Higher Frequency of Premature Atrial Contractions Correlates With Atrial Fibrillation Detection after Cryptogenic Stroke.

Background: Covert atrial fibrillation (AF) is a major cause of cryptogenic stroke. This study investigated whether a dose-dependent relationship exists between the frequency of premature atrial contractions (PACs) and AF detection in patients with cryptogenic stroke using an insertable cardiac monitor (ICM).
Methods: We enrolled consecutive patients with cryptogenic stroke who underwent ICM implantation between October 2016 and September 2020 at 8 stroke centers in Japan. Patients were divided into 3 groups according to the PAC count on 24-hour Holter ECG: ≤200 (group L), >200 to ≤500 (group M), and >500 (group H). We defined a high AF burden as above the median of the cumulative duration of AF episodes during the entire monitoring period. We evaluated the association of the frequency of PACs with AF detection using log-rank trend test and Cox proportional hazard model and with high AF burden using logistic regression model, adjusting for age, sex, CHADS ₂ score.
Results: Of 417 patients, we analyzed 381 patients with Holter ECG and ICM data. The median age was 70 (interquartile range, 59.5-76.5), 246 patients (65%) were males, and the median duration of ICM recording was 605 days (interquartile range, 397-827 days). The rate of new AF detected by ICM was higher in groups with more frequent PAC (15.5%/y in group L [n=277] versus 44.0%/y in group M [n=42] versus 71.4%/y in group H [n=62]; log-rank trend P <0.01). Compared with group L, the adjusted hazard ratios for AF detection in groups M and H were 2.11 (95% CI, 1.24-3.58) and 3.23 (95% CI, 2.07-5.04), respectively, and the adjusted odds ratio for high AF burden in groups M and H were 2.57 (95% CI, 1.14-5.74) and 4.25 (2.14-8.47), respectively.
Conclusions: The frequency of PACs was dose-dependently associated with AF detection in patients with cryptogenic stroke.
Competing Interests: Disclosures Dr Todo reports lecture fees from Pfizer, Bristol-Myers Squibb, Daiichi-Sankyo, Bayer, Medtronic, Abbott, and Otsuka Pharmaceutical. Dr Doijiri reports lecture fees from Medtronic, Abbott, Biotronic, Daiichi Sankyo, Bristol-Myers Squibb, and Bayer. Dr Yamazaki reports lecture fees from Medtronic, Abbott, Daiichi Sankyo, Bristol-Myers Squibb, and Bayer. Dr Iwata reports lecture fees from Daiichi-Sankyo, and Medtronic. Dr Sonoda reports lecture fees from Medtronic, Abbott, and Daiichi-Sankyo. Dr Koge reports lecture fees from Medtronic. Dr Koga reports honoraria from Daiichi-Sankyo and research support from Daiichi-Sankyo. Dr Nagata reports lecture fees from Otsuka Pharmaceutical, Daiichi-Sankyo, Eli Lilly, and Amgen. Dr Ueno reports research funds from Bristol-Myers Squibb. Dr Yamagami reports lecture fees from Medtronic, Abbott, Daiichi-Sankyo, Bristol-Myers Squibb, and Bayer, and grant support from Bristol-Myers Squibb. Dr Gon reports lecture fees from Eisai, Kyowa Kirin, and Pfizer. The other authors report no conflicts.