Background: Risk stratification of patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) is an important clinical method, but long-term studies on patients subjected to all-treatment strategies are lacking. Therefore, the aim was to compare several established risk scores in the all-treatment NSTE-ACS cohort during long-term follow-up.
Methods: Consecutive patients (n = 276) with NSTE-ACS undergoing coronary angiography were recruited between September 2012 and May 2015. Six risk scores for all patients were calculated, namely GRACE 2.0, ACEF, SYNTAX, Clinical SYNTAX, SYNTAX II PCI and SYNTAX II CABG. The primary end-point was Major Adverse Cardiovascular Events (MACE) which was a composite of cardiac death, nonfatal myocardial infarction, ischemic stroke or urgent coronary revascularization.
Results: During a median follow-up of 33 months, 64 MACE outcomes were recorded (23.2%). There was no difference between risk score categories, except in the highest risk group of ACEF and SYNTAX II PCI scores which exhibited significantly more MACE (51.6%, N = 33 and 45.3%, N = 29, P = 0.024, respectively). In the multivariate Cox regression analysis of individual variables, only age and atrial fibrillation were significant predictors for MACE (HR 1.03, 95% CI 1.00-1.05, P = 0.023 and HR 2.02, 95% CI 1.04-3.89, P = 0.037, respectively). Furthermore, multivariate analysis of the risk scores showed significant prediction of MACE only with ACEF score (HR 2.16, 95% CI 1.36-3.44, P = 0.001). The overall performance of GRACE, SYNTAX, Clinical SYNTAX and SYNTAX II CABG was poor with AUC values of 0.596, 0.507, 0.530 and 0.582, respectively, while ACEF and SYNTAX II PCI showed the best absolute AUC values for MACE (0.630 and 0.626, respectively).
Conclusions: ACEF risk score showed better discrimination than other risk scores in NSTE-ACS patients undergoing all-treatment strategies over long-term follow-up and it could represent a fast and user-friendly tool to stratify NSTE-ACS patients.
Keywords: All-treatment strategies; Non-ST-elevation acute coronary syndrome; Risk scores.