434 Feasibility and reproducibility of parameters of cardiac function and dimension by transthoracic echocardiography in obesity patients
Authors: Snelder S , Younge J O , Van Velzen J E , Akkerhuis J A , Zijlstra F , Van Dalen B M 
Published: January 2020

Abstract

Background
Cardiac disease occurs more frequently in obesity patients. Imaging by transthoracic echocardiography (TTE) can be limited due to poor acoustic windows. An increase of the number of obesity patients who need to undergo TTE is expected.

Purpose
The aim of this study was to evaluate the feasibility, test-retest variability and inter- and intra-observer variability of parameters of cardiac function and dimension by TTE in obesity patients as compared to non-obese controls.

Methods
100 obesity patients (BMI≥35kg/m2) and 50 non-obese controls (BMI &lt; 30kg/m2) without known cardiovascular disease were prospectively enrolled and underwent an echocardiogram. Feasibility of echocardiographic parameters was assessed by categorizing the image quality and by evaluating the availability of the echocardiographic parameters. Intra-observer reproducibility was assessed by one observer on the same echocardiographic loop in 50 patients. A second observer assessed interobserver reproducibility in these patients. In 37 obesity patients and 17 non-obese controls images were obtained by two physicians to investigate test-retest variability.

Results
Image quality was excellent in 11% of the obesity patients as compared to 60% of the non-obese controls. Nevertheless, apart from global longitudinal strain (GLS), all investigated parameters of cardiac function and dimension were available in both groups (Table). GLS was obtainable in 93% of obesity patients versus 98% of non-obese controls (p = 0.20). For the vast majority of parameters inter- and intra-observer variability was comparable between obesity patients and non-obese controls. There were no significant differences between obesity patients and non-obese controls regarding the test-retest variability (Table).

Conclusion
Although non-obese controls on average had better echocardiographic image quality than obesity patients, feasibility of assessment of a broad variety of parameters of cardiac function and dimension was excellent in obesity patients and there were no important differences regarding variability of measurements.
Echocardiographic parameters Available obesity patients (n = 100) Available non-obese controls (n-50) Intra-observer variability obese (n = 50) Intra-observer variability non-obese (n = 25) Inter-observer variability obese (n = 50) Interobeserver variability non-obese (n = 25) Test-retest variability obese (n = 37) Test-rest variability non-obese(n= 17) IVSd 100% 100% 10.6 ± 6.3 6.8 ± 6.3* 10.8 ± 6.9 8.5 ± 4.5 11.1 ± 9.0 10.1 ± 6.4 LVEDD 100% 100% 5.4 ± 4.7 6.7 ± 5.3 5.5 ± 3.7 5.5 ± 3.3 6.7 ± 5.1 6.1 ± 5.2 PWd 100% 100% 12.4 ± 9.0 13.7 ± 9.6 11.5 ± 9.7 9.7 ± 6.7 12.4 ± 9.4 9.8 ± 6.4 E/A ratio 100% 100% 5.9 ± 9.6 2.1 ± 3.0 4.9 ± 5.0 3.8 ± 3.4 8.9 ± 5.7 8.5 ± 5.7 LA-volume index 100% 100% 12.3 ± 7.8 8.7 ± 6.5 11.0 ± 6.9 9.2 ± 4.8 13.6 ± 11.8 10.1 ± 6.3 GLS 93% 98% 6.8 ± 5.2 5.6 ± 4.6 6.4 ± 4.9 5.6 ± 4.6 8.8 ± 7.6 6.9 ± 5.3 Selection of various echocardiographic parameters. *p &lt; 0.05