Background: Hospitalized patients are complex and often receive concurrent treatment for multiple diseases. Patients presenting with shortness of breath and infiltrates on chest x-ray may be treated for pneumonia, congestive heart failure (CHF) or both. Fluid and blood pressure management may be particularly challenging for these patients. Our goal was to define the impact of CHF on pneumonia treatment and outcomes in hospitalized patients.

Methods: We conducted a retrospective cohort study of patients admitted with pneumonia between July 2010 and June 2015 to 651 US hospitals that contributed data to the Perspective (Premier Inc) database. We included patients aged ≥18 years with a principal discharge diagnosis of pneumonia who underwent chest radiography and received antibiotics by hospital day 1. We compared patients with and without a secondary diagnosis of CHF. The primary outcome was inpatient mortality. Secondary outcomes included late initiation (after hospital day 2) of a vasopressor, invasive mechanical ventilation, or transfer to the intensive care unit (ICU); hospital length of stay, 30-day readmissions, and cost. We compared characteristics of patients with CHF to those without using chi-square or nonparametric Kruskal-Wallis tests. We used generalized linear mixed models to assess the associations between CHF and our primary and secondary outcomes while adjusting for the effects of age, sex, race/ethnicity, insurance payer, comorbidities and initial severity of illness.

Results: Of 762,671 patients included, 206,725 (27%) had a secondary diagnosis of CHF. Compared to patients without CHF, patients with CHF were older (78 vs. 70 years, p<0.001) and had higher combined comorbidity scores (5 vs. 2, p<0.001). On the first hospital day, patients with CHF were less likely to receive fluids (46% vs 58%, p<0.001) and more likely to receive loop diuretics (37% vs. 8%, p<0.001). Of patients who received diuretics on the first day, 38% also received intravenous fluids, and 7.5% of patients with CHF received both fluids and diuretics on two consecutive days. Compared to patients with diastolic dysfunction, those with systolic dysfunction were more likely to receive ACEI/ARB (47.5% vs, 36.6%) and beta-blockers (71.7% vs. 56.4%) during hospitalization; 82% of patients in both groups received diuretics. Compared to patients without CHF, patients with CHF had worse adjusted outcomes: inpatient mortality [OR 1.07 (1.04-1.09)], cost [Ratio 1.08 (1.07-1.09)], length of stay [Ratio 1.07 (1.06-1.08)], 30-day readmissions [OR 1.06 (1.02-1.10)], late ICU transfer [OR 1.30 (1.27-1.34)], late vasopressor use [OR 1.13 (1.10-1.16)], and late mechanical ventilation [OR 1.33 (1.29-1.37)].

Conclusions: After adjusting for differences in demographics and co-morbidities and initial severity of illness, patients with CHF had worse outcomes. Concomitant treatment with diuretic and fluids was common.