Abstract
Background: Several studies have shown that low lung function (even within normal limits) as well as respiratory symptoms are associated with increased cardiovascular mortality. In a case referent study we have compared sputum from patients hospitalised for acute myocardial infarction (AMI) with sputum from a random sample in the general population. The objective was to investigate the association between inflammatory cells in the airways and AMI.
Method: The cases (N=58, mean age 58 years) had a confirmed diagnosis of AMI and performed induced sputum within 96 hours after the onset of chest pain. The references (N=120)were selected by random sampling from the hospital's catchment area. Subjects aged 40–74 years (mean age 55 years) were invited to participate.
Results: Only six patients (10%) were females and 27 patients (47%) were current smokers. The corresponding prevalences in the reference group was 59 (49%) and 27 (23%), respectively. The total number (mean,SD) of sputum cells was 3.9×106/mL (4.2) and macrophage count was 1.10×106/mL (1.2) among cases, and 3.1×106/mL (2.8) (p=0.12) and 0.72×106/mL (0.69) (p=0.011) among references. The difference in total macrophage count between the cases and the references increased with declining cholesterol (p=0.028). There was also a negative association with increasing age, systolic blood pressure, and current smoking, although not significant.
Conclusion: AMI is associated with a high macrophage count in induced sputum from patients with a low cardiovascular risk profile, suggesting multifocal inflammatory activity.
- © 2011 ERS