P352 Global myocardial wall strain decreases in patients with atrial fibrillation: a pilot cohort study
Authors: Pop S , Budurea C , Iliescu A M , Iancu S D , Coman V , Manole S , Coman M , Ciortea C , Balint Z 
Published: January 2020

Abstract

Funding Acknowledgements
Competitiveness Operational Programme 2014-2020 POC-A1-A1.1.4-E-2015, financed under the European Regional Development Fund, project number P_37_245

Background
Atrial fibrillation (AF) is the most common human arrhythmia, associated with substantial morbidity and mortality. Histopathological studies of persistent AF have reported extracellular matrix remodelling with fibrotic infiltration in the myocardium, causing atrial dilation and electrical remodelling.

Purpose
In this pilot cohort study, we aimed to identify markers of persistent AF by comparing clinical data (ECG, echocardiography, cardiac MRI) from AF patients and age- and sex-matched healthy controls.

Methods
The study imATFIBis an observational, single-centre, cohort study (NCT03584126). The study was approved by the hospital ethics committee.Patients with AF visiting the outpatient clinic and healthy adult volunteers were examined clinically, by electrocardiography, echocardiography and cardiac MRI. For this primary analysis, we compared data from 16 patients (53 [50–59]YOA) and 16 age- and sex-matched controls (53.5 [50–59]YOA). We also compared AF patients with (N = 11; 67 [53–69]YOA) and without (N = 16; 56 [50–67]YOA) fibrosis (MRI). The unpaired Mann-Whitney t-test was used to test for significant differences. P values &lt;0.05 were considered significant. Values are presented as medians and interquartile ranges, unless otherwise stated.

Results
Patients with AF presented a significant decrease in global myocardial wall strain as compared to healthy controls (-15%vs-19.5%, p = 0.008, N = 16), whereas there was no difference in their global ventricular systolic function (ejection fraction). Left atrial (LA) echocardiographic volume (110.90 [79.13–143.3] vs59.59 [43.32–69.50] cm3) and LA volume normalized to body surface area (BSA) (54.66 [41.00–70.83] vs32.71 [22.74–35.46] cm3/m2) were significantly higher in patients (all p &lt; 0.001). Similarly, on cardiac MRI, a significantly increased LA volume of patients with AF (98.97 [78.12–116.7] vs65.92 [49.99–80.48]cm3) and LA volume/BSA (46.28 [39.68–60.98] vs32.32 [25.62–38.55]cm3/m2) were observed (all p &lt; 0.001). Moreover, the LA transversal (53 [46–58] vs45 [40–50] mm) and LA longitudinal diameters (63 [50-68] vs48 (41–53.5] mm), and LA area (26.5 [22.3–32.0] vs19.5 [15.3–22.0] cm2) were significantly higher in patients with AF (all p &lt; 0.01). When comparing LA volume and LA volume/BSA, we did not find significant differences between echocardiography and cardiac MRI. When analysing AF patients with and without fibrosis via cardiac MRI, LA volume had an increased trend in fibrotic patients (111.30 [100.30–140.20] vs98.58 [77.41–118.10] cm3, p = 0.054); whereas, LA volume/BSA (61.38 [58.88–80.35] vs45.09 [38.51–59.25] cm3/m2, p &lt; 0.01) and LA area (30.80 [27.60–35.80]vs23.45 [20.93–31.28] cm2, p = 0.008) were significantly higher in fibrotic patients.
Conclusions.There was an increased left atrial volume and diameters in patients with AF as compared to healthy controls. Patients with AF had a decreased global myocardial strain suggesting incipient left ventricular systolic dysfunction.