Cardiovascular outcomes in obstructive sleep apnoea and implications of clinical phenotyping on effect of CPAP treatment.

BACKGROUND: There is a growing awareness of the heterogeneity of obstructive sleep apnoea (OSA). Clinical trials of CPAP treatment on cardiovascular protection have been mostly negative. We aimed to assess the association between polysomnographic parameters and incident major adverse cardiovascular events (MACEs), and to investigate if the CPAP effect could be better delineated among clinical subgroups. METHODS: This sleep cohort study was conducted using a clinical database and territory-wide electronic health administration data in Hong Kong. Cox regressions were used to calculate HRs. Latent class analysis was used to cluster patients with OSA according to clinical and polysomnographic features. RESULTS: Of 1860 eligible Chinese subjects who underwent polysomnography (2006-2013), 1544 (83%) had OSA. Over median follow-up of 8.3 years, 278 (14.9%) experienced MACEs. Apnoea-hypopnoea index (AHI) did not predict MACEs (HR: 0.95; 95% CI 0.76 to 1.17), whereas sleep time with oxygen saturation <90% (TST90) (HR: 1.41; 95% CI 1.10 to 1.81) was an independent predictor of MACEs, as were wake and nocturnal heart rate. In moderate-severe OSA (n=1108) who were indicated for CPAP treatment, regular CPAP was not associated with reduction of incident MACEs. Further cluster analysis identified a subgroup (n=333) who was younger, more obese, had more severe OSA (higher AHI and TST90) and more cardiovascular risks, in whom regular CPAP was associated with a lower risk of MACEs (HR:0.49, 95% CI 0.25 to 0.95). CONCLUSIONS: OSA-related TST90 and mean heart rate, but not AHI, were robust predictors of MACEs. A clinical phenotype subgroup who demonstrated beneficial effect of CPAP treatment was identified.

Indwelling Pleural Catheter: Management of Complications.

Multiple randomized clinical trials have established the advantages of indwelling pleural catheter (IPC) in the management of malignant pleural effusions, resulting in its widespread adoption in clinical practice. Complications can occur with IPC use and must be recognized and managed effectively. This review provides a comprehensive overview of IPC complications and their best care. Pain postinsertion or during drainage of IPC is easily manageable and must be distinguished from tumor-related chest wall pain. IPC-related infections require systemic antibiotics and often intrapleural fibrinolytic/deoxyribonuclease therapy. The removal of IPC for infection is usually unnecessary. Symptomatic loculation usually responds to fibrinolytics but may recur. Catheter tract metastases are common in mesothelioma patients and usually respond to radiotherapy without inducing damages to the IPC. Less common complications include dislodgement, irreversible blockage, and fractures (upon removal) of the catheter. Recommendations on the management of IPC complications by recent consensus statement/guideline are discussed. Expert opinions on management approaches are included in areas where evidence is lacking to guide care.

Implementation of evidence on management of pleural diseases: insights from a territory-wide survey of clinicians in Hong Kong.

BACKGROUND: Major advances in management of common pleural diseases have taken place in the past decade. However, pleural diseases are often managed by physicians of diverse training background and research on implementation of new knowledge is scanty. We aim to evaluate the practice pattern in pleural medicine among physicians in Hong Kong, for identification of possible gaps for clinical service improvement. METHODS: The Hong Kong Thoracic Society undertook a cross-sectional questionnaire survey in 2019, targeting clinicians of various subspecialties in internal medicine and levels of experience (basic and higher trainees, specialists) from twelve regional hospitals of diverse service scopes throughout Hong Kong. Respondents were selected by non-probability quota sampling. The questionnaire tool consisted of 46 questions covering diagnostic and therapeutic aspects of common pleural diseases. The responses were anonymous, and analysed independently using SPSS statistics software. RESULTS: The survey collected 129 responses, 47(36%) were from clinicians specialized in respiratory medicine. Majority of the respondents (98%) managed pleural diseases, including performing pleural procedures in their practice. Fifty-five percent of all the respondents had not received any formal training in transthoracic ultrasonography. A significant proportion of clinicians were unaware of pleuroscopy for investigation of exudative pleural effusion, indwelling pleural catheter for recurrent malignant pleural effusion, and combined intra-pleural Alteplase plus DNase for treatment of pleural infection (30%, 15% and 70% of non-respiratory clinicians respectively). Significant heterogeneity was found in the management of pleural infection, malignant pleural effusion and pneumothorax among respiratory versus non-respiratory clinicians. Contributing factors to the observed heterogeneity included lack of awareness or training, limited accessibility of drugs, devices, or dedicated service support. CONCLUSION: Significant heterogeneity in management of pleural diseases was observed among medical clinicians in Hong Kong. Continuous medical education and training provision for both specialists and non-specialists has to be strengthened to enhance the implementation of advances, improve quality and equity of healthcare provision in pleural medicine.

Circulating adipocyte fatty acid-binding protein is reduced by continuous positive airway pressure treatment for obstructive sleep apnea-a randomized controlled study.

PURPOSE: The circulating level of adipocyte fatty acid-binding protein (AFABP), a biomarker with prognostic and therapeutic importance in metabolic disorders, has been shown to be elevated in obstructive sleep apnea (OSA). This randomized controlled study aimed to investigate the effect of continuous positive airway pressure (CPAP) treatment for OSA on AFABP levels. METHODS: Consecutive subjects attending sleep study were invited if they were confirmed to have severe OSA and were free of metabolic diseases. Participants were randomized (1:1) into CPAP or observation group for 4 weeks. Demographics, anthropometric data, and circulating biomarkers were checked at baseline and after the 4-week study period. RESULTS: Ninety subjects were randomized. The mean age was 46 ± 9 years old; 82% were male. Their mean body mass index (BMI) was 29 ± 5 kg/m2. By intention-to-treat approach, the CPAP group showed significant reductions in Epworth sleepiness scale and morning systolic blood pressure (- 7.2 mmHg, - 12.7 to - 1.7 mmHg, p = 0.011), but no significant difference in AFABP, adiponectin, C-reactive protein (CRP), and 8-isoprostane levels. In the per-protocol analysis, when only those who were compliant to CPAP were included, a significant reduction in AFABP (- 7.32 ng/ml, - 13.58, - 1.06, p = 0.023) were found in the CPAP-treated group compared with the control group, along with improvements in clinical parameters. Changes in AFABP were independently associated with both systolic blood pressure (ß = 0.289, p = 0.028) and diastolic blood pressure (ß = 0.217, p = 0.030). CONCLUSION: CPAP therapy used regularly over 4 weeks for severe OSA lowered circulating AFABP level, suggesting a potential beneficial effect of OSA treatment on alleviating metabolic risks. TRIAL REGISTRATION: The research protocol was registered at the National Institutes of Health clinical trials registry (NCT01173432).

Rapid versus gradual lung function decline in bronchiolitis obliterans syndrome after haematopoietic stem cell transplantation is associated with survival outcome.

BACKGROUND AND OBJECTIVE: Bronchiolitis obliterans syndrome (BOS) after haematopoietic stem cell transplantation (HSCT) presents with lung function decline. The pattern of lung function decline after BOS diagnosis could impact prognostication of BOS as a complication after HSCT. The aim of this study was to assess the impact of lung function decline on overall survival (OS) in BOS subjects. METHODS: Subjects with BOS were compared to those without BOS and matched for age, gender, primary diagnoses, conditioning regimes and chronic graft versus host disease. Lung function tests at baseline, at BOS diagnosis and every 3 months after HSCT were evaluated. RESULTS: Of the 1461 subjects undergoing allogeneic HSCT (allo-HSCT) between 1998 and 2015, 95 (6.5%) were diagnosed with BOS. A total of 159 matched HSCT recipients without BOS were identified. A 25% decline in FEV1 within the first 3 months after BOS diagnosis would separate BOS subjects into a subgroup with initial rapid decline and another subgroup with initial gradual decline in lung function. The rapid decline group showed lower subsequent lung function parameters and significantly worse OS compared to the gradual decline group (P = 0.013). CONCLUSION: Post-HSCT BOS subjects with initial rapid lung function decline within 3 months after BOS diagnosis will have significantly poorer lung function and worse OS compared to those with initial gradual decline in lung function after BOS diagnosis. HSCT BOS patients with rapid initial decline in lung function warrant closer monitoring for the development of other post-HSCT complications that could affect their survival.

Phenotyping malignant pleural effusions.

PURPOSE OF REVIEW: Patients with malignant pleural effusions (MPEs) are heterogenous in their disease course, symptom severity, responses to cancer therapies, fluid recurrence rates, and thus need for definitive fluid control measures. To tailor the most appropriate treatment for individual patients, clinicians need to 'phenotype' the patients and predict their clinical course. This review highlights the recent efforts to develop better predictive tools and knowledge gaps for further research. RECENT FINDINGS: The LENT scoring system, which includes pleural fluid lactate dehydrogenase, performance status, serum neutrophil-to-lymphocyte ratio and tumor type, allows prediction of the survival of patients with MPE. Symptomatic response after therapeutic pleural drainage is highly variable; ongoing studies aim to identify those who would derive symptomatic benefit from fluid drainages. Multivariate analysis found that patients with low pleural fluid pH [odds ratio (OR) 37.04], large effusions (OR 3.31), and increasing age (OR 1.02) were more likely to require pleurodesis or indwelling pleural catheter placement for fluid control. Better predictive tools for rate of fluid recurrence and likelihood of successful pleurodesis would help guide clinical decision-making. SUMMARY: Phenotyping MPE would guide the formulation of optimal management for individual MPE patients.

Screening for Obstructive Sleep Apnea in a Diverse Bariatric Surgery Population.

OBJECTIVE: Obstructive sleep apnea (OSA) is common among bariatric surgery patients and is associated with perioperative risk. Preoperative screening is recommended, but some screening tools lack validation, and their relative performance is unclear in this population. The study objective was to compare the ability of four existing tools (STOP-BANG, NO-OSAS, No-Apnea, and the Epworth Sleepiness Scale [ESS]) to screen for moderate to severe OSA in a diverse bariatric cohort. METHODS: Data from patients presenting for first-time bariatric surgery who underwent a sleep study within 1 year of the initial encounter were retrospectively reviewed. Performance of the four tools for detecting moderate to severe OSA was compared based on the area under the receiver operating characteristic curves (AUC). RESULTS: Of the included 214 patients (83.2% female, median age 39 years), 45.3% had moderate to severe OSA. Based on AUC, STOP-BANG (0.75 [95% CI: 0.68-0.81], N = 185), NO-OSAS (0.76 [95% CI: 0.69-0.82], N = 185), and No-Apnea (0.69 [95% CI: 0.62-0.76], N = 190) had similar performance (P > 0.16). Compared with STOP-BANG and NO-OSAS, ESS (0.61 [95% CI: 0.54-0.68], N = 198) had a significantly lower AUC (P < 0.01). Hispanic/Latino self-identification, sex, or obesity class did not significantly modify test performance. CONCLUSIONS: STOP-BANG and NO-OSAS may be preferable to No-Apnea and ESS when screening bariatric surgery patients for moderate to severe OSA. Efforts to screen bariatric patients for OSA are recommended.

Incident Type 2 Diabetes in OSA and Effect of CPAP Treatment: A Retrospective Clinic Cohort Study.

BACKGROUND: The relationship between OSA and glucose metabolism remains controversial. This retrospective study investigated the relationship between OSA and incident type 2 diabetes (T2D) in a clinic cohort of Chinese adults in Hong Kong, and the effect of long-term CPAP treatment. METHODS: Data for diagnosis of incident T2D and CPAP usage were obtained from the territory-wide electronic health administration system and records of protocolized evaluation of CPAP adherence at the sleep clinic. The relationship between baseline OSA and incident T2D and the effect of CPAP therapy were examined by Cox regression models. Risk of incident T2D over the continuum of apnea-hypopnea index was examined with cubic spline analysis. RESULTS: Of 1,206 subjects with overnight sleep studies and clinical assessment in 2006 through 2013, 152 developed diabetes (median follow-up, 7.3 years). In fully adjusted models, untreated moderate or patients with severe OSA had higher risk of developing diabetes, hazard ratios 2.01 (95% CI, 1.06-3.81) and 2.62 (95% CI, 1.40-4.93) respectively, with a trend to plateau in those with severe OSA. No interaction was demonstrated between OSA and obesity. Regular CPAP use, which was attained in about one-third of subjects with moderate-severe OSA, was associated with reduction of diabetes incidence from 3.41 to 1.61 per 100 person-years, and of adjusted hazard risk to that of non-OSA. CONCLUSIONS: OSA severity independently predicted incident diabetes. Regular long-term CPAP use was associated with reduced risk of incident T2D, after adjustment for various baseline metabolic risk factors and subsequent body weight change.

Untreated Obstructive Sleep Apnea Is Associated With Myocardial Injury Independent of Blood Pressure Control in Hypertension.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) and hypertension are independent risk factors of cardiovascular morbidities. This study aims to investigate the relationship between OSA, blood pressure (BP) control, and myocardial injury in patients with difficult-to-control hypertension. METHODS: Patients with hypertension who required three or more medications were prospectively recruited at a tertiary referral center. In-laboratory polysomnography, followed by blood tests for fasting glucose, glycated hemoglobin, lipids, high-sensitivity troponin I (hsTnI), B-type natriuretic peptide (BNP), C-reactive protein, and advanced oxidation protein products were performed. After polysomnography, 24-hour ambulatory BP monitoring was arranged. RESULTS: A total of 98 participants were analyzed, with mean age 51 ± 9 years and body mass index 30 ± 5 kg/m2. Previously undiagnosed severe OSA (apneahypopnea index [AHI] ≥ 30 events/h) was present in 51 patients (52%). hsTnI was negatively correlated with nocturnal dip in systolic BP (r = -.205, P = .048). After controlling for confounders, including BP control, AHI and oxygen desaturation index (ODI) were positively correlated with hsTnI (r = .282, P = .009 and r = .279, P = .010, respectively) and C-reactive protein (r = .302, P = .005 and r = .285, P = .008, respectively), but not with BNP or advanced oxidation protein products. Age, ODI, and loss of nocturnal systolic BP dip were significant determinants of hsTnI level (ß = .225, P = .022; ß = .293, P = .003; and ß = -.215, P = .029; R2 = .151). Age, female sex, 24-hour mean diastolic BP, and metabolic syndrome, but not indices of apnea severity, were predictors of BNP level. CONCLUSIONS: Unrecognized severe OSA was common in patients with difficult-to-control hypertension, and OSA severity was associated with myocardial injury, independent of BP control with medications. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov, Title: A Cross-sectional Study of the Occurrence and Effect of Obstructive Sleep Apnea in Subjects With Resistant Hypertension, Identifier: NCT00843583, URL: https://clinicaltrials.gov/ct2/show/NCT00843583.

Complications of indwelling pleural catheter use and their management.

The growing utilisation of indwelling pleural catheters (IPCs) has put forward a new era in the management of recurrent symptomatic pleural effusions. IPC use is safe compared to talc pleurodesis, though complications can occur. Pleural infection affects <5% of patients, and is usually responsive to antibiotic treatment without requiring catheter removal or surgery. Pleural loculations develop over time, limiting drainage in 10% of patients, which can be improved with intrapleural fibrinolytic therapy. Catheter tract metastasis can occur with most tumours but is more common in mesothelioma. The metastases usually respond to analgaesics and/or external radiotherapy. Long-term intermittent drainage of exudative effusions or chylothorax can potentially lead to loss of nutrients, though no data exist on any clinical impact. Fibrin clots within the catheter lumen can result in blockage. Chest pain following IPC insertion is often mild, and adjustments in analgaesics and drainage practice are usually all that are required. As clinical experience with the use of IPC accumulates, the profile and natural course of complications are increasingly described. We aim to summarise the available literature on IPC-related complications and the evidence to support specific strategies.

Plasma EGFR Mutation Detection Associated With Survival Outcomes in Advanced-Stage Lung Cancer.

UNLABELLED: We confirmed the performance of an array method for plasma epidermal growth factor receptor (EGFR) mutation detection and showed the association of plasma EGFR mutation with survival outcomes. BACKGROUND: Noninvasive detection of epidermal growth factor receptor (EGFR) mutation in plasma is feasible and could be adjunct for therapeutic monitoring especially when repeated biopsy of tumor tissue is challenging. The aims of this study were to establish the diagnostic performance of peptide nucleic acid-locked nucleic acid polymerase chain reaction followed by custom array for plasma EGFR mutation and to evaluate the association of detection with clinical characteristics and survival outcomes. MATERIALS AND METHODS: Plasma genomic DNA from consecutive advanced lung cancer subjects was tested for EGFR mutations before anticancer treatment, and compared with mutation status in tumor tissue. Clinical characteristics were compared between patients who were EGFR-mutant and wild type; and within EGFR mutants, whether EGFR mutations could be detected in plasma. RESULTS: In 74 lung cancer patients, the sensitivity, specificity, and positive and negative predictive values of plasma EGFR detection were 79.1%, 96.8%, 97.1%, and 76.9%, respectively. EGFR mutants with concomitant detection of plasma EGFR mutation showed worse survival compared with mutants with no concomitant plasma mutation detected in biopsy specimens. CONCLUSION: Plasma EGFR mutation detected using this method demonstrated high diagnostic performance. In EGFR mutants, plasma EGFR mutation detection correlated not only EGFR mutation status in biopsy but was also associated with worse prognosis compared with EGFR mutant without plasma EGFR mutation detection.

Disorders of glucose metabolism in sleep-disordered breathing.

Despite proliferating literature, the exact relationship between obstructive sleep apnea (OSA) and alterations in glucose metabolism is still controversial. There is growing evidence to suggest that OSA imposes adverse effects on glucose metabolism, but the translation into clinical effect is not well delineated. Many potential mechanisms are being explored, mostly relating to peripheral tissue response to insulin and more recently regarding pancreatic beta cell function of insulin secretion. The effect of OSA on glucose metabolism is likely to be influenced by many personal characteristics. Age, degree of adiposity, lifestyle, comorbidities, and even the stage of glucose disorder itself may modify the relationship between OSA and glucose metabolism. In the biologic system of the human body, all these interact to culminate in clinically relevant outcomes.

Prevalence and recognition of obstructive sleep apnea in Chinese patients with type 2 diabetes mellitus.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with disorders of glucose metabolism. Previous studies revealed a high prevalence of OSA among subjects with type 2 diabetes mellitus (DM). The aims of this study were to determine the prevalence of OSA and associated clinical factors in Chinese patients with DM. METHODS: All records of the DM clinic at a teaching hospital in Hong Kong were screened between January 2007 and June 2008. Inclusion criteria for patients were Chinese, aged 18 to 75 years, with type 2 DM. Patients with unstable medical illnesses, gestational diabetes, or on renal replacement therapy were excluded. RESULTS: Of 3,489 records screened, 1,859 subjects were eligible. A random sample of 663 (mean age, 58.2 ± 10.8; mean BMI, 26.0 ± 4.6), except six with known OSA, were invited for polysomnography (PSG). Of 165 subjects on which PSG was performed, OSA was diagnosed (apnea-hypopnea index [AHI] ≥ 5.0/h) in 89 subjects (53.9%, median Epworth Sleepiness Scale, 6 [interquartile range 3, 10]). Fifty-four (32.7%) had moderate/severe OSA (AHI ≥ 15/h). The estimated OSA prevalence in this diabetic cohort was 17.5% (24.7% in men, 10.3% in women). Regression analysis identified that AHI was associated independently with higher BMI, advanced age, male sex, and higher diastolic BP (R(2) = 29.6%). The adjusted OR of requiring three or more antihypertensive drugs in moderate/severe OSA was 2.48 (95% CI, 1.05-5.87). No association between glycemic control (HbA1c) and sleep was identified. CONCLUSIONS: In conclusion, OSA is more prevalent in Chinese adults with DM than in the general population. A high index of suspicion for OSA in patients with DM is warranted, because they may not have overt daytime sleepiness.