Left atrial to ventricular volume ratio is a specific marker of atrial cardiopathy. Evidence from the UK Biobank and an ischemic stroke patient cohort.

BackgroundAtrial cardiopathy is an important cause of embolic stroke and a potential cause of cognitive dysfunction. Increased left atrial volume indexed to body surface area (LAVi) has been widely used as marker for atrial cardiopathy. However, since physiological remodeling may also increase LAVi, it lacks specificity. Left atrial to left ventricular volume (LA:LV) ratio was recently suggested as a better marker of atrial cardiopathy allowing a more accurate detection of imbalanced, pathological atrial remodeling. We investigated if LA:LV ratio is associated with different established sequelae of atrial cardiopathy and if it is superior to LAVi for the detection of atrial fibrillation/flutter (AF) as cause of stroke. MethodsWe compared the association of LAVi and LA:LV ratio with risk of ischemic stroke or transient ischemic attack (TIA) in the population-based UK Biobank cohort (n= 38848), using cause specific hazard models. In addition, we tested for an association with cognitive function using multivariate linear regression models. Finally, we investigated the association of LAVi and LA:LV ratio with probability of atrial fibrillation/flutter being identified as stroke etiology in a cohort of ischemic stroke patients (n = 1273). We compared the test performance of LAVi and LA:LV ratio for identifying atrial fibrillation/flutter as stroke etiology. ResultsWhile LAVi was not significantly associated with risk of ischemic stroke/TIA (HR: 1.11, 95% CI 0.97 - 1.26, p = 0.14), LA:LV ratio was (HR: 1.15, 95% CI 1.01-1.30, p = 0.04). Besides, LA:LV ratio was more strongly associated with worse cognitive function in healthy adults [LA:LV ratio: -0.024 (95% CI (- 0.032) - (- 0.015)), LAVi: - 0.010 (95% CI (- 0.019) - (- 0.002))]. In a stroke patient cohort, LA:LV ratio showed a significantly better performance in identifying AF as underlying cause of ischemic stroke compared to LAVi (Receiver Operating Characteristic Area under the Curve 0.856 (0.803- 0.908) vs. 0.808 (0.750 - 0.866) p = 0.03). ConclusionsWe provide evidence that LA:LV ratio is a promising marker of atrial cardiopathy. Hence, LA:LV ratio has the potential to improve diagnosis of atrial cardiopathy, facilitating prevention of ischemic stroke and maintaining of brain health.