Anemia and 90-day mortality in COPD patients requiring invasive mechanical ventilation

Lone Rasmussen1,2, Steffen Christensen1,2, Poul Lenler-Petersen2, Søren P Johnsen11Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2Department of Anaesthesiology and Intensive Care, Silkeborg Hospital, Silkeborg, DenmarkBackground: There are data to suggest that anemia is associated with increased mortality in patients with chronic obstructive pulmonary disease (COPD). In contrast, critically ill patients with low hemoglobin levels (4.3–5.5 mmol/L, 7.0–9.0 g/dL) in general do not appear to have a worsened clinical outcome. The effects of anemia in critically ill patients with COPD remain to be clarified. We examined the association between anemia (hemoglobin < 7.4 mmol/L, <12.0 g/dL) and 90-day mortality in COPD patients with acute respiratory failure treated with invasive mechanical ventilation in a single-institution follow-up study.Method: We identified all COPD patients at our institution (n = 222) admitted for the first time to the intensive care unit (ICU) requiring invasive mechanical ventilation in 1994–2004. Data on patient characteristics (eg, hemoglobin, pH, blood transfusions, and Charlson Comorbidity Index), and mortality were obtained from population-based clinical and administrative registries and medical records. We used Cox’s regression analysis to estimate mortality rate ratios (MRR) in COPD patients with and without anemia.Results: A total of 42 (18%) COPD patients were anemic at time of initiating invasive mechanical ventilation. The overall 90-day mortality among anemic COPD patients was 57.1% versus 25% in nonanemic patients. The corresponding adjusted 90-day MRR was 2.6 (95% confidence interval 1.5–4.5). Restricting analyses to patients not treated with blood transfusions during their intensive care unit stay did not materially change the MRR.Conclusion: We found anemia to be associated with increased mortality among COPD patients with acute respiratory failure requiring invasive mechanical ventilation.Keywords: anemia, mortality, chronic obstructive pulmonary disease, intensive car

The Interaction Effect Between Previous Stroke and Hip Fracture on Postoperative Mortality:A Nationwide Cohort Study

PURPOSE: It remains uncertain how a history of stroke impacts the prognosis for patients with hip fracture. This study aimed to evaluate mortality following hip fracture surgery by comparing patients with and without a history of stroke. PATIENTS AND METHODS: All patients aged 65 years or above in Denmark receiving hip fracture surgery between 2010 and 2018. For every patient, 10 individuals from the general population without hip fracture were sampled. Comparators had a similar stroke history, age, and sex on the date of hip fracture surgery (index date). We established four cohorts: hip fracture patients with/without stroke and non-hip fracture patients with/without stroke. Outcomes were all-cause mortality at 0–30 days, 31–365 days and 1 to 5 years. Direct standardized mortality rates (MR) with 95% confidence intervals (CI) were computed. We calculated the interaction contrast to estimate excess absolute mortality among patients with both hip fracture and stroke. Through a Cox proportional hazards model, we estimated the hazard ratio (HR) and the attributable proportion as a measure of excess relative mortality attributable to interaction. RESULTS: Of the hip fracture patients, 8433 had a stroke history and 44,997 did not. Of the non-hip fracture patients, 84,330 had a stroke history and 449,962 did not. Corresponding 30-day MRs/100 person years were 148.4 (95% CI: 138.8–158.7), 124.3 (95% CI: 120.7–128.1), 14.3 (95% CI: 13.4–15.2) and 8.4 (95% CI: 8.1–8.7). The interaction contrast was 18.2 (95% CI: 7.5–28.8), and the attributable proportion was 9.0% (95% CI: 2.9–15.1). No interaction was present beyond 30 days. CONCLUSION: We observed excess short-term mortality in patients with stroke and hip fracture, but the effect disappeared at later follow-up periods. Clinicians are encouraged to pay rigorous attention to early complications among hip fracture patients with stroke, as this may serve as a way to reduce mortality

Risk and Subtypes of Stroke Following New-Onset Postoperative Atrial Fibrillation in Coronary Bypass Surgery:A Population-Based Cohort Study

BACKGROUND: New‐onset postoperative atrial fibrillation (POAF) develops in approximately one‐third of patients undergoing cardiac surgery and is associated with a higher incidence of ischemic stroke and increased mortality. However, it remains unknown to what extent ischemic stroke events in patients with POAF are cardioembolic and whether anticoagulant therapy is indicated. We investigated the long‐term risk and pathogenesis of postoperative stroke in patients undergoing coronary artery bypass grafting experiencing POAF. METHODS AND RESULTS: This was a register‐based cohort study. Data from the WDHR (Western Denmark Heart Registry) were linked with the DNPR (Danish National Patient Register), the Danish National Prescription Register, and the Cause of Death Register. All stroke diagnoses were verified, and ischemic stroke cases were subclassified according to pathogenesis. Furthermore, investigations of all‐cause mortality and the use of anticoagulation medicine for the individual patient were performed. A total of 7813 patients without a preoperative history of atrial fibrillation underwent isolated coronary artery bypass grafting between January 1, 2010, and December 31, 2018, in Western Denmark. POAF was registered in 2049 (26.2%) patients, and a postoperative ischemic stroke was registered in 195 (2.5%) of the patients. After adjustment, there was no difference in the risk of ischemic stroke (hazard ratio [HR], 1.08 [95% CI, 0.74–1.56]) or all‐cause mortality (HR, 1.09 [95% CI, 0.98–1.23]) between patients who developed POAF and non‐POAF patients. Although not statistically significant, patients with POAF had a higher incidence rate (IR; per 1000 patient‐years) of cardioembolic stroke (IR, 1 [95% CI, 0.6–1.6] versus IR, 0.5 [95% CI, 0.3–0.8]), whereas non‐POAF patients had a higher incidence rate of large‐artery occlusion stroke (IR, 1.1 [95% CI, 0.8–1.5] versus IR, 0.7 [95% CI, 0.4–1.4]). Early initiation of anticoagulation medicine was not associated with a lower risk of ischemic stroke. However, patients with POAF were more likely to die of cardiovascular causes than non‐POAF patients (P<0.001). CONCLUSIONS: We found no difference in the adjusted risk of postoperative stroke or all‐cause mortality in POAF versus non‐POAF patients. Patients with POAF after coronary artery bypass grafting presented with a higher, although not significant, proportion of ischemic strokes of the cardioembolic type

Use of reperfusion therapy and time delay in patients with ischaemic stroke by immigration status:a register-based cohort study in Denmark

BACKGROUND AND PURPOSE: Reperfusion therapy is the mainstay of treatment for acute ischaemic stroke (AIS); however, little is known about the use of reperfusion therapy and time delay amongst immigrants. METHODS: This is a Danish nationwide register‐based cohort study of patients with AIS aged ≥18 years (n = 49,817) recruited from 2009 to 2018. Use of reperfusion therapy (intravenous thrombolysis and/or mechanical thrombectomy) and time delay between immigrants and Danish‐born residents were compared using multivariable logistics and quantile regression. RESULTS: Overall, 10,649 (39.8%) Danish‐born residents and 452 (39.0%) immigrants with AIS were treated with reperfusion therapy in patients arriving <4.5 h following stroke onset. Compared with Danish‐born residents, immigrants had lower odds of receiving reperfusion therapy after adjustment for prehospital delay, age, sex, stroke severity, sociodemographic factors and comorbidities (adjusted odds ratio 0.67; 95% confidence interval 0.49‒0.92, p = 0.01). The lowest odds were observed amongst immigrants originating from Poland and non‐Western countries. Similarly, immigrants had a longer prehospital delay than Danish‐born residents in the fully adjusted model in patients arriving <4.5 h after stroke onset (15 min; 95% confidence interval 4‒26 min, p = 0.03). No evidence was found that system delay and clinical outcome differed between immigrants and Danish‐born residents in patients eligible for reperfusion therapy after adjustment for sociodemographic factors and comorbidities. CONCLUSION: Immigration status was significantly associated with lower chances of receiving reperfusion therapy and there may be differences in patient delay between immigrants and Danish‐born residents in patients arriving to a stroke unit <4.5 h after stroke onset

Catalog of 199 register-based definitions of chronic conditions

Introduction: The aim of the current study was to present and discuss a broad range of register-based definitions of chronic conditions for use in register research, as well as the challenges and pitfalls when defining chronic conditions by the use of registers. Materials and methods: The definitions were defined based on information from nationwide Danish public healthcare registers. Medical and epidemiological specialists identified and grouped relevant diagnosis codes that covered chronic conditions, using the International Classification System version 10 (ICD-10). Where relevant, prescription and other healthcare data were also used to define the chronic conditions. Results: We identified 199 chronic conditions and subgroups, which were divided into four groups according to a medical judgment of the expected duration of the conditions, as follows. Category I: Stationary to progressive conditions (maximum register inclusion time of diagnosis since the start of the register in 1994). Category II: Stationary to diminishing conditions (10 years of register inclusion after time of diagnosis). Category III: Diminishing conditions (5 years of register inclusion after time of diagnosis). Category IV: Borderline conditions (2 years of register inclusion time following diagnosis). The conditions were primarily defined using hospital discharge diagnoses; however, for 35 conditions, including common conditions such as diabetes, chronic obstructive lung disease and allergy, more complex definitions were proposed based on record linkage between multiple registers, including registers of prescribed drugs and use of general practitioners’ services. Conclusions: This study provided a catalog of register-based definitions for chronic conditions for use in healthcare planning and research, which is, to the authors’ knowledge, the largest currently compiled in a single study