Association between SYNTAX II score and electrocardiographic evidence of no-reflow in patients with ST-segment elevation myocardial infraction

Objectives: This study was performed to examine the association between the SYNTAX II score (SS-11) and no-reflow observed on electrocardiography and examine their use in the evaluation of risk of an in-hospital major adverse cardiovascular event (MACE) in patients with ST-segment elevation myocardial infarction (STEMI). Methods: A total of 126 consecutive STEMI patients who underwent primary percutaneous coronary intervention (pPCI) were recruited. The SS-II was derived using angiographic and basic patient clinical features. The difference in the sum of ST-segment elevations measured between before the pPCI and the assessment determined approximately 60 minutes after the pPCI was interpreted as the sum of ST-segment resolution (Sigma STR). MACE is a composite endpoint frequently used in cardiovascular research and usually includes endpoints reflecting safety and effectiveness. Sigma STR <50% was defined as incomplete Sigma STR (no-reflow group; n=44), while Sigma STR >= 50% was defined as complete Sigma STR (normal-flow group, n=82). Results: The SS-II was significantly higher in the no-reflow group (p<0.001). SS-II and no-reflow findings were associated with MACE. Logistic regression analysis demonstrated significant predictive values of SS-II (Odds ratio [OR]: 1.169; 95% confidence interval [CI]: 1.084-1.260; p<0.001) and Sigma STR (OR: 0.764; 95% CI: 0.632-0.924; p=0.006) for in-hospital MACE. Conclusion: SS-II was significantly associated with no-reflow as assessed by electrocardiography. In patients with STEMI, SS-II and no-reflow (incomplete Sigma STR) may be important predictive factors for in-hospital MACE.