When transient new-onset atrial fibrillation (AF) begins during hospitalization for noncardiac surgery or medical illness, recurrence within 1 year is common, affecting about one-third of patients, researchers report. “The risk for having AF detected is markedly higher than in matched control participants,” the authors conclude. “Future studies are required to assess the efficacy of oral anticoagulation for stroke prevention in this population.”
At 3 academic hospitals in Ontario, patients hospitalized for noncardiac surgery or medical illness who had transient new-onset AF were enrolled in the study. Compared with age- and sex-matched control participants with no history of AF from the same hospital ward, all of whom were discharged in normal sinus rhythm, the authors found: “Among 139 participants with transient new-onset AF (70 patients with medical illness and 69 surgical patients) and 139 matched control participants, the mean age was 71 years (SD, 10), the mean CHA2DS2-VASc score was 3.0 (SD, 1.5), and 59% were male. The median duration of AF during the index hospitalization was 15.8 hours (IQR, 6.4 to 49.6 hours). After 1 year, recurrent AF was detected in 33.1% (95% CI, 25.3% to 40.9%) of participants in the transient new-onset AF group and 5.0% (CI, 1.4% to 8.7%) of matched control participants; after adjustment for the number of ECG monitors worn and for baseline clinical differences, the adjusted relative risk was 6.6 (CI, 3.2 to 13.7). After exclusion of participants who had electrical or pharmacologic cardioversion during the index hospitalization (n = 40) and their matched control participants and limiting to AF events detected by the patch ECG monitor, recurrent AF was detected in 32.3% (CI, 23.1% to 41.5%) of participants with transient new-onset AF and 3.0% (CI, 0% to 6.4%) of matched control participants.”