The relationship between serum rheumatoid factor level and SYNTAX score I in patients with acute myocardial infarction

OBJECTIVE
Rheumatoid factor (RF) has been associated with an increased likelihood of developing coronary artery disease and cardiovascular mortality. This study aimed to evaluate the relationship between serum RF levels and SYNTAX score I (SSI) in patients with acute myocardial infarction.

METHODS
This study included 418 consecutive patients who were diagnosed with acute myocardial infarction and underwent coronary angiography. The baseline serum RF levels of all patients were measured. The study population was divided into 2 groups, namely, ST-segment elevation myocardial infarction (STEMI) group (218 patients) and non-ST-segment elevation myocardial infarction (NSTEMI) group (200 patients). Each group was further divided into 2 subgroups, namely, SSI ≤22 group and SSI >22 group.

RESULTS
In the STEMI group, RF levels were significantly higher in the SSI >22 group than that in the SSI ≤22 group (13.0 IU/mL [7.0-51.0 IU/mL] versus 11.0 IU/mL [4.0-37.0 IU/mL], respectively, p=0.002). In the NSTEMI group, RF levels were significantly higher in the SSI >22 group than that in the SSI ≤22 group (15.5 IU/mL [8.0-69.5 IU/mL] versus 13.0 IU/mL [4.0-36.0 IU/mL, respectively], p<0.001). Forward conditional logistic regression analysis demonstrated that neutrophil-to-lymphocyte ratio, total cholesterol level, positive RF, and left ventricular ejection fraction were independently associated with intermediate and high SSI in patients with STEMI. Furthermore, cardiac troponin T levels and positive RF were independently associated with intermediate and high SSI in patients with NSTEMI.

CONCLUSION
Serum RF concentrations are independently associated with SSI in patients with acute myocardial infarction.