Long-term follow-up of silent and symptomatic atrial fibrillations during acute myocardial infarction: Not an epiphenomenon!

Abstract

Silent or symptomatic atrial fibrillation (AF), assessed by continuous ECG monitoring (CEM), are common in acute myocardial infarction (AMI), and associated with long-term mortality. We aim to determine whether silent or symptomatic AF during AMI increased the risk of AF at follow-up. All consecutive patients admitted to our university hospital for AMI between January 2012 and August 2015 were prospectively included for CEM. A retrospective follow-up (FU) was performed, based on the medical records and phone interviews between December 2016 and January 2017. Among the 1560 patients included 258, were followed-up in a preliminary analysis, of whom 56 with previous AF were excluded. Among the remaining 202 patients, 137 (68%) had persistent sinus rhythm (SR) during AMI, 26 (13%) had silent AF, and 39 (19%) presented symptomatic AF. After a FU of 933 ± 635 days, new onset AF were recorded in 15 patients (11%) of the SR group, 6 (23%) in the silent AF group and 19 (48%) in the symptomatic AF group. Kaplan Meier analysis showed that the risk of new onset AF after AMI was higher in the symptomatic AF and silent AF groups (Log Rank test: P = 0.012 and P = 0.028, respectively). After Cox multivariate analysis, age (OR (95% CI): 1.05 (1.02–1.08)), and symptomatic AF (OR (95% CI): 4.99 (2.35–10.62)) were risk factors for AF after AMI, while silent AF showed only a trend toward a higher risk of AF (OR (95%CI): 2.04 (0.77–5.37)) ( Fig. 1 ). The preliminary results of our large-scale study suggest that patients experiencing AF (silent or symptomatic) during AMI are at higher risk of AF at long-term FU. Our data calls into question the management of these brief and often neglected episodes, and may have important implications with regard to anticoagulation therapy.