Supraventricular Extrasystoles on Standard 12-lead Electrocardiogram Predict New Incident Atrial Fibrillation after Embolic Stroke of Undetermined Source: The AF-ESUS Study

Abstract

Background: The diagnosis of covert atrial fibrillation (AF) remains a major challenge to guide secondary prevention of patients with embolic stroke of undetermined source (ESUS).

Aims: We analyzed consecutive ESUS patients from 3 prospective stroke registries to assess whether the presence of supraventricular extrasystoles (SVE) on standard 12-lead electrocardiogram (ECG) is associated with the detection of AF (primary outcome), stroke recurrence and death (secondary outcomes) during follow-up.

Methods: We measured the number of SVEs in all available ECGs of patients hospitalized for ESUS. Multivariate stepwise regression with forward selection of covariates assessed the association between SVE (classified in 4 groups according to their number per 10 seconds of ECG: no SVE, >0-1SVEs, >1-2SVEs, and >2SVEs) and outcomes during follow-up. The Kaplan-Meier product limit method estimated the 10-year cumulative probabilities of outcomes in each SVE group. We calculated the negative prognostic value (NPV) of the presence of any SVE to predict new AF, defined as the probability that AF will not be detected during follow-up if there is no SVE.

Results: Among 853 ESUS patients followed for 2857 patient-years (median age: 67 years, 43.0% women), 226 (26.5%) patients had at least 1 SVE at the standard 12-lead ECGs performed during hospitalization. AF was detected in 125 (14.7%) of patients in the overall population during follow-up: 8.9%, 22.5%, 28.1%, and 48.3% in patients with no SVE, greater than 0-1SVE, greater than 1-2SVE and greater than 2SVE respectively. In multivariate regression analysis, compared to patients with no SVEs, the corresponding hazard-ratios were 1.80 [95% confidence intervals (95%CI):1.06-3.05], 2.26 (95%CI:1.28-4.01) and 3.19 (95%CI:1.93-5.27). The NPV of the presence of any SVE for the prediction of new AF was 91.4%. There was no statistically significant association of SVE with the risk of ischemic stroke recurrence and death.

Conclusions: In ESUS patients without SVEs during hospitalization, the probability that AF will not be detected during a follow-up of 3.4 years is more than 91%.

Keywords: Embolic stroke of undetermined source; atrial fibrillation; death; standard 12-lead electrocardiogram; stroke recurrence; supraventricular extrasystole.