Value of the SYNTAX score in patients treated by primary percutaneous coronary intervention for acute ST-elevation myocardial infarction: The MI SYNTAXscore study

Aims: The aims of this study were to evaluate the SYNTAX score (SXscore) calculated at 2 stages during a primary percutaneous intervention (PPCI), that is, SXscore I (diagnostic) and SXscore II (postwiring), and assess its additional value to standard clinical risk scores in acute myocardial infarction. Methods and Results: SXscores I and II were applied to 736 consecutive acute ST-elevation myocardial infarction patients referred for PPCI between November 2006 and February 2008. SXscore changed significantly before (I: 16, interquartile range 9.5-23) and after wiring (II: 11, interquartile range 6-19), P < .001. Kaplan-Meier methods were used to compare the primary end point major adverse coronary events (MACE; composite of repeat MI, target vessel revascularization [TVR], and mortality) and secondary end point mortality at 1.5 years in tertiles of SXscore I and SXscore II. Major adverse coronary event was highest in the higher SXscore I tertile (11% vs 15% vs 23%, log-rank <0.01), driven primarily by increased rate of mortality (9% vs 11% vs 17%, log-rank 0.02). Major adverse coronary event was also highest in SXscore II tertile, by a combination of increased mortality and also TVR (TVR rate 2% vs 3% vs 9%, log-rank <0.01). Predictive Cox regression models for mortality and MACE were significantly and similarly improved by the addition of either SXscore I or SXscore II (hazard ratio 1.63, 95% CI 1.18-2.26, P < .01 for MACE) with respective c indices of 0.61 and 0.63 for MACE and 0.60 and 0.61 for mortality. Conclusions: SXscore during PPCI is a useful tool that provides additional risk stratification to known risk factors of long-term mortality and MACE in patients with ST-elevation myocardial infarction.