While the presence of a pacemaker is associated with an increased risk for atrial fibrillation (AF), this appears to be attributable to continuous monitoring as opposed to an adverse effect of pacing, according to a study recently published in the Journal of Electrocardiology.

This follow-up study included data from 17,428 individuals implanted with a dual-chamber pacemaker from 2000 to 2014, all of whom were in Danish national registries. A control group of age and sex-matched individuals without pacemakers or AF were used for comparison (5:1 ratio), as well as an AF-free population with an implanted loop recorder (1:1 ratio). The total number of controls was 86,167.

The primary end point of the study was the incidence of AF in the ≤2 years following the 3-month implantation follow-up visit. The time period after 3-month follow-up was chosen to control for possibility of pre-existing AF. The statistical model included censorship for all-cause mortality, which was considered a competing risk. The Kruskal-Wallis test was used to compare median values of continuous variables, and chi-square analysis was used to compare proportional variables (as absolute numbers or percentages).

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By the 3-month post-implantation mark, 16,383 participants still met the inclusion criteria for the risk-assessment study (3% [n=535] experienced AF and 2.9% [n=507] died). Those with a pacemaker experienced an AF rate of 5.2% (n=860) within 2 years, while the control group experienced an AF incidence of 2.7% (n=2346; P <.001). Compared with 8.5% (n=7361) in the control group, 10.3% (n=1695) of those with a pacemaker suffered all-cause mortality.

To account for interaction by age, the population was divided by age group for relative AF risk for pacemaker vs no pacemaker: <70 years (n=31,727; adjusted hazard ratio [HR], 4.94; 95% CI, 4.09-5.96), 70-79 years (n=37,618; adjusted HR, 2.63; 95% CI, 2.23-2.98), and age ≥80 years (n=52,304; adjusted HR, 1.40; 95% CI, 1.22-1.55; P <.001 overall).

Being a man vs a woman was associated with a hazard ratio of 1.61 (95% CI, 1.29-2.00; P <.001). Finally, there was a higher incidence of AF in patients with a pacemaker (8.4%; n=2202) compared with those with a loop recorder (7.9%; n=2202).

Limitations of this study included a lack of data on pacemaker settings or ventricular/atrial pacing, which could have potentially influenced the pacemaker-AF correlation; a lack of data on AF diagnosis criteria; the potential for missed detection of subclinical AF or potential underreporting of AF; and the increased rate of comorbidities among those with pacemakers.

The study researchers concluded that “[patients] with pacemaker have an increased likelihood of being diagnosed with AF,” and that this complication is “most likely due to the continuous monitoring and not necessarily due to adverse effect of pacing.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Tayal B, Riahi S, Sogaard P, et al. Risk of atrial fibrillation after pacemaker implantation: A nationwide Danish registry-based follow-up study [published online October 22, 2019]. J Electrocardiol. doi: 10.1016/j.jelectrocard.2019.09.021