Device-based longitudinal monitoring of premature atrial contractions before atrial fibrillation onset.

BACKGROUND

Frequent premature atrial complexes (PACs) are associated with atrial fibrillation (AF); however, the temporal PAC frequency pattern preceding AF onset remains unclear.

OBJECTIVE

This study aimed to evaluate whether PAC frequency increases before AF onset using long-term monitoring data from cardiovascular implantable electronic devices (CIEDs).

METHODS

This retrospective study had 2 phases. In phase 1, a total of 101 patients with Boston Scientific CIEDs (mean follow-up 5.2 years) were divided into 2 groups: 48 who developed AF (age 68 ± 15 years) and 53 who did not (age 65 ± 15 years). AF was defined as any episode lasting >5.5 minutes. Daily PAC counts were derived from remote monitoring, and receiver operating characteristic analysis identified a threshold predictive of AF onset. In phase 2, in patients who developed AF, PAC frequency was compared across 3 time points: 1 year before AF onset, at onset, and 1 year after onset.

RESULTS

In phase 1, median PAC count was significantly higher in the AF group than in the non-AF group (172.5 vs 21.1 PACs/d; P < .0001). A threshold of 31.8 PACs/d effectively ruled out AF presence (area under the curve 0.828; positive predictive value 71%, negative predictive value 97%). In phase 2, PAC frequency increased by 63% in the year preceding AF onset (105.7-172.5/d; P = .04) and remained elevated in the next year (P = .52).

CONCLUSION

In our population of patients with CIEDs, those who developed AF had higher PAC frequencies, with a marked increase in the year before onset. A PAC burden of <31.8 PACs/d was rarely associated with future AF.