Analysis of the early rise in aortic transvalvular gradient after aortic valvuloplasty

The relationship between dynamic changes in aortic valve gradient and left ventricular ejection performance in the early period after successful percutaneous aortic valvuloplasty has not been described in detail. Accordingly 20 adult patients with severe symptomatic calcific aortic stenosis underwent first-pass radionuclide angiography and Doppler echocardiography before, immediately after, and 2 to 4 days after the valvuloplasty procedure. A significant (p < 0.001) reduction in peak-to-peak (72 ± 24 mm Hg to 36 ± 11 mmHg) and mean (60 ± 20 mm Hg to 34 ± 9 mm Hg) transaortic gradient and an increase in aortic valve area (0.5 ± 0.2 cm² to 0.8 ± 0.2 cm²) were measured by high-fidelity micromanometer catheters immediately after aortic valvuloplasty. Results of Doppler echocardiography showed a significant (p < 0.001) immediate decrease in peak instantaneous (81 ± 22 mm Hg to 53 ± 15 mm Hg) and mean (48 ± 14 mm Hg to 31 ± 9 mm Hg) aortic gradients. However, 2 to 4 days later a significant (p < 0.001) return of peak (56 ± 15 mm Hg to 65 ± 20 mm Hg) and mean (31 ± 9 mm Hg to 39 ± 12 mm Hg) transvalvular gradient occurred. Aortic valve area as determined by the continuity equation also increased from 0.4 ± 0.2 cm² to 0.6 ± 0.2 cm² immediately after the procedure (p < 0.001), then partially returned to baseline (0.5 ± 0.2 cm²; p < 0.005) at 2 to 4 days. Results of serial first-pass radionuclide angiography performed at the same time as the Doppler evaluations showed a continued decrement in left ventricular end-diastolic volume (184 ± 42 ml to 158 ± 35 ml to 151 ± 35 ml) and a trend toward an increase in stroke volume. Additionally the mean ejection fraction continued to improve during this period (42 ± 18% to 49 ± 19% to 52 ± 19%). These data indicate that the early rise in aortic valve gradient seen after percutaneous aortic valvuloplasty is likely due to both remodeling of the aortic valve architecture and a small increase in stroke volume.