Machine learning-based scoring system to predict in-hospital outcomes in patients hospitalized with COVID-19

BACKGROUND

The evolution of patients hospitalized with coronavirus disease 2019 (COVID-19) is still hard to predict, even after several months of dealing with the pandemic.

AIMS

To develop and validate a score to predict outcomes in patients hospitalized with COVID-19.

METHODS

All consecutive adults hospitalized for COVID-19 from February to April 2020 were included in a nationwide observational study. Primary composite outcome was transfer to an intensive care unit from an emergency department or conventional ward, or in-hospital death. A score that estimates the risk of experiencing the primary outcome was constructed from a derivation cohort using stacked LASSO (Least Absolute Shrinkage and Selection Operator), and was tested in a validation cohort.

RESULTS

Among 2873 patients analysed (57.9% men; 66.6±17.0 years), the primary outcome occurred in 838 (29.2%) patients: 551 (19.2%) were transferred to an intensive care unit; and 287 (10.0%) died in-hospital without transfer to an intensive care unit. Using stacked LASSO, we identified 11 variables independently associated with the primary outcome in multivariable analysis in the derivation cohort (n=2313), including demographics (sex), triage vitals (body temperature, dyspnoea, respiratory rate, fraction of inspired oxygen, blood oxygen saturation) and biological variables (pH, platelets, C-reactive protein, aspartate aminotransferase, estimated glomerular filtration rate). The Critical COVID-19 France (CCF) risk score was then developed, and displayed accurate calibration and discrimination in the derivation cohort, with C-statistics of 0.78 (95% confidence interval 0.75-0.80). The CCF risk score performed significantly better (i.e. higher C-statistics) than the usual critical care risk scores.

CONCLUSIONS

The CCF risk score was built using data collected routinely at hospital admission to predict outcomes in patients with COVID-19. This score holds promise to improve early triage of patients and allocation of healthcare resources.

History of heart failure in patients with coronavirus disease 2019: Insights from a French registry

BACKGROUND

Although cardiovascular comorbidities seem to be strongly associated with worse outcomes in patients with coronavirus disease 2019 (COVID-19), data regarding patients with preexisting heart failure are limited.

AIMS

To investigate the incidence, characteristics and clinical outcomes of patients with COVID-19 with a history of heart failure with preserved or reduced ejection fraction.

METHODS

We performed an observational multicentre study including all patients hospitalized for COVID-19 across 24 centres in France from 26 February to 20 April 2020. The primary endpoint was a composite of in-hospital death or need for orotracheal intubation.

RESULTS

Overall, 2809 patients (mean age 66.4±16.9years) were included. Three hundred and seventeen patients (11.2%) had a history of heart failure; among them, 49.2% had heart failure with reduced ejection fraction and 50.8% had heart failure with preserved ejection fraction. COVID-19 severity at admission, defined by a quick sequential organ failure assessment score>1, was similar in patients with versus without a history of heart failure. Before and after adjustment for age, male sex, cardiovascular comorbidities and quick sequential organ failure assessment score, history of heart failure was associated with the primary endpoint (hazard ratio [HR]: 1.41, 95% confidence interval [CI]: 1.06-1.90; P=0.02). This result seemed to be mainly driven by a history of heart failure with preserved ejection fraction (HR: 1.61, 95% CI: 1.13-2.27; P=0.01) rather than heart failure with reduced ejection fraction (HR: 1.19, 95% CI: 0.79-1.81; P=0.41).

CONCLUSIONS

History of heart failure in patients with COVID-19 was associated with a higher risk of in-hospital death or orotracheal intubation. These findings suggest that patients with a history of heart failure, particularly heart failure with preserved ejection fraction, should be considered at high risk of clinical deterioration.

D-dimer at hospital admission for COVID-19 are associated with in-hospital mortality, independent of venous thromboembolism: Insights from a French multicenter cohort study

Background

Coronavirus disease 2019 (COVID-19) has been associated with coagulation disorders, in particular high concentrations of D-dimer, and increased frequency of venous thromboembolism.

Aim

To explore the association between D-dimer at admission and in-hospital mortality in patients hospitalised for COVID-19, with or without symptomatic venous thromboembolism.

Methods

From 26 February to 20 April 2020, D-dimer concentration at admission and outcomes (in-hospital mortality and venous thromboembolism) of patients hospitalised for COVID-19 in medical wards were retrospectively analysed in a multicenter study in 24 French hospitals.

Results

Among 2878 patients enrolled in the study, 1154 (40.1%) patients had D-dimer measurement at admission. Receiver operating characteristic curve analysis identified a D-dimer concentration > 1128 ng/mL as the best cut-off value for in-hospital mortality (area under the curve 64.9%, 95% confidence interval [CI] 60–69), with a sensitivity of 71.1% (95% CI 62–78) and a specificity of 55.6% (95% CI 52–58), which did not differ in the subgroup of patients with venous thromboembolism during hospitalisation. Among 545 (47.2%) patients with D-dimer concentration > 1128 ng/mL at admission, 86 (15.8%) deaths occurred during hospitalisation. After adjustment, in Cox proportional hazards and logistic regression models, D-dimer concentration > 1128 ng/mL at admission was also associated with a worse prognosis, with an odds ratio of 3.07 (95% CI 2.05–4.69; P < 0.001) and an adjusted hazard ratio of 2.11 (95% CI 1.31–3.4; P < 0.01).

Conclusions

D-dimer concentration > 1128 ng/mL is a relevant predictive factor for in-hospital mortality in patients hospitalised for COVID-19 in a medical ward, regardless of the occurrence of venous thromboembolism during hospitalisation.

Characteristics and outcomes of patients hospitalized for COVID-19 in France: The Critical COVID-19 France (CCF) study

Background

The coronavirus disease 2019 (COVID-19) pandemic has led to a public health crisis. Only limited data are available on the characteristics and outcomes of patients hospitalized for COVID-19 in France.

Aims

To investigate the characteristics, cardiovascular complications and outcomes of patients hospitalized for COVID-19 in France.

Methods

The Critical COVID-19 France (CCF) study is a French nationwide study including all consecutive adults with a diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection hospitalized in 24 centres between 26 February and 20 April 2020. Patients admitted directly to intensive care were excluded. Clinical, biological and imaging parameters were systematically collected at hospital admission. The primary outcome was in-hospital death.

Results

Of 2878 patients included (mean ± SD age 66.6 ± 17.0 years, 57.8% men), 360 (12.5%) died in the hospital setting, of which 7 (20.7%) were transferred to intensive care before death. The majority of patients had at least one (72.6%) or two (41.6%) cardiovascular risk factors, mostly hypertension (50.8%), obesity (30.3%), dyslipidaemia (28.0%) and diabetes (23.7%). In multivariable analysis, older age (hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.03 − 1.06; P < 0.001), male sex (HR 1.69, 95% CI 1.11 − 2.57; P = 0.01), diabetes (HR 1.72, 95% CI 1.12 − 2.63; P = 0.01), chronic kidney failure (HR 1.57, 95% CI 1.02 − 2.41; P = 0.04), elevated troponin (HR 1.66, 95% CI 1.11 − 2.49; P = 0.01), elevated B-type natriuretic peptide or N-terminal pro-B-type natriuretic peptide (HR 1.69, 95% CI 1.0004 − 2.86; P = 0.049) and quick Sequential Organ Failure Assessment score ≥ 2 (HR 1.71, 95% CI 1.12 − 2.60; P = 0.01) were independently associated with in-hospital death.

Conclusions

In this large nationwide cohort of patients hospitalized for COVID-19 in France, cardiovascular comorbidities and risk factors were associated with a substantial morbi-mortality burden.