BACKGROUND: An association between periodontitis and cardiovascular diseases has been suggested.

AIMS: To study whether a combination of clinical variables in a functional risk diagram enhanced the ability to differentiate between subjects with or without an immediate history of acute myocardial infarction (AMI).

MATERIAL AND METHODS: A functional periodontal pentagon risk diagram (PPRD) with five periodontal risk vectors was created. The surface of individual PPRDs was calculated using data from 88 subjects with recent AMI and 80 matched control subjects with no history of AMI.

RESULTS: Age, gender, number of remaining teeth (mean value: 21.1 versus 21.6 teeth), smoking status, and pocket probing depth (PPD) distribution did not differ by group. Gingival recession was greater in control subjects (mean difference: 5.7, SD: +/- 1.9, p<0.01, 95% CI: 1.8-9.6). Bone loss > or = 4.0 mm was at all levels studied was significantly greater in subjects with AMI and bone loss > or = 50% (> or = 4 mm) was the best individual predictor of AMI (beta = 2.99, p < 0.000, 95% CI: 7.5-53.4). Only PPRD scores were associated with AMI status when factors not included in the PPRD were studied (beta = 22.1, SE: 5.9, p < 0.0001, 95% CI: 10.3-33.7). The best association between AMI status and study variables was the combination of > or = 4 mm of bone loss > or = 50%, proportion of bleeding on probing (%BOP), %PPDs > or = 6 mm, and tooth loss (Nagelkirke r2 = 0.46).

CONCLUSIONS: The combination of five periodontal parameters in a PPRD added predictive value, suggesting that comprehensive data should be used in studies of associations between periodontitis and heart diseases. Radiographic evidence of bone loss was the best individual parameter.