Non-conducted premature atrial complexes: A new independent predictor of atrial fibrillation in cryptogenic stroke

Introduction: Atrial fibrillation (AF) is the main cardiac cause of stroke, but it frequently remains undetected. In patients with cryptogenic stroke an Holter electrocardiogram (ECG) monitoring for AF is recommended.Objective: To evaluate the prognostic role of Non-Conducted Premature Atrial Complexes (ncPACs) recorded on Holter ECG.Methods: We prospectively enrolled consecutive patients admitted to the Stroke Unit of our hospital with a diagnosis of cryptogenic stroke between December 2018 and January 2020; all patients underwent 24-h Holter ECG monitoring during hospitalization. Two follow-up visits were scheduled, including a 24-h Holter ECG at 3 and 6 months to detect AF.Results: Among 112 patients, 58% were male with an average age of 72.2 +/- 12.2 years. At follow-up, AF was diagnosed in 21.4% of the population. The baseline 24-h Holter ECG burden of ncPACs and Premature Atrial Complexes (PACs) was higher in patients with AF detected on follow-up (13.5 vs 2, p = 0.001; 221.5 vs 52; p = 0.01). ROC analysis showed that ncPACs had the best diagnostic accuracy in predicting AF (AUC:0.80; 95% CI 0.68-0.92). Cut-off value of >= 7 for ncPACs burden showed the highest accuracy with sensitivity of 62.5% and specificity 97.7% to predict AF onset at follow-up. Moreover, at multivariate Cox-proportional hazard analysis ncPACs burden >= 7 was a powerful independent predictor of AF onset (HR 12.4; 95% CI 4.8-32.8; p < 0.0001).Conclusions: NcPACs burden >= 7 represents a new predictor of AF that could guide the screening of this arrhythmia in cryptogenic stroke patients.