Very low intravenous contrast volume protocol for computed tomography angiography providing comprehensive cardiac and vascular assessment prior to transcatheter aortic valve replacement in patients with chronic kidney disease

Abstract

Background Transcatheter aortic valve replacement (TAVR) is a lifesaving procedure for many patients high risk for surgical aortic valve replacement. The prevalence of chronic kidney disease (CKD) is high in this population, and thus a very low contrast volume (VLCV) computed tomography angiography (CTA) protocol providing comprehensive cardiac and vascular imaging would be valuable. Methods 52 patients with severe, symptomatic aortic valve disease, undergoing pre-TAVR CTA assessment from 2013-4 at Columbia University Medical Center were studied, including all 26 patients with CKD (eGFR<30mL/min) who underwent a novel VLCV protocol (20mL of iohexol at 2.5mL/s), and 26 standard-contrast-volume (SCV) protocol patients. Using a 320-slice volumetric scanner, the protocol included ECG-gated volume scanning of the aortic root followed by medium-pitch helical vascular scanning through the femoral arteries. Two experienced cardiologists performed aortic annulus and root measurements. Vascular image quality was assessed by two radiologists using a 4-point scale. Results VLCV patients had mean(±SD) age 86±6.5, BMI 23.9±3.4 kg/m2 with 54% men; SCV patients age 83±8.8, BMI 28.7±5.3 kg/m2, 65% men. There was excellent intra- and inter-observer agreement for annular and root measurements, and excellent agreement with 3D-transesophageal echocardiographic measurements. Both radiologists found diagnostic-quality vascular imaging in 96% of VLCV and 100% of SCV cases, with excellent inter-observer agreement. Conclusions This study is the first of its kind to report the feasibility and reproducibility of measurements for a VLCV protocol for comprehensive pre-TAVR CTA. There was excellent agreement of cardiac measurements and almost all studies were diagnostic quality for vascular access assessment.

320-row CT transcatheter aortic valve replacement planning with a single reduced contrast media bolus injection

“…One of the most effective precaution to prevent this complication is to decrease the total dose of iodine CM to the lowest possible [ 19 ]. As described below, a number of authors [ 20 – 25 ] have studied different acquisition protocols to achieve this goal.…”

Validation of a low-dose contrast 64-slice cardiac computed tomography angiography protocol for aortic valve annulus sizing

“…19 The most comprehensive study to date utilized a 320-slice volumetric CT scanner that is not currently available in most centers. 18 Thus, our study offers information that matches real-world scenarios in terms of patient population as well as imaging capabilities.…”

“…First, the majority of these studies have examined small numbers of patients, ranging from 8 to 33 patients undergoing an LDCT protocol-less than half of the number of patients included in our analysis. [16][17][18][19] Second, prior reports have focused on specific patient populations such as octogenarians 16 or patients with chronic kidney disease, 18 whereas our study included all TAVI candidates. One published protocol required direct injection of contrast into the aorta through a pigtail catheter inserted through the femoral or radial artery.…”

“…1,2,14 Previous reports regarding reduced-dose CCTA have lacked comparison groups, 15 included small sample sizes, 16,17 or utilized advanced, high-slice computed tomography (CT) systems that are not available in most centers. 18,19 Herein, we review our center's experience with a low-dose contrast CCTA protocol using a 64-slice CT scanner in a series of consecutive TAVI candidates.…”

Transcarotid Transcatheter Aortic Valve Replacement in an Octogenarian With Complex Type B Aortic Dissection and Aneurysm: A Case Report

“…7 One study used a very low contrast volume of 20 ml of iohexol for MDCT to define aortic annulus and peripheral vascular measurements before TAVR in subjects with an eGFR< 30 mL/min. 8 Another study by Maffeo D et al proposed zero contrast medium use both in pre-TAVR MDCT and during CoreValve implantation, with assistance of two pigtail catheters for annulus plain estimation in 12 cases with advanced CKD. In our case, non-contrast MDCT helped to incidentally find the complex type B aortic dissection involving aortic arch, descending thoracic and abdominal aorta with extension to right common iliac artery.…”