Value of Image Fusion in Coronary Angiography for the Detection of Coronary Artery Bypass Grafts

Computed Tomography Cardiac Angiography Before Invasive Coronary Angiography in Patients With Previous Bypass Surgery: The BYPASS-CTCA Trial

BACKGROUND

Patients with previous coronary artery bypass grafting often require invasive coronary angiography (ICA). However, for these patients, the procedure is technically more challenging and has a higher risk of complications. Observational studies suggest that computed tomography cardiac angiography (CTCA) may facilitate ICA in this group, but this has not been tested in a randomized controlled trial.

METHODS

This study was a single-center, open-label randomized controlled trial assessing the benefit of adjunctive CTCA in patients with previous coronary artery bypass grafting referred for ICA. Patients were randomized 1:1 to undergo CTCA before ICA or ICA alone. The co-primary end points were procedural duration of the ICA (defined as the interval between local anesthesia administration for obtaining vascular access and removal of the last catheter), patient satisfaction after ICA using a validated questionnaire, and the incidence of contrast-induced nephropathy. Linear regression was used for procedural duration and patient satisfaction score; contrast-induced nephropathy was analyzed using logistic regression. We applied the Bonferroni correction, with P<0.017 considered significant and 98.33% CIs presented. Secondary end points included incidence of procedural complications and 1-year major adverse cardiac events.

RESULTS

Over 3 years, 688 patients were randomized with a median follow-up of 1.0 years. The mean age was 69.8±10.4 years, 108 (15.7%) were women, 402 (58.4%) were White, and there was a high burden of comorbidity (85.3% hypertension and 53.8% diabetes). The median time from coronary artery bypass grafting to angiography was 12.0 years, and there were a median of 3 (interquartile range, 2 to 3) grafts per participant. Procedure duration of the ICA was significantly shorter in the CTCA+ICA group (CTCA+ICA, 18.6±9.5 minutes versus ICA alone, 39.5±16.9 minutes [98.33% CI, -23.5 to -18.4]; P<0.001), alongside improved mean ICA satisfaction scores (1=very good to 5=very poor; -1.1 difference [98.33% CI, -1.2 to -0.9]; P<0.001), and reduced incidence of contrast-induced nephropathy (3.4% versus 27.9%; odds ratio, 0.09 [98.33% CI, 0.04-0.2]; P<0.001). Procedural complications (2.3% versus 10.8%; odds ratio, 0.2 [95% CI, 0.1-0.4]; P<0.001) and 1-year major adverse cardiac events (16.0% versus 29.4%; hazard ratio, 0.4 [95% CI, 0.3-0.6]; P<0.001) were also lower in the CTCA+ICA group.

CONCLUSIONS

For patients with previous coronary artery bypass grafting, CTCA before ICA leads to reductions in procedure time and contrast-induced nephropathy, with improved patient satisfaction. CTCA before ICA should be considered in this group of patients.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03736018.

Improved stereo perception in coronary angiography using the X-ray tube as the viewpoint and validation with 3D printed models

Coronary angiography (CAG) provides two-dimensional images, but a clinician who is experienced in percutaneous coronary interventions can use information from these images to interpret spatial depth and infer the three-dimensional (3D) locations of vessels. We hypothesized that CAG results were equivalent to the mirror image of a coronary artery perspective projection, and a stereo perception could be easily established when the viewpoint of the angiogram was the X-ray tube instead of the detector. To eliminate the influence of heartbeat and respiration, a 3D-printed a coronary artery model was constructed for analysis. The effects of gantry movements during digital subtraction angiography (DSA) on the image were used to identify factors that affected DSA image transformation. Then, based on these factors, DSA imaging was simulated using UG NX software with three methods: (i) a perspective projection with the detector as the viewpoint; (ii) a parallel projection; and (iii) a mirror image of the perspective projection with the X-ray tube as the viewpoint. Finally, the resulting 3D images were compared with the DSA image. Our mirror image of the coronary artery perspective projection that used the X-ray tube as the viewpoint fused precisely with the CAG results and provided exact simulations of all the effects of DSA gantry movements on the DSA image. CAG results were equivalent to the mirror image of coronary artery perspective projection, and the stereo perception was easily established using the X-ray tube as the viewpoint.

Coronary CTA Would Facilitate Invasive Angiography in Patients With Acute Coronary Syndrome and Coronary Bypass Grafting History

Background

The uncertainties of grafts’ ostium and patency would cause prolonged procedure/fluoroscopy time and extra contrast agent consumption of the invasive coronary angiography (ICA) in patients with coronary artery bypass grafting (CABG) history. This study was conducted to evaluate whether the identification of grafts’ ostium and patency by coronary computed tomographic angiography (CTA) could facilitate ICA procedure.

Methods

Patients with acute coronary syndrome (ACS) and CABG history who underwent ICA during hospitalization were enrolled. The patients were divided into the CTA–ICA group and the direct ICA group according to whether a coronary CTA was performed before ICA. The complete direct ICA was defined by successful selective angiography of all recorded grafts. The procedure/fluoroscopy time and contrast agent consumption of ICA were compared.

Results

There were 14 patients in the CTA–ICA group and 24 patients in the direct ICA group. In the direct ICA group, twelve cases were conducted complete ICA. The CTA–ICA group had reduced procedure time (17.8 ± 7.1 vs. 25.9 ± 15.4 min, p = 0.03) and fluoroscopy time (fluor-time; 4.6 ± 2.3 vs. 9.8 ± 5.3 min, p &lt; 0.01), and less contrast agent consumption (30.4 ± 5.6 vs. 49.8 ± 20.9 ml, p &lt; 0.01) than the direct ICA group. In a subgroup analysis, the incomplete direct ICA had the longest procedure time (32.8 ± 16.5 min) or fluor-time (12.0 ± 5.5 min) and the most contrast agent consumption (58.3 ± 25.8 ml), whereas the difference between CTA–ICA and complete direct ICA groups was non-significant.

Conclusion

The CTA would facilitate invasive angiography in patients with CABG by reducing procedure/fluoroscopy time and contrast agent consumption.

The BYPASS-CTCA Study: the value of Computed Tomography Cardiac Angiography (CTCA) in improving patient-related outcomes in patients with previous bypass operation undergoing invasive coronary angiography: Study Protocol of a Randomised Controlled Trial

Background

Patients with ischaemic heart disease and previous coronary artery bypass grafting (CABG) often need coronary evaluation by means of invasive coronary angiography (ICA). ICA in such patients is technically more challenging and carries a higher risk of complications including kidney damage, myocardial infarction, stroke and death. Improvements in Computed Tomography Cardiac Angiography (CTCA) technology have ensured its emergence as a useful clinical tool in CABG assessment, allowing for its potential use in planning interventional procedures in this patient group.

Methods

The BYPASS-CTCA study is a prospective, single centre, randomised controlled trial assessing the value of upfront CTCA in patients with previous surgical revascularisation undergoing ICA procedures. A total of 688 patients with previous CABG, requiring ICA for standard indications, will be recruited and randomised to receive ICA alone, or CTCA prior to angiography. Subjects will be followed up over a 12-month period post procedure. The primary endpoints are ICA procedural duration, incidence of contrast-induced nephropathy (CIN) and patient satisfaction scores post ICA. Secondary endpoints include contrast dose (mL) and radiation dose (mSv) during ICA, number of catheters used, angiography-related complications and cost-effectiveness of CTCA (QALY) over 12 months.

Discussion

The study will investigate the hypothesis that CTCA prior to ICA in patients with previous CABG can reduce procedural duration, post-procedural kidney damage and improve patient satisfaction, therefore strengthening its role in this group of patients.

Trial Registration

The study is registered on ClinicalTrials.gov which is a resource maintained by the U.S. National Library of Medicine. Registration number NCT03736018.

Application of cardiac computed tomographic imaging and fluoroscopy fusion for guiding left atrial appendage occlusion

OBJECTIVE

Evaluate the value of 3D computed tomography (CT) and CT-integrating fluoroscopy for procedural guidance during WATCHMAN implantation.

METHODS

This observational study compared the clinical and procedural parameters for LAAO with and without fusion imaging. Forty-one pairs of patients-matched by procedure month and with or without the use of the image fusion system-were enrolled. Using the image fusion Advanced Workstation 4.6 software (GE Healthcare), we identified the 3D cardiac anatomy and safe zones for septal punch. The LAA orifice anatomy outlines were then projected onto the real-time fluoroscopy image during the procedure to guide all the steps of LAAO.

RESULTS

The use of image fusion significantly reduced the procedural time, compared to the time required for the control group (44.73 ± 20.03 min vs. 63.73 ± 26.10 min, respectively; P < 0.001). When compared to the standard procedure, the use of image fusion significantly reduced both the total radiation dose (448.80 ± 556.35 mGy vs. 798.42 ± 616.34 mGy; P = 0.004) and dose area product (DAP) (38.03 ± 47.15 Gy∙cm2 vs. 67.66 ± 52.23 Gy∙cm², P = 0.004). Corresponding to the radiation dose, the contrast volume was also reduced (67.32 ± 18.65 vs. 90.98 ± 25.03 ml; P = 0.0004). During short-term follow-up at 6 months, there was only one femoral hematoma and incomplete LAA sealing (>3 mm) in either group.

CONCLUSIONS

Automated real-time integration of cardiac CT and fluoroscopy is feasible, safe, and applicable in LAAO. It may significantly reduce the radiation exposure, procedure duration, and volume of contrast media. Following these results, the potential of merging reconstructed 3D CT scans with real-time coronary angiography should be fully exploited in LAAO.

Long-term evolution of stents implanted in branch pulmonary arteries

BACKGROUND

Branch pulmonary artery stenosis complicates the management of congenital heart diseases. Surgical branch pulmonary artery angioplasty is associated with a high reintervention rate. As an alternative, percutaneous or intraoperative branch pulmonary artery stents have been implanted to improve efficiency, but long-term evaluations are limited.

AIM

To describe the long-term evolution of branch pulmonary artery stents.

METHODS

We conducted a retrospective cohort study at Tours University Hospital. All stents implanted by surgery or catheterization in branch pulmonary arteries with a minimum follow-up of 12 months and at least one catheterization control were included. The primary endpoint combined cardiovascular mortality, surgical or percutaneous reintervention for stent complication or new stent implantation.

RESULTS

Between 2007 and 2017, 76 stents in 51 patients were included (62 stents implanted by surgery, 14 by catheterization). At implantation, the patients' mean age and weight were 4.7years (interquartile range 4.2years) and 17.3kg (interquartile range 11.0kg), respectively. Mean branch pulmonary artery minimum diameter was 4.1±2.1mm (mean Z-score-4.9±2.9), and mean initial stent diameter was 9.1±3.1mm. During a follow-up of 5.3years (range 0-11.2 years), freedom from primary endpoint was 86.8% (95% confidence interval 79.6-94.8%) at 1 year, 71.5% (95% confidence interval 61.9-82.7%) at 5years and 69.6% (95% confidence interval 59.6-81.2%) at 10 years. We did not identify any factors associated with major adverse cardiovascular events. Among stents without major adverse cardiovascular events, the mean branch pulmonary artery diameter Z-score at last evaluation had increased by +4.8±3.2 compared with the initial diameter (P<0.001). After stent implantation, a median of 2 re-expansions were performed for each stent (range 0-7).

CONCLUSIONS

Stent implantation should offer a good long-term solution for branch pulmonary artery stenosis, although iterative re-expansions are required.

Impact of proximal radiopaque coronary bypass graft markers on postbypass surgery coronary angiography

BACKGROUND

Implantation of radiopaque bypass graft markers during coronary artery bypass surgery (CABG) has the potential of facilitating subsequent coronary angiography. This study sought to investigate the impact of proximal coronary bypass graft markers on angiographic outcomes during subsequent coronary angiography in a large cohort.

METHODS AND RESULTS

Between 2005 and 2016, we enrolled 1378 patients (331 with and 1047 without bypass graft markers) with a history of CABG who underwent their first subsequent coronary angiography at our institution. Primary endpoints were radiation time and absolute amount of contrast media used. In unadjusted analyses, radiation time, duration of angiography, dose area product, and the amount of contrast agent were significantly lower in patients with proximal bypass graft markers (P < .001). After full adjustment, proximal coronary bypass graft markers remained a significant predictor for less radiation time and a lower consumption of contrast agent but not for dose area product, which was mainly associated with body mass index and sex. Bypass graft markers were not associated with a lower graft patency.

CONCLUSIONS

Radiopaque coronary bypass graft markers can improve the detection of bypass grafts during subsequent coronary angiography and are associated with a lower radiation time and less consumption of contrast agent. Thus, this easy and cost-efficient technique might significantly reduce the risk of coronary angiography after CABG.

[Multimodality imaging in the cardiac catheterization laboratory]

Cardiac catheterization has greatly contributed to the progress made in the management of congenital heart diseases (CHD). Initially used in diagnosis, it allowed the understanding of heart diseases, their anatomy and hemodynamics. Gradually, the development of interventional cardiology has played a major role in the management of these malformations (Patent ductus arteriosus [PDA] and atrial septal defect [ASD] closure, pulmonary dilatation, percutaneous pulmonary valve implantation…). The development of such technology was made possible through the concomitant development of imaging techniques: fluoroscopy, ultrasound, MRI and CT. Imaging should provide an accurate view of the lesions, the surrounding cardiac structures, as well as medical devices and catheters used. Here we address the field of fusion images. The principle of image fusion is based on the association by superposition of several imaging techniques: real-time fluoroscopy and slice imaging performed offline, or ultrasound imaging performed simultaneously. The goal is to improve the overall view of the organ, its surrounding structures and as the consequence to help the interventional cardiologist.