Humoral responses against HDL are linked to lipoprotein traits, atherosclerosis, inflammation and pathogenic pathways during early arthritis stages.

OBJECTIVE: Chronic inflammation and immune dysregulation are crucial mechanisms for atherosclerosis in RA. Recent evidence suggests a link via humoral responses against high-density lipoproteins (HDL). This study aimed to characterize the specificity, clinical relevance and emergence of humoral responses against HDL along disease course, especially during the earliest phases of arthritis. METHODS: IgG and IgM serum levels of antibodies against HDL (anti-HDL) and apolipoprotein A1 (anti-ApoA1) were measured in 82 early RA patients, 14 arthralgia individuals and 96 controls. Established RA patients (n = 42) were included for validation. Atherosclerosis and vascular stiffness were measured by Doppler ultrasound. Lipoprotein content, particle numbers and size were measured by H-NMR. Cytokines were measured by immunoassays. A cardiometabolic-related protein panel was evaluated using high-throughput targeted proteomics. RESULTS: Anti-HDL and anti-ApoA1 responses were increased in early RA compared with controls (both P < 0.001) and were comparable to established disease. Only anti-ApoA1 antibodies were increased in arthralgia. IgG anti-HDL and anti-ApoA1 were associated with unfavourable lipoprotein traits in RA and arthralgia, respectively. A similar picture was observed for inflammatory mediators. No associations with clinical features or risk factors were found. IgG anti-HDL were independently associated with atherosclerosis occurrence in early RA, and outperformed patient stratification over conventional algorithms (mSCORE) and their anti-ApoA1 counterparts. Anti-HDL antibodies correlated with proteins involved in immune activation, remodelling and lipid metabolism pathways in early RA. CONCLUSION: Humoral responses against HDL particles are an early event along the arthritis course, although quantitative and qualitative differences can be noticed among stages. These differences informed distinct capacities as biomarkers and underlying pathogenic circuits.

A new tool to screen patients with severe obstructive sleep apnea in the primary care setting: a prospective multicenter study.

BACKGROUND: The coordination between different levels of care is essential for the management of obstructive sleep apnea (OSA). The objective of this multicenter project was to develop a screening model for OSA in the primary care setting. METHODS: Anthropometric data, clinical history, and symptoms of OSA were recorded in randomly selected primary care patients, who also underwent a home sleep apnea test (HSAT). Respiratory polygraphy or polysomnography were performed at the sleep unit to establish definite indication for continuous positive airway pressure (CPAP). By means of cross-validation, a logistic regression model (CPAP yes/no) was designed, and with the clinical variables included in the model, a scoring system was established using the ß coefficients (PASHOS Test). In a second stage, results of HSAT were added, and the final accuracy of the model was assessed. RESULTS: 194 patients completed the study. The clinical test included the body mass index, neck circumference and observed apneas during sleep (AUC 0.824, 95% CI 0.763-0.886, P < 0.001). In a second stage, the oxygen desaturation index (ODI) of 3% (ODI3% ≥ 15%) from the HSAT was added (AUC 0.911, 95% CI 0.863-0.960, P < 0.001), with a sensitivity of 85.5% (95% CI 74.7-92.1) and specificity of 67.8% (95% CI 55.1-78.3). CONCLUSIONS: The use of this model would prevent referral to the sleep unit for 55.1% of the patients. The two-stage PASHOS model is a useful and practical screening tool for OSA in primary care for detecting candidates for CPAP treatment. Clinical Trial Registration Registry: ClinicalTrials.gov; Name: PASHOS Project: Advanced Platform for Sleep Apnea Syndrome Assessment; URL: https://clinicaltrials.gov/ct2/show/NCT02591979 ; Identifier: NCT02591979. Date of registration: October 30, 2015.

Angioid streaks and obstructive sleep apnea syndrome: are they related?

BACKGROUND: Sleep apnea syndrome (OSAS) has been associated with different ocular manifestations including glaucoma, floppy eye syndrome, punctate keratitis, keratoconus, and optic neuropathy. Angioid streaks are mainly associated with pseudoxanthoma elasticum (PXE) although they can appear in other systemic conditions affecting the elastic fibers. METHODS: This is a prospective, cross-sectional study. A complete ophthalmic examination was performed in 92 patients undergoing overnight polysomnography for suspicion of OSAS. Diagnosis and classification of OSAS were made based on apnea-hypopnea index (AHI). Stereoscopic optic disc photographs were taken in all patients and independently evaluated by two ophthalmologists. Patients with angioid streaks were referred to a dermatologist for axillary skin biopsy in order to rule out pseudoxanthoma elasticum or other skin abnormalities. RESULTS: Bilateral angioid streaks were observed in three patients who had been diagnosed with severe OSAS (AHI > 30/h). No clinical features characteristic of pseudoxanthoma elasticum or other pathological skin signs were observed. Skin biopsies were normal for all three patients, supporting the diagnosis of idiopathic angioid streaks. One of the patients developed bilateral choroidal neovascularization secondary to the angioid streaks over subsequent years. CONCLUSIONS: In view of the low prevalence of idiopathic angioid streaks in the general population, the finding of angioid streaks in patients with severe OSAS suggests OSAS as a possible risk factor for its development. The hypothesis of a connective tissue abnormality that could explain an association between both entities deserves further elucidation.

Analysis of LDL and HDL size and number by nuclear magnetic resonance in a healthy working population: The LipoLab Study.

BACKGROUND AND AIM: Atherosclerosis is the underlying process in cardiovascular disease (CVD), the first cause of death in developed countries. We aimed to identify people with no known CVD and normal values of LDL-C and HDL-C, but with alterations in the number and size of lipoprotein particles (as measured by nuclear magnetic resonance [NMR]) and to analyse their sociodemographic, clinical and biochemical characteristics. METHODS: Cross-sectional study in occupational risks prevention centre in Castellón (Spain) in 2017 and 2018, in consecutively recruited adults (18-65 years) with no known CVD. Sociodemographic, clinical and biochemical variables were collected. Lipid profiles were analysed (Liposcale test), along with the concentration, size and number of the main types of lipoprotein particles, determined by 2D diffusion-ordered NMR spectroscopy. Using contingency tables, we analysed the characteristics of people with normal LDL and HDL cholesterol but abnormal levels of LDL and HDL particles. The magnitude of association between explanatory variables and abnormal levels of each kind of lipoprotein was assessed with multivariable logistic regression models. RESULTS: Of the 400 total participants (31.3% women; age 46.4 ± 4.3 years), 169 had normal LDL and HDL cholesterol. Abnormal lipoprotein particle values depended on the subtype: prevalence of abnormal LDL levels ranged from 8.3% to 36.7%; and of HDL, from 28.4% to 42.6%. High systolic blood pressure and total cholesterol were significantly associated with abnormal LDL levels. Male sex and high systolic blood pressure were associated with abnormalities in HDL. CONCLUSIONS: An extended lipids profile, obtained by NMR, enables the identification of people with normal HDL-C and LDL-C levels who present abnormal levels of LDL-P and/or HDL-P. Higher total cholesterol, systolic blood pressure, BMI and male sex were significantly associated with these abnormal values.

Glycoprotein A and B Height-to-Width Ratios as Obesity-Independent Novel Biomarkers of Low-Grade Chronic Inflammation in Women with Polycystic Ovary Syndrome (PCOS).

The polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting women in reproductive age. Obesity and low-grade chronic inflammation are frequently associated with PCOS. Recently, proton nuclear magnetic resonance (1H-NMR)-derived glycoprotein profiles have emerged as potential biomarkers that reflect systemic inflammation in type 2 diabetes, obesity, and other pathological processes. The aim of this work is to study plasma glycoprotein profiles as metabolic/inflammatory biomarkers underlying PCOS and its association with inflammation and obesity. We used 1H-NMR spectroscopy to study five glycoprotein variables, namely GlycA, GlycB, and GlycF and the height-to-width (H/W) ratio of GlycA and GlycB, in 17 women with PCOS (9 non-obese and 8 obese), 17 control women (9 non-obese and 8 obese), and 19 healthy men (10 non-obese and 9 obese). H/W ratios of GlycA and GlycB, but not glycoprotein areas, were specifically associated with PCOS independently of obesity. When considered as a whole, obese subjects presented higher GlycA, GlycB, and GlycF areas and higher H/W GlycA and GlycB ratios than their non-obese counterparts. All glycoprotein variables were associated with hsCRP, IL-6, and TNF-α, showing different correlations among PCOS, women, and men. Our present exploratory results suggest that 1H-NMR-derived glycoprotein profiles might serve as novel diagnostic markers of low-grade chronic inflammation in women with PCOS.

Characterization of 1H NMR Plasma Glycoproteins as a New Strategy To Identify Inflammatory Patterns in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease associated with a high index of morbidity and mortality from cardiovascular diseases. We used 1H NMR to characterize the plasma glycoprotein and lipoprotein profiles of a cohort of patients with RA ( n = 210) versus healthy individuals ( n = 203) to associate them with the RA disease and its severity. Using 1H NMR, we developed a line-shape method to characterize the two peaks associated with glycoproteins (GlycA and GlycB) and its derived variables: areas of GlycB (Area GlycB) and GlycA (Area GlycA), shape factors of these two peaks (H/W = height/width), and the distance between them (Distance GlycB-GlycA). We also used the advanced lipoprotein test Liposcale (CE) to characterize the lipoprotein subclasses. The standard lipid panel and traditional inflammatory markers such as C-reactive protein, the erythrocyte sedimentation rate, fibrinogen, the rheumatoid factor, anticitrullinated peptide antibodies, and the DAS28 index have also been determined. RA patients presented a significant 10.65% increase in the GlycA associated area compared with the control group ( p = 2.21 × 10-10). They also presented significantly higher H/W GlycA and GlycB ratios than the control population (H/W GlycB p = 7.88 × 10-8; H/W GlycA p = 5.61 × 10-8). The prediction model that uses the traditional inflammatory variables and the 1H NMR-derived parameters presented an AUC that was almost 10% higher than the model that only uses the traditional inflammatory variables (from 0.7 to 0.79 AUC). We have demonstrated that GlycA and GlycB variables derived from 1H NMR, along with classic inflammatory parameters, help to improve the classification of individuals with high RA disease activity.

Inflammatory markers as predictors of postoperative adverse outcome in octogenarian surgical patients: an observational prospective study.

INTRODUCTION: The value of inflammatory proteins, interleukin-6 and alpha-1-acid glycoprotein as prognostic factors in elderly people undergoing surgery has not been determined yet. OBJECTIVE: To know whether preoperatively determined inflammatory markers may predict the postoperative outcome of elderly patients undergoing surgery. A scoring system for predicting postoperative morbidity was assessed. METHODS: Hospital-based observational prospective study, with geriatric surgical patients. Preoperative determination of following data: age, gender, scheduled or urgent operation, comorbid diseases, malignancy, physical, mental and nutritional profile. Biochemical markers of inflammation, C Reactive Protein, interleukin-6, and alpha-1-acid glycoprotein were also studied. Preoperative data and postoperative complications were recorded. Binary logistic regression analysis was used to obtain a morbidity risk prediction model. RESULTS: A total of 225 patients were included. Fifty-five patients (24.4%) had postoperative complications, with a mortality rate of 5.3%. Binary logistic regression analysis showed an independent relation between morbidity and the variables malignancy, alpha-1-acid glycoprotein and interleukin-6. The risk (R) of postoperative morbidity adjusted by age was calculated. The model showed a 22.2% sensitivity, 94.8% specificity, and a percentage of correct classification of 78.3%. The area under the ROC curve was 0.781 (95% CI: 0.703-0.858). CONCLUSIONS: An age-adjusted equation for predicting 30-day morbidity that included malignancy, serum IL-6 and alpha 1-acid glycoprotein levels may be useful for risk assessment in octogenarian surgical patients.

Advanced Lipoproteins and Lipidomic Profile in Plasma Determined by Nuclear Magnetic Resonance Before and After Bariatric Surgery.

BACKGROUND: Obesity is related to cardiovascular risk factors (CVRF) such as dyslipidemia, diabetes, and hypertension, which increase mortality. Basic lipid determinations could underestimate the true atherogenic risk of patients and the impact of bariatric surgery. The objective of the study is to demonstrate the change in the advanced molecular profile of lipoproteins determined by nuclear magnetic resonance spectroscopy in plasma after bariatric surgery, thus reducing the risk of cardiovascular disease. MATERIAL AND METHODS: Descriptive, observational, and prospective study in obese patients undergoing bariatric surgery. Advanced lipid profile was analyzed in plasma from the immediate preoperative period and at the 18th postoperative month by sending samples and performing plasma magnetic resonance spectroscopy in the BiosferTreslab® laboratory. RESULTS: Fifty-two patients were included. Average age of 46.3 years; 63.46% were women, 36.54% men. The average BMI was 43.57; the abdominal perimeter 133.50 cm; 32.6% were diabetics under medical treatment, 44.23% hypertensive, and 19.23% smokers; 86.53% of the patients presented alterations in at least one of the analytical parameters in the lipid study. Twenty-nine (55.7%) underwent banded gastric bypass (PGB), 19.23% underwent GBP, and 17.31% vertical gastrectomy. The rest were revision surgeries, two BPG-A and two biliopancreatic diversions after GV. All patients presented some improvement in advanced molecular profile of lipoproteins. Twenty percent of the patients normalized all the parameters. CONCLUSIONS: Bariatric surgery improves advanced molecular profile of lipoproteins, decreasing CVRF. Analysis of the characteristics of lipoprotein particles by NMR spectrometry is optimal for studying lipoprotein metabolism in patients undergoing bariatric surgery.

Deficient Emotional Self-Regulation and Sleep Problems in ADHD with and without Pharmacological Treatment.

OBJECTIVE: The purpose of this study is to analyse DESR and its influence on sleep parameters in three different groups of children and adolescents: a group newly diagnosed with ADHD naïve, a group with ADHD under pharmacological treatment and a control group. METHOD: Subjects were a total of 327 children and adolescents. Two groups diagnosed with ADHD: 108 medication-naïve and 80 under pharmacological treatment; and one group with 136 healthy subjects. DESR was defined using anxious/depressed, attention problems and aggressive behaviors (AAA) scales from the Child Behavior Checklist (CBCL), and sleep through the Sleep Disturbance Scale for Children. RESULTS: Significant differences were found comparing the three groups (p = .001), with a significantly higher profile on DESR in ADHD subjects, especially those who did not undergo treatment, and a positive correlation between DESR and sleep. CONCLUSION: Children and adolescents with ADHD without treatment present higher DESR than healthy controls and consequently higher sleep problems.

Influence of PACE score and conduction disturbances in the incidence of early new onset atrial fibrillation after typical atrial flutter ablation.

PURPOSE: Patients undergoing cavotricuspid isthmus (CTI) ablation for typical flutter (AFL) have a high incidence of new onset atrial fibrillation (AF). We aimed to analyze the influence of PACE score to predict new onset AF in this subset of patients to stratify thromboembolic risk. METHODS: Between 2017 and 2019, patients undergoing CTI ablation for AFL and without history of AF were prospectively included. All patients were monitored continuously by implantable loop recorder and followed by remote monitoring. RESULTS: Overall 48 patients were included. New onset AF rate at 12 months was 56.3%. We observed two very strong independent predictors for new onset AF: a PACE score ≥ 30 (HR:6.9; 95% CI:1.71-27.91; p = 0.007) and an HV interval ≥ 55 (HR:11.86; 95% CI:2.57-54.8; p = 0.002). CONCLUSIONS: The incidence of newly diagnosed AF is high in patients with AFL after CTI ablation, and can occur early. A high PACE score and/or long HV interval predict even higher risk, and may be useful in the decision for empiric long-term anticoagulation.

Acute-phase glycoprotein profile responses to different oral macronutrient challenges: Influence of sex, functional hyperandrogenism and obesity.

Acute-phase glycoprotein 1H-NMR spectroscopy profiles serve as surrogate markers of chronic inflammation in metabolic disorders such as obesity, diabetes and polycystic ovary syndrome (PCOS). The latter is associated with increased height-to-width (H/W) ratios of GlycA and GlycB after fasting, but not to glycoprotein areas, regardless of obesity. We studied the responses to separate glucose, lipid and protein oral challenges of five glycoprotein variables (GlycA, GlycB, and GlycF areas and the GlycA and GlycB H/W ratios) in 17 women with PCOS, 17 control women, and 19 healthy men. Glucose and protein ingestion resulted into decreases in all glycoprotein variables, whereas lipid ingestion increased GlycA, GlycF and induced minimal changes in GlycB and GlycB H/W. We found no effects of obesity or group of subjects on postprandial glycoprotein variables regardless of the macronutrient being ingested. However, a statistically significant interaction indicated that obesity blunted the decrease in some of these variables in control women and men, whereas obese women with PCOS showed larger changes when compared with their non-obese counterparts. In conclusion, acute-phase glycoprotein profiles indicate an anti-inflammatory response during postprandial phase that is less pronounced after lipid ingestion, and is counteracted by the chronic inflammatory background associated with obesity and PCOS.

Incidence of pulmonary embolism in patients with non-invasive respiratory support during COVID-19 outbreak.

While the incidence of thrombotic complications in critically ill patients is very high, in patients under non-invasive respiratory support (NIS) is still unknown. The specific incidence of thrombotic events in each of the clinical scenarios within the broad spectrum of severity of COVID-19, is not clearly established, and this has not allowed the implementation of thromboprophylaxis or anticoagulation for routine care in COVID-19. Patients admitted in a semi-critical unit treated initially with NIS, especially Continuous-Positive Airway Pressure (CPAP), were included in the study. The cumulative incidence of pulmonary embolism was analyzed and compared between patients with good response to NIS and patients with clinical deterioration that required orotracheal intubation. 93 patients were included and 16% required mechanical ventilation (MV) after the NIS. The crude cumulative incidence of the PE was 14% (95%, CI 8-22) for all group. In patients that required orotracheal intubation and MV, the cumulative incidence was significantly higher [33% (95%, CI 16-58)] compared to patients that continued with non-invasive support [11% (CI 5-18)] (Log-Rank, p = 0.013). Patients that required mechanical ventilation were at higher risk of PE for a HR of 4.3 (95%CI 1.2-16). In conclusion, cumulative incidence of PE is remarkably higher in critically patients with a potential impact in COVID-19 evolution. In this context, patients under NIS are a very high-risk group for developing PE without a clear strategy regarding thromboprophylaxis.

Primary care and sleep unit agreement in management decisions for sleep apnea: a prospective study in Spain.

STUDY OBJECTIVES: Involvement of primary care teams in the care of patients with OSA is a focus of interest. The study objective was to compare diagnostic and therapeutic agreement between decisions taken by primary care professionals and sleep unit specialists. METHODS: This was a prospective multicenter study conducted at primary care and specialized care centers in the urban area of Barcelona, Spain. Men and women aged 18-75 years who visited the participating primary care centers for any reason were recruited. Both primary care physicians and sleep specialists made a diagnostic and therapeutic decision with clinical data and results of a home sleep apnea test. All patients were finally assessed with respiratory polygraphy or polysomnography as a gold-standard test. RESULTS: A total of 229 patients underwent a home sleep apnea test and were evaluated at the primary care centers and the sleep units. Diagnostic agreement using the same tools and excluding indeterminate decisions was 69.8% (Cohen's kappa = 0.64; 95% confidence interval, 0.56-0.72). Agreement for therapeutic decisions (PAP vs conservative treatment) was obtained in 82.5% of patients (Cohen's kappa = 0.62; 95% confidence interval, 0.51-0.73), increasing to 92.5% (Cohen's kappa = 0.49, 95% confidence interval, 0.40-0.58) when indeterminate options were excluded. As compared with the final therapeutic decisions made at the sleep unit with respiratory polygraphy/polysomnography, primary care physicians agreed regarding 83.3% (Cohen's kappa = 0.62; 95% confidence interval, 0.49-0.74) of patients. CONCLUSIONS: Primary care professionals may assume an important role in the management of OSA in coordination with sleep centers, identifying patients who require specific treatment and should be referred to specialized care. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: PASHOS Project: Advanced Platform for Sleep Apnea Syndrome Assessment; URL: https://clinicaltrials.gov/ct2/show/NCT02591979; Identifier: NCT02591979.

Coordinated program between primary care and sleep unit for the management of obstructive sleep apnea.

The purpose of this study is to develop and validate a work model in the primary health-care setting for identifying patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) based on clinical variables and an ambulatory sleep monitoring study. After screening, patients with mild-moderate OSAHS could be managed by primary care physicians, whereas those identified with severe OSAHS would be referred to specialists from sleep units for starting specific treatment. The proposed model does not move the entire health-care process to a generally overburdened primary care level and favors the coordinated work and the necessary flexibility to adapt the model to challenges and perspectives of OSAHS.

Increased Urinary Erythropoietin Excretion in Severe Sleep Apnea-Hipoapnea Syndrome: The Effect of CPAP. / El síndrome de apneas-hipoapneas del sueño (SAHS) grave incrementa la excreción urinaria de eritropoyetina. Efecto del tratamiento con CPAP.

INTRODUCTION: Tissue hypoxia stimulates the production of erythropoietin (EPO), the main effect of which is, in turn, to stimulate erythropoiesis. Sleep apnea-hypopnea syndrome (SAHS) is an entity characterized by repeated episodes of hypoxemia during sleep. OBJECTIVE: To analyze whether hypoxemia stimulated increased urinary excretion of EPO, and if so, to evaluate if treatment with continuous positive airway pressure (CPAP) can inhibit this phenomenon. METHODS: We studied 25 subjects with suspected SAHS who underwent a polysomnography study (PSG). EPO levels in first morning urine (uEPO) and blood creatinine and hemoglobin were determined in all patients. Patients with severe SAHS repeated the same determinations after CPAP treatment. RESULTS: Twelve subjects were diagnosed with severe SAHS (mean ± SD, AHI 53.1 ± 22.7). Creatinine and hemoglobin levels were normal in all subjects. uEPO was 4 times higher in the SAHS group than in the control group (1.32 ± 0.83 vs. 0.32 ± 0.35 UI/l, p <.002). CPAP treatment reduced uEPO to 0.61 ± 0.9 UI/l (p <.02), levels close to those observed in healthy subjects. No dose-response relationship was observed between severity of PSG changes and uEPO values. CONCLUSIONS: Patients with severe SAHS show increased uEPO excretion, but this normalizes after treatment with CPAP.

Comparison of the risk prediction systems POSSUM and P-POSSUM with the Surgical Risk Scale: A prospective cohort study of 721 patients.

INTRODUCTION: The outcomes of surgery are subject to variability and difficult to be accurately predicted. Different score systems have been developed to estimating the risk of undergoing a surgical procedure. The aim of this study was to assess the predictive ability of POSSUM and P-POSSUM scoring systems, compared to the Surgical Risk Scale (SRS), in Spanish patients undergoing general surgery. PATIENTS AND METHODS: In this prospective observational study, 721 consecutive patients needing a surgical procedure were included. Observed morbidity and mortality after surgery were compared to the expected ones obtained by applying POSSUM, P-POSSUM and SRS. RESULTS: Mean age was 59.2 years (standard deviation (SD): 17.4 years), 43.5% were women. 616 (85.5%) patients underwent elective general surgery and 105 (14.5%) emergency surgery. The 30-day morbidity was 15.4%. The reintervention rate was 2.1% and mortality was 2.1%. The discrimination ability was excellent in predicting mortality. The Area Under the Curve (AUC) values were: POSSUM: AUC = 0.97, C.I.95%: 0.948-0.992, p < 0.0001; P-POSSUM: AUC = 0.966, C.I.95%: 0.941-0.991, p < 0.0001; SRS: AUC = 0.91, C.I.95%:0.853-0.967, p < 0.0001. POSSUM was also discriminative in the prediction of morbidity (AUC = 0.772, C.I.95%: 0.719-0.826, p < 0.0001). POSSUM predicted morbidity and mortality were higher than the observed ones (p = 0.01 and p = 0.04). Predicted and observed mortality were very similar for P-POSSUM (p = 0.93) and SRS (p = 0.37). CONCLUSIONS: Expected morbidity and mortality determined by POSSUM score showed values significantly above the observed ones. P-POSSUM and SRS systems were effective in predicting mortality. The SRS application is simple and may contribute to appropriate medical decision making.

Long-term Impact of Continuous Positive Airway Pressure Therapy on Arrhythmia and Heart Rate Variability in Patients With Sleep Apnea.

INTRODUCTION: Autonomic dysfunction can alter heart rate variability and increase the incidence of arrhythmia. We analyzed the impact of continuous positive airway pressure (CPAP) on this pathophysiological phenomenon in patients with severe sleep apnea-hypopnea syndrome. METHODS: Consecutive patients with recently diagnosed severe sleep apnea-hypopnea syndrome were prospectively considered for inclusion. Incidence of arrhythmia and heart rate variability (recorded on a 24-hour Holter monitoring device) were analyzed before starting CPAP therapy and 1 year thereafter. RESULTS: A total of 26 patients were included in the study. CPAP was administered for 6.6 ± 1.8 hours during Holter monitoring. After starting CPAP, we observed a marginally significant reduction in mean HR (80 ± 9 to 77 ± 11 bpm, p=.05). CPAP was associated with partial modulation (only during waking hours) of r-MSSD (p=.047) and HF (p=.025) parasympathetic parameters and LF (p=.049) sympathetic modulation parameters. None of these parameters returned completely to normal levels (p<.001). The number of unsustained episodes of atrial tachycardia diminished (p=.024), but no clear effect on other arrhythmias was observed. CONCLUSIONS: CPAP therapy only partially improves heart rate variability, and exclusively during waking hours, and reduces incidence of atrial tachycardia, both of which can influence cardiovascular morbidity and mortality in sleep apnea-hypopnea syndrome patients.

Obstructive sleep apnea in patients with typical atrial flutter: prevalence and impact on arrhythmia control outcome.

BACKGROUND: The clinical yield of cavotricuspid isthmus (CTI) radiofrequency ablation of atrial flutter (AF) is limited by a high incidence of atrial fibrillation (AFib) in the long term. Among other acknowledged variables, the association of obstructive sleep apnea (OSA) could favor incomplete arrhythmia control in this setting. We assessed the impact of CPAP in reducing the occurrence of AFib after CTI ablation. METHODS: Consecutive patients with AF who were undergoing CTI ablation were screened for OSA. Relationship of the following variables with the occurrence of AFib during follow-up (12 months) was investigated: CPAP initiation, hypertension, BMI, underlying structural heart disease, left atrial diameter, and AFib documentation prior to ablation. RESULTS: We prospectively included 56 patients (mean age: 66 (± 11) years; 12 female patients), of whom 46 (82%) had OSA and 25 (45%) had severe OSA. Twenty-one patients (38%) had AFib during follow-up after CTI ablation. Both freedom from AFib prior to ablation and CPAP initiation in those patients without previously documented AFib at inclusion were associated with a reduction of AFib episodes during follow-up (P = .019 and P = .025, respectively). Inversely, CPAP was not protective from AFib recurrence when this arrhythmia was documented prior to ablation (P = .25). CONCLUSIONS: OSA is a prevalent condition in patients with AF. Treatment with CPAP is associated with a lower incidence of newly diagnosed AFib after CTI ablation. Screening for OSA in patients with AF appears to be a reasonable clinical strategy.