Association of Left Atrial Sphericity with Risk of Stroke in Patients with Atrial Fibrillation. Sub-Analysis of the ASSAM Study

Katarzyna Dudzińska-Szczerba,Wojciech Niemiro,Roman Piotrowski,Ilona Michałowska,Agnieszka Sikorska,Jakub Baran,Piotr Kułakowski,Marta Zalewska

doi:10.1007/s13239-021-00587-y

Abstract

PurposeThe study was designed to evaluate the value of left atrial (LA) sphericity (LASP) in the identification of patients with atrial fibrillation (AF) who had prior ischemic stroke. The secondary aim was to investigate the possibility of improving stroke risk assessment based on six geometrical variables of LA.MethodsThis prospective observational study involved 157 patients: 74 in the stroke group and 83 in the control. All patients had cardiac computed tomography (CT) performed to analyze LA volume and dimensions. LASP and the discriminant function of six geometrical measurements were calculated.ResultsMultivariate logistic regression analysis showed a significant association of stroke with and gender, diabetes, CHA2DS2-VASc score, LA anteroposterior diameter, and LA sphericity. Patients with prior stroke had lower LASP than those without (66.6 ± 10.3% vs. 70.5 ± 7%; p = 0.0062). The most accurate identification of patients with a history of ischemic stroke was achieved by using a function of six geometrical measurements, the sphericity and volume coefficient. The C-statistic was higher for the above discriminant function (0.7273) than for LASP (0.3974). The addition of the discriminant function to the CHA2DS2-VASc score increased the performance of the risk score alone.ConclusionLASP is associated with prior stroke in AF patients. The proposed new formula for identification of AF patients who are at risk of stroke, based on geometrical measurements of LA, is superior to the basic LASP in identification of AF patients with a history of stroke.

Highlights

Atrial fibrillation (AF) is the most common arrhythmia, and has become an increasingly serious public health problem in an aging population
The association between the left atrial (LA) shape and the risk of stroke was found using a simple computation of the anatomical measurement of the LA based on computed tomography (CT) imaging
It was found that a function of six geometrical measurements, the sphericity coefficient and volume coefficient, had a greater ability than left atrial sphericity (LASP) alone to identify patients at risk of TE

Summary

Introduction

Atrial fibrillation (AF) is the most common arrhythmia, and has become an increasingly serious public health problem in an aging population. It doubles the risk of death and increases the risk of ischemic stroke fivefold.[7, 14]. Stroke is the main cause of long-term disability, and is a serious problem for healthcare systems.[9]. It has been estimated that 20% of ischemic strokes are caused by cardiac embolisms, most often in the course of AF.[6]. It is common practice to assess the risk of thromboembolic (TE) events in patients with AF by calculating the CHA2DS2-VASc score. Multiple studies have shown that the score allows only moderately for the identification of patients at risk of stroke or peripheral embolism.[5, 13]. Multiple studies have shown that the score allows only moderately for the identification of patients at risk of stroke or peripheral embolism.[5, 13] new factors are still being searched for to improve stratification of the risk of TE in the AF population

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