Prognostic value of early changes in the frontal QRS-T angle in patients with heart failure and left bundle branch block undergoing cardiac resynchronization therapy.
BACKGROUND: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in selected patients with heart failure (HF). The frontal QRS-T angle (FQTA), reflecting ventricular depolarization-repolarization heterogeneity, has been associated with major adverse cardiovascular events (MACE). We aimed to assess the prognostic value of changes in the FQTA after CRT in predicting long-term MACE. METHODS: A total of 223 consecutive HF patients with left bundle branch block who underwent CRT between 2018 and 2022 were retrospectively analyzed. The FQTA was measured before and after CRT, and the change (ΔFQTA) was calculated. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff value for predicting the primary outcome, MACE. Patients were subsequently stratified according to this cutoff value. Independent predictors were identified using multivariable Cox proportional hazards regression analysis. RESULTS: ROC analysis identified 22.5° as the optimal cutoff value for predicting MACE (AUC: 0.711; 95% CI: 0.642-0.781; p < 0.001). During a mean follow-up of 34.6 ± 17.6 months, patients with ΔFQTA <22.5° had a significantly higher incidence of MACE compared with those with greater angle reduction (44.7% vs. 11.9%; p < 0.001). In multivariable Cox regression analysis, chronic kidney disease (HR: 2.517; p = 0.002) and ΔFQTA <22.5° (HR: 4.56; p < 0.001) were independently associated with MACE. CONCLUSION: A greater reduction in FQTA after CRT is associated with improved long-term outcomes and may serve as a practical electrocardiographic marker for risk stratification.