Prevalence and clinical significance of interatrial block in very older persons

The presence in older patients of an interatrial block (IAB) may be a predictor of atrial fibrillation (AF). The objective of the study was to assess in a group of very older participants: the prevalence of IAB, its association with the presence of functional and cognitive status, of new AF diagnosis and mortality after 2-year of follow-up.

A prospective subcohort of the OCTABAIX population-based study with 75 inhabitants, all 85-year-olds, at baseline in sinus rhythm were assessed. Functional and cognitive status, nutritional risk, and previous falls were recorded. Participants were classified according to the presence or absence of IAB.

23 patients had IAB (30.7%). We did not observe significant differences regarding gender, comorbidity, functional status, nutritional risk and global geriatric assessment according to interatrial conduction. The patients with IAB had statistically significant better cognitive performance (p = 0.029) and a lower number of previous falls (p = 0.008). During the 2 years follow-up 3 participants (4%) died; without statistical differences between both groups. A non-significant trend to a higher incidence of new-onset AF was observed in patients with IAB (8.7 vs. 6.1%; p = 0.652).

Nearly one-third of very older patients with sinus rhythm have IAB. They had a tendency to higher incidence of AF and no association with mortality after 2 years of follow-up.