Canadian Journal of Cardiology

String Sign and Heart Shape After 34-mm Evolut R Valve Implantation

Published:September 22, 2022DOI:
      An 83-year-old diabetic man underwent transcatheter aortic valve replacement (TAVR) for symptomatic severe aortic stenosis (mean gradient 51 mm Hg, valve area 0.7 cm2, calcium score: 4560 HU) (Fig. 1A). According to the computed tomography (CT) measurement performed with the use of Osirix and Trimensio software at 20% and 60% of the cardiac phase (perimeter 83.8 mm at 60% and 84.2 mm at 20%, sinus of Valsalva width > 31 mm) (Fig. 1B) and the presence of a chunk of calcium extending to the outflow tract (Fig. 1, C and D), a Medtronic 34-mm Evolut R transcatheter heart valve (THV) was implanted transfemorally without predilatation. Considering the residual mean gradient of 19 mm Hg (Fig. 1E) and the presence of the string sign or sign of underexpansion (vertical line along the valve frame corresponding to an infolding of the frame) (Fig. 1F), postdilatation was performed with the use of a 25-mm Nucleus balloon (Fig. 1G). The infolding persisted, but the final mean gradient was 9 mm Hg (Fig. 1H). Transthoracic echocardiography at discharge showed mild leak and a mean gradient of 8 mm Hg (Fig. 1I). At 30-day follow-up, CT scan showed highly calcified leaflets behind the valve frame and persistent frame infolding (Fig. 1, J and K); transesophageal echocardiography (Fig. 1L) and CT scan demonstrated that the prosthesis has a heart-shape inflow (Fig. 1M). At 3-year follow-up, the patient was asymptomatic and the echocardiographic control remained unchanged.
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      Figure 1(A) Pre–transcatheter atrial valve replacement simultaneous aortic mean gradient. (B-D) Calcium distribution and computed tomography (CT) scan measurement at 60% of the cardiac phase. (C) Sinus of Valsava width: green line, 33.0 mm; blue line, 35.6 mm; orange line, 33.6 mm). (E) Simultaneous aortic mean gradient after valve deployment. (F) Vertical line along the valve frame corresponding to a frame infolding (arrow). (G) Postdilatation with balloon full expansion. (H) Final simultaneous aortic mean gradient. (I) Transthoracic echocardiography at discharge showing mild leak. (J, K) CT scan at 30 days showing highly calcified native leaflets behind the stent frame and persistent frame infolding (arrow). (L) Heart-shaped prosthesis inflow at transeosophageal echocardiography. (M) CT scan showing heart-shaped prosthesis inflow, which explain the infolding.
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        • Ancona M.B.
        • Beneduce A.
        • Romano V.
        • et al.
        Self-expanding transcatheter aortic valve infolding: current evidence, diagnosis, and management.
        Catheter Cardiovasc Interv. 2021; 98: e299-e305