Clinical question: Is there an association between peri-operative AF and long-term risk of ischemic stroke in patients undergoing any type of surgery?
Background: Peri-operative AF is usually viewed as a transient response to physiological stress, and the long-term risk of stroke after peri-operative AF is unclear. The incidence of peri-operative AF ranges widely, from 1% to 40%. Data are scarce regarding the long-term risk of stroke from peri-operative AF in patients undergoing various types of surgery.
Study design: Retrospective cohort.
Setting: Nonfederal California acute care hospitals.
Synopsis: The goal of this study was to evaluate the relationship between peri-operative AF and long-term post-operative ischemic stroke by measuring newly diagnosed AF during the index hospitalization among 1,729,360 adult patients who underwent inpatient cardiac and noncardiac surgeries between 2007 and 2010. The main outcome variable was ischemic stroke in any hospital discharge diagnosis, which was adjusted for age, sex, race, insurance status, and cardiovascular comorbidities (hypertension, diabetes mellitus, coronary heart disease, congestive heart failure, peripheral vascular disease, chronic kidney disease, and chronic obstructive pulmonary disease). Kaplan-Meier survival statistics were used to calculate cumulative rates of stroke after surgery; cumulative stroke rates were stratified by the CHA2DS2VASc score.
Of 1.73 million eligible patients with diagnoses of ischemic strokes after discharge from the index hospitalization for surgery, 24,711 had new-onset peri-operative AF during the index hospitalization, and 13,952 experienced a stroke after discharge.
At one year after hospitalization for cardiac surgery, cumulative rates of stroke were 0.99% in those with peri-operative AF and 0.83% in those without AF. At one year after noncardiac surgery, cumulative rates of stroke were 1.47% in those with peri-operative AF and 0.36% in those without AF.
In a Cox proportional hazards analysis accounting for potential confounders, peri-operative AF was associated with subsequent stroke after both cardiac and noncardiac surgery.
Bottom line: Among patients hospitalized for surgery, peri-operative AF was associated with an increased long-term risk of ischemic stroke, especially following noncardiac surgery.