Risk factors for pneumonia in patients with cardiovascular diseases

A case-control-study was performed to identify patients at particularly high risk of community-acquired pneumonia and nosocomial pneumonia with a special focus on cardiovascular diseases as potential risk factors. Thirty-six consecutive hospitalized patients with cardiovascular diseases and pneumonia were matched with 36 controls also suffering from cardiovascular diseases but without pneumonia. From all cardiovascular diseases only heart failure proved to be an independent risk factor for pneumonia (OR 5.69, 95 % KI 1.69 - 19.04, p = 0.0048). Both chronic (p = 0.009) and acute heart failure (p = 0.028) were associated with an increased risk of pneumonia. The risk of pneumonia was closely related to the degree of ventricular function impairment. Coronary heart disease, valvular disease, arrythmia, myocarditis, endocarditis and cardiomyopathy did not increase the risk for pneumonia unless accompanied by heart failure. Pulmonary (OR 9.24, 95 % KI 1.48 - 57.74, p = 0.00174) and renal diseases (OR 7.49, 95 % KI 1.38 - 40.76, p = 0.0197) were validated as additional independent risk factors. A history of smoking was also associated with an increased risk of pneumonia (p = 0,023). This study supports the hypothesis that heart failure resulting from cardiovascular disease and not cardiovascular disease itself mounts the risk for pneumonia.