Objective:: To evaluate feasibility, image quality and accuracy of a reduced contrast volume protocol for pre-procedural CT imaging in transcatheter aortic valve implantation (TAVI) using a third generation wide array CT scanner.
Methods:: 115 consecutive patients (51F, mean age 82.5 ± 6.2 y, mean BMI 26.7 ± 3.6) referred for TAVI were examined with wide-array CT scanner with a combined scan protocol and a total amount of 50 ml contrast agent. A 4-point visual scale (4-1) was used to assess image quality . Contrast attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the level of the aortic root, ascending/descending aorta, subrenal aorta and at the level of right and left common femoral arteries. Coronary tree was assessed and compared with invasive coronary angiography (ICA). Aortic annulus measurements were compared with final procedural results. Patients creatinine was monitored at the baseline and 72 h after procedure.
Results:: Median quality score value was >3. Mean CNR at the level of the aortic root, ascending/descending aorta, subrenal aorta and at the level of right and left common femoral arteries were 14.8 ± 2.3, 15.7 ± 1.7, 14.9 ± 3.1, 15.8 ± 4.7, 20.3 ± 9.9, 20.8 ± 6.9 respectively. Only 1 patient had moderate paravalvular regurgitation. In comparison with ICA for coronary assessment CTA showed in a segment based analysis sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 97, 85, 99,62 and 88% respectively. Mean creatinine before CT and 72 h after procedure were 1.21 ± 0.52 and1.22 ± 0.49 mg dl-1. Mean DLP was 442.4 ± 21.2 mGy/cm.
Conclusion:: CT with low contrast volume is feasible and clinically useful, allowing precise pre-procedural TAVI planning with accurate assessment of coronary tree.
Advances in knowledge:: third generation CT scanner with whole heart coverage allows examinations for assessment of aorta and coronary arteries in TAVI planning using low dose of contrast medium maintaining good quality and high diagnostic accuracy.