Prognostic indicators of vector electrocardiography in patients with chronic heart failure with reduced left ventricular ejection fraction

Relevance . Computed vector electrocardiography (VECG) is a method of visualization of the total electrical vector of the heart in 3‑dimensional space based on 12 leads and a known computational procedure. VECG may be an additional method to assess the severity and prognosis of patients with chronic heart failure (CHF). Objective . To determine VECG parameters associated with unfavorable prognosis in patients with CHF with reduced ejection fraction (CHFpEF). Materials and methods . VECGs of 100 patients with CHFpEF were analyzed. All patients underwent baseline clinical examination, echocardiography and natriuretic peptide (NT-proBNP) determination. Patients with both ischemic (55 patients, of whom 10 died) and non-ischemic (45 patients, of whom 6 died) etiologies were included. During follow-up for 24 months, fatal outcomes were recorded. The correlation of ECG and NT-proBNP parameters with patients’ prognosis was evaluated. Results . A total of 16 patients died in the study. According to VECG data the surviving patients had lower spatial QRS-T angle in comparison with the deceased ones (p=0,025). There was a trend towards lower planarity index in the group of deceased patients (p=0.09). ROC-analysis was carried out, according to the results of which with sensitivity 76,5% and specificity 62,7% the cut-off value of 156º of QRS-T spatial angle was obtained, exceeding which the probability of lethal outcome will increase (p=0,002). There was a correlation between lethal outcome in patients with a QRS-T angle value greater than 156º and NT-proBNP level (p=0.017). The threshold value of unfavorable prognosis for NT-proBNP was 927.1 pg/ml. Conclusion. The VECG method is available and promising in the diagnosis and monitoring of patients with CHFpEF. The most informative parameters of ECG for detection of suspicion of CHFpEF are spatial QRS-T angle and planarity index. The results obtained in this study allow us to speak about the prognostic value of the QRS-T angle for patients with CHFpEF.