Zero-contrast imaging for the assessment of transcatheter aortic valve implantation in candidates with renal dysfunction

Background Candidates for transcatheter aortic valve implantation (TAVI) are currently evaluated using computed tomography angiography and invasive cardiac catheterization as an essential part of case selection and pre-procedure interventional planning. However, both imaging methods utilize iodinated agents, which may cause contrast-induced nephropathy, particularly in patients with baseline renal dysfunction. This study aimed to describe a zero-contrast imaging protocol for pre-TAVI evaluation in patients with advanced renal impairment. Methods The pre-TAVI zero-contrast scheme consisted of the following multi-modality combinations: (1) gadolinium-free magnetic resonance imaging (three-dimensional navigator-echo with electrocardiogram-gated steady-state free-precession series); (2) iodinated-free multislice computed tomography electrocardiogram-gated; (3) lower limb arterial duplex scan ultrasound; and (4) transesophageal echocardiography. Ultimately, TAVI was performed for those deemed good candidates, and contrast was allowed during the intervention; however, operators were strongly advised to utilize the least volume possible of iodinated agents. This pilot survey included ten patients with symptomatic aortic stenosis and renal dysfunction who underwent zero-contrast multi-modality imaging. Results All the patients ultimately underwent TAVI. The intervention was successful in all cases, without >= moderate residual aortic regurgitation, prosthesis embolization, annulus rupture, major vascular complications, stroke, or death during index hospitalization. The creatinine clearance remained stable throughout the observation period (baseline: 26.85 +/- 12.55 mL/min; after multi-modality imaging: 26.76 +/- 11.51 mL/min; post-TAVI at discharge: 29.84 +/- 13.98 mL/min; p = 0.3 all). Conclusion The proposed contrast-free imaging protocol appears to be a promising clinical tool for pre-TAVI evaluation in patients with severe renal dysfunction.