Long-term cognitive and pulmonary functions following a lower versus a higher oxygenation target in the HOT-ICU and HOT-COVID trials: A protocol update

BACKGROUND

The Handling Oxygenation Targets in the Intensive Care Unit (HOT-ICU) trial was a multicentre, randomised, parallel-group trial of a lower oxygenation target (arterial partial pressure of oxygen [PaO2 ] = 8 kPa) versus a higher oxygenation target (PaO2  = 12 kPa) in adult ICU patients with acute hypoxaemic respiratory failure; the Handling Oxygenation Targets in coronavirus disease 2019 (HOT-COVID) tested the same oxygenation targets in patients with confirmed COVID-19. In this study, we aim to evaluate the long-term effects of these oxygenation targets on cognitive and pulmonary function. We hypothesise that a lower oxygenation target throughout the ICU stay may result in cognitive impairment, whereas a higher oxygenation target may result in impaired pulmonary function.

METHODS

This is the updated protocol and statistical analysis plan of two pre-planned secondary outcomes, the long-term cognitive function, and long-term pulmonary function, in the HOT-ICU and HOT-COVID trials. Patients enrolled in both trials at selected Danish sites and surviving to 1 year after randomisation are eligible to participate. A Repeatable Battery for the Assessment of Neuropsychological Status score and a full-body plethysmography, including diffusion capacity for carbon monoxide, will be obtained. The last patient is expected to be included in the spring of 2024.

CONCLUSION

This study will provide important information on the long-term effects of a lower versus a higher oxygenation target on long-term cognitive and pulmonary functions in adult ICU patients with acute hypoxaemic respiratory failure.

Electronic nudges to increase influenza vaccination uptake among patients with heart failure: A pre-specified analysis of the NUDGE-FLU trial

AIMS

Seasonal influenza vaccination is strongly recommended in patients with heart failure (HF). The NUDGE-FLU trial recently found two electronic behavioural nudging letter strategies - a letter highlighting potential cardiovascular benefits of vaccination and a repeated letter at day 14 -effective in increasing influenza vaccination in Denmark. The aims of this pre-specified analysis was to further examine vaccination patterns and effects of these behavioural nudges in patients with HF including potential off-target effects on guideline-directed medical therapy (GDMT) use.

METHODS AND RESULTS

The nationwide NUDGE-FLU trial randomized 964 870 Danish citizens ≥65 years to usual care or nine different electronic nudging letter strategies. Letters were delivered through the official Danish electronic letter system. The primary endpoint was the receipt of an influenza vaccine; additional outcomes for this analysis included GDMT use. In this analysis, we also assessed influenza vaccination rates in the overall Danish HF population including those <65 years (n = 65 075). During the 2022-2023 season, influenza vaccination uptake was 71.6% in the overall Danish HF population but this varied considerably with only 44.6% uptake in those <65 years. A total of 33 109 NUDGE-FLU participants had HF at baseline. Vaccination uptake was higher among those on higher levels of baseline GDMT (≥3 classes: 85.3% vs. ≤2 classes: 81.9%; p < 0.001). HF status did not modify the effects of the two overall successful nudging strategies on influenza vaccination uptake (cardiovascular gain-framed letter: pinteraction  = 0.37; repeated letter: pinteraction  = 0.55). No effect modification was observed across GDMT use levels for the repeated letter (pinteraction  = 0.88), whereas a trend towards attenuated effect among those on low levels of GDMT was observed for the cardiovascular gain-framed letter (pinteraction  = 0.07). The letters had no impact on longitudinal GDMT use.

CONCLUSIONS

Approximately one in four patients with HF did not receive influenza vaccination with a pronounced implementation gap in those <65 years where less than half were vaccinated. HF status did not modify the effectiveness of cardiovascular gain-framed and repeated electronic nudging letters in increasing influenza vaccination rates. No unintended negative effects on longitudinal GDMT use were observed.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT05542004.

Early biomarker-guided prediction of bloodstream infection in critically ill patients: C-reactive protein, procalcitonin and leukocytes

Background

Bloodstream infections (BSIs) often lead to critical illness and death. The primary aim of this study was to determine the diagnostic accuracy of the biomarkers C-reactive protein (CRP), procalcitonin (PCT), and leukocyte count for the diagnosis of BSI in critically ill patients.

Methods

This was a nested case–control study based on the Procalcitonin And Survival Study (PASS) trial (n = 1200). Patients who were admitted to the intensive care unit (ICU) <24 hours, and not expected to die within <24 hours, were recruited. For the current study, we included patients with a BSI within ±3 days of ICU admission and matched controls without a BSI in a 1:2 ratio. Diagnostic accuracy for BSI for the biomarkers on days 1, 2, and 3 of ICU admission was assessed. Sensitivity, specificity, and negative and positive predictive values were calculated for prespecified thresholds and for a data-driven cutoff.

Results

In total, there were 525 patients (n = 175 cases, 350 controls). The fixed low threshold for all 3 biomarkers (CRP = 20 mg/L; leucocytes = 10 × 10⁹/L; PCT = 0.4 ng/mL) resulted in negative predictive values on day 1: CRP = 0.91; 95% CI, 0.75–1.00; leukocyte = 0.75; 95% CI, 0.68–0.81; PCT = 0.91; 95% CI, 0.84–0.96). Combining the 3 biomarkers yielded similar results as PCT alone (P = .5).

Conclusions

CRP and PCT could in most cases rule out BSI in critically ill patients. As almost no patients had low CRP and ∼20% had low PCT, a low PCT could be used, along with other information, to guide clinical decisions.

Changes over time in characteristics, resource use and outcomes among ICU patients with COVID-19 - a nationwide, observational study in Denmark

BACKGROUND

Characteristics and care of ICU patients with COVID-19 may have changed during the pandemic, but longitudinal data assessing this are limited. We compared patients with COVID-19 admitted to Danish ICUs in the first wave with those admitted later.

METHODS

Among all Danish ICU patients with COVID-19, we compared demographics, chronic comorbidities, use of organ support, length of stay and vital status of those admitted 10^th March to 19^th May 2020 (first wave) versus 20^th May 2020 to 30^th June 2021. We analysed risk factors for death by adjusted logistic regression analysis.

RESULTS

Among all hospitalised patients with COVID-19, a lower proportion was admitted to ICU after the first wave (13 vs 8%). Among all 1374 ICU patients with COVID-19, 326 were admitted during the first wave. There were no major differences in patient's characteristics or mortality between the two periods, but use of invasive mechanical ventilation (81% vs 58% of patients), renal replacement therapy (26% vs. 13%) and ECMO (8% vs 3%) and median length of stay in ICU (13 vs 10 days) and in hospital (20 vs 17 days) were all significantly lower after the first wave. Risk factors for death were higher age, larger burden of co-morbidity (hearth failure, pulmonary disease, and kidney disease), and active cancer, but not admission during or after the first wave.

CONCLUSIONS

After the first wave of COVID-19 in Denmark, a lower proportion of hospitalised patients with COVID-19 was admitted to ICU. Among ICU patients, use of organ support was lower and length of stay was reduced, but mortality rates remained at a relatively high level.

EDITORIAL COMMENT

This study assessed the temporal changes in the care of patients with COVID-19 requiring ICU care in Denmark. The findings showed that while a lower ratio of patients with documented infections required ICU and they required less organ support, ICU mortality remained unchanged. This might reflect the effects of vaccines on disease severity and improvement in floor management of hypoxic patients, but also underscores that COVID-19 remains a serious threat to the health of many patients, in particularly elderly patients with a high degree of comorbidity.

Association between anticoagulant therapy, exacerbations and mortality in a Danish cohort of patients with Chronic Obstructive Pulmonary Disease

OBJECTIVES

Pulmonary Embolism has been frequently reported in Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AE-COPD). The study aimed to determine whether COPD patients who receive anticoagulant (AC) therapy have a reduced risk of hospitalization due to AE-COPD and death.

METHODS

This nationwide population-based study was based on data from the Danish Register of COPD (DrCOPD), which contains complete data on COPD outpatients between 1st January 2010 and 31st December 2018. National registers were used to obtain information regarding comorbidities and vital status. Propensity-score matching and Cox proportional hazards models were used to assess AE-COPD and death after one year.

RESULTS

The study cohort consisted of 58,067 patients with COPD. Of these, 5194 patients were on AC therapy. The population was matched 1:1 based on clinical confounders and AC therapy, resulting in two groups of 5180 patients. We found no association between AC therapy and AE-COPD or all-cause mortality in the propensity-score matched population (HR 1.03, 95% CI 0.96-1.10, p = 0.37). These findings were confirmed in a competing risk analysis. In the sensitivity analysis, we performed an adjusted analysis of the complete cohort and found a slightly increased risk of AE-COPD or death in patients treated with AC therapy. This study found a low incidence of pulmonary embolisms and deep venous thrombosis in both groups.

CONCLUSIONS

AC therapy was not associated with the risk of hospitalization due to AE-COPD or all-cause mortality.

Echocardiographic abnormalities and predictors of mortality in hospitalized COVID-19 patients: the ECHOVID-19 study

AIMS

The present study had two aims: (i) compare echocardiographic parameters in COVID-19 patients with matched controls and (2) assess the prognostic value of measures of left (LV) and right ventricular (RV) function in relation to COVID-19 related death.

METHODS AND RESULTS

In this prospective multicentre cohort study, 214 consecutive hospitalized COVID-19 patients underwent an echocardiographic examination (by pre-determined research protocol). All participants were successfully matched 1:1 with controls from the general population on age, sex, and hypertension. Mean age of the study sample was 69 years, and 55% were male participants. LV and RV systolic function was significantly reduced in COVID-19 cases as assessed by global longitudinal strain (GLS) (16.4% ± 4.3 vs. 18.5% ± 3.0, P < 0.001), tricuspid annular plane systolic excursion (TAPSE) (2.0 ± 0.4 vs. 2.6 ± 0.5, P < 0.001), and RV strain (19.8 ± 5.9 vs. 24.2 ± 6.5, P = 0.004). All parameters remained significantly reduced after adjusting for important cardiac risk factors. During follow-up (median: 40 days), 25 COVID-19 cases died. In multivariable Cox regression reduced TAPSE [hazard ratio (HR) = 1.18, 95% confidence interval (CI) [1.07-1.31], P = 0.002, per 1 mm decrease], RV strain (HR = 1.64, 95%CI[1.02;2.66], P = 0.043, per 1% decrease) and GLS (HR = 1.20, 95%CI[1.07-1.35], P = 0.002, per 1% decrease) were significantly associated with COVID-19-related death. TAPSE and GLS remained significantly associated with the outcome after restricting the analysis to patients without prevalent heart disease.

CONCLUSIONS

RV and LV function are significantly impaired in hospitalized COVID-19 patients compared with matched controls. Furthermore, reduced TAPSE and GLS are independently associated with COVID-19-related death.

P2442Myocardial performance index predicts mortality in people with obstructive lung function from the general population

Background

Forced expiratory volume in one second (FEV1) is a significant predictor of mortality in patients with obstructive lung function (OL). Whether echocardiography can be used to identify patients at high risk, and whether it provides incremental prognostic information on mortality in patients with OL, remains unknown.

Methods

In a large, low-risk general population study, 1873 participants underwent a health examination with spirometry and echocardiography, including tissue Doppler imaging (TDI). The myocardial performance index (MPI) was calculated as the sum of the isovolumic contraction time (IVCT) and the isovolumic relaxation time (IVRT) divided by the left ventricle ejection time (LVET). Spirometry included measurements of (FEV1) and the forced vital capacity (FVC). OL was defined as FEV1/FVC <0.70. The primary endpoint was all-cause mortality.

Results

The mean age was 59±16 years, 57% were women, 43% had hypertension, 11% had diabetes, and 6% had ischemic heart disease. Of the 1873 included participants, 288 (15%) were classified as having OL at baseline. During follow up (median 13.7 years (IQR 13.2–16.2)), 584 (31%) persons died, hereof 178 (62%) in the subgroup of participants with OL and 406 (26%) in the subgroup of participants with normal lung function.

OL was associated with presence of left ventricular hypertrophy (higher left ventricular mass index), impaired diastolic function (lower E, higher A, lower E/A ratio, longer deceleration time, lower e' and higher E/e'), lower global longitudinal strain, and higher MPI.

In unadjusted analysis, higher MPI was associated with all-cause mortality for participants with OL (HR=1.18 (1.11–1.26), p<0.001, per 0.1 increase) and for participants with normal lung function (HR=1.42 (1.34–1.50), p<0.001, per 0.1 increase). The predictive value of MPI was significantly modified by the presence of obstructive lung function (p<0.001).

After multivariable adjustment for age, sex, FEV1/FVC, heart rate, systolic blood pressure, smoking status, body mass index (BMI), hypertension, diabetes, ischemic heart disease, ischemic stroke and heart failure at baseline, MPI remained an independent predictor of all-cause mortality (HR=1.19 (1.06–1.34), p=0.004, per 0.1 increase) for participants with OL but not for participants with normal lung function (HR=1.02 (0.94–1.11), p=0.598, per 0.1 increase).

When adding the MPI to the updated Age, Dyspnea and Obstruction (ADO) index, MPI provided incremental prognostic information beyond the updated ADO index, as determined from a significant increase in the Harrell's C-statistics (0.785 to 0.792, p=0.003).

Conclusion

Presence of OL is associated with subtle impairment of left ventricular systolic function, impaired left ventricular diastolic function, and higher MPI. MPI is an independent predictor of mortality in people with OL and provides incremental prognostic information regarding all-cause mortality in this population.

Acknowledgement/Funding

Herlev & Gentofte University Hospital PhD fund

Pseudomonas aeruginosa and risk of death and exacerbations in patients with chronic obstructive pulmonary disease: an observational cohort study of 22 053 patients

OBJECTIVES

The role of Pseudomonas aeruginosa in the long-term prognosis of chronic obstructive pulmonary disease (COPD) is unknown. The purpose of this study was to determine whether P. aeruginosa is associated with increased risk of exacerbations or death in patients with COPD.

METHODS

This is a multiregional epidemiological study based on complete data on COPD outpatients between 1 January 2010 and 31 October 2017 and corresponding microbiology and national register data. Time-dependent Cox proportional hazards models and propensity matching was used to estimate hospitalization-demanding exacerbations and death after 2 years, separately and in combination.

RESULTS

A total of 22 053 COPD outpatients were followed for a median of 1082 days (interquartile-range: 427-1862). P. aeruginosa was present in 905 (4.1%) patients. During 730 days of follow-up, P. aeruginosa strongly and independently predicted an increased risk of hospitalization for exacerbation or all-cause death (HR 2.8, 95%CI 2.2-3.6; p <0.0001) and all-cause death (HR 2.7, 95%CI 2.3-3.4; p <0.0001) in analyses adjusted for known and suspected confounders. The signal remained unchanged in unadjusted analyses as well as propensity-matched subgroup analyses. Among patients 'ever colonized' with P. aeruginosa, the incidence of hospital-demanding exacerbations doubled after the time of the first colonization.

CONCLUSIONS

COPD patients in whom P. aeruginosa can be cultured from the airways had a markedly increased risk of exacerbations and death. It is still not clear whether this risk can be reduced by offering patients targeted antipseudomonal antibiotics. A randomized trial is currently recruiting patients to clarify this (ClinicalTrials.gov: NCT03262142).