European Journal of Echocardiography | 2021
18F-Sodium fluoride PET/CT detects transcatheter aortic valve degeneration
Abstract
\n \n \n Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by the British Heart Foundation, London, United Kingdom\n \n \n \n Early detection of transcatheter aortic valve implantation (TAVI) degeneration is challenging and only feasible when advanced haemodynamic valve dysfunction is apparent.\xa0\n \n \n \n We tested whether\xa018F-sodium fluoride (18F-NaF) positron emission tomography and computed tomography (PET/CT) could detect structural TAVI degeneration and haemodynamic valve dysfunction.\xa0\n \n \n \n After TAVI implantation, patients underwent baseline echocardiography, CT angiography and\xa018F-NaF PET/CT (Figure). We assessed for morphological changes, stenosis or regurgitation on Doppler echocardiography, CT (hypoattenuated leaflet thickening [HALT] or spotty calcification) and PET (18F-NaF uptake; maximum target-to-background ratio, TBRmax). We categorised structural valve degeneration (SVD) according to the\xa0standardised definition for surgical and transcatheter bioprosthetic valves, as proposed in a recent consensus statement.\xa0\n \n \n \n We recruited 47 patients (81\u2009±\u20096 years old, 79% male) 1 month (n\u2009=\u20099), 2 years (n\u2009=\u200922) or 5 years (n\u2009=\u200916) after TAVI: 25 (53%) had received a balloon expanded bioprosthesis and 22 (47%) a self-expanding valve. There was moderate valve dysfunction on Doppler echocardiography in 3 (6%) patients, HALT on CT in 6 (13%) patients, spotty calcification in one patient and\xa018F-NaF uptake in 7 patients\xa0(15%)\xa0(TBRmax range: 1.59-5.88); all enrolled 5 years post-TAVI.\n All patients with increased\xa018F-NaF uptake (TBRmax\xa0≥1.59) demonstrated either SVD without haemodynamic valve dysfunction (stage 1, n\u2009=\u20094) or structural valve dysfunction with moderate valve dysfunction and mean transprosthetic pressure gradients >20 mmHg (stage 2, n\u2009=\u20093). In patients without increased\xa018F-NaF uptake there was no evidence of structural valve degeneration (n\u2009=\u200940).\n Within the increased\xa018F-NaF uptake (n\u2009=\u20097) group, patients with stage 2 SVD (n\u2009=\u20093) demonstrated higher uptake compared to patients with stage 1 SVD (TBRmax 4.3 [3.02-5.88] versus 1.8 [1.59-2.28]). Patients with stage 2 SVD (n\u2009=\u20093) had over 3 times higher TBRmax than those without SVD (n\u2009=\u200940) (4.30 [3.02, 5.88] versus 1.31 [1.21, 1.46]; p\u2009<\u20090.001); Figure).\n \n \n \n 18F-NaF PET/CT detects patients with SVD and potentially identifies those at risk of valve failure.\n Abstract Figure.\n