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

Background 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. Methods 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. Findings 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). Conclusions 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.