Risk of exacerbation following pneumonia in adults with heart failure or chronic obstructive pulmonary disease

<div><p>Background</p><p>Recent evidence demonstrates increased short-term risk of cardiac complications and respiratory failure among patients with heart failure (HF) and chronic obstructive pulmonary disease (COPD), respectively, concurrent with an episode of community-acquired pneumonia (CAP). We evaluated patients with pre-existing HF or COPD, beginning 30 days after CAP diagnosis, to determine if CAP had a prolonged impact on their underlying comorbidity.</p><p>Methods</p><p>A retrospective matched-cohort design using US healthcare claims was employed. In each month of accrual, patients with HF or COPD who developed CAP (“CAP patients”) were matched (1:1, without replacement, on demographic and clinical profiles) to patients with HF or COPD who did not develop CAP (“comparison patients”). All patients were aged ≥40 years, and were pneumonia free during prior 1-year period. Exacerbation beginning 30 days after the CAP diagnosis and for the subsequent 1-year period were compared between CAP and comparison patients.</p><p>Findings</p><p>38,010 (4·6%) HF patients and 48,703 (5·9%) COPD patients experienced a new CAP episode requiring hospitalization or outpatient care only, and were matched to comparison patients. In the HF subset, CAP patients were 47·2% more likely to experience an exacerbation vs patients without CAP (17·8% vs. 12·1%; p<0·001); in the COPD subset, CAP patients were 42·3% more likely to experience an exacerbation (16·2% vs. 11·4%; p<0·001).</p><p>Conclusions</p><p>Our data provide evidence that CAP foreshadows a prolonged increase in risk of exacerbation of underlying HF or COPD in adults, and suggests a potential benefit to CAP prevention strategies.</p></div

Characteristics of hospitalized CAP patients and matched comparison patients in heart failure and chronic obstructive pulmonary disease populations^*.

<p>Characteristics of hospitalized CAP patients and matched comparison patients in heart failure and chronic obstructive pulmonary disease populations^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184877#t001fn002" target="_blank">*</a>}.</p

Cumulative percentage of hospitalized pneumonia patients and matched comparison patients who experienced an HF/COPD-related exacerbation*.

<p>CAP: Community-acquired pneumonia; COPD: chronic obstructive pulmonary disease; HF: heart failure. Exacerbation: Hospitalization with principal diagnosis of condition of interest, or emergency department visit with diagnosis of condition of interest in any position. *Patients identified between 1/2010 and 5/2013 within Truven Health Analytics MarketScan Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits Databases. †Follow-up began 30 days after CAP diagnosis and ended 12 months later. ‡All comparisons p<0.001.</p

Outcome of challenge with SP Pilus-1 overexpressing mutant in RrgB321 immunized animals.

<p>Density of colonization in middle ear fluid in RrgB321 immunized and control chinchillas challenged with SP Taiwan19F-14 pMU1328_<i>Pc-rlrA</i> (100% pilus +).</p

Pilus expression of SP Taiwan19F-14 wt in nasal and middle ear washes compared to inoculum.

<p>Flow cytometry analysis of Pilus-1 expression in nasal wash (NW) [A] and middle ear Fluid (MEF) [B] following challenge with SP Taiwan19F-14 wt.</p

Evaluation of pilus expression on surface of <i>Streptococcus pneumoniae</i>.

<p>Flow cytometry on SP Taiwan19F-14 wt and its derivatives (ΔPI-1/PI-2 mutant and pMU1328_<i>Pc-rlrA</i> + strain) performed with pAb against RrgB. The percentage of pilus positive and negative bacteria for each strain was reported.</p

Outcome of challenge with SP Taiwan19F-14 wt in RrgB321 immunized and control animals.

<p>Density of colonization in nasopharynx (a) and middle ear fluid (b) in RrgB321 immunized and control chinchillas challenged with SP Taiwan19F-14 wt (pilus +).</p

Nasopharyngeal colonization and middle ear challenge with SP Taiwan19F-14 wt and PI-1/PI-2 mutant.

<p>Density of colonization in nasopharynx (A) and middle ear fluid (B) in chinchillas challenged with SP Taiwan19F-14 wt (pilus +) or with Taiwan19F-14 ΔPI-1/PI-2 mutant.</p

Pilus expression of SP Taiwan19F-14 wt in nasal and middle ear washes of RrgB321 immunized and control animals.

<p>Flow cytometry analysis of Pilus-1 expression in nasal wash (NW) [A] and middle ear Fluid (MEF) [B] in RrgB321 immunized and control animals following challenge with SP Taiwan19F-14 wt.</p

Scenario analyses, societal perspective.

*<p>Mixed public and private incremental vaccine cost was calculated by weighing the public and private vaccine cost by the proportion of those who receive the vaccine at public cost.</p