[Development and prospective validation of an ischemic risk score for acute chest pain patients with normal high-sensitivity troponin I levels and without obvious ST-segment deviation].

Objective

To develop and prospectively validate a risk score for acute chest pain patients with normal high-sensitivity troponin I (hs-TnI) levels and without obvious ST-segment deviation in China.

Methods

Chest pain patients admitted to the emergency department of Beijing Anzhen Hospital from September 2014 to July 2015 were enrolled. Baseline characteristics of patients met inclusion criteria including normal hs-TnI levels and without obvious ST-segment deviation were included. The endpoint (major adverse cardiovascular events) was a composite of acute myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft, and all-cause death within 3 months after initial presentation. Predictors were screened and used to develop the risk score model by logistic regression analysis in a retrospective cohort. Then, the risk score model was evaluated in a prospective validation cohort.

Results

The study population of derivation cohort included 1 735 consecutive chest pain patients. Finally, 1 030 eligible patients were enrolled. Multivariate regression analysis defined five independent predictors: male gender (β=0.88); history of chest pain (β value of moderate and high suspicion of coronary heart artery was 2.70 and 3.51 respectively); electrocardiogram (β=0.84); ≥60 years old (β=0.51) and ≥3 risk factors (β=0.85).The range of weighted score was set as 0-13. The area under a receiver operating characteristic (ROC) curve was 0.75 (95%CI 0.72-0.78) in the final model. Major adverse cardiovascular events rates increased in proportion to score increase (P<0.01). The internal validity used bootstrap technique showed the same predictor factors as the final model, and its area under a ROC curve was 0.75(95%CI 0.72-0.78).MACE rates in the low risk group (score 0-3), intermediate risk group (score 4-7), and high risk group (score 8-13) were 1.3% (1/77) ,19.0% (22/116) ,and 42.2% (122/289) in the prospective validation cohort, respectively (P<0.01).

Conclusion

The developed ischemic risk score is feasible for risk stratification of acute chest pain patients with normal hs-TnI and without obvious ST-segment deviation, this score might be helpful to the decision making of treatment and management strategies for these patients.