Intra left-atrial dyssynchrony as a predictor of new onset supraventricular tachyarrhythmias in dilated cardiomyopathy
M Luzzi, L Bianchi, B Nihant, A Heymans, P Deissler, G Peretto, J Verdonschot, A Raafs, S HeymansAbstract
Background
Supraventricular tachyarrhythmias (SVTs) are common in patients with dilated cardiomyopathy (DCM) and are associated with worse clinical outcomes. Early predictors of SVTs are therefore crucial for risk stratification. While the left atrial volume index (LAVi) is the strongest known predictor, intra-left atrial dyssynchrony (ILAD) may better reflect atrial remodeling. However, its prognostic role in DCM remains unclear.
Purpose
To evaluate the association between ILAD and the incidence of new onset SVTs in DCM patients.
Methods
The retrospective study cohort consisted of 190 patients diagnosed with DCM and 18 healthy controls. ILAD was defined as the time interval, in milliseconds, between the onset of the P wave on the ECG and the beginning of the a’ wave on Tissue Doppler Imaging (TDI). ILAD was retrospectively measured at baseline echocardiogram and reassessed after a median follow-up of two years prior to the occurrence of SVT or last clinical evaluation. SVTs, including atrial fibrillation, atrial flutter and atrial tachycardia, were detected by repeated Holter ECG exams and ILR interrogation. ROC analysis was used to define optimal predictive cutoffs for ILAD and LAVi. Kaplan-Meier survival analysis assessed event-free-survival.
Results
ILAD values were significantly higher in DCM patients compared to healthy controls at baseline (20 ms [10 – 40] vs 10 ms [2 – 20], p 0.02). DCM patients who developed new onset SVT (n=55) had markedly higher ILAD values compared to those with uneventful follow-up at the echocardiography before SVT development (30 ms [20 – 70] vs 20 ms [10 – 30], p <0.01), which was not observed at baseline. ILAD at follow-up was an independent predictor for SVT development after adjustment for age, sex, LAVi, LVEF, P wave duration and PQ interval (HR 2.34, 95% CI: 1.13 – 4.83, p 0.02). The combination of ILAD and LAVi yielded the best predictive performance (AUC 0.793, 95% CI: 0.70–0.89) compared to the other models. The optimal predictive cutoffs for SVT development were 20 ms for ILAD and 38.9 ml/m² for LAVi. Patients with a combination of a prolonged ILAD and elevated LAVi had a significantly worse prognosis compared to the other subgroups (p < 0.01).
Conclusions
ILAD is an independent predictor of new-onset SVTs in DCM. Its combination with LAVi enhances predictive accuracy and allows identification of high-risk patients. Validation of the quantitative ILAD cutoff offers new opportunities for personalized monitoring and early intervention in DCM.ILAD evolution across patients' groupsFor image description, please refer to the figure legend and surrounding text.Event free survival Kaplain Maier analysFor image description, please refer to the figure legend and surrounding text.