Potential utility of the SYNTAX score 2 in patients undergoing left main angioplasty

Background: The revascularization strategy of the left main disease is determinant for clinical outcomes.Objective: We sought to 1) validate and compare the performance of the SYNTAX Score 1 and 2 for predicting major cardiovascular events at 4 years in patients who underwent unprotected left main angioplasty and 2) evaluate the long-term outcome according to the SYNTAX score 2--recommended revascularization strategy. Methods: We retrospectively studied 132 patients from a single--centre registry who underwent unprotected left main angioplasty between March 1999 and December 2010. Discrimination and calibration of both models were assessed by ROC curve analysis, calibration curves and the Hosmer--Lemeshow test. Results: Total event rate was 26.5% at 4 years. The AUC for the SYNTAX Score 1 and SYNTAX Score 2 for percutaneous coronary intervention, was 0.61 (95% CI:0.49--0.73) and 0.67 (95% CI:0.57--0.78), respectively. Despite a good overall adjustment for both models, the SYNTAX Score 2 tended to underpredict risk. In the 47 patients (36%) who should have undergone surgery according to the SYNTAX Score 2, event rate was numerically higher (30% vs. 25%; p = 0.54), and for those with a higher difference between the two SYNTAX Score 2 scores (Percutaneous coronary intervention vs. Coronary artery by--pass graft risk estimation greater than 5.7%), event rate was almost double (40% vs. 22%; p = 0.2).Conclusion: The SYNTAX Score 2 may allow a better and individualized risk stratification of patients who need revascularization of an unprotected left main coronary artery. Prospective studies are needed for further validation.