Basic Overview of Conventional Coronary Angiography for Planning Cardiac Surgery

Coronary angiography is a common procedure performed by the cardiologist to evaluate coronary atherosclerotic disease (CAD) and the result is utilized by both cardiologists and cardiac surgeons to perform catheter and surgical interventions on the coronary artery. In addition to evaluating CAD, other useful investigative modalities such as left ventriculography and aortography can be performed at the time of coronary angiography. Despite its limitations and the emergence of newer investigative modalities like coronary computed tomography angiography, intravascular ultrasound scan, and magnetic resonance coronary angiography, conventional coronary angiography has remained the gold standard for the evaluation of coronary artery disease. Hence, it remains an investigative modality that every member of the cardiothoracic team performing coronary artery bypass grafting must learn how to interpret.

A Rare Case of Single Coronary Artery: Getting to the Heart of the Matter

Single coronary artery anomaly represents a particularly rare entity, which may present with variable clinical scenarios, but in most cases remains asymptomatic. It is considered to be one of the pathological states to cause sudden death, especially in young adults [1]. We hereby report a rare case of a R-III type of single coronary artery as classified by Lipton et al., which is only about 15% of all the cases of coronary anomalies. Coronary CT angiography as well as invasive coronarography provide accurate details regarding the origin, course and termination of coronary anomalies, as well as evaluation of associated coronary lesions, further guiding the optimal treatment strategy in each case. Teaching Point: The main teaching point of this case report is to clearly underline the importance of coronary CT angiography in obtaining a comprehensive evaluation of coronary artery anatomy and associated coronary lesions, representing important aspects, which further guide accurate treatment and management.

Deep learning applications in coronary anatomy imaging: a systematic review and meta-analysis

Background

The application of deep learning on medical imaging is growing in prevalence in the recent literature. One of the most studied areas is coronary artery disease (CAD). Imaging of coronary artery anatomy is fundamental, which has led to a high number of publications describing a variety of techniques. The aim of this systematic review is to review the evidence behind the accuracy of deep learning applications in coronary anatomy imaging.

Methods

The search for the relevant studies, which applied deep learning on coronary anatomy imaging, was performed in a systematic approach on MEDLINE and EMBASE databases, followed by reviewing of abstracts and full texts. The data from the final studies was retrieved using data extraction forms. A meta-analysis was performed on a subgroup of studies, which looked at fractional flow reserve (FFR) prediction. Heterogeneity was tested using tau², I² and Q tests. Finally, a risk of bias was performed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS) approach.

Results

A total of 81 studies met the inclusion criteria. The most common imaging modality was coronary computed tomography angiography (CCTA) (58%) and the most common deep learning method was convolutional neural network (CNN) (52%). The majority of studies demonstrated good performance metrics. The most common outputs were focused on coronary artery segmentation, clinical outcome prediction, coronary calcium quantification and FFR prediction, and most studies reported area under the curve (AUC) of ≥80%. The pooled diagnostic odds ratio (DOR) derived from 8 studies looking at FFR prediction using CCTA was 12.5 using the Mantel-Haenszel (MH) method. There was no significant heterogeneity amongst studies according to Q test (P=0.2496).

Conclusions

Deep learning has been used in many applications on coronary anatomy imaging, most of which are yet to be externally validated and prepared for clinical use. The performance of deep learning, especially CNN models, proved to be powerful and some applications have already translated into medical practice, such as computed tomography (CT)-FFR. These applications have the potential to translate technology into better care of CAD patients.

Coronary-Cameral Fistula, Thebesian Veins, and Anomalous Coronary Vein on Cardiac Computed Tomography

A 63-year-old female with a history of hypertension presented with progressively worsening shortness of breath. She underwent a cardiac catheterization and was found to have prominent Thebesian veins as well as anomalous connections between the proximal right coronary artery and the right ventricle. Cardiac computed tomography was ordered for further evaluation and showed a coronary fistula to the right ventricular outflow tract confirming the diagnosis of a coronary-cameral fistula (CCF). CCF are rare congenital anomalous communications that occur between coronary arteries and a cardiac chamber. They are usually an incidental finding and patients are rarely symptomatic. As the use of coronary computed tomography angiography is rapidly expanding, the detection of CCF will likely increase in the general population.

Double right coronary artery: a plea for a standardized nomenclature

BACKGROUND

Double coronary artery is a rare anomaly with just a few cases reported in the literature. This anomaly started being reported recently with the wide use of coronary angiography. Before the advent of advanced imaging and catheterization facilities most of the available data came from the work of anatomists. Two patients were recently operated in our department. In the first patient the preoperative coronary angiography showed two right coronary arteries. In the second patient a double ostium of the right coronary artery was encountered intraoperatively. We wanted to know the incidence of this anomaly and the available data in the literature.

METHODS

A PubMed research was conducted by using the term 'double right coronary artery'. More than 50 case reports and small case series were identified.

RESULTS

The review of the literature revealed a lot of controversy and debate. When using the term 'double right coronary artery' authors do not always refer to the same entity. Different definitions and classifications have proposed without, however, gaining wide acceptance. In fact, there is a lot of confusion in the literature and cases that are rather common are presented as being 'extremely rare'.

CONCLUSIONS

Even though the real incidence could be over or underestimated due to variability in coronary angiography interpretation, clinicians must be aware of this entity in order to avoid troubleshooting during percutaneous coronary interventions and cardiac surgery. There is need for a close collaboration between interventional cardiologists, anatomists and cardiac surgeons in order to standardize the nomenclature.

The Leiden Convention coronary coding system: translation from the surgical to the universal view

Aims

The Leiden Convention coronary coding system structures the large variety of coronary anatomical patterns; isolated and in congenital heart disease. It is widely used by surgeons but not by cardiologists as the system uses a surgeons’ cranial view. Since thoracic surgeons and cardiologists work closely together, a coronary coding system practical for both disciplines is mandatory. To this purpose, the ‘surgical’ coronary coding system was adapted to an ‘imaging’ system, extending its applicability to different cardiac imaging techniques.

Methods and results

The physician takes place in the non-facing sinus of the aortic valve, oriented with the back towards the pulmonary valve, looking outward from the sinus. From this position, the right-hand sinus is sinus 1, and the left-hand sinus is sinus 2. Next, a clockwise rotation is adopted starting at sinus 1 and the encountered coronary branches described. Annotation of the normal anatomical pattern is 1R-2LCx, corresponding to the ‘surgical’ coding system. The ‘imaging’ coding system was made applicable for Computed Tomography (CT), Magnetic Resonance Imaging (MRI), echocardiography, and coronary angiography, thus facilitating interdisciplinary use. To assess applicability in daily clinical practice, images from different imaging modalities were annotated by cardiologists and cardiology residents and results scored. The average score upon evaluation was 87.5%, with the highest scores for CT and MRI images (average 90%).

Conclusion

The imaging Leiden Convention is a coronary coding system that unifies the annotation of coronary anatomy for thoracic surgeons, cardiologists, and radiologists. Validation of the coding system shows it can be easily and reliably applied in clinical practice.

Long-Term Clinical Outcomes Following Revascularization in High-Risk Coronary Anatomy Patients With Stable Ischemic Heart Disease

Background The ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial failed to show a reduction in hard clinical end points with an early invasive strategy in stable ischemic heart disease (SIHD). However, the influence of left main disease and high-risk coronary anatomy was left unaddressed. In a large angiographic disease-based registry, we examined the modulating effect of revascularization on long-term outcomes in anatomically high-risk SIHD. Methods and Results 9016 patients with SIHD with high-risk coronary anatomy (3 vessel disease with ≥70% stenosis in all 3 epicardial vessels or left main disease ≥50% stenosis [isolated or in combination with other disease]) were selected for study from April 1, 2002 to March 31, 2016. The primary composite of all-cause death or myocardial infarction (MI) was compared between revascularization versus conservative management. A total of 5487 (61.0%) patients received revascularization with either coronary artery bypass graft surgery (n=3312) or percutaneous coronary intervention (n=2175), while 3529 (39.0%) patients were managed conservatively. Selection for coronary revascularization was associated with improved all-cause death/MI as well as longer survival compared with selection for conservative management (Inverse Probability Weighted hazard ratio [IPW-HR] 0.62; 95% CI 0.58 to 0.66; P<0.001; IPW-HR 0.57; 95% CI 0.53-0.61; P<0.001, respectively). Similar risk reduction was noted with percutaneous coronary intervention (IPW-HR 0.64, 95% CI 0.59-0.70, P<0.001) and coronary artery bypass graft surgery (IPW-HR 0.61; 95% CI 0.57-0.66; P<0.001). Conclusions Revascularization in patients with SIHD with high-risk coronary anatomy was associated with improved long-term outcome compared with conservative therapy. As such, coronary anatomical profile should be considered when contemplating treatment for SIHD.

Bilateral internal thoracic artery grafting: in situ or composite?

Bilateral internal thoracic artery (BITA) grafting is considered a superior choice for coronary artery bypass grafting (CABG). While the 10-year outcomes of BITA grafting from the recent Arterial Revascularization Trial (ART) are still pending, numerous observational studies have demonstrated the advantages of BITA grafting. These include better long-term graft patency and freedom from arteriosclerosis, in addition to higher survival rate compared to CABG using only the left internal thoracic artery (ITA). The different BITA configurations are in situ and composite-the choice of optimal grafting configuration is challenging. Patient factors such as coronary anatomy, presence of a diseased ascending aorta and the potential need for a future redo sternotomy will influence the choice of the grafting strategy. In situ BITA grafting is associated with excellent clinical outcomes and has been extensively described in the literature. However, uncertainties remain regarding the ideal in situ configuration and design. Composite BITA grafting is the other option that maximizes right ITA (RITA) utilization. In this configuration, the RITA is able to reach the distal circumflex and right coronary artery branches. This approach decreases the need for a third graft conduit.

Negative predictive value of stress myocardial perfusion imaging and coronary computed tomography angiography: A meta-analysis

BACKGROUND

Comparing the prognostic value of a negative finding by stress single-photon emission computed tomography myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) may be useful to evaluate how better identify low-risk patients. We performed a meta-analysis to compare the long-term negative predictive value (NPV) of normal stress MPI and normal CCTA in subjects with suspected coronary artery disease (CAD).

METHODS AND RESULTS

Studies published between January 2000 and November 2016 were identified by database search. We included MPI and CCTA studies that followed-up ≥100 subjects for ≥5 years and providing data on clinical outcome for patients with negative tests. Summary risk estimates for normal perfusion at MPI or <50% coronary stenosis at CCTA were derived in random effect regression analysis, and causes of heterogeneity were determined in meta-regression analysis. We identified 12 eligible articles (6 MPI and 6 CCTA) including 33,129 patients (26,757 in MPI and 6372 in CCTA studies) with suspected CAD. The pooled annualized event rate (AER) for occurrence of hard events (death and nonfatal myocardial infarction) was 1.06 (95% confidence interval, CI 0.49-1.64) in MPI and 0.61 (95% CI 0.35-0.86) in CCTA studies. The pooled NPV was 91% (95% CI 86-96) in MPI and 96 (95% CI 95-98) in CCTA studies. The summary rates between MPI and CCTA were not statistically different. At meta-regression analysis, no significant association between AER and clinical and demographical variables considered was found for overall studies.

CONCLUSIONS

Stress MPI and CCTA have a similar ability to identify low-risk patients with suspected CAD.

A novel method of standardized myocardial infarction in aged rabbits

The incidence of both myocardial infarction (MI) and sudden cardiac death increases with age. Here, we describe the development of a minimally invasive large animal model of MI that can be applied to young or aged animals. We demonstrate that rabbit coronary anatomy is highly variable, more so than described in previous literature. In this work, we categorize the coronary pattern of 37 young rabbits and 64 aged rabbits. Aged rabbits had a higher degree of branching from the left main coronary artery. Standardizing the model across age cohorts required a new approach, targeting an area of myocardium rather than a specific vessel. Here, we present a method for achieving a reproducible infarct size, one that yielded a consistent scar encompassing ~30% of the apical left ventricular free wall. The model's consistency allowed for more valid comparisons of MI sequelae between age cohorts.NEW & NOTEWORTHY This study describes the coronary angiographic imaging of young and aged rabbits. We developed and improved a novel minimally invasive approach for coil embolization that targets a specific area of myocardium and yielded a consistent scar encompassing ~30% of the left ventricular free wall of young and aged rabbit hearts.

Coronary anatomy, anatomic variations and anomalies: a retrospective coronary angiography study

INTRODUCTION

The incidence of coronary artery anomalies (CAAs) varies from 0.2% to 8.4%. Knowledge of such anatomical variations is important as coronary procedures are regularly performed these days. We aimed to find the coronary dominance pattern, intermediate artery (IMA) frequency and CAA incidence in our clinic, and compare them to those in the literature.

METHODS

The medical reports of 5,548 patients who had undergone coronary angiography (CAG) between 2005 and 2009 were retrospectively investigated. Dominance pattern and presence of IMA and CAA were recorded. CAAs were described using two different classifications: Angelini and Khatami's classification, and a new modified classification that was derived from Angelini and Khatami's classification. Some procedural details and clinical features of the patients with CAA were also investigated.

RESULTS

Coronary dominance pattern was: 81.6% right coronary artery, 12.2% circumflex artery and 6.2% co-dominant. IMA was present in 613 (11.0%) patients. The incidences of overall anomaly were 2.7% and 1.4%, according to the different classifications. Absent left main coronary artery, which was the most common anomaly in the present study, was found in 51 (0.9%) patients. Incidences of myocardial bridge, coronary arteriovenous fistulae and aneurysms were 1.1%, 0.2% and 0.3%, respectively.

CONCLUSION

CAAs are generally asymptomatic, isolated lesions. Some may lead to anginal symptoms, myocardial infarction or sudden death. We found that CAA was associated with increased radiation and contrast exposure in patients who underwent CAG. This risk could be reduced if appropriate catheters were designed and training programmes on ostial cannulation were developed.

Prevalence of congenital coronary artery anomalies as shown by multi-slice computed tomography coronary angiography: a single-centre study from Turkey

Objective Coronary artery anomaly (CAA) is a remarkable etiological factor for sudden cardiac death in young adults. The incidence of CAA is unknown, with most reliable data available based on postmortem/angiography investigations. This study aimed to assess the prevalence of different forms of coronary anomalies, and to investigate the relationships between demographic data and occurrence of CAA. Methods A total of 2401 consecutive patients (1805 men; mean age, 56 ± 11.7 years), who were referred between January 2005 and December 2008 for noninvasive multi-slice computed tomography (MSCT) imaging, were retrospectively analysed. Results A total of 225 cases (191 men; mean age, 55.9 ± 12) of CAAs were identified (9.37%). Because 11 patients had multiple muscular bridges of the coronary arteries, 236 coronary artery anomalies were found in these 225 patients. Cases were classified into three groups: group 1, coronary anomalies of origin and distribution (n = 36, 1.5%); group 2, anomalies of intrinsic coronary arterial anatomy (n = 180, 7.49%); and group 3, anomalies of coronary termination (n = 9, 0.4%). Conclusion The prevalence of CAA was 9.37% in our single-centre study, which is consistent with previous research. A minimally invasive tool, such as MSCT angiography, should be used to identify CAA.

Revascularization options in stable coronary artery disease: it is not how to revascularize, it is whether and when to revascularize

Patients with acute coronary syndromes and severe multivessel or left main coronary artery disease have better outcomes when prompt revascularization is performed in addition to optimal medical therapy (OMT). However, in patients with stable ischemic heart disease, randomized strategy trials have revealed equipoise between initial strategies of OMT alone and OMT plus revascularization. Conducted in diverse stable ischemic heart disease patient populations and throughout the spectrum of atherosclerotic and ischemic burden, the RITA-2, MASS II, COURAGE, BARI 2D and FAME 2 trials demonstrate that OMT alone and OMT plus revascularization yield similar outcomes with respect to mortality and myocardial infarction. What remains unclear is whether there may be one or more subsets of patients with stable ischemic heart disease in whom revascularization may be associated with a reduction in mortality or myocardial infarction, which is to be addressed in the ongoing ISCHEMIA trial.

Clinical and detailed angiographic findings in patients with ambulatory electrocardiographic ischemia without critical coronary narrowing: results from the Asymptomatic Cardiac Ischemia Pilot (ACIP) Study

BACKGROUND

Patients with ambulatory electrocardiographic (AECG) ST-segment depression and critical coronary narrowing are known to be at increased risk for adverse outcome, but little is known about patients with AECG ST-segment depression without critical coronary narrowing.

HYPOTHESIS

The objectives of this study were to characterize the coronary angiographic pathology in patients with AECG ST-segment depression but without critical (< 50% diameter stenosis) coronary narrowing and to compare demographic and clinical findings in these patients with those enrolled in the Asymptomatic Cardiac Ischemia Pilot Study with AECG ST-segment depression and critical (> or = 50% diameter stenosis) coronary narrowing.

METHODS

Coronary angiograms from patients with AECG ST-segment depression were reviewed in a central laboratory and quantitative measurement of percent stenosis was performed. Clinical and angiographic comparisons were made between patients with and without critical coronary narrowing.

RESULTS

Patients without critical coronary narrowing (n = 64) were younger (p = 0.02), less likely to be male (p < 0.001) or to have risk factors for coronary atherosclerosis or a history of myocardial infarction (p < 0.001), and had fewer ischemic episodes per 24 h on the screening AECG (p = 0.02) than patients with critical coronary narrowing (n = 441). Of patients without critical narrowing, one half had angiographic evidence for coronary artery disease (> or = 20% stenosis) and 60% had an ejection fraction > 70%.

CONCLUSIONS

Patients with AECG ST-segment depression without critical coronary narrowing are heterogeneous, with half having measurable coronary artery disease. Demographically and clinically, they appear to be different than patients with AECG ST-segment depression with critical coronary narrowing.