Heart Failure is Highly Prevalent and Difficult to Diagnose in Severe Exacerbations of COPD Presenting to the Emergency Department

Background: Some 20% of patients with stable Chronic Obstructive Pulmonary Disease (COPD) might have heart failure (HF). HF contribution to acute exacerbations of COPD (AECOPD) presenting to the emergency department (ED) is not well established. Aims: To assess (1) the HF incidence in patients presenting to the ED with AECOPD; (2) the concordance between ED and respiratory ward (RW) diagnosis; (3) the factors associated with risk of death after hospital discharge. Methods: Retrospective chart review of 119 COPD patients presenting to ED for acute exacerbation of respiratory symptoms and then admitted to RW where a final diagnosis of AECOPD, AECOPD and HF and AECOPD and OD (other diagnosis), was obtained. ED and RW diagnosis were then compared. Factors affecting survival at follow-up were investigated. Results: At RW, 40.3% of cases were diagnosed of AECOPD, 40.3% of AECOPD and HF and 19.4% of AECOPD and OD, with ED diagnosis coinciding with RW’s in 67%, 23%, and 57% of cases respectively. At RW, 60% of patients in GOLD1 had HF, of which 43% were diagnosed at ED, while 40% in GOLD4 had HF that was never diagnosed at ED. Lack of inclusion in a COPD care program, HF, and early readmission for AECOPD were associated with mortality. Conclusions: HF is highly prevalent and difficult to diagnose in patients in all GOLD stages presenting to the ED with severe AECOPD, and along with lack of inclusion in a COPD care program, confers a high risk for mortality.


EMERGENCY DEPARTMENT (ED) DIAGNOSIS
Patients presenting with acute severe exacerbation of respiratory symptoms to the ED, were diagnosed by ED physicians according to the patient's ED chart as: 1) respiratory failure secondary to only acute exacerbation of COPD (AECOPD).
The abbreviated form of the original ED diagnosis: AECOPD, AECOPD+HF and AECOPD+OD were used throughout the manuscript.

RESPIRATORY WARD (RW) DIAGNOSIS
A detailed diagnostic workout was performed in the RW in order to obtain the correct diagnosis in each patient.
The diagnostic denomination of AECOPD, AECOPD+HF and AECOPD+OD used in ED was maintained for the correct discharge diagnosis from the RW.
The diagnostic tests and how often were they requested by ED and RW physicians are summarized in Table S1.

Statistical analysis
Patients characteristics were described using mean±SD and counts and percentages for categorical variables. Comparisons among groups were evaluated with Kruskal-Wallis and Mann-Whitney U tests. Distributions of categorical variables were compared with the χ2test or Fisher exact-test when the sample size was small (n < 5). Analyses of overall survival were performed by Kaplan-Meier survival curves. Cox proportional risk regression model was used to evaluate independent prognostic factors. Variables included in the Cox regression analysis had to be significant in the respective univariate analyses. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for all the variables entered in the final model.
All analyses were performed using SPSS (version 25.0.0.1 for Windows). Statistical significance was assumed for a p value <0.05.

Baseline medications
The use of respiratory medications was similar in the three diagnostic groups with 86/119 (72%) using inhaled corticosteroids and bronchodilators, 19/119 (16%) using single or double bronchodilators and only 14/119 (12%) with no regular treatment.

Other diagnosis at the ED and RW
The group AECOPD+OD included patients with acute exacerbations of respiratory symptoms thought to be due to diagnosis other than AECOPD or AECOPD+HF. At the ED, the AECOPD+OD diagnosis included 43 patients of which: 18 were diagnosed of "respiratory failure", 9 pneumonia, 7 lung infection, 4 asthma exacerbation in patients with chronic bronchitis, 2 haemoptysis, 1 pleural effusion, 1 pulmonary embolism, 1 opioid toxicity. In the 18 patients diagnosed as respiratory failure the label "respiratory failure" was an unspecific diagnosis conferred in the absence of a clear identifiable cause for acute worsening of respiratory symptoms. In the 4 patients diagnosed as "asthma exacerbation in patients with chronic bronchitis", the presence of a history of asthma was carefully excluded at the RW evaluation.
At the RW, the AECOPD+OD discharge diagnosis was modified from the ED diagnosis and included 23 patients of which: 15 were diagnosed of pneumonia, 3 pulmonary embolism, 1 pulmonary aspergillosis, 1 opioid toxicity and 3 respiratory symptoms deterioration due to complications of advanced neoplasia.

Other diagnostic tests
A CT scan, available in 117/119 patients, showed emphysema in 53/117 (45%) and bronchiectasis in 25/117 (21%) with no difference found among the three diagnostic group.
Cardiac Doppler was performed when deem indicated in 76/119 patients and heart failure was diagnosed in 48/76 according to the European Society of Cardiology guidelines [1].

Table S2. Medications at baseline in whole population and in the three RW groups.
Data are expressed as number (%).