Clinical characteristics of patients with asymptomatic recurrences of atrial fibrillation in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-Atrial Fibrillation (GISSI-AF) trial.

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia that frequently recurs after restoration of sinus rhythm. In a consistent percentage of cases, AF recurrences are asymptomatic, thus making its clinical management difficult in relation to both therapeutic efficacy and thromboembolic risk. METHODS: The GISSI-AF trial enrolled 1,442 patients in sinus rhythm with previous AF episodes. Patients were randomized to valsartan or placebo and followed for 12 months. To improve the likelihood of detecting arrhythmic recurrences, arrhythmic follow-up was based on both programmed or symptom-related control visits and transtelephonic electrocardiographic transmissions. The present post hoc analysis was performed on 1,638 arrhythmic episodes that occurred in 623 patients. RESULTS: Asymptomatic AF recurrences were present in 49.5% of patients. In multivariable analysis, asymptomatic AF recurrences were significantly associated with a longer duration of qualifying arrhythmias (odds ratio [95% CI] 1.57 (1.26-1.97), P < .0001). A lower ventricular response (P < .001) and a longer duration of the arrhythmic recurrence (P < .001) characterized asymptomatic episodes. Patients with asymptomatic events were more likely to be in AF at the time of electrocardiographic control at the end of the 12-month follow-up (adjusted odds ratio [95% CI] 4.9 (2.8-8.4), P < .001). Moreover, a higher CHADS(2) (Congestive heart failure, history of Hypertension, Age≥75 years, Diabetes mellitus, and past history of Stroke or TIA doubled) score and a more frequent use of amiodarone, calcium-channel blockers, and digitalis characterized patients with asymptomatic, whereas 1C drugs were more often used in subjects with symptomatic recurrences. CONCLUSION: Asymptomatic AF recurrences were frequent in the GISSI-AF study population in patients who were more likely to develop persistent-permanent AF and were characterized by an increased thromboembolic risk.