Abstract 16671: Supraventricular Ectopic Activity Predicts Postoperative Atrial Fibrillation, New-Onset Atrial Fibrillation, and Worse Survival in Hypertrophic Cardiomyopathy

Abstract

Introduction: Supraventricular ectopic activity (SEA), in the form of frequent premature atrial contractions (PACs) and runs of PACs, has been considered a marker of foci that are capable of firing rapidly to initiate atrial fibrillation (AF), but the cut-off value has not been determined. Therefore, we aimed to examine the association between SEA and postoperative AF (POAF) and clinical outcomes and to investigate the cut-off value in patients with hypertrophic cardiomyopathy. Methods: This cohort included 1491 consecutively recruited patients, of which 530 were excluded for various reasons, leaving 961 patients for final analysis. All patients received 24-hour Holter ECG monitoring 2-5 days before surgery. Results: The mean age of the study population was 48.4 (SD,12.3) years and 397 patients (41.3%) were female. The incidence of POAF was 20.7% and increased with PACs severity. Multivariable logistic regression analysis showed that supraventricular tachycardia (SVT) was independently associated with higher incidence of POAF and the model including SVT had the largest area under the curve (AUC) [AUC=0.710] among all the multivariable models. Furthermore, Kaplan-Meier survival curves demonstrated that patients in the tertile 3 (upper tertile of the total numbers of PACs), PACs>100, PACs >200, ESVEA (top decile of PACs plus top decile length of short atrial runs), and ESVEA3 (PACs>100 plus top decile length of short atrial runs) group had significantly higher cumulative rates of new-onset AF and composite endpoints compared to their counterparts. On multivariable Cox regression analysis, PACs> 100, PACs>200, ESVEA, and ESVEA3 were independent indicators for higher incidence of new-onset AF and composite endpoints. Among those multivariate models, PACs >200 had the higher effect size for predicting new-onset AF [Hazard ratio (HR) 3.13, 95% confidence interval (CI) 1.74-5.62] and composite endpoints [HR =2.00, 95%CI 1.30-3.06]. Conclusions: The incidence of POAF was 20.7% increasing with the severity of the PACs burden. Moreover, among supraventricular arrhythmias, SVT was the best indicator for predicting POAF. Likewise, PACs>200 may consider as the best candidate for predicting a higher incidence of new-onset AF and composite endpoints.