Abstract 16464: QRS-T Angle: A Challenge to Improve Long-Term Risk Stratification of Patients With Post-Infarction Left Ventricular Dysfunction
Introduction: A wide angle between the axes of the QRS and T wave (known as the QRS-T angle) has been recently reported as a risk marker for cardiovascular death. The aim of this study was to evaluate the ability of this angle in the risk stratification of patients with severe ventricular dysfunction after acute myocardial infarction (AMI).
Methodology: We evaluated 467 consecutive patients (70.7 ± 12.5 years) who had been discharged with diagnosis of AMI (47.3% ST segment elevation) and left ventricular ejection fraction (LVEF) ≤ 40% (2004-2010), excluding patients with pacemaker. We analyzed the ECG at admission, calculating the QRS-T angle with the automatic values provided by the electrocardiograph. Patients were followed with a median of 3.9 years (IQR: 2.1-5.9).
Results: The median QRS-T angle was 99.0° (IQR: 42.0 to 151.0). 217 patient died during the follow-up (52.5% cardiac-death). Patients who died had a higher QRS-T angle (116.6 ± 52.8 vs 77.9 ± 55.1, p<0.001), being a predictor of follow-up death (HR 1.008, 95% CI: 1.005-1.010, p<0.001), independent of age, diabetes, LVEF, peak of troponine, creatinine, implantable cardioverter desfibrillator (ICD), malignant disease, GRACE risk score and treatments (antiplatelet therapy, B-blockers, ACE inhibitors/ARB, antialdosteronic drugs, and statins). This association was maintained even by subgroups (left and/or right bundle branch block, AMI localization). The value of QRS-T angle with higher sensitivity and specificity for follow-up death was 90° (sens: 73.3%, spec: 63.2%). A QRS-T angle >90° was an independent predictor of all-cause death (figure), and also of cardiac death and appropiate ICD therapy.
Conclusion: The QRS-T angle is an automatic parameter, easy to calculate, with high accuracy to stratify the long-term risk of all cause death and cardiac death of patients with severe ventricular dysfunction after AMI. This finding could be useful to select patients for an ICD implantation as primary prevention.
- © 2013 by American Heart Association, Inc.