For patients undergoing any inpatient surgery, is the presence of new-onset perioperative atrial fibrillation associated with a greater long-term risk of ischemic stroke?
Perioperative atrial fibrillation (AF) is associated with an increased risk of ischemic stroke for patients who are hospitalized for surgery. (LOE = 2b)
Inpatient (any location)
New-onset perioperative AF is very common but its long-term association with ischemic stroke is unknown. Using administrative data, these investigators identified all adult patients who underwent inpatient surgery during a 4-year period. Patients with preexisiting AF and those with documented cerebrovascular disease were excluded. More than 1.7 million patients were included in the study, with a mean follow-up of 2 years.
Overall, perioperative AF was found in 1.4% of this population, more frequently following cardiac surgery than any other type of surgery (16% vs 0.78%; P < .001). Patients who experienced perioperative AF were also more likely to have high vascular comorbidities, such as hypertension, diabetes, and coronary artery disease. The incidence of ischemic stroke after discharge in the overall cohort was 0.81%.
After adjusting for potential confounders, including age, sex, race, and cardiovascular comorbidities, perioperative AF was independently associated with ischemic stroke both following noncardiac surgery (hazard ratio [HR] 2.0, 95% CI 1.7 - 2.3) and cardiac surgery (HR 1.3, 95% CI 1.1 - 1.6). A further analysis using a specific diagnostic code for cardioembolic stroke showed an even greater association between perioperative AF and this subset of stroke (noncardiac surgery: HR 4.9, 95% CI 3.5 - 6.7; cardiac surgery: HR 2.1, 95% CI 1.4 - 3.1).
Of note, sicker patients in this study may have had more intense cardiac monitoring following their surgeries, leading to an ascertainment bias that could overestimate the association between perioperative AF and stroke. However, a sensitivity analysis using a comorbidity index did not change the findings of the primary analysis.
Dr. Kulkarni is an assistant professor of hospital medicine at Northwestern University in Chicago.