Initial Precipitants and Recurrence of Atrial Fibrillation

Abstract

Background: Atrial fibrillation (AF) may occur after an acute precipitant and subsequently resolve. Management guidelines for AF in these settings are unclear as the risk of recurrent AF and related morbidity is poorly understood. We examined the relations between acute precipitants of AF and long-term recurrence of AF in a clinical setting.

Methods: From a multi-institutional longitudinal electronic medical record database, we identified patients with newly diagnosed AF between 2000 and 2014. We developed algorithms to identify acute AF precipitants (surgery, sepsis, pneumonia, pneumothorax, respiratory failure, myocardial infarction, thyrotoxicosis, alcohol, pericarditis, pulmonary embolism, and myocarditis). We assessed risks of AF recurrence in individuals with and without a precipitant and the relations between AF recurrence and heart failure, stroke, and mortality.

Results: Among 10 723 patients with newly diagnosed AF (67.9±9.9 years, 41% women), 19% had an acute AF precipitant, the most common of which were cardiac surgery (22%), pneumonia (20%), and noncardiothoracic surgery (15%). The cumulative incidence of AF recurrence at 5 years was 41% among individuals with a precipitant compared with 52% in those without a precipitant (adjusted hazard ratio [HR], 0.75 [95% CI, 0.69-0.81]; P<0.001). The lowest risk of recurrence among those with precipitants occurred with postoperative AF (5-year incidence 32% in cardiac surgery and 39% in noncardiothoracic surgery). Regardless of the presence of an initial precipitant, recurrent AF was associated with increased adjusted risks of heart failure (hazard ratio, 2.74 [95% CI, 2.39-3.15]; P<0.001), stroke (hazard ratio, 1.57 [95% CI, 1.30-1.90]; P<0.001), and mortality (hazard ratio, 2.96 [95% CI, 2.70-3.24]; P<0.001).

Conclusions: AF after an acute precipitant frequently recurs, although the risk of recurrence is lower than among individuals without an acute precipitant. Recurrence is associated with substantial long-term morbidity and mortality. Future studies should address surveillance and management after newly diagnosed AF in the setting of an acute precipitant.

Keywords: atrial fibrillation; heart failure; mortality; risk factor; stroke.

Figure 1.

Distribution of precipitants in 2,089 patients with newly diagnosed atrial fibrillation and an acute precipitant. Since precipitants may coexist, the figure displays both the number of individuals with AF with a precipitant as well as the number of individuals with AF with overlapping precipitants. The side plot shows overall number of individuals with each precipitant. The main plot demonstrates the number of individuals with only one precipitant type (illustrated by individual bubbles), as well as number of individuals with multiple concurrent precipitants (intersection sets are denoted by connected bubbles).

Figure 2.

Unadjusted cumulative risk of atrial fibrillation recurrence. Unadjusted curves displaying cumulative risk of recurrent AF, generated using Kaplan-Meier method. Panel A) overall risk of recurrent AF among individuals with and without acute precipitants. Panel B) overall risk of recurrent AF among individuals with infection, cardiac surgery, and non-cardiothoracic surgery, as compared to no precipitant. These three precipitants were selected for display because the risk of recurrent AF was significantly reduced as compared to the referent group without precipitants in multivariable adjusted models. Individuals with other AF precipitants excluded from this plot for clarity. CT = cardiothoracic.

Figure 3.

Multivariable-adjusted association between acute atrial fibrillation precipitants and atrial fibrillation recurrence. Multivariable models taking the competing risk of death into account and adjusted for age, sex, race, hypertension, diabetes mellitus, myocardial infarction, heart failure, valvular disease, stroke/transient ischemic attack, peripheral artery disease, chronic lung disease, cancer, tobacco use, alcohol use, and stratified by admission status at AF diagnosis. Green bars signify statistically significant lower risk of association with AF recurrence, comparing to newly diagnosed AF without a precipitant. Data are number of AF cases with acute precipitant and subdistribution hazard ratio (95% confidence interval). AF = Atrial fibrillation.