Prognostic significance of present atrial fibrillation on a single office electrocardiogram in patients with atrial fibrillation

BACKGROUND: Evidence for the association of atrial fibrillation (AF) present on the ECG and cardiovascular outcomes in AF patients is limited. OBJECTIVE: To investigate the prognostic significance of AF on a single surface ECG for cardiovascular outcomes in AF patients. METHODS: A total of 3642 AF patients were prospectively enrolled. Main exclusion criteria were rhythms other than sinus rhythm (SR) or AF. The primary end-point was a composite of all-cause death and hospitalizations for congestive heart failure (CHF). Secondary end-points were all-cause death, CHF hospitalizations, cardiovascular death, myocardial infarction, any stroke and stroke subtypes. Associations were assessed with multivariable Cox proportional hazards models. RESULTS: Mean age was 71 years, 28% were female, and mean follow-up was 3.4 years. Patients with SR on the ECG at study enrolment (56%) were younger (69 vs. 74 years, P < 0.0001), had more often paroxysmal AF (73 vs. 18%, P < 0.0001) and fewer comorbidities. The incidence of the primary end-point was 1.8 and 3.1 per 100 person-years in patients with SR and AF, respectively. The multivariable-adjusted hazard ratio was 1.4 (95% confidence intervals 1.1; 1.7; P = 0.001) for patients with AF on the ECG compared to patients with SR. The hazard ratios (95% confidence intervals) were 1.4 (1.1; 1.8; P = 0.006) for all-cause death, 1.5 (1.2; 1.9; P = 0.001) for CHF and 1.6 (1.1; 2.2; P = 0.006) for cardiovascular death. None of the other associations were statistically significant. CONCLUSIONS: The presence of AF in a single office ECG had significant prognostic implications with regard to mortality and CHF hospitalizations in patients with AF. These patients present a high-risk group and might benefit from intensified treatment.