preoperative diagnosis of OSA. The primary outcome was atrial fibrillation, defined by clinician diagnosis or documented arrhythmia. The secondary outcome was delirium assessed twice during the initial five postoperative days using the Confusion Assessment Method for ICU. We assessed the association between OSA, and atrial fibrillation and delirium using a logistic regression model adjusted for confounders using inverse probability of treatment weighting.

RESULTS

590 patients were included in the final analysis. 133 were diagnosed with OSA and 457 had no OSA. Satisfactory balance between groups for most confounders (absolute standardized difference < 0.10) was achieved after weighting. The atrial fibrillation incidence was 37% (n = 49) in the patients with OSA and 33% (n = 150) in the non-OSA patients. OSA was not associated with atrial fibrillation with an estimated odds ratio of 1.22 (95% CI: 0.75,1.99;p = 0.416). The delirium incidence was 17% (n = 22) in patients with OSA and 15% (n = 67) in the non-OSA patients. OSA was not associated with delirium with an estimated odds ratio of 0.93 (95% CI: 0.51,1.69;p = 0.800).

CONCLUSION

In adult patients having cardiac surgery, OSA is not associated with a higher incidence of postoperative atrial fibrillation and delirium. These results suggest different prominent factors rather than OSA affect the incidence of these postoperative outcomes.

Obstructive Sleep Apnea and Obesity Are Associated with Hypertension in a Particular Pattern: A Retrospective Study

Obstructive sleep apnea (OSA) and obesity can increase the risk of hypertension, but the combined effects of these two conditions on hypertension are not yet known. We collected the basic characteristics, sleep parameters, and glucose levels of subjects with a polysomnography test and divided them into four groups, according to whether they had severe OSA and obesity or not. The main effects of severe OSA and obesity and the interactions of the two on systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels were detected using analysis of covariance. The association between obesity and severe OSA and abnormal blood pressure and their combined effects were detected with logistic regression. In total, 686 subjects were included. After adjusting for multiple confounding factors, the strong main effects of obesity and severe OSA were detected in the SBP and DBP levels, with no combined effects from the two conditions on SBP or DBP. Obesity was independently associated with the presence of hyper-systolic blood pressure (hyper-SBP) and hypertension, and severe OSA was independently associated with the presence of hyper diastolic blood pressure (hyper-DBP) and hypertension. No effects of the interaction between severe OSA and obesity on the presence of abnormal blood pressure were observed. Both severe OSA and obesity were associated with hypertension, while obesity was closely associated with hyper-SBP, and severe OSA was associated with hyper-DBP. No effects of the interaction between these two on hypertension were observed.

Impact of sleep disordered breathing on postoperative atrial fibrillation in patients who underwent cardiac surgery: a meta-analysis

Objective: An increasing number of studies suggest that sleep disordered breathing (SDB) may be associated with postoperative atrial fibrillation (POAF), but these studies present discrepant results. Thus, this meta-analysis aimed to synthesize the data associating SDB with POAF in patients who underwent cardiac surgery.Methods: A literature search was performed in the Scopus, PubMed, Web of Science, EMBASE, CENTRAL, Weipu, Wanfang Data, and China National Knowledge Infrastructure databases before August 2022. Data were extracted, and the strength of the relationship between SDB and the risk of POAF was evaluated using odds ratio (OR) and 95% confidence intervals (CIs). All statistical analysis was carried out using the Stata 12.0 software.Results: A total of 24 studies with 660,685 subjects were included in current meta-analysis. SDB was significantly associated with the risk of POAF in the patients who underwent cardiac surgery (OR = 1.49; 95% CI, 1.30-1.70; p < .001). Next subgroup analysis revealed that such association may be increased in the group with medical equipment-measured SDB (OR = 2.27; 95% CI, 1.59-3.23; p < .001), prospective studies (OR = 2.17; 95% CI, 1.55-3.03; p < .001), patients without a previous history of atrial fibrillation (OR = 2.04; 95% CI, 1.47-2.82; p < .001), and patients who received a coronary artery bypass graft (OR = 2.10; 95% CI, 1.45-3.05; p < .001). No publication bias was identified.Conclusion: The results of meta-analysis support that SDB may be associated with an increased risk of POAF in patients who had undergone cardiac surgery, and these results should be confirmed in more rigorously designed studies.KEY MESSAGESPatients with SDB who underwent cardiac surgery showed increased risk of POAF.The relationship between SDB and POAF should be explained with caution with the consideration of various covariate.The effect of pre-treatment of SDB on POAF should be examined in future.

Sleep Study and Oximetry Parameters for Predicting Postoperative Complications in Patients With OSA

In the surgical setting, OSA is associated with an increased risk of postoperative complications. At present, risk stratification using OSA-associated parameters derived from polysomnography (PSG) or overnight oximetry to predict postoperative complications has not been established. The objective of this narrative review is to evaluate the literature to determine the association between parameters extracted from in-laboratory PSG, portable PSG, or overnight oximetry and postoperative adverse events. We obtained pertinent articles from Ovid MEDLINE, Ovid MEDLINE In-Process & Other Non-Indexed Citations, and Embase (2008 to December 2017). The search included studies with adult patients undergoing surgery who had OSA diagnosed with portable PSG, in-laboratory PSG, or overnight oximetry that reported on specific sleep parameters and at least one adverse outcome. The search was restricted to English-language articles. The search yielded 1,810 articles, of which 21 were included in the review. Preoperative apnea-hypopnea index (AHI) and measurements of nocturnal hypoxemia such as oxygen desaturation index (ODI), cumulative sleep time percentage with oxyhemoglobin saturation (Spo₂) < 90% (CT90), minimum Spo₂, mean Spo₂, and longest apnea duration were associated with postoperative complications. OSA is associated with postoperative complications in the population undergoing surgery. Clinically and statistically significant associations between AHI and postoperative adverse events exists. Complications may be more likely to occur in the category of moderate to severe OSA (AHI ≥ 15). Other parameters from PSG or overnight oximetry such as ODI, CT90, mean and minimal Spo₂, and longest apnea duration can be associated with postoperative complications and may provide additional value in risk stratification and minimization.