A randomised comparison of the use of 4 and 6 French diagnostic catheters:the limits of downsizing

Background: The use of small catheters for coronary angiography can reduce the risk of vascular complications and allow early ambulation, but excessiv e downsizing may lead to poor quality imaging. The aim of this study was to assess the feasibility of performing coronary angiography using 4 French ( 4 F) femoral catheters. Methods: In total, 400 consecutive elective patient s were randomised to undergo coronary angiography with 4 F or 6 F catheters . The puncture site was manually compressed and inspected before and after ambulation, and 24 h later. The handling difficulty of the catheters was se mi-quantitatively evaluated using a three grade scoring system; angiogram q uality was evaluated by two independent physicians. Results: No major proce dure-related complications were observed. Coronary arteriography with 4 F c atheters was possible in all of the attempted cases. There were no statisti cal differences between the two groups in terms of procedural or fluoroscop y time, the amount of contrast medium used, or the incidence of vascular co mplications, while compression time was significantly shorter in the patien ts studied using the smaller catheter (3.4 vs. 9.9 min; P < 0.0001). Cathet er stability was similar in the two groups, whereas catheter torque and the quality of the coronary angiograms were statistically better in the patien ts studied using six French catheters. Conclusions: Coronary angiography wi th 4 F catheters is technically feasible and permits early ambulation after the procedure. Although the radiological resolution of the images obtained using 4 F catheters was always adequate for clinical decision-making, the angiogram quality and catheter handling were significantly better using the 6 F system. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.