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Background: Bioprosthetic aortic valve degeneration is increasingly common, often unheralded, and can have catastrophic consequences.Objectives: The authors sought to assess whether 18F-fluoride positron emission tomography (PET)-computed tomography (CT) can detect bioprosthetic aortic valve degeneration and predict valve dysfunction.Methods: Explanted degenerate bioprosthetic valves were examined ex vivo. Patients with bioprosthetic aortic valves were recruited into 2 cohorts with and without prosthetic valve dysfunction and underwent in vivo contrast-enhanced CT angiography, 18F-fluoride PET, and serial echocardiography during 2 years of follow-up.Results: All ex vivo, degenerate bioprosthetic valves displayed 18F-fluoride PET uptake that colocalized with tissue degeneration on histology. In 71 patients without known bioprosthesis dysfunction, 14 had abnormal leaflet pathology on CT, and 24 demonstrated 18F-fluoride PET uptake (target-to-background ratio 1.55 [interquartile range (IQR): 1.44 to 1.88]). Patients with increased 18F-fluoride uptake exhibited more rapid deterioration in valve function compared with those without (annualized change in peak transvalvular velocity 0.30 [IQR: 0.13 to 0.61] vs. 0.01 [IQR: -0.05 to 0.16] ms-1/year; p < 0.001). Indeed 18F-fluoride uptake correlated with deterioration in all the conventional echocardiographic measures of valve function assessed (e.g., change in peak velocity, r = 0.72; p < 0.001). Each of the 10 patients who developed new overt bioprosthesis dysfunction during follow-up had evidence of 18F-fluoride uptake at baseline (target-to-background ratio 1.89 [IQR: 1.46 to 2.59]). On multivariable analysis, 18F-fluoride uptake was the only independent predictor of future bioprosthetic dysfunction.Conclusions: 18F-fluoride PET-CT identifies subclinical bioprosthetic valve degeneration, providing powerful prediction of subsequent valvular dysfunction and highlighting patients at risk of valve failure. This technique holds major promise in the diagnosis of valvular degeneration and the surveillance of patients with bioprosthetic valves. (18F-Fluoride Assessment of Aortic Bioprosthesis Durability and Outcome [18F-FAABULOUS]; NCT02304276). [ABSTRACT FROM AUTHOR]

Abstract Objectives This study investigated processes causing leaflet thickening and structural valve degeneration (SVD). Background Although transcatheter aortic valve replacement (TAVR) has changed the treatment of aortic stenosis, concerns remain regarding SVD, potentially related to valve thrombosis and thickening, based on studies using computed tomography (CT). Detailed histological analyses are provided to help attain insights into these processes. Methods Explanted transcatheter heart valves (THVs) were evaluated for thrombosis, fibrosis, and calcification for quantification of leaflet thickness. Immunohistochemical and microscopy approaches were used to investigate SVD-associated mechanisms. Results THVs (n = 23) were obtained from 22 patients (median 81 years of age; 50% male) from 0 to 2,583 days post TAVR. Maximal leaflet thickness increased relative to implant duration (ρ = 0.427; p = 0.027). THVs explanted after >2 years were thicker than those explanted after <2 years (p = 0.007). All THVs had adherent thrombus on both aortic and ventricular sides, which beyond 60 days was seen in combination with fibrosis and beyond 4 years had calcification. Early thrombus formation (<60 days) occurred despite rapid endothelialization with an abnormal hyperplastic phenotype. Fibrosis was observed in 6 patients on both the aortic and the ventricular THV surfaces, remodeled over time, and was associated with matrix metalloproteinase-1 expression. Five THVs showed overt calcification associated with adherent thrombus and fibrosis. Conclusions There is a time-dependent degeneration of THVs consisting of thrombus formation, endothelial hyperplasia, fibrosis, tissue remodeling, proteinase expression, and calcification. Future investigation is needed to further understand these mechanisms contributing to leaflet thickening and SVD. Graphical abstract [ABSTRACT FROM AUTHOR]

Treatment of unprotected severely calcified left main coronary artery (LMCA) disease is a complex interventional procedure. Intravascular lithotripsy (IVL) and rotational atherectomy (RA) are safe and effective methods of treating coronary calcification in the non-LMCA setting. This retrospective analysis assessed the feasibility of IVL versus RA in unprotected LMCA disease. We analyzed IVL and RA procedures performed at a large tertiary hospital in the Northeast of England from January 1, 2019 to April 31, 2022. Major safety and efficacy endpoints were procedural and angiographic success, defined by stent delivery with <50 % residual stenosis and without clinical or angiographic complications, respectively. Another important clinical endpoint was the composite of major adverse cardiac events (MACE) at 1 year. From 242 patients, 44 had LMCA IVL, 81 had LMCA RA and 117 had non-LMCA IVL. Patients with LMCA disease were older and more likely to have aortic stenosis. IVL was a second-line or bailout technique in 86.4 % LMCA and 92.2 % non-LMCA cases. Procedural and angiographic success rates were ≥ 84 % across all groups (p > 0.05). In 3 LMCA IVL and 3 LMCA RA cases arrhythmias and cardiac tamponade complicated the procedures respectively. At 1 year, MACE occurred in 10/44 (22.7 %) LMCA IVL, 16/81 (19.8 %) LMCA RA and 25/117 (21.4 %) cases (p > 0.05). In our single center retrospective analysis, IVL is feasible in unprotected calcified LMCA as a second-line and third-line adjuvant calcium modification technique. Its use in unprotected calcified LMCA disease should be formalized with the undertaking of large randomized controlled trials. [Display omitted] • Left main coronary artery (LMCA) patency is life-sustaining and life-prolonging. • Calcific LMCA disease is a significant interventional challenge. • Intravascular lithotripsy (IVL) acoustic shockwaves modify coronary calcium. • IVL is feasible with specific risks and benefits in the setting of calcific LMCA disease. • Treatment of calcific LMCA disease should be guided by the heart team. [ABSTRACT FROM AUTHOR]