Utility of multislice computed tomography as a strategic tool for complex percutaneous coronary intervention

Quantitative angiography methods for bifurcation lesions: a consensus statement update from the European Bifurcation Club

Bifurcation lesions represent one of the most challenging lesion subsets in interventional cardiology. The European Bifurcation Club (EBC) is an academic consortium whose goal has been to assess and recommend the appropriate strategies to manage bifurcation lesions. The quantitative coronary angiography (QCA) methods for the evaluation of bifurcation lesions have been subject to extensive research. Single-vessel QCA has been shown to be inaccurate for the assessment of bifurcation lesion dimensions. For this reason, dedicated bifurcation software has been developed and validated. These software packages apply the principles of fractal geometry to address the "step-down" in the bifurcation and to estimate vessel diameter accurately. This consensus update provides recommendations on the QCA analysis and reporting of bifurcation lesions based on the most recent scientific evidence from in vitro and in vivo studies and delineates future advances in the field of QCA dedicated bifurcation analysis.

Dual-Source Computed Tomography for Chronic Total Occlusion of Coronary Arteries

OBJECTIVES

We compared dual-source CT (DSCT) and conventional angiography (CA) in evaluation of chronic total occlusion (CTO) of coronary arteries.

BACKGROUND

Percutaneous coronary intervention (PCI) in CTO is technically difficult and has comparatively lower success rate than intervention in non-occluded artery. Accurate assessment of lesion morphology is an important determinant of PCI success in CTO.

METHODS

Nineteen symptomatic patients (18 men, age: 58.6 ± 10.6 years) with a CTO on CA were subjected to a DSCT (Definition, Siemens, Germany). Heart rate (HR) control was not performed. Dedicated post-processing software was used for lesion analysis on both modalities. Presence of bridging collaterals, stump morphology, calcification, side branch, proximal tortuosity, occlusion length, distal vessel interpretability, and distal lesions were statistically compared.

RESULTS

There were 20 CTOs. HR during DSCT ranged from 53 to 131 bpm. Bridging collaterals were seen in 3/20 (15%) lesions on CA and in none on DSCT. Stump anatomy and side branch were identified equally well. Plaque calcification was identified in 5/20 (25%) lesions on CA and in 12/20 (60%) lesions on DSCT (P = 0.025). Nature and extent of calcification were better visualized on DSCT. No proximal tortuosity was noted. Distal vessel was better interpretable on DSCT (15/20; 75%) compared to CA (9/20; 45%) (P = 0.05). No significant difference in lesion length was noted.

CONCLUSION

DSCT performs as well as CA for most features of CTO. Avoidance of need to control HR, ability to better detect and characterize calcium and to interpret distal vessels make it a useful pre-intervention investigation. © 2014 Wiley Periodicals, Inc.

Korean guidelines for the appropriate use of cardiac CT

The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease.

Comparison of stent length reported by the stent's manufacturer to that determined by quantitative coronary angiography at the time of implantation versus that determined by coronary computed tomographic angiography at a later time

The aim of this study was to assess whether coronary computed tomographic angiography (CCTA) would allow accurate length measurements that may help select optimal stent length. In 19 patients who underwent stent implantation and CCTA, the lengths of 30 implanted stents were assessed independently using quantitative coronary angiography (QCA) at the time of implantation and CCTA during follow-up. Measurements on CCTA and QCA were compared with the actual lengths of the implanted stents. The mean actual stent length was 17.3 ± 6.3 mm; the mean length of the stents measured using CCTA was 17.25 ± 5.54 mm, and the mean length of the stents measured using QCA was 15.92 ± 5.86 mm. There was a stronger positive correlation between measurements on CCTA versus actual stent lengths (R = 0.99, p = 0.0001) than between measurements on QCA versus actual stent lengths (R = 0.82, p = 0.0001) (p <0.0001 for the difference between correlation coefficients). In conclusion, the length measurements obtained with CCTA correlate better with an anatomic gold standard (actual stent lengths) than those obtained using QCA.

On mixed reality environments for minimally invasive therapy guidance: systems architecture, successes and challenges in their implementation from laboratory to clinic

Mixed reality environments for medical applications have been explored and developed over the past three decades in an effort to enhance the clinician's view of anatomy and facilitate the performance of minimally invasive procedures. These environments must faithfully represent the real surgical field and require seamless integration of pre- and intra-operative imaging, surgical instrument tracking, and display technology into a common framework centered around and registered to the patient. However, in spite of their reported benefits, few mixed reality environments have been successfully translated into clinical use. Several challenges that contribute to the difficulty in integrating such environments into clinical practice are presented here and discussed in terms of both technical and clinical limitations. This article should raise awareness among both developers and end-users toward facilitating a greater application of such environments in the surgical practice of the future.

Cardiac computed tomography in the management of iatrogenic coronary ostial stenosis after aortic valve replacement

Although rare, iatrogenic coronary ostial stenosis is an important complication of aortic valve replacement and Bentall procedure. We report a 32-year-old male presenting an acute coronary syndrome post-Bentall procedure and the role of computed tomography in diagnosis and management of iatrogenic coronary ostial stenosis. Such occlusions are commonly identified in the left main coronary artery, but can develop in venous bypass grafts at anastomoses with Dacron aortic grafts. Cardiac computed tomography is valuable to exclude noncoronary causes of chest pain, assess ostial stenosis of manipulated arteries post reimplantation, and shed light on mechanisms and management of these lesions.

Stent sizing by coronary computed tomographic angiography: comparison with conventional coronary angiography in an experienced setting

OBJECTIVES

The goal was to compare stent sizing by coronary computed tomographic angiography (CCTA) with that deployed in an experienced setting based upon conventional coronary angiography (CA).

BACKGROUND

Stent sizing is currently performed by visual estimation, with infrequent guidance by intravascular ultrasound. CCTA permits quantitative determination of stent length (Stent L) and diameter (Stent D).

METHODS

Projected L (CTA-Stent L) and D (CTA-Stent D) were determined from CCTA obtained in 248 patients with 352 lesions undergoing percutaneous coronary intervention within 4 months of the CCTA, and were compared to the Stent-L and Stent-D of the actually deployed stents. The effects of lesion modification and calcified plaque were also evaluated.

RESULTS

There were significant correlations between CTA-Stent L and Stent L (r = 0.656, P < 0.0001) and between CTA-Stent D and Stent D (r = 0.40, P < 0.001). Median predicted CTA-Stent L was slightly longer (20 mm vs. 18 mm, P < 0.0001) and predicted CTA-Stent D was slightly smaller (3.0 mm vs. 3.2 mm, P < 0.0001) than Stent-L and Stent-D, respectively. The differences were unchanged in stents with lesion modification by pre-dilation or intracoronary nitroglycerin. CTA Stent-L and CTA Stent-D increased significantly with increasing calcium (P < 0.0001 and P = 0.019, respectively).

CONCLUSIONS

(1) There are significant correlations between CCTA and CA based stent sizing in an experienced setting. (2) CCTA projects slightly longer and slightly smaller diameter stents than those deployed during PCI irrespective of lesion modification; the small differences are unlikely to have clinical significance. (3) CCTA may offer a noninvasive alternative to intravascular ultrasound for stent planning.

Coming of age: coronary computed tomography angiography

Technical development has substantially improved diagnostic performance of coronary computed tomography angiography (CCTA). A large number of studies have addressed proof of concept, feasibility, and clinical robustness of this noninvasive diagnostic technique, and most have consistently described the ability of CCTA to reliably rule out significant coronary artery stenosis. Clinical evidence supports the significant role of CCTA in an increasing number of scenarios, including the detection of coronary disease in symptomatic patients who are at intermediate risk and evaluation of coronary revascularization procedures. After initial feasibility testing, the scientific evaluation of CCTA now points toward analyzing prognosis, outcome, and cost-effectiveness of this noninvasive diagnostic tool. In this article, appropriate clinical indications, diagnostic performance, current clinical applications, prognostic value, and cost-effectiveness of CCTA are reviewed.

[Chronic coronary artery occlusion: questions from the cardiologist and surgeon, answers from the radiologist]

The main issue with chronic coronary artery occlusion relates to optimal treatment and cross sectional imaging is a valuable source of information. Cardiac MR imaging can identify candidates to revascularization by demonstrating viable myocardium. Coronary CTA allows evaluation of the entire coronary system and detection of factors predicting the success of revascularization, either percutaneous (angioplasty) or surgical.

CT clinical perspective: challenges and the impact of future technology developments

Computed tomography is not the most frequent radiologic imaging procedure, but is arguably the most important in terms of clinical impact. CT is used extensively for emergencies, cardiovascular, pulmonary, gastrointestinal, endocrine, neurological, orthopedic and other applications -often as the first and only imaging procedure needed for diagnosis. The chances are very high that a patient will have a CT scan in the emergency department, as an outpatient or as an inpatient for a multitude of indications - pain, trauma, suspected infection or malignancy, and frequently to investigate symptoms such as pain, or to answer a question raised by another abnormal test, such as an EKG abnormality or ultrasound finding. Despite the universality of CT in hospitals and clinics as well as free-standing imaging centers, the technology continues to evolve with greater coverage, faster acquisition and multienergy sources or detectors. The most demanding imaging applications are cardiovascular, where complex motion and small morphologic features coexist, so imaging methods that are very satisfactory elsewhere in the body may not be successful. Clinical CT scanning consists of administering toxic materials, e.g., contrast media, often monitoring the EKG and illuminating the body with high brightness x-rays. Larger area detectors and higher acquisition rates are welcome improvements, but don't solve all of the problems encountered with scan variability due to respiratory, random body, and cardiac motion, especially in a spectrum of patients from infant to massively obese adult sizes (< 1 kg to 250 kg or more). The challenges and pitfalls in CT will be delineated and evaluated relative to current and future technology.