Prognostic Value of SYNTAX Scores for Predicting Major Cardiac Adverse Events in Patients with Acute Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention

Background: SYNTAX scores (SS) and clinical SYNTAX scores (CSS) together are widely used in clinical practice as predictors for major adverse cardiac events (MACEs) after an elective primary percutaneous intervention (PCI).

Objectives: We sought to investigate prognostic values of the combination of SS and CSS in predicting MACEs in a cohort of patients with acute myocardial infarction treated by primary PCI with a 12-month follow-up.

Methods: This prospective, longitudinal study included patients from two referral hospitals who had an acute myocardial infarction and underwent primary PCI. SS and CSS were calculated by researchers blinded to patient details using web-based software and clinical factors. SS and CSS were classified into three categories: low/SS1: < 11.75, moderate/SS2: 11.75 – 23.25, or high/SS3 > 23.25, and low/CSS1: < 22.95, moderate/CSS2: 22.95 – 35.95, or high/CSS3: > 35.95. We followed the patients 12 months after the procedure and recorded clinical examination results and MACEs. Data analysis included the chi-squared test (c2), student's t-test, and Cox regression analysis. Cumulative survival rates were estimated through Kaplan–Meier curve analysis.

Results: Among 296 subjects, those with a MACE predominated in the SS3 (16.8%) and CSS3 (14.0%) categories. SS had a significant relationship with all-cause mortality (P = 0.015), re-infarction (P = 0.019), cardiovascular death (P = 0.03), and MACE (P = 0.04). CSS had a significant relationship with all-cause mortality (P < 0.001), re-infarction (P = 0.02), cardiovascular death (P = 0.016), and MACE (P = 0.045). The risk of death by 12-month follow-up of the SS3 patient group was 2.99 times higher than that of the SS1 group (HR = 2.99; 95% CI: 1.11 – 7.84; P = 0.029). The CSS3 patient group had a 4.23 times higher risk of death than the CSS1 group (HR = 4.23; 95% CI: 1.94 – 9.36; P < 0.001). According to Kaplan-Meier curve analysis, the difference in survival rates of the three patient groups categorized by SS or CSS was significant. The SS1 group had the highest survival rate of 91.8%, followed by the SS2 (85.0%) and SS3 (77.9%) groups. Regarding CSS, the CSS1 group had the highest survival rate of 93.0%, followed by the CSS2 (85.1%) and CSS3 (73.8%) groups.

Conclusions: The classification of SS (low SS1, moderate SS2, high SS3) and CCS (low CSS1, moderate CSS2, high CSS3) has important roles in the risk assessment of patients with ACS treated by primary PCI.