A Novel Handheld Echocardiography Device with Continuous-Wave Doppler Capability: Implications for the Evaluation of Aortic Stenosis Severity.

BACKGROUND

The aim of this study was to evaluate the ability of a novel handheld echocardiography (HHE) device with continuous-wave Doppler (CWD) capability to measure aortic valve peak jet velocity (Vmax) and facilitate aortic stenosis (AS) severity grading.

METHODS

One hundred twenty-one consecutive patients with known or suspected AS were prospectively included. All patients were scanned with the HHE device and a high-end echocardiography system (the reference standard) to obtain CWD signal across the aortic valve. Aortic Vmax measurements were acquired from the apical five-chamber view using both methods and were compared to assess method agreement using the intraclass correlation coefficient, linear regression analysis, and Bland-Altman analysis. Diagnostic accuracy for the detection of at least moderate AS (Vmax ≥ 3 m/sec) was calculated. Also, the utility of HHE with CWD to reclassify patients compared with the visual estimation of AS severity was assessed.

RESULTS

The acquisition of CWD signal using HHE was feasible in 118 of 121 patients (mean age, 68 ± 17 years; 57% men). There was excellent agreement between the HHE CWD and the cart-based measurements (intraclass correlation coefficient = 0.97 [95% CI: 0.83-0.99] and r = 0.98 [95% CI: 0.91-0.99], P < .001 for both). The Bland-Altman plot showed a small underestimation bias of -0.2 m/sec (P < .001), with limits of agreement ±0.44 m/sec for Vmax. Detection of at least moderate AS using HHE with CWD was feasible with sensitivity of 93% (95% CI: 83%-98%), specificity of 98% (95% CI: 91%-100%), positive predictive value of 98% (95% CI: 88%-100%), negative predictive value of 94% (95% CI: 85%-97%), and total diagnostic accuracy of 96%. Patients visually assessed as having mild AS were reclassified as having no stenosis (17%), mild AS (72%), or moderate AS (11%) with the addition of CWD imaging.

CONCLUSIONS

Use of a novel HHE device with CWD spectral analysis by experienced operators can reliably detect clinically significant AS and facilitate AS grading. This technology may improve screening and diagnostic workup of AS compared with current practice.