A case-control study examining association between infectious agents and acute myocardial infarction

Abstract

Background: Coronary heart disease is multi-factorial in origin and its burden is expected to rise in developing countries, including India. Evidence suggests that the inflammation caused by infection is associated with the development of atherosclerosis and heart disease. An increasing number of clinical and experimental studies point to a contribution of various infectious organisms to the development of atherosclerosis in humans. Acute myocardial infarction (AMI) is associated with atherosclerosis. Objectives: The objective of the following study is to study the association between Helicobacter pylori, Chlamydia pneumoniae and C-reactive protein (CRP) with AMI. Materials and Methods: This group-matched case-control study was carried out in Government Medical College, Nagpur, Maharashtra, India. The study compared the risk of occurrence of AMI (outcome) if subjects were ever-infected with H. pylori or C. pneumoniae; and their CRP positivity (exposure). Incident cases of myocardial infarctions in a tertiary care hospital were included as cases. Results: The study recruited 265 cases and 265 controls and detected an odds ratio (OR) of 2.50 (95% confidence interval [CI]: 1.69-3.70) and an OR of 2.50 (95% CI: 1.71-3.65) for C. pneumoniae and H. pylori, respectively. Raised CRP levels had an OR of 3.85 (95% CI: 2.54-5.87). Conclusion: Although our study indicates the role of infections in the etiology of AMI in study population, the relative public health impact of these agents in the overall prevalence of AMI needs urgent research attention.

Keywords

• Acute myocardial infarction
• Atherosclerosis
• Case-control study
• Infection