Comparison of the TIMI and the GRACE risk scores with the extent of coronary artery disease in patients with non-ST-elevation acute coronary syndrome

Objective: To compare the accuracy of the Global Registry of Acute Coronary Events risk score and the Thrombolysis In Myocardial Infarction risk score in predicting the extent of coronary artery disease in patients with non-ST segment elevation acute coronary syndrome. Methods: The cross-sectional study comprising 406 consecutive patients was conducted at the National Institute of Cardiovascular Diseases, Karachi, from August 2010 to March 2011. For all patients, the GRACE and TIMI RS's relevant scores on the two indices were calculated on admission using specified variables. The patients underwent coronary angiography to determine the extent of the disease. A significant level was defined as >= 70% stenosis in any major epicardial artery or >= 50% stenosis in the left main coronary artery. SPSS 19 was used for statistical analysis. Results: Both the indices showed good predictive value in identifying the extent of the disease. A Thrombolysis In Myocardial Infarction score >4 and Global Registry of Acute Coronary Events score >133 was significantly associated with 3vessel disease and left main disease, while for the former score <= 4 and latter score <= 133 was associated with normal or non-obstructive coronary disease (p<0.01). On comparison of the two risk scores, the discriminatory accuracy of the latter was significantly superior to the former in predicting 2vessel, 3vessel and left main diseases (p<0.05). Conclusion: Although both the indices were helpful in predicting the extent of the disease, the Global Registry showed better performance and was more strongly associated with multi-vessel and left main coronary artery disease.