Quantitative Doppler for Estimation of Paravalvular Leakage after Transcatheter Aortic Valve Implantation

BACKGROUND: The echocardiographic grading of paravalvular aortic leakage (PVL) after transcatheter aortic valve implantation (TAVI) severity is challenging. The study aim was to assess the value of quantitative Doppler echocardiography to monitor PVL severity.
METHODS: A total of 100 subjects was enrolled in the study, including 65 consecutive patients who had undergone TAVI with a CoreValve prosthesis and without valvular aortic regurgitation, and 35 normal controls. The PVL volume was calculated using the quantitative Doppler method as the difference of left and right ventricular stroke volume (SV). PVL severity was assessed both visually and quantitatively as the circumferential extent on a short-axis view (SAX).
RESULTS: The inter-observer variabilities for SVs in TAVI patients were disappointing: 14 ± 11% for the left ventricular SV and 18 ± 14% for right ventricular SV. The correlation (r2) between the averaged regurgitant PVL volume and circumferential SAX extent of PVL was 0.02 (p = NS). The relationship between PVL volumes and categories, defined quantitatively by the circumferential SAX extent of PVL and qualitatively by visual assessment of severity of PVL were poor. The results improved when only patients with optimal quality images were included but were still statistically non-significant.
CONCLUSIONS: The relationship between calculated PVL volume in TAVI patients and other estimates of PVL severity was poor, most likely due to intrinsic errors made in the quantitative Doppler method. Therefore, one should be prudent to include the quantitative Doppler method in TAVI patients in clinical trials and clinical decision-making, in particular in patients with reduced image quality.