Patients with chronic obstructive pulmonary disease (COPD) who develop community-acquired pneumonia (CAP) may experience worse clinical outcomes. However, COPD is not included as a distinct diagnosis in validated instruments that predict mortality in patients with CAP. The aim of the present study was to evaluate the impact of COPD as a comorbid condition on 30- and 90-day mortality in CAP patients. A retrospective observational study was conducted at two hospitals. Eligible patients had a discharge diagnosis and radiological confirmation of CAP.Among 744 patients with CAP, 215 had a comorbid diagnosis of COPD and 529 did not have COPD. The COPD group had a higher mean pneumonia severity index score (105±32versus87±34) and were admitted to the intensive care unit more frequently (25versus18%). After adjusting for severity of disease and processes of care, CAP patients with COPD showed significantly higher 30- and 90-day mortality than non-COPD patients.Chronic obstructive pulmonary disease patients hospitalised with community-acquired pneumonia exhibited higher 30- and 90-day mortality than patients without chronic obstructive pulmonary disease. Chronic obstructive pulmonary disease should be evaluated for inclusion in community-acquired pneumonia prediction instruments.

Hospitalization of the elderly for invasive pneumococcal disease is frequently accompanied by the occurrence of an adverse cardiac event; these are primarily new or worsened heart failure and cardiac arrhythmia. Herein, we describe previously unrecognized microscopic lesions (microlesions) formed within the myocardium of mice, rhesus macaques, and humans during bacteremic Streptococcus pneumoniae infection. In mice, invasive pneumococcal disease (IPD) severity correlated with levels of serum troponin, a marker for cardiac damage, the development of aberrant cardiac electrophysiology, and the number and size of cardiac microlesions. Microlesions were prominent in the ventricles, vacuolar in appearance with extracellular pneumococci, and remarkable due to the absence of infiltrating immune cells. The pore-forming toxin pneumolysin was required for microlesion formation but Interleukin-1β was not detected at the microlesion site ruling out pneumolysin-mediated pyroptosis as a cause of cell death. Antibiotic treatment resulted in maturing of the lesions over one week with robust immune cell infiltration and collagen deposition suggestive of long-term cardiac scarring. Bacterial translocation into the heart tissue required the pneumococcal adhesin CbpA and the host ligands Laminin receptor (LR) and Platelet-activating factor receptor. Immunization of mice with a fusion construct of CbpA or the LR binding domain of CbpA with the pneumolysin toxoid L460D protected against microlesion formation. We conclude that microlesion formation may contribute to the acute and long-term adverse cardiac events seen in humans with IPD. Hospitalization for community-acquired pneumonia carries a documented risk for adverse cardiac events. These occur during infection and contribute to elevated mortality rates in convalescent individuals up to 1 year thereafter. We describe a previously unrecognized pathogenic mechanism by which Streptococcus pneumoniae, the leading cause of community-acquired pneumonia, causes direct cardiotoxicity and forms microscopic bacteria-filled lesions within the heart. Microlesions were detected in experimentally infected mice and rhesus macaques, as well as in heart sections from humans who succumbed to invasive pneumococcal disease (IPD). Cardiac microlesion formation required interaction of the bacterial adhesin CbpA with host Laminin receptor and bacterial cell wall with Platelet-activating factor receptor. Microlesion formation also required the pore-forming toxin pneumolysin. When infected mice were rescued with antibiotics, we observed robust signs of collagen deposition at former lesion sites. Thus, microlesions and the scarring that occurs thereafter may explain why adverse cardiac events occur during and following IPD.

Recent studies suggest that macrolides may have beneficial effects for patients at risk for certain infections. The current authors examined the effect of macrolide therapy on 30- and 90-day mortality for patients with severe sepsis caused by pneumonia.A retrospective cohort study was conducted at two tertiary teaching hospitals. Eligible subjects were admitted with a diagnosis of, had chest radiography consistent with, and had a discharge diagnosis of pneumonia and clinical criteria of severe sepsis. Subjects were considered to be on macrolides if they received at least one dose within 48 h of admission.Severe sepsis was present in 237 (30.1%) subjects, out of whom 104 (43.9%) received macrolides. Mortality was 20.3% at 30 days and 24.5% at 90 days. In the multivariable analysis, the use of macrolide was associated with decreased mortality at 30 days (hazard ratio (HR) 0.3, 95% confidence interval (CI) 0.2–0.7) and at 90 days (HR 0.3, 95% CI 0.2–0.6) in patients with severe sepsis and in patients with macrolide-resistant pathogens (HR 0.1, 95% CI 0.02–0.5).Macrolide use was associated with decreased mortality in patients with severe sepsis due to pneumonia and macrolide-resistant pathogens. Confirmatory studies are needed to determine whether macrolide therapy may be protective for patients with sepsis.

Pneumonia and influenza together are the eighth leading cause of death and the leading causes of infectious death in the United States.¹ Professional societies including the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) have published clinical practice guidelines for community-acquired pneumonia,² which recommend the use of macrolides as part of combination antimicrobial therapy for patients hospitalized with community-acquired pneumonia. Although there is observational evidence that the empirical use of macrolides is associated with improved survival after pneumonia,^3-6 there is little randomized clinical trial evidence.⁷ However, there is some evidence that azithromycin is associated with QT prolongation and cardiac arrhythmias.^8,9