Association of computed tomography-derived left atrial size with major cardiovascular events in the general population: The Heinz Nixdorf Recall Study

•We determined the association of left atrial (LA) size with cardiovascular events.•LA size was quantified from non-contrast cardiac CT in the general population.•CT-derived LA was associated with events, independent of traditional risk factors.•This effect was stronger for subjects with low coronary artery calcification score.•LA may complement prognostic implications from cardiac CT.

BackgroundEchocardiography based data suggests that left atrial (LA) size is associated with cardiovascular morbidity and mortality. Once non-contrast cardiac CT is performed for prevention purposes, information on the LA is readily available. We aimed to determine whether LA area from non-contrast cardiac CT is associated with incident major cardiovascular (CV) events, independent of CV risk factors and coronary artery calcium (CAC), based on a general population cohort.MethodsSubjects aged 45-75 years without prevalent CV disease from the population-based Heinz Nixdorf Recall Study were enrolled between 2000 and 2003. LA area at the level of the mitral valve was quantified from non-contrast cardiac CT. Major CV events (coronary event, stroke, CV death) were assessed during follow-up. The association of LA with events was assessed using Cox regression analysis.ResultsOverall, 3958 subjects (59.2 ± 7.7 years, 53% female) were included. Mean LA area was 17.64 ± 4.22 cm2 (range: 7.16-44.13 cm2). During 8.0 ± 1.5 years of follow-up, 221 major CV events occurred. In univariate analysis, increase of LA size by 1 standard deviation was associated with nearly 50% excess events (HR (95%CI): 1.48 (1.32-1.65)), which remained significant after adjustment for CV risk factors (HR (95%CI): 1.25 (1.09-1.43)) and when additionally adjusting for CAC (HR (95%CI): 1.22 (1.07-1.40)). Associations for LA size were similar for each endpoint and again independent of risk factors and CAC (coronary event: HR (95%CI): 1.21 (1.01-1.45); stroke: 1.31 (1.05-1.63); CV death: 1.33 (1.03-1.71)).ConclusionLA size is associated with incident major CV events independent of risk factors and CAC-score. Once cardiac CT imaging is performed, assessment of LA size may complement information of this imaging modality.