Coronary artery disease (CAD) is the leading cause of illness and death globally. Acute myocardial infarction (AMI), its most severe manifestation, results from plaque rupture and thrombus formation within the coronary arteries. Although conventional risk factors such as hypertension, diabetes, dyslipidemia, and smoking contribute significantly to the burden of coronary artery disease (CAD), there is growing evidence that chronic inflammatory conditions may also play a role in its development [1–3]. Periodontal disease, a prevalent chronic inflammatory disorder affecting the supporting tissues of the teeth, has emerged as a potential non-traditional risk factor for cardiovascular disease. In addition to causing local tissue damage, periodontitis promotes systemic inflammation through bacteremia, the release of endotoxins, and increased levels of pro-inflammatory cytokines, which may accelerate atherosclerosis and thrombosis. [4–7]. Several epidemiological studies and meta-analyses have reported associations between periodontal disease and myocardial infarction, although questions regarding causality remain [8–11]. Standardised indices such as Russell's Periodontal Index (RPI) and the Total Dental Index (TDI) allow quantification of periodontal burden and facilitate comparison across populations [12,13]. However, limited data are available comparing these indices specifically between AMI patients and otherwise healthy controls without systemic risk factors. The present study was designed to compare periodontal status, assessed using RPI and TDI, between AMI patients and matched healthy controls. By examining these indices, we aimed to determine whether AMI patients exhibit increased periodontal involvement, thus enhancing the understanding of oral health in cardiovascular risk assessment.

Study Design and Setting This cross-sectional study was conducted at the Government Medical College and Hospital and the Government Dental College, Aurangabad, India. Study Population A total of 60 participants were enrolled and divided equally into two groups: Group A (AMI patients): Thirty consecutive patients under 60 years old were admitted to the Intensive Coronary Care Unit with a confirmed diagnosis of acute transmural myocardial infarction (AMI). Diagnosis was established using clinical features, electrocardiographic changes based on Goldman's criteria, and elevated serum glutamic-oxaloacetic transaminase (SGOT) levels. Group B (Healthy controls): Thirty age- and sex-matched community volunteers. Individuals in this group were excluded if they had evidence of periodontal disease, systemic illness, or any recognized risk factor for coronary artery disease (CAD). Inclusion and Exclusion Criteria Inclusion criteria (AMI group): Age <60 years, confirmed diagnosis of AMI, and provision of informed consent. Inclusion criteria (Control group): Age- and sex-matched healthy adults without systemic illness, periodontal disease, or CAD risk factors. Exclusion criteria (both groups): History of systemic inflammatory conditions, recent antibiotic use, or immunosuppressive therapy. Data Collection and Periodontal Assessment All participants underwent a structured history-taking, systemic examination, and laboratory investigations. A calibrated periodontist assessed the periodontal status using the following indices: Russell's Periodontal Index (RPI), which is a standardized index for evaluating the severity of periodontal disease [14-15]. Score 0 Negative. There is neither overt inflammation in the investing tissues nor loss of function due to destruction of supporting tissue. 1 Mild gingivitis. There is an overt area of inflammation in the free gingivae which does not circumscribe the tooth. 2 Gingivitis. Inflammation completely circumscribes the tooth, but there is no apparent break in the epithelial attachment. 4 Used when radiographs are available. There is early notch like resorption of the alveolar crest. 6 Gingivitis with pocket formation. The epithelial attachment has been broken and there is a pocket (not merely a deepened gingival crevice due to swelling in the free gingivae). There is no interference with normal masticatory function, the tooth is firm in its socket, and has not drifted. 8 Advanced destructions with loss of masticatory function. The tooth may be loose; may have drifted; may sound dull on percussion with a metallic instrument; may be depressible in its socket. Total Dental Index (TDI): A cumulative score reflecting overall dental and periodontal pathology. Each person was given scores according to the severity of the dental disease (table 1). The arithmetic sum of the scores formed the “Total Dental Index”[16]. Table 1: Scheme for calculating the Total Dental Index (TDI) used to evaluate dental health Type of Disease Condition Score Caries No carious lesions 0 1–3 carious lesions 1 4–7 carious lesions OR no teeth in maxilla/mandibula 2 ≥8 carious lesions OR no teeth 3 Periodontitis None 0 Gingival pocket 4–5 mm deep 1 Gingival pocket ≥6 mm deep 2 Macroscopic pus in gingival pocket 3 Periapical lesions None 0 1 lesion OR vertical bone pocket, or both 1 2 lesions 2 ≥3 lesions 3 Pericoronitis Absent 0 Present 1 Statistical Analysis Descriptive statistics, including the mean and standard deviation, were computed for continuous variables. Intergroup comparisons of RPI and TDI were performed using independent-sample t-tests. A p-value <0.05 was considered statistically significant. Statistical analyses were conducted using standard methods.

A total of 60 participants were included: 30 patients with acute myocardial infarction (AMI) in Group A and 30 healthy controls in Group B. The average age was 41.80 ± 6.24 years for the AMI group and 42.43 ± 5.15 years for the control group, showing no statistically significant difference (p > 0.05). Both groups demonstrated a male-to-female ratio of 9:1. Periodontal Indices Russell's Periodontal Index (RPI): The mean RPI score was significantly higher in AMI patients (6.65 ± 1.40) compared with controls (0.105 ± 0.305) (t = 25.19, p < 0.001). Total Dental Index (TDI): The mean TDI score was 5.87 ± 1.61 in the AMI group and 0 in the control group, a difference that was also highly significant (p < 0.001). Table 2: Comparison of Periodontal Indices Between AMI Patients and Healthy Controls Parameter AMI (n=30) Control (n=30) p-value RPI (mean ± SD) 6.65 ± 1.40 0.105 ± 0.305 <0.001 TDI (mean ± SD) 5.87 ± 1.61 0 <0.001

The present study demonstrated that patients with AMI exhibited significantly higher periodontal burden, as reflected by both RPI and TDI scores, compared to healthy controls. These findings provide additional evidence for a possible association between periodontal disease and acute coronary events. Our findings align with previous epidemiological studies and meta-analyses indicating a higher prevalence and severity of periodontitis in individuals with CAD[1,4,8–10]. The large differences observed in our study are partly attributable to the strict exclusion of any periodontal disease in the control group, which highlights the magnitude of periodontal involvement among AMI patients. The biological basis for this association is well established. Periodontitis generates a chronic systemic inflammatory response through continuous release of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and acute-phase proteins such as C-reactive protein. These mediators can accelerate atherosclerosis and destabilize plaques. Moreover, periodontal pathogens and their byproducts have been detected in atherosclerotic lesions, suggesting direct microbial invasion as an additional mechanism [17-28]. The significant periodontal issues among patients with acute myocardial infarction (AMI) indicate that oral health assessments should be included in cardiovascular risk screening. Periodontal treatment may be a modifiable factor to reduce systemic inflammation and potentially improve cardiovascular outcomes.[6,18,24,26]. Our findings align with extensive observational data, including the PAROKRANK study [4-5], which showed that individuals with periodontitis have an increased risk of myocardial infarction, even after adjusting for conventional risk factors. On the other hand, Mendelian randomization studies have raised questions about causality, suggesting that the observed relationship may be partly explained by confounding factors that are shared between the two conditions. Strengths The study used standardized indices like Russell’s Periodontal Index (RPI) and the Total Dental Index (TDI). Furthermore, including age- and sex-matched groups reduced the risk of demographic confounding. Limitations The cross-sectional design of the study prevents any conclusions about cause and effect. Additionally, the small sample size limits how widely the findings can be applied. Furthermore, the design of the control group, which excluded individuals with periodontal disease or cardiovascular risk factors, may have exaggerated the differences observed.

Patients who experienced acute myocardial infarction displayed significantly higher scores on Russell's Periodontal Index and Total Dental Index when compared to healthy controls. This indicates a considerable burden of periodontal disease among these patients. These findings underscore the potential role of periodontal disease as a modifiable non-traditional risk factor for cardiovascular disease. Including periodontal assessments in cardiovascular risk evaluations may help in the early identification of individuals at high risk and support integrated prevention strategies.

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