Frontal QRS-T (fQRST) angle is an electrocardiogram (ECG)-derived marker, indicating the concordance between ventricle depolarization and repolarization. A wide fQRST angle has been found to be associated with cardiovascular mortality. The authors aim to investigate the relationship between fQRST angle and the extent and severity of coronary artery disease in patients with ST-segment elevation myocardial infarction (STEMI).
Three hundred and forty patients presenting with STEMI were enrolled in the study. SYNTAX, SYNTAX II, and residual SYNTAX scores were calculated. The patients were categorized into two groups in terms of SYNTAX score: Low (SYNTAX score < 23) and intermediate-high score (SYNTAX score ≥ 23). SYNTAX II score was also classified as low and intermediate-high score. Residual SYNTAX score > 8 was evaluated as high score.
104 patients had SYNTAX score ≥ 23. Age (p = 0.001), peripheral arterial disease (p = 0.006), infarct-related artery (p = 0.001), and fQRST angle (p = 0.015) were significantly higher in intermediate-high SYNTAX group, while the values for left ventricle ejection fraction (p < 0.001) and hemoglobin level (p = 0.036) were found to be lower in this group. Pre- and post-procedural fQRST angle was higher in patients with SYNTAX II score > 21.9 and residual SYNTAX >8, respectively. The cut-off levels for fQRST angle established according to ROC analysis in terms of SYNTAX, SYNTAX II, and residual SYNTAX were found to be 91°, 76.5°, and 79.5° respectively. In multivariate analysis, fQRST angle, infarct-related artery, and age were independent predictors of intermediate-high SYNTAX score.
fQRST angle is an independent predictor of coronary atherosclerotic burden in STEMI patients.