Transcatheter aortic valve implantation of the direct flow medical aortic valve with minimal or no contrast

摘要

The 18F Direct Flow Medical (DFM) THV has conformable sealing rings, which minimizes aortic regurgitation and permits full hemodynamic assessment of valve performance prior to permanent implantation. During the DISCOVER trial, three patients who were at risk for receiving contrast media, two due to severe CKD and one due to a recent hyperthyroid reaction to contrast, underwent DFM implantation under fluoroscopic and transesophageal guidance without aortography during either positioning or to confirm the final position. Valve positioning was based on the optimal angiographic projection as calculated by the pre-procedural multislice CT scan. Precise optimization of valve position was performed to minimize transvalve gradient and aortic regurgitation. Prior to final implantation, transvalve hemodynamics were assessed invasively and by TEE. The post-procedure mean gradients were 7, 10, 11mm Hg. The final AVA by echo was 1.70, 1.40 and 1.68cm2. Total aortic regurgitation post-procedure was none or trace in all three patients. Total positioning and assessment of valve performance time was 4, 6, and 12minutes. Contrast was only used to confirm successful percutaneous closure of the femoral access site. The total contrast dose was 5, 8, 12cc. Baseline eGFR and creatinine was 28, 22, 74mL/min/1.73m2 and 2.35, 2.98, and 1.03mg/dL, respectively. Renal function was unchanged post-procedure: eGFR=25, 35, and 96mL/min/1.73m2 and creatinine=2.58, 1.99, and 1.03mg/dL, respectively. In conclusion, the DFM THV provides the ability to perform TAVI with minimal or no contrast. The precise and predictable implantation technique can be performed with fluoro and echo guidance.