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Purpose: Obstructive sleep apnea (OSA) is independently associated with increased risk for stroke and other cardiovascular diseases. Since activated platelets play an important role in cardiovascular disease, the objective of this study was to determine whether platelet reactivity was altered in OSA subjects with intermittent nocturnal hypoxemia. Methods: Thirty-one subjects, without hypertension or cardiovascular disease and not taking medication, participated in the study. Subjects were stratified based on OSA-related oxygen desaturation index (ODI) recorded during overnight polysomnography. Platelet reactivity to a broad panel of agonists (collagen, thrombin, protease-activated receptor1 hexapeptide, epinephrine, ADP) was measured by monitoring platelet aggregation and ATP secretion. Expression of platelet activation markers CD154 (CD40L) and CD62P (P-selectin) and platelet-monocyte aggregates (PMA) was quantified by flow cytometry. Results: Epinephrine-induced platelet aggregation was substantially decreased in OSA subjects with significant intermittent hypoxemia (ODI ≥ 15) compared with subjects with milder hypoxemia levels (ODI < 15) (area under curve, p = 0.01). In addition, OSA subjects with ODI ≥ 15 exhibited decreased thrombin-induced platelet aggregation (p = 0.02) and CD40L platelet surface expression (p = 0.05). Platelet responses to the other agonists, CD62P platelet surface expression, and PMA levels were not significantly different between groups. Reduction in platelet responses to epinephrine and thrombin, and decreased CD40L surface marker expression in significant hypoxemic OSA individuals, is consistent with their platelets being in an activated state. Conclusions: Increased platelet activation was present in otherwise healthy subjects with intermittent nocturnal hypoxemia due to underlying OSA. This prothrombotic milieu in the vasculature is likely a key contributing factor toward development of thrombosis and cardiovascular disease. Trial registration: NCT00859950 [ABSTRACT FROM AUTHOR]

Levels of iron and iron-related proteins including ferritin are higher in the lung tissue and lavage fluid of individuals with chronic obstructive pulmonary disease (COPD), when compared to healthy controls. Whether more iron in the extracellular milieu of the lung associates with distinct clinical phenotypes of COPD, including increased exacerbation susceptibility, is unknown. We measured iron and ferritin levels in the bronchoalveolar lavage fluid (BALF) of participants enrolled in the SubPopulations and InteRmediate Outcome Measures In COPD (SPIROMICS) bronchoscopy sub-study (n = 195). BALF Iron parameters were compared to systemic markers of iron availability and tested for association with FEV1 % predicted and exacerbation frequency. Exacerbations were modelled using a zero-inflated negative binomial model using age, sex, smoking, and FEV1 % predicted as clinical covariates. BALF iron and ferritin were higher in participants with COPD and in smokers without COPD when compared to non-smoker control participants but did not correlate with systemic iron markers. BALF ferritin and iron were elevated in participants who had COPD exacerbations, with a 2-fold increase in BALF ferritin and iron conveying a 24% and 2-fold increase in exacerbation risk, respectively. Similar associations were not observed with plasma ferritin. Increased airway iron levels may be representative of a distinct pathobiological phenomenon that results in more frequent COPD exacerbation events, contributing to disease progression in these individuals. [ABSTRACT FROM AUTHOR]

Patients with primary or secondary antiphospholipid syndrome (APS) have an increased risk of recurrent venous, arterial thrombosis and pregnancy complications. Therefore, determining thrombotic risk is important when individualizing antithrombotic therapy in patients with APS. To identify thrombotic risk factors in a cohort of APS patients. We conducted a retrospective review of APS patients who received care at a Hematology clinic of a university medical center from 2004 to 2017. Demographics, clinical features, antithrombotic therapy and thrombotic outcomes were collected. Time to event analysis identified clinical risk factors for thrombosis. The time varying effects of antithrombotic treatments on thrombosis outcome were analyzed. We identified 84 subjects with APS with a median age at diagnosis of 40.7 years [interquartile range [IQR] 33.5–57.6]. The majority were female (n = 63, 75%) and White (n = 45, 54%). Twenty-eight (33%) patients had concomitant autoimmune disease (AID) and of these, 15 (54%) had systemic lupus erythematosus. A thrombotic event occurred in 15 (18%) patients during a median follow-up of 48 months. A significantly higher rate of thrombotic events was observed in APS patients with AID compared to those without AID (hazard ratio (HR) 4.93, 95% CI 1.7–14.3, p = 0.04), and in black patients compared to whites (HR 5.94, 95% CI 1.1–32.1, p = 0.039). Patients on therapeutic anticoagulation regardless of type (warfarin, low molecular weight heparin or direct oral anticoagulants) were significantly less likely to have a recurrent thrombotic event compared to those on prophylactic anticoagulation (HR 0.11, 95% confidence interval [CI] 0.031–0.395, p = 0.001). However the numbers are too small to draw conclusions. Our study suggests that APS patients with concomitant AID and of Black race are at increased risk of recurrent thrombotic events. [ABSTRACT FROM AUTHOR]

Background: Studies have shown that prophylactic biologic therapy can reduce post-surgical Crohn's disease recurrence.Aims: We aimed to identify the frequency of delay and risk factors associated with a delay in the initiation of prophylactic post-surgical biologic therapy in high-risk patients.Methods: We performed a cohort study of Crohn's disease patients who underwent a bowel resection. We identified those at risk of recurrence and explored multiple characteristics for those with and without a delay post-operatively.Results: A total of 84 patients were included in our analysis of which 69.0% had a greater than 4-week delay and 56.0% a greater than 8-week delay in post-surgical biologic prophylaxis. Publicly insured patients had a 100% delay in post-surgical prophylaxis initiation (p = 0.039, p = 0.003 at 4 and 8 weeks, respectively). Patients on a biologic pre-surgery were less likely to have a delay (p < 0.001) in post-operative prophylaxis. Care at an inflammatory bowel disease (IBD) center was associated with timely therapy when considering a post-operative immunomodulator or biologic strategy.Conclusions: There are a substantial number of delays in initiating post-operative prophylactic biologic therapy in high-risk patients. Identifying susceptible patients by insurance type or absence of pre-operative therapy can focus future improvement efforts. Additionally, consultation with IBD-specialized providers should be considered in peri-surgical IBD care. [ABSTRACT FROM AUTHOR]

Background: Positive pressure ventilation can decrease venous return and cardiac output. It is not known if expiratory ventilation assistance (EVA) through a small endotracheal tube can improve venous return and cardiac output.Results: In a porcine model, switching from conventional positive pressure ventilation to (EVA) with − 8 cmH20 expiratory pressure increased the venous return and cardiac output. The stroke volume increased by 27% when the subjects were switched from conventional ventilation to EVA [53.8 ± 7.7 (SD) vs. 68.1 ± 7.7 ml, p = 0.003]. After hemorrhage, subjects treated with EVA had higher median cardiac output, higher mean systemic arterial pressure, and lower central venous pressure at 40 and 60 min when compared with subjects treated with conventional ventilation with PEEP 0 cmH20. The median cardiac output was 41% higher in the EVA group than the control group at 60 min [2.70 vs. 1.59 L/min, p = 0.029].Conclusion: EVA through a small endotracheal tube increased venous return, cardiac output, and mean arterial pressure compared with conventional positive pressure ventilation. The effects were most significant during hypovolemia from hemorrhage. EVA provided less effective ventilation than conventional positive pressure ventilation. [ABSTRACT FROM AUTHOR]