Usefulness of the SYNTAX score to predict "no reflow" in patients treated with primary percutaneous coronary intervention for ST-segment elevation myocardial infarction.

The no-reflow phenomenon has been shown to have a significant effect on clinical outcomes in patients with acute ST-segment elevation myocardial infarction. Angiographic features incorporated in the SYNTAX Score (SXScore) obtained on diagnostic angiography during primary percutaneous coronary intervention (PPCI) may be associated with the occurrence of myocardial no-reflow. The aim of this study was to assess the ability of the SXScore to predict no-reflow during PPCI. The SXScore was applied to 669 consecutive patients presenting with acute ST-segment elevation myocardial infarction from November 2006 to February 2008. Angiographic analysis of the PPCI procedure was used to determine no-reflow. The median SXScore was 16 (range 9.5 to 23). No-reflow occurred in 77 patients (12%). On univariate logistic regression analysis, the SXScore showed a strong association (for each 10-unit increase in SXScore, odds ratio 1.42, 95% confidence interval 1.16 to 1.76, p <0.001). On multivariate logistic regression in a model including clinical variables, SXScore was an independent predictor of no-reflow (odds ratio 1.29, 95% confidence interval 1.02 to 1.63, p <0.001). Classification and regression tree analysis identified SXScore >21 as the best cutoff, with patients having double the risk for no-reflow compared to those with SXScore ≤21 (events 9% vs 18%, p = 0.006). In conclusion, the SXScore obtained in the diagnostic phase of PPCI for acute ST-segment elevation myocardial infarction can identify patients at risk for developing no-reflow.