Validation of a hand-held ultrasound device in the evaluation of aortic stenosis

Abstract

Hand-held ultrasound devices (HHUD) are increasingly used in routine clinical practice, though they lacked continuous (CW) Doppler capability until recent times. There is limited evidence on the utility of HHUD in assessing aortic stenosis (AS) in real-world settings. Our goal was to validate a new HHUD with CW Doppler assessing AS hemodynamic severity. An observational, single-center study at the Valdecilla University Hospital, Santander, Spain between October 2022 and August 2023 was conducted. Patients previously diagnosed with AS were consecutively recruited. Following a reference echocardiographic examination in the cardiac imaging laboratory by an experienced operator (American Society of Echocardiography, level III), a HHUD with CW Doppler (Kosmos, EchoNous™) was used by an operator with intermediate echocardiography experience (American Society of Echocardiography, level II). The focus was on measuring aortic transvalvular Doppler velocities. Agreement between the mean trans-aortic gradient (mAG) was assessed using the intraclass correlation coefficient (ICC) test. A total of 101 patients were included. The reference test obtained a mAG of 29 mmHg [19.8-42.2], while the HHUD test showed 27.2 mmHg [16.2-43.9]. A strong correlation was observed (r = 0.89), with an ICC value of 0.87 and no significant bias (1.61 ± 0.9). The HHUD demonstrated very good ability to identify severe AS (kappa = 0.81, 95% CI 0.68-0.94; global agreement 92.1%) and good agreement for moderate (kappa = 0.58; global agreement = 80.2%) and mild (kappa = 0.73; global agreement = 88.1%) AS. Agreement was lower in patients with obesity (ICC = 0.63), poor acoustic windows (ICC = 0.74), or atrial fibrillation (ICC = 0.74). The HHUD showed good agreement with standard echocardiography in assessing AS. While it slightly underestimated mAG, it was accurate enough to reliably quantify AS severity.

Keywords: Aortic stenosis; Echocardiography; Hand-held ultrasound; Point of care ultrasound.