Development of Diagnostic Score for Acute Pericarditis in Patients Admitted for Chest Pain

Background Despite the presence of clinical, laboratory and electrocardiographic characteristics suggestive of acute pericarditis, there is no multivariate diagnostic score developed for this condition. Objective To develop a clinical score for diagnosis of pericarditis as the cause of acute chest pain, using data from admission. Methods In a diagnostic case-control study, we compared consecutive 45 patients of the Chest Pain Registry diagnosed of pericarditis (confirmed by magnetic resonance imaging or the presence of pleural effusion in echocardiography) versus 90 patients with an alternative confirmed diagnosis, randomly selected from our registry. Six clinical characteristics, 16 chest pain characteristics and 4 additional tests were candidates as predictors. Logistic regression was used to derivate a model composed by independent predictors of pericarditis. Results Among 17 variables associated with pericarditis, 5 remained independent predictors: age; pain aggravation with thorax movement; positive troponin; diffuse ST-segment elevation and C-reactive protein. Each independent predictor was attributed points proportional to its regression coefficient. The final score presented discriminatory capacity represented by C-statistic of 0.97 (95% CI = 0.93 – 1.0). The best cutoff point was defined as > 6 points, with sensitivity of 96% (95% CI = 85 – 100), specificity of 87% (95% CI = 78 – 93), positive likelihood ratio of 7.2 (95% CI = 4.2 – 12) and negative likelihood ratio of 0.05 (95% CI = 0.01 – 0.2). Conclusion The proposed multivariate score seems to be accurate for the diagnosis of pericarditis and require further validation in an independent sample.