Background: Nocturnal hypoxaemia measured as the percentage of total sleep time spent with saturation below 90% (TST90%) may better predict cardiovascular consequences of obstructive sleep apnoea (OSA) than the number of obstructive respiratory events measured with the apnoea–hypopnea index (AHI). Deeper hypoxaemia may potentially induce more severe pathophysiological consequences. However, the additional value of the percentage of total sleep time spent with saturation below 80% (TST80%) to TST90% is not fully explored. Methods: Comprehensive medical history was taken and fasting lipid and C-reactive protein levels were measured in 797 volunteers participating in two cohort studies in Hungary and Romania. Sleep parameters, including AHI, TST90% and TST80%, were recorded following a polysomnography (PSG, n = 598) or an inpatient cardiorespiratory polygraphy (n = 199). The performance of TST80% to predict cardiovascular risk was compared with TST90% using linear and logistic regression analyses as well receiver operating characteristics curves. Sensitivity analyses were performed in patients who had PSG, separately. Results: Both parameters are significantly related to cardiovascular risk factors; however, TST80% did not show better predictive value for cardiovascular risk than TST90%. On the other hand, patients with more severe hypoxaemia reported more excessive daytime sleepiness. Conclusions: TST80% has limited additional clinical value compared to TST90% when evaluating cardiovascular risk in patients with OSA.

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. Work-related asthma has become a highly prevalent occupational lung disorder. Objective. Our study aims to evaluate occupational exposure as a predictor for asthma exacerbation. Method. We performed a retrospective evaluation of 584 consecutive patients diagnosed and treated for asthma between October 2017 and December 2019 in 4 clinics from Western Romania. We evaluated the enrolled patients for their asthma control level by employing the Asthma Control Test (ACT < 20 represents uncontrolled asthma), the medical record of asthma exacerbations, occupational exposure, and lung function (i.e., spirometry). Then, we used statistical and data mining methods to explore the most important predictors for asthma exacerbations. Results. We identified essential predictors by calculating the odds ratios (OR) for the exacerbation in a logistic regression model. The average age was 45.42 ± 11.74 years (19-85 years), and 422 (72.26%) participants were females. 42.97% of participants had exacerbations in the past year, and 31.16% had a history of occupational exposure. In a multivariate model analysis adjusted for age and gender, the most important predictors for exacerbation were uncontrolled asthma (OR 4.79, p < 0.001), occupational exposure (OR 4.65, p < 0.001), and lung function impairment (FEV1 < 80%) (OR 1.15, p = 0.011). The ensemble machine learning experiments on combined patient features harnessed by our data mining approach reveal that the best predictor is professional exposure, followed by ACT. Conclusions. Machine learning ensemble methods and statistical analysis concordantly indicate that occupational exposure and ACT < 20 are strong predictors for asthma exacerbation.

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 and Objectives: Coronavirus disease 2019 (COVID-19) is characterized by excessive inflammatory responses, including the so-called cytokine storm, which contributes substantially to morbidity and mortality in hospitalized patients. The vagus nerve, through the cholinergic anti-inflammatory pathway, represents a theoretically attractive therapeutic target for modulating systemic inflammation. Vagus nerve stimulation (VNS) has emerged as a potential adjunctive treatment for COVID-19, with several randomized controlled trials (RCTs) investigating its efficacy on inflammatory biomarkers and clinical outcomes. The quality of this evidence base has not been rigorously evaluated. This systematic review critically appraises all available RCT evidence for VNS in hospitalized COVID-19 patients. Materials and Methods: We systematically searched PubMed, Scopus, Cochrane (CENTRAL), and Web of Science from database inception to January 2026, for RCTs evaluating any form of VNS (invasive, non-invasive, cervical, or auricular) in hospitalized patients with confirmed acute COVID-19. Two reviewers independently screened titles, abstracts, and full texts according to pre-specified eligibility criteria. Risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool, with assessments initially performed using multiple artificial intelligence tools and subsequently validated by the authors in accordance with PRISMA 2020 guidelines. Given substantial heterogeneity and high risk of bias, narrative synthesis was performed rather than meta-analysis. Also, GRADE assessment was performed. Results: From 437 records identified, six RCTs comprising 221 patients met the inclusion criteria. Five trials (83%) were rated as high risk of bias, primarily due to inadequate blinding, substantial baseline imbalances, significant missing data and extensive multiple testing without statistical correction. The single double-blind trial with a credible sham control (Rangon et al.) found null results across all outcomes, including clinical progression, ICU transfer, and mortality, while the five “high” risk-of-bias trials generally reported positive findings on various inflammatory markers and clinical outcomes. One trial (Corrêa et al.) measured heart rate variability as a direct indicator of vagal activation and found no change despite claiming anti-inflammatory effects, contradicting the proposed mechanism of action. Significant cognitive findings from an interim analysis (Uehara et al., n = 21) disappeared in the larger completed trial (Corrêa et al., n = 52), providing empirical demonstration of false positive findings in small, underpowered studies. Conclusions: Currently available evidence supporting the use of VNS for acute COVID-19 remains scarce; however, the physiological rationale remains sound, although the absence of reliable target engagement markers in the included studies limits confidence in this treatment method. Large-scale, double-blind, sham-controlled trials are required before VNS can be firmly recommended for COVID-19 management.

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.