Impact of catheter size on reliability of quantitative coronary angiographic measurements (comparison of 4Fr and 6Fr catheters)

Abstract

To evaluate the feasibility of catheter down sizing for QCA, the reliability of a 4Fr catheter as a calibration device was evaluated. Repeated coronary angiograms of 9 lesions were obtained using 4Fr and 6Fr catheters under otherwise identical conditions. The calibration factor was measured 10 times by 4Fr and 6Fr catheters. QCA measurements including minimal lumen diameter (MLD), interpolated normal reference (Int N), percent diameter stenosis (%DS), and lesion length (LL) were performed by two technicians twice with a 3-month interval. The intraobserver and interobserver variability of each parameter was evaluated using intraclass correlation coefficients (ICCs). Mean of mean SD of calibration factor was significantly larger in 4Fr than in 6Fr in 9 lesions. The mean of mean coefficient of variance was significantly larger in 4Fr catheters vs in 6Fr catheters. A 6Fr catheter showed excellent reliability for both intraobserver and interobserver variability in MLD, Int N, %DS, and LL. In contrast, 4Fr showed that reliability in intraobserver variability depended on the analyst. Although reliability of interobserver variability in Int N measured by the 4Fr catheter was >0.80, the value was less than that by the 6Fr catheter. Taking these results into consideration, 4Fr catheters are less reliable than 6Fr catheters when measuring QCA data especially for follow-up data that need most accurate measurements of MLD and %DS. It would be better to use a 6Fr catheter to evaluate QCA measurements such as acute gain, late loss, restenosis rate, and device size.

Inter- and intra-core laboratory variability in the quantitative coronary angiography analysis for drug-eluting stent treatment and follow up

“…(2) Cine angiographic acquisition protocol (guidelines to angiography) in the J-D study At least a 6-Fr (diagnostic and/or guiding catheter) size was required as the reference source. 3 Quality evaluation of cine angiograms taken at research sites and feedback to each site using feedback sheets were performed to improve and unify cine angiograms among research sites at the beginning of the J-D study. (3) Cine projections and cine frames were selected independently by experts in ACL and CICL.…”

“…(5) Image calibration was performed using the contrast-filled diagnostic or guiding catheter (at least 6-Fr size). 3…”

“…At least a 6-Fr (diagnostic and/or guiding catheter) size was required as the reference source. 3 Quality evaluation of cine angiograms taken at research sites and feedback to each site using feedback sheets were performed to improve and unify cine angiograms among research sites at the beginning of the J-D study.…”

Impact of Cine Frame Selection on Quantitative Coronary Angiography Results

“…This cine film selection process and QCA were undertaken in the original research, but not included in the authors’ previously published study. 10…”

Clinical expert consensus document on quantitative coronary angiography from the Japanese Association of Cardiovascular Intervention and Therapeutics

“…The size of the catheter is preferably ≥ 6 French. Indeed, Ito et al reported that 4 French catheters are less reliable than 6 French catheters when measuring QCA data especially for follow-up data that need most accurate measurements of minimal lumen diameter and diameter stenosis [42]. Additional information regarding the catheter is not required, although a previous report showed the influence of the catheter type on the calibration [43].…”