A new score for risk stratification of patients with acute coronary syndromes undergoing percutaneous coronary intervention: the ACUITY-PCI (Acute Catheterization and Urgent Intervention Triage Strategy-Percutaneous Coronary Intervention) risk score.

OBJECTIVES: This study sought to develop a new score specific for patients with non-ST-segment elevation acute coronary syndromes (NSTEACS) undergoing percutaneous coronary intervention (PCI) (the ACUITY-PCI [Acute Catheterization and Urgent Intervention Triage Strategy-Percutaneous Coronary Intervention] risk score).

BACKGROUND: The TIMI (Thrombolysis In Myocardial Infarction) and GRACE (Global Registry for Acute Coronary Events) risk scores are recommended for risk stratification of patients with NSTEACS. However, these scores were not optimized for patients undergoing an early invasive strategy with PCI.

METHODS: The ACUITY-PCI risk score was created from data for 1,692 patients enrolled in the formal angiographic substudy of the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial by integrating clinical, angiographic, laboratory, and electrocardiographic variables selected by multivariable analysis. The score was subsequently validated in a different population of 846 patients and compared with the GRACE and TIMI risk scores, and the SYNTAX (Synergy Between PCI with Taxus and Cardiac Surgery) and Clinical SYNTAX scores.

RESULTS: Six variables (2 clinical, 1 laboratory/electrocardiographic, and 3 angiographic) were included in the ACUITY-PCI score: insulin-treated diabetes; renal insufficiency; baseline cardiac biomarker elevation or ST-segment deviation; bifurcation lesion; small vessel/diffuse coronary artery disease; and the extent of coronary artery disease. Event rates increased significantly across tertiles of ACUITY-PCI score. Compared with the other scores, the ACUITY-PCI score had the best discrimination (C-statistic), calibration (Hosmer-Lemeshow statistic), and index of separation. Moreover, the net reclassification improvement varied from 9% to 38% and the integrated discrimination index from 1.9% to 2.7%.

CONCLUSIONS: The ACUITY-PCI risk score is a new tool integrating clinical, angiographic, and laboratory/electrocardiographic variables specifically developed for patients with NSTEACS undergoing PCI. This score displayed better prognostic accuracy in terms of discrimination and calibration than other currently available scores for risk stratification of patients with NSTEACS. (Comparison of Angiomax Versus Heparin in Acute Coronary Syndromes [ACS]; NCT00093158).