Central Sleep Apnea Predicts Pulmonary Complications After Cardiac Surgery

Pooled prevalences of obstructive sleep apnea and heart failure: a systematic review and meta-analysis

Obstructive sleep apnea (OSA) is a disease with intermittent hypoxemia during sleep. It has been shown that OSA is related to several cardiovascular diseases including heart failure. Both OSA and heart failure have a close association bidirectionally. This study aimed to estimate the pooled prevalence of OSA in patients with heart failure as well as pooled prevalence of heart failure in patients with OSA. This was a systematic review with a meta-analysis. The inclusion criteria were observational or epidemiological studies conducted in adult patients with heart failure to evaluate the prevalence of OSA and patients with OSA to evaluate the prevalence of heart failure. The outcomes of this study were prevalence of OSA in patients with heart failure and prevalence of heart failure in patients with OSA. Four databases were used for systematic searching including PubMed, Science Direct, Scopus, and CINAHL Plus. Manual searches for related studies were also conducted. Proportion meta-analyses using a random-effects model were conducted to identify pooled proportion (prevalence) of heart failure in patients with OSA and vice versa. Among 3,941 articles from the four databases met the study criteria. Thirty-three studies showed the prevalence of OSA in patients with heart failure, while thirteen studies presented the prevalence of heart failure in patients with OSA. The prevalence of OSA in patients with heart failure was 38.4% (95% CI 31.9 to 45.2; I2 of 96.1%). Using a diagnostic criterion of OSA of more than 10 events/hr had the highest prevalence of OSA in patients with heart failure at 53.4% (95% CI 42.0 to 64.5). The highest prevalence of OSA in patients with heart failure was 60.1% (95% CI 51.4 to 68.3) in a report from India. The pooled prevalence of heart failure in patients with OSA was 12.8% (95% CI 8.1 to 19.5; I2 of 94.6%). The prevalence in Romania was highest at 22.6% (95% CI 20.4 to 24.9). The pooled prevalence of OSA in patients with heart failure was higher than the pooled prevalence of heart failure in patients with OSA. The pooled prevalence rates of these associations varied among the diagnostic criteria of OSA and countries.

Sleep-Disordered Breathing, Advanced Age, and Diabetes Mellitus Are Associated with De Novo Atrial Fibrillation after Cardiac Surgery

Background: Postoperative de novo atrial fibrillation (POAF) is one of the most frequently encountered complications following cardiac surgery. Despite the identification of several risk factors, the link between sleep-disordered breathing (SDB) and POAF has barely been examined. The objective of this prospective observational study was to determine whether severe SDB is associated with POAF in patients after elective coronary artery bypass grafting (CABG) surgery. Study design and methods: The incidence and preoperative predictors of in-hospital POAF were assessed in 272 patients undergoing CABG surgery at the University Medical Center Regensburg (Germany). In-hospital POAF was detected by continuous telemetry-ECG monitoring and 12-lead resting ECGs within the first seven postoperative days. POAF that occurred after hospital discharge within 60 days post CABG surgery was classified as post-hospital POAF and was ascertained by standardized phone interviews together with the patients' medical files, including routinely performed Holter-ECG monitoring at 60 days post CABG surgery. The night before surgery, portable SDB monitoring was used to assess the presence and type of severe SDB, defined by an apnea-hypopnea index ≥ 30/h. Results: The incidence of in-hospital POAF was significantly higher in patients with severe SDB compared to those without severe SDB (30% vs. 15%, p = 0.009). Patients with severe SDB suffered significantly more often from POAF at 60 days post CABG surgery compared to patients without severe SDB (14% vs. 5%, p = 0.042). Multivariable logistic regression analysis showed that severe SDB (odds ratio, OR [95% confidence interval, CI]: 2.23 [1.08; 4.61], p = 0.030), age ≥ 65 years (2.17 [1.04; 4.53], p = 0.038), and diabetes mellitus (2.27 [1.15; 4.48], p = 0.018) were significantly associated with in-hospital POAF. After additional adjustment for heart failure, the association between sleep apnea and postoperative atrial fibrillation was attenuated (1.99 [0.92; 4.31], p = 0.081). Conclusions: Amongst established risk factors, severe SDB was significantly associated with in-hospital POAF in patients undergoing CABG surgery. Whether SDB contributes to POAF independently of heart failure and whether risk for POAF may be alleviated by proper treatment of SDB merits further investigation.

Development of a nomogram for predicting nosocomial infections among patients after cardiac valve replacement surgery

AIMS AND OBJECTIVES

To construct a predictive nomogram of the risk of nosocomial infections among patients after cardiac valve replacement surgery.

BACKGROUND

Nosocomial infections are a standout challenge that worsens the prognosis of patients after valve replacement surgery. However, studies on the nomogram of nosocomial infections in these patients have remained scarce.

DESIGN

A retrospective cohort study.

METHODS

Patients (n = 720) following valve replacement surgery from 2018 to 2019 were selected. LASSO regression and multivariate logistic regression were utilised to ascertain predictors of nosocomial infections. The predictive performance of the nomogram was appraised by calibration and discrimination. Decision and impact curves were used to assess the clinical utility. Internal validation was implemented via 1000 bootstrap samples to mitigate overfitting. TRIPOD guidelines were used in this study.

RESULTS

One hundred and fifty one patients (20.97%) experienced nosocomial infections following valve replacement surgery. Heart failure, preoperative anaemia, valve material, American Society of Anesthesiologists score ≥ IV, prolonged duration of surgery, duration of mechanical ventilation ≥ 24 h and indwelling nasogastric tube were predictors of nosocomial infections. Using these variables, we developed a predictive nomogram of the occurrence of nosocomial infections and the internal validation results demonstrated good discrimination and calibration of the nomogram. The clinical decision and impact curve revealed significant clinical utility.

CONCLUSIONS

The present study constructed a nomogram for predicting the risk of nosocomial infections in patients following cardiac valve replacement surgery. This nomogram may strengthen the effective screening of patients at high risk of nosocomial infections.

RELEVANCE TO CLINICAL PRACTICE

This risk warning tool can assist clinical staff in making decisions and providing individualised infection control measures for patients, which has a significant reference value for clinical practice.

NO PATIENT OR PUBLIC CONTRIBUTION

The data for this study were obtained from the hospital database, and the entire process of the study did not involve patient participation.

Perioperative Risk Factors for Post-operative Pneumonia after Type A Acute Aortic Dissection Surgery

OBJECTIVE

Type A acute aortic dissection (TAAAD) is a dangerous and complicated condition with a high death rate before hospital treatment. Patients who are fortunate to receive prompt surgical treatment still face high in-hospital mortality. A series of post-operative complications further affects the prognosis. Post-operative pneumonia (POP) also leads to great morbidity and mortality. This study aimed to identify the prevalence as well as the risk factors for POP in TAAAD patients and offer references for clinical decisions to further improve the prognosis of patients who survived the surgical procedure.

METHODS

The study enrolled 89 TAAAD patients who underwent surgical treatment in Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei province, China from December 2020 to July 2021 and analyzed the perioperative data and outcomes of these patients. Logistic regression analyses were used to identify the risk factors for POP.

RESULTS

In the study, 31.5% of patients developed POP. Patients with POP had higher proportions of severe oxygenation damage, pneumothorax, reintubation, tracheotomy, renal replacement therapy, arrhythmia, gastrointestinal bleeding, and longer duration of mechanical ventilation, fever, ICU stay, and length of stay (all with P<0.05). The in-hospital mortality was 2.3%. Smoking, preoperative white blood cells, and intraoperative transfusion were the independent risk factors for POP in TAAAD.

CONCLUSION

Patients who underwent TAAAD surgery suffered poorer outcomes when they developed POP. Furthermore, patients with risk factors should be treated with caution.

Impact of transcatheter edge-to-edge mitral valve repair on central sleep apnoea

Aims

Sleep-disordered breathing (SDB) and its subtype central sleep apnoea (CSA) are highly prevalent in patients with heart failure and associated with worse prognosis. Whereas pharmacological therapy of heart failure has been shown to ameliorate CSA, results from previous studies on the effect of mitral regurgitation therapy on SDB are contradicting. The aim of this study was to assess the impact of transcatheter edge-to-edge mitral valve repair (TEER) on prevalence and severity of CSA.

Methods and results

We enrolled 47 patients undergoing TEER for symptomatic mitral regurgitation in a prospective study. Secondary mitral regurgitation and left ventricular ejection fraction < 50% were present in 79% and 68% of patients, respectively. Respiratory polygraphy was performed before TEER in a compensated condition and four weeks after the procedure. 34 patients completed the follow-up. At baseline, 19 (56%) patients showed moderate-to-severe SDB, of whom 13 (68%) were classified as CSA. Both apnoea-hypopnoea index and percentage of recorded time spent in Cheyne-Stokes respiration strongly decreased from baseline to follow-up (median [IQR] 16 [7–30] vs. 7 [4–15] /h, p = 0.007; 6 [0–34] vs. 0 [0–8] %, p = 0.008). Median relative reduction of central apnoea index was 75% (p = 0.023), while obstructive apnoea index did not change significantly. Increase in stroke volume after TEER and high systolic pulmonary artery pressure at baseline predicted a > 50% reduction of both Apnoea-hypopnoea index and Cheyne-Stokes respiration.

Conclusion

TEER is associated with a significant short-term reduction of CSA and Cheyne-Stokes respiration in high-risk patients, strengthening its value as an effective treatment option for advanced heart failure.

Graphical abstract

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.

Prevalence and predictors of sleep-disordered breathing in chronic heart failure: the SchlaHF-XT registry

AIMS

Heart failure with preserved ejection fraction (HFpEF) is a condition with increasing prevalence. Sleep-disordered breathing (SDB) is an important co-morbidity in HFpEF. The SchlaHF-XT registry evaluated the sex-specific prevalence and predictors of SDB, including obstructive (OSA) and central sleep apnoea, in patients with HFpEF compared with heart failure with mildly reduced (HFmrEF) or reduced (HFrEF) ejection fraction.

METHODS AND RESULTS

Consecutive adults with chronic heart failure treated according to current guidelines were enrolled. The presence of moderate-to-severe SDB (apnoea-hypopnoea index ≥15/h) was determined using Type 3 polygraphic devices. Of 3289 patients included, 2032 had HFpEF, 559 had HFmrEF, and 698 had HFrEF, of whom 34, 21, 23, and 42%, respectively, were female. Prevalence of SDB in HFpEF was high, but significantly lower than in HFmrEF or HFrEF (36% vs. 41 and 48%, respectively). Rates of SDB in males and females were 41 and 28% in HFpEF, 44 and 30% in HFmrEF, and 50 and 40% in HFrEF. The proportion of males and females with SDB who had OSA was significantly greater in those with HFpEF vs. HFrEF. Male sex, older age, higher body mass index, and New York Heart Association functional Class III/IV were significant predictors of moderate-to-severe SDB in HFpEF patients.

CONCLUSIONS

Prevalence of SDB in HFpEF was high, but lower than in patients with HFmrEF or HFrEF. Moderate-to-severe SDB occurred more frequently in males than in females across the whole spectrum of heart failure. In both sexes, the proportion of OSA in SDB patients with HFpEF was higher than in those with HFrEF.

Prehabilitation of Cardiac Surgical Patients, Part 1: Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation

The concept of "prehabilitation" consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

Female Patients With Sleep-Disordered Breathing Display More Frequently Heart Failure With Preserved Ejection Fraction

Objective: Sleep-disordered breathing (SDB) is a widespread disease that is often associated with heart failure (HF) with preserved ejection fraction (HFpEF). HFpEF is more frequent in women than in men, but detailed pathomechanisms remain unclear. We investigated HFpEF in women and men in a high-risk cohort with SDB monitoring.

Methods and Results: Three hundred twenty-seven patients (84.4% men) undergoing elective coronary artery bypass grafting were prospectively subjected to SDB monitoring, and an apnea–hypopnea index (AHI) ≥15/h defined SDB. HF was classified according to current guidelines. HFpEF was significantly more frequent in SDB patients compared to those without SDB (28 vs. 17%, P = 0.016). This distribution was driven by an increased frequency of HFpEF in female SDB patients (48% vs. only 25% in male, P = 0.022). In accordance, female patients with SDB exhibited significantly more impaired diastolic left ventricular filling compared to men (echocardiographic E/e′). In contrast to men, in women, minimum oxygen saturation (O_2min, measured by polygraphy, R² = 0.470, P < 0.001) and time of oxygen saturation <90% (R² = 0.165, P = 0.044) were significantly correlated with E/e′. Moreover, the correlation between O_2min and E/e′ was significantly different in women compared to men (P < 0.001). Intriguingly, this association remained independent of clinical covariates in women [age, body mass index, systolic contractile dysfunction, diabetes mellitus, and glomerular filtration rate (GFR), R² = 0.534, P = 0.042, multivariate regression analysis]. Since angiotensin II signaling has been mechanistically linked to HF, we measured protein expression of its cleavage enzyme ACE2 in human right atrial appendage biopsies (Western blot). Intriguingly, we found a significantly decreased ACE2 expression preferentially in women with SDB (2.66 ± 0.42 vs. 4.01 ± 2.47 in men with SDB, P = 0.005). In accordance, left ventricular mass index was significantly increased in women with SDB compared to women without SDB.

Conclusion: In patients with SDB, HFpEF and diastolic dysfunction were more frequent in women compared to men. In contrast to men, the severity of SDB was associated with the degree of diastolic dysfunction in women. These insights might help to find sex-specific therapies for patients with sleep-disordered breathing and heart failure.

Clinical Trial Registration: Unique identifier: NCT02877745, URL: http://www.clinicaltrials.gov.