Randomized comparison of coronary angiography using 4F catheters: 4F manual versus "Acisted" power injection technique

A Practical Approach to Preventing Renal Complications in the Catheterization Laboratory

Kidney injury following cardiac catheterization is an infrequent, though persistent, complication, which in some cases may be preventable. Patients at increased risk for renal complications following catheterization can be identified through individual and procedural risk factors, and several risk-prediction models are readily available. The authors advocate for the development of an easily implemented and standardized protocol, readily accessible to catheterization laboratory staff, for the identification and treatment of those patients who may be at increased risk for renal complications following cardiac catheterization.

Device-Based Therapy in the Prevention of Contrast-Induced Nephropathy

Contrast-induced nephropathy (CIN) is a common condition that is associated with short- and, likely, long-term adverse outcomes. Although periprocedural intravenous hydration is the simplest and most widely used technique to prevent CIN, the limited ability of this approach to mitigate the CIN risk in high-risk populations has provided an impetus to develop new preventive strategies. A range of potentially useful device-based approaches offers new preventive techniques. Well-designed and adequately powered randomized studies of these device-based therapies are urgently needed to determine the expanding role they will play in future clinical practice.

Meta-analysis of the effect of automated contrast injection devices versus manual injection and contrast volume on risk of contrast-induced nephropathy

Contrast-sparing devices have been slowly adopted into routine patient care. Randomized trial evidence of automated contrast injectors (ACIs) has not been analyzed to evaluate the true reduction in contrast volume during coronary angiography and intervention. It has been thought that reducing the amount of contrast exposure will result in a simultaneous reduction in the risk of contrast-induced nephropathy (CIN). Therefore, we sought to synthesize published evidence on contrast-sparing devices, contrast volume, and the incidence of CIN. We searched Medline, the Cochrane Library, and Clinicaltrials.gov. The search criteria included ACIs versus manual injection, contrast media volume, and the incidence of CIN. Data were extracted by 2 independent reviewers. The weighted mean difference of contrast volume was calculated using random effects models in RevMan, version 5.4.1, software to derive a summary estimate. A total of 79,694 patients from 10 studies were included (ACI arm, n = 20,099; manual injection arm, n = 59,595). On average, ACIs reduced contrast volume delivery by 45 ml/case (p <0.001, 95% confidence interval -54 to -35). The CIN incidence was significantly reduced by 15%, with an odds ratio of 0.85 (p <0.001, 95% confidence interval 0.78 to 0.93) for those using ACIs compared with manual injection. In conclusion, the use of ACIs in angiography significantly reduces the volume of contrast delivered to the patient and the incidence of CIN.

The ACIST power injection system reduces the amount of contrast media delivered to the patient, as well as fluoroscopy time, during diagnostic and interventional cardiac procedures

The ACIST injection system is an automatic power injection device that allows for online control of injection rate and volume of contrast. Limited data is available whether this technology allows reducing use of contrast and fluoroscopy time. Accordingly, we compared the use of this system to manual injection among 450 consecutive patients who underwent diagnostic coronary angiography and/or angioplasty who were randomly assigned to either manual contrast injection (control; n=198) or to the ACIST system (study group; n=252). The amount of contrast, fluoroscopy and total procedural times were recorded for each patient. In the diagnostic group, the mean total amount of contrast (including wasted) was reduced by 63% when the ACIST was used compared to control (100+/-42 ml versus 163+/-56 ml; P<0.001, respectively). When only the net amount of contrast delivered to the patient was considered, the differences were smaller (20%, P=0.004). During angioplasty, the amount of contrast was also lower in the ACIST group (206+/-65 versus 230+/-69, P=0.008), whereas no difference were noted in net amount of contrast. Fluoroscopy time was significantly shorter in the ACIST group compared to control both during diagnostic catheterization (4.7+/-3.5 min versus 6.3+/-5.5 min, respectively; P=0.014), and angioplasty (16.7+/-9.1 min versus 19.6+/-12.4 min, respectively; P=0.05). Routine utilization of the ACIST system during diagnostic and interventional procedure significantly reduced the total amount of contrast media used and fluoroscopy time.

Measuring pressure-derived fractional flow reserve through four French diagnostic catheters

Measurement of fractional flow reserve (FFR) with a pressure wire is used to discriminate between patients with and without functionally significant lesions. FFR can be assessed through a conventional 4Fr diagnostic catheter, which is a more convenient method of assessment. The aim of this study was to assess the feasibility, safety, repeatability, and reliability of routine FFR measurements through 4Fr diagnostic catheters. From a single-center prospective registry, results of FFR assessment through a 4Fr catheter were used to determine: (1) feasibility and safety, by the procedural success rate and immediate and 30-day clinical outcome; (2) repeatability, by the intraclass correlation coefficient and comparison of the difference (means +/- 2 SDs); and (3) reliability, by comparison of results obtained using 4Fr versus 7Fr guiding catheters. During the study period, FFR was measured in 190 patients, in 122 using a diagnostic 4Fr catheter (study population) and in 68 using a 7Fr guiding catheter. Measurement of FFR wa successful in 115 of 122 patients (94%). No complications related to the use of the 4Fr catheter occurred. Repeatability was determined from 108 repeated measurements: the intraclass correlation coefficient was 0.942 and the mean difference between repeated FFR measurements was -0.001 +/- 0.038. Reliability was determined from 15 unselected patients; there was no systematic error and only 1 value was out of the range of 2 SDs of the mean difference. Using a threshold value of 0.75, the Kappa coefficient for the qualitative agreement was 0.84. Thus, pressure-derived FFR assessment can safely be performed through 4Fr diagnostic catheters, with similar repeatability and reliability as 7Fr guiding catheters, resulting in a simplification of the measurement procedure.

[Coronary angiography with 4 f catheters by the radial: minimally invasive catheterization]

INTRODUCTION AND OBJECTIVES

Experience with 4 F catheters in cardiac catheterization is limited. These devices appear to be more suitable for the radial artery approach than conventional 6 F catheters.

METHODS

We analyze our preliminary experience with diagnostic catheterization of the radial artery with 4 F catheters. Angiographic images were evaluated using a predefined scale (1. poor; 2. acceptable; 3. optimal). In a subgroup of patients who underwent coronary angioplasty, the quantitative angiographic data obtained with the 4 F catheter were compared to those obtained with the 6 F guide catheter. In all cases the patients were clinically followed-up at 24 h and 7 days.

RESULTS

Two hundred and six studies performed over a 12-month period were reviewed. In 6 cases (2.9%) the femoral vein had to be used instead and in 4 cases (1.9%) the 4 F catheters were replaced by 6 F catheters. The left coronary angiography was graded as optimal in 83% and as acceptable in 15%. Right coronary artery images were considered optimal in 93% and acceptable in 7%. There was an excellent correlation between the reference diameter obtained by quantitative angiography with the 4 F catheter and values obtained with a 6 F guide catheter (r = 0.92; p < 0.01). No major vascular complications occurred.

CONCLUSION

4 F catheters are appropriate for systematic use in diagnostic procedures using the radial access.