Acute myocardial infarction in hospitalized patients with community-acquired pneumonia

Background. An epidemiological link between respiratory infection and acute myocardial infarction (AMI) has been suggested, and recent data indicate that there is an association between AMI and pneumococcal community-acquired pneumonia (CAP) in hospitalized patients. The objective of this study was to investigate the association of AMI with the severity of pneumonia at hospitalization and clinical failure during hospitalization among patients with CAP. Methods. An observational, retrospective study involving consecutive patients hospitalized with CAP was performed at the Veterans Hospital of Louisville, Kentucky. Patients admitted to the intensive care unit were defined as having severe CAP. Clinical failure was defined as the development of respiratory failure or shock. AMI was diagnosed on the basis of abnormal troponin levels and electrocardiogram findings. Propensity-adjusted models that controlled for clinical and nonclinical factors were used to investigate the association between AMI and pneumonia severity index and between AMI and clinical failure. Results. Data for a total of 500 patients were studied. At hospital admission, AMI was present in 13 (15%) of 86 patients with severe CAP. During hospitalization, AMI was present in 13 (20%) of 65 patients who experienced clinical failure. Following risk adjustment, significant associations were discovered between AMI and the pneumonia severity index score (modeled with a restricted cubic spline) (P = .05) and between AMI and clinical failure (P = .04). Conclusions. A combined diagnosis of CAP and AMI is common among hospitalized patients with severe CAP. In cases in which the clinical course of a hospitalized patient with CAP is complicated by clinical failure, AMI should be considered as a possible etiology.