Risk Stratification in the Setting of Non-ST Elevation Acute Coronary Syndromes 1999-2007

Abstract

It is unclear if clinician risk stratification has changed with time. The aim of this study was to assess the temporal change in the concordance between patient presenting risk and the intensity of evidence-based therapies received for non-ST-segment elevation acute coronary syndromes over a 9-year period. Data from 3,562 patients with non-ST-segment elevation acute coronary syndromes enrolled in the Australian and New Zealand population of the Global Registry of Acute Coronary Events (GRACE) from 1999 to 2007 were analyzed. Patients were stratified to risk groups on the basis of the GRACE risk score for in-hospital mortality. Main outcome measures included in-hospital use of widely accepted evidence-based medications, investigations, and procedures. Invasive management was consistently higher in low-risk patients than in intermediate- or high-risk patients (coronary angiography 66.7% vs 63.5% vs 35.3%, p <0.001; percutaneous coronary intervention 31.1% vs 22.0% vs 12.9%, p <0.001). Absolute rates of angiography and percutaneous coronary intervention in the high-risk group remained 24% and 15% lower compared to the low-risk group in the most recent time period (2005 to 2007). In-hospital use of thienopyridine, low-molecular weight heparin, and glycoprotein IIb/IIIa inhibitors showed a similar inverse relation with risk. Prescription of aspirin, beta blockers, statins, and angiotensin receptor blockers was inversely related to risk before 2004, although this inverse relation was no longer present in the most recent time period (2005 to 2007). Only in-hospital use of unfractionated heparin showed use concordant with patient risk status. In conclusion, despite an overall increase in the uptake of evidence-based therapies, most investigations and treatments are not targeted on the basis of patient risk. Clinician risk stratification remains suboptimal compared to objective measures of patient risk.