Usefulness of pain presentation characteristics for predicting outcome in patients presenting to the hospital with chest pain of uncertain origin

BACKGROUND: Decision making in chest pain of uncertain origin is challenging. OBJECTIVES: To evaluate the predictive value of simple characteristics of pain presentation in patients coming to the emergency department with chest pain and without electrocardiogram ischaemia or raised troponin. METHODS: 789 patients were studied. The following categorical pain characteristics were collected: effort related pain, pressing character, radiation, associated symptoms, and ≥ 2 episodes in 24 h. Additionally, a predefined semi-quantitative pain score including seven items (Geleijnse score) was completed. Risk factors and co-morbidities were also recorded. The primary and secondary endpoints were cardiac events at 30 days and at 1 year. RESULTS: After adjusting for risk factors and co-morbidites, the pain characteristics associated with the primary and secondary endpoints were effort related pain (HR=2.1, 95% CI 1.5 to 3.0, p=0.0001; HR=1.8, 95% CI 1.3 to 2.5, p=0.0003) and ≥ 2 episodes in 24 h (HR=2.4, 95% CI 1.7 to 3.5, p=0.0001; HR=2.3, 95% CI 1.7 to 3.2, p=0.0001). Both variables retained their predictive value in women, diabetics and elderly (>70 years) patients. The discriminatory capacity of the predictive models including these two pain characteristics for the primary and secondary endpoints (C-statistic 0.76 and 0.76) was better than using the complex semi-quantitative pain score (C-statistic 0.69 and 0.71). CONCLUSION: In patients presenting to the emergency department with chest pain and without electrocardiogram ischaemia or raised troponin, effort related pain and ≥ 2 episodes in 24 h are the main characteristics to be considered for decision making.