The prognostic implications of lack of palpitations in patients hospitalised with atrial fibrillation: observations from a 20-year registry

Abstract

It is well recognised that patients differ in the clinical presentation of atrial fibrillation (AF), ranging from the typical symptom of palpitations, atypical symptoms in others and a substantial that are asymptomatic. Whether the different patterns of presentation are associated with differences in outcomes is not known. The aim of this study was to evaluate the prevalence and the prognostic implications of lack of palpitations among patients hospitalised with AF in a large prospective registry. Retrospective analysis of all patients hospitalised with AF in Qatar from 1991 to 2010 was made. Patients were divided into two groups according to the presence or absence of palpitations on presentation. Clinical characteristics and outcome were analysed. During the 20-year period, 3850 patients were hospitalised for AF; 1724 (44.8%) had palpitations on presentation while 2126 (55.2%) had no palpitations. Patients who lacked palpitations were 9 years older, had a higher prevalence of diabetes mellitus (64.7% vs. 35.3%), underlying coronary artery disease (CAD; 14.6% vs. 6.2%) and severe left ventricular dysfunction on echocardiography (25.5% vs. 6.6%), (all, p = 0.001). There were 141 deaths among the group with no palpitations compared with 19 among the group with palpitations (6.6% vs. 1.1%). Multivariate analysis of mortality predictors identified 'lack of palpitations' as an independent predictor of in-hospital mortality (relative risk 5.56; 95% confidence interval 1.20-25.0, p = 0.03). Our study demonstrates for the first time that lack of palpitations as the presenting symptom of patients with AF is associated with worse in-hospital outcome independent of other risk factors or therapy. The underlying mechanisms and the role of confounders warrant further investigation.