OBJECTIVES: A link between periodontal disease (PD) and cardiovascular events has been proposed, but confounding by shared risk factors such as smoking and diabetes remains a concern. We examined the prevalence of PD and its contribution to C-reactive protein (CRP) levels in acute myocardial infarction (AMI) patients and in subjects without AMI and with angiographically nonobstructive coronary disease in the absence of these confounding risk factors. METHODS: Periodontal status and admission CRP levels were evaluated in 87 non-diabetic and non-smoking subjects undergoing cardiac catheterization. The study group comprised of 47 patients with documented AMI, and 40 subjects without AMI and with angiographically nonobstructive coronary disease (ANCD group). RESULTS: Both the prevalence of PD and CRP levels were significantly higher in AMI patients compared with ANCD subjects (38.3% vs. 17.5%, p=0.03 and 44.3 vs. 8.5 mg/L, p<0.001 respectively). PD was associated with higher CRP levels in AMI patients (52.5 vs. 36.1 mg/L, p=0.04) as well as in ANCD subjects, however, in this group this was not significant (12.6 vs. 7.6 mg/L, p=0.5). Multivariable regression analysis confirmed two separate measures of PD as strong and independent contributors to elevated CRP levels in AMI patients (R2 = 0.28, R2 = 0.30, p=0.001). CONCLUSIONS: PD contributes to elevated CRP levels in non-diabetic, non-smoking AMI patients, independently of other confounding factors. These findings imply that periodontitis may emerge as a novel target for reducing future risk in AMI survivors.