Propensity score matching analysis of the impact of Syntax score and Syntax score II on new onset atrial fibrillation development in patients with ST segment elevation myocardial infarction.

Background: New-onset atrial fibrillation (NOAF) is a common complication in the setting of ST segment elevation myocardial infarction (STEMI), and worsened short/long-term prognosis. Several clinical parameters have already been associated with NOAF development. However, relationship between NOAF and coronary artery disease (CAD) severity in STEMI patients is unclear. This study evaluates the relationship between NOAF and CAD severity using Syntax score (SS) and Syntax score II (SSII) in STEMI patients who were treated with primary percutaneous coronary intervention (pPCI).

Method: We enrolled 1,565 consecutive STEMI patients who were treated with pPCI. Patients with NOAF were compared to patients without NOAF in the entire study population and in a matched population defined by propensity score matching.

Results: Patients with NOAF had significantly higher SS and SSII than those without, both in the matched population (18.6 ± 4 vs 16.75 ± 3.6; p < .001 and 42 ± 13.4 vs 35.1 ± 13.1; p < .001, respectively), and in all study population (18.6 ± 4 vs 16.5 ± 4.6; p < .001 and 42 ± 13.3 vs 31.5 ± 11.9; p < .001 respectively). SSII, compared to its components, was the only independent predictor of NOAF (OR: 1,041 95% CI: 1.015-1.068; p = .002). In the long-term follow-up, all-cause long-term mortality was significantly higher in patients with NOAF than those without NOAF (23.3% vs. 11%; p = .032).

Conclusion: This is the first study to comprehensively examine the relationship between NOAF development and CAD severity using SS and SSII. We demonstrated that, in STEMI patients, high SSII was significantly related to NOAF and was an independent predictor of NOAF. Furthermore, patients with NOAF were associated with poor prognosis.