An Investigation of the Association Between Coronary Artery Dominance and Coronary Artery Variations With Coronary Arterial Disease by Multidetector Computed Tomographic Coronary Angiography:

Clinical Significance of Coronary Arterial Dominance: A Review of the Literature

Coronary dominance describes the anatomic variation of coronary arterial supply, notably as it relates to perfusion of the inferior cardiac territories. Differences in the development and outcome in select disease states between coronary dominance patterns are increasingly recognized. In particular, observational studies have identified higher prevalence of poor outcomes in left coronary dominance in the setting of ischemic, conduction, and valvular disease. In this qualitative literature review, we summarize anatomic, physiologic, and clinical implications of differences in coronary dominance to highlight current understanding and gaps in the literature that should warrant further studies.

Left and right coronary artery blood flow distribution method based on dominant type

The purpose of the current study was to investigate the effects of left/right coronary artery flow distribution on calculation of fractional flow reserve derived from coronary computed tomography angiography (FFRct) in different dominant types. First, 195 patients were collected to count the distribution ratios of the three categories: right dominance (RD), balanced dominance (BD), and left dominance (LD). Ratios of diameters of the left/right coronary arteries (DLCA :DRCA ) of the three types were calculated and used to represent the ratio of flow distribution (QLCA :QRCA ) in the dominant type method. The other method was known as the fixed ratio method (QLCA :QRCA  = 6:4). Second, a total of 73 patients with coronary artery disease (CAD) were enrolled for numerical calculation. A 0D/3D geometric multiscale model was used for the numerical simulation of FFR and the results of the fixed ratio method and the dominant type method were recorded as F-FFRct and D-FFRct. Lastly, invasive FFR(clinic-FFR)was used as a standard to evaluate the consistency and diagnostic performance of F-FFRct and D-FFRct. Corresponding flow distributions for the dominant type method were QLCA :QRCA  = 5:5 for RD, QLCA :QRCA  = 5.5:4.5 for BD, and QLCA :QRCA  = 6:4 for LD. D-FFRct showed a better correlation than F-FFRct (r = 0.85 vs. r = 0.81, both p < .001); the AUC (95%CI) were 0.974 (0.906-0.997, p < .0001) and 0.960 (0.886-0.992, p < .0001). Accuracy, specificity, sensitivity, positive predictive value (PPV) and negative predictive values (NPV) for D-FFRct and F-FFRct were 94.52%, 93.75%, 94.74%, 83.33%, 98.18% and 90.41%, 87.50%, 91.23%, 73.68%, 96.30%, respectively. Overall, the left/right coronary artery flow distribution was affected by the dominant type and the dominant type method was superior to the fixed ratio method in detecting coronary ischemic lesions.

Influence of coronary dominance on coronary artery calcification burden

OBJECTIVE

To evaluate the influence of coronary artery dominance on observed coronary artery calcification burden in outpatients presenting for coronary computed tomography angiography (CCTA).

METHODS

A 12-month retrospective review was performed of all CCTAs at a single institution. Coronary arterial dominance, Agatston score and presence or absence of cardiovascular risk factors including hypertension (HTN), hyperlipidemia (HLD), diabetes and smoking were recorded. Dominance groups were compared in terms of calcium score adjusted for covariates using analysis of covariance based on ranks. Only covariates observed to be significant independent predictors of the relevant outcome were included in each analysis. All statistical tests were conducted at the two-sided 5% significance level.

RESULTS

1223 individuals, 618 women and 605 men were included, mean age 60 years (24-93 years). Right coronary dominance was observed in 91.7% (n = 1109), left dominance in 8% (n = 98), and codominance in 1.3% (n = 16). The distribution of patients among Agatston score severity categories significantly differed between codominant and left (p = 0.008), and codominant and right (p = 0.022) groups, with higher prevalence of either zero or severe CAC in the codominant patients. There was no significant difference in Agatston score between dominance groups. In the subset of individuals with coronary artery calcification, Agatston score was significantly higher in codominant versus left dominant patients (mean Agatston score 595 ± 520 vs. mean 289 ± 607, respectively; p = 0.049), with a trend towards higher scores in comparison to the right-dominant group (p = 0.093). Significance was not maintained upon adjustment for covariates.

CONCLUSIONS

While the distribution of Agatston score severity categories differed in codominant versus right- or left-dominant patients, there was no significant difference in Agatston score based on coronary dominance pattern in our cohort. Reporting and inclusion of codominant subsets in larger investigations may elucidate whether codominant anatomy is associated with differing risk.

Prevalence and characteristics of dual left anterior descending artery in adult patients undergoing coronary angiography

Aim: To determine the prevalence and characteristics of dual left anterior descending artery (LAD) in adults undergoing catheter coronary angiography. Materials & methods: We identified cases with dual LAD by retrospectively analyzing 3233 angiograms done from January 2017 to June 2019. Results: Dual LAD was seen in 22 patients (0.68%). We identified type I dual LAD in 14 cases, type II in 7 cases and type III in 1 case. Significant stenosis was seen in proximal part of long LAD in 12 cases, in LAD proper in 7 cases and in proximal part of short LAD in 4 cases. Conclusion: Dual LAD is a rare anomaly. Its sound knowledge is essential for proper management of patients with coronary artery disease.

Coronary artery anatomy in peri-crux cordis area on computed coronary tomography angiography

Background

The peri-crux area is an anatomical structure of the heart. Unfortunately, important information on this area mainly derives from autopsy heart with a small, under-representative sample size, resulting in limited clinical applications. Furthermore, little has been done to standardize the definition of the peri-crux area on coronary computed tomography angiography (CCTA) images or to investigate coronary artery anatomy wherein potential values are attracting experienced inventional cardiologists in terms of the revascularization strategies. The current study aimed to identify the peri-crux cordis area and to observe coronary artery anatomical distributions in this area on CCTA.

Methods

A total of 1,006 consecutive patients undergoing CCTA exams were enrolled. We delineated the peri-crux cordis area based on the posterior interatrial sulcus, posterior interventricular sulcus (PIS), left and right posterior atrioventricular groove on the diaphragmatic surface of the heart. Then we observed the coronary artery distributions in the peri-crux cordis area in different sexes.

Results

We have defined the peri-crux cordis area according to the anatomical landmarks on the diaphragmatic surface of the heart on CCTA images. We have observed 8 coronary artery distributions in the peri-crux cordis area. Right dominance has 4 types (types 1-4); left, 1 type (type 0) and balanced, 3 types (types 5-7). Out of the 1,006 cases, the type 1 is commonest with 834 cases (82.9%). There are no statistically significant differences in terms of coronary dominances and coronary artery distributions in the peri-crux cordis area between sexes (P>0.05).

Conclusions

We have defined the peri-crux cordis area utilizing the anatomical landmarks of the heart on CCTA images, where 8 types of coronary artery distributions have been identified. The current study may provide interventional cardiologists with useful information on recognition of coronary artery dominance, use of collateral channels for revascularization of chronic total occluded lesions, and evaluation of prognosis in patients with coronary artery disease (CAD).

Association between coronary dominance and acute inferior myocardial infarction: a matched, case-control study

Background

Previous studies have found a connection between left coronary artery dominance and worse prognoses in patient with acute coronary syndrome, which remains a predominant cause of morbidity and mortality globally. The aim of this study was to investigate whether coronary dominance is associated with the incidence of acute inferior myocardial infarction (MI).

Methods

Between January 2011 and November 2014, 265 patients with acute inferior MI and 530 age-matched and sex-matched controls were recruited for a case-control study in the Second Affiliated Hospital of Xi’an Jiaotong University in Xi’an, China. All participants underwent coronary angiography. The exclusion criteria included history of coronary artery bypass graft surgery, chronic or systemic diseases (including hepatic failure, kidney failure, hypothyroidism and Grave’s disease), ventricular fibrillation, and known allergy to iodinated contrast agent. Patients with left- or co-dominant anatomies were placed into the LD group and those with right-dominant anatomy were included in the RD group. The association of acute inferior MI and coronary dominant anatomy were assessed using multivariable conditional logistic regression, and to estimate the odds ratio (OR) and 95% confidence interval (95%CI).

Results

Distributions of right dominance were significantly different between the acute inferior MI group and control group (94.0% vs. 87.9%, P = 0.018). Univariable conditional logistic regression revealed that right dominance may be a risk factor for the incident acute inferior MI (OR: 2.137; 95% CI: 1.210–3.776; P = 0.009). After adjusting for baseline systolic blood pressure, heart rate, smoking status, diabetes mellitus, hypertension, hyperlipidaemia, and family history of coronary artery disease, results of multivariate conditional logistic regression showed that right dominance was associated with the incidence of acute inferior MI (OR: 2.396; 95% CI: 1.328–4.321; P = 0.004).

Conclusions

Right coronary dominance may play a disadvantageous role in the incidence of acute inferior MI. However, further studies are needed to verify our findings, especially with regard to the underlying mechanisms.

Association of coronary dominance with the severity of coronary artery disease: a cross-sectional study in Shaanxi Province, China

OBJECTIVE

To investigate whether coronary artery dominance is associated with the severity of coronary artery disease (CAD).

DESIGN

Cross-sectional study.

SETTING

Single-centre.

PARTICIPANTS

Between July 2015 and February 2017, 1654 patients who underwent coronary angiography (CAG) were recruited into this cross-sectional study.

MEASUREMENT AND METHODS

According to coronary dominance, patients were classified into left dominance (LD), right dominance (RD) and codominance (CD) based on the CAG results. Multiple linear regression analysis was performed to test the association between severity of CAD and coronary dominance.

RESULTS

The total Gensini score was significantly higher in the RD group than in the left-CD group (42.3±33.6 vs 36.3±29.8; p=0.033). After adjusting for potential confounding factors, the results of multivariate linear regression showed that RD was associated with the severity of CAD (β=6.699, 95% CI 1.193 to 12.205, p=0.017).

CONCLUSIONS

The results suggest that right coronary dominance was associated with the severity of CAD.

Left dominant circulation increases mortality in acute coronary syndrome: A systematic review and meta-analysis of observational studies involving 255,718 patients

BACKGROUND

The effect of coronary dominance on mortality in patients with acute coronary syndrome (ACS) remains unclear. We performed a meta-analysis to evaluate the effect of coronary dominance in patients with ACS.

METHODS

Several data sources were searched for studies which compared studies that compared outcomes between right and left dominant coronary circulation in patients with ACS. The measured outcomes were in-hospital, 30-day or long-term mortality as reported in individual studies. The Generic inverse variance method was used in a random-effects model to pool mortality as an outcome. Odds ratio (OR) was calculated for mortality in the left dominant circulation relative to a right dominant one. Sub-group analysis was performed after stratification of mortality by duration.

RESULTS

A total of 5 studies with 8 comparisons and 255,718 participants revealed an increased risk mortality (OR = 1.27 (95% CI: 1.13 - 1.42; P < 0.0001; I(2)  = 34%). Sub-group analysis revealed that the increased risk was evident at all time periods after the ACS; in-hospital (OR = 1.37; 95% CI: 1.07 - 1.76; P = 0.01; I(2)  = 50%), at 30 days (OR = 1.69; 95% CI: 1.14 - 2.52; P = 0.009; I(2)  = 18%) and long-term (OR = 1.15; 95% CI: 1.03 - 1.28; P = 0.01; I(2)  = 0%).

CONCLUSIONS

In this meta-analysis we found that there is an increased risk of mortality with LD coronary circulation in patients with ACS. The knowledge of coronary dominance may not only be helpful as an incremental prognostic factor beyond pre-procedural risk scores in all patients with ACS, but may also aid in clinical decision making in a subset of these patients. © 2015 Wiley Periodicals, Inc.

A heart with multiple coronaries anomalies: myocardial bridging, left dominance and high takeoff of ostia-an autopsy case

Myocardial bridging is a segment of coronary artery that runs intramurally through the myocardium. Though it is commonly seen in the anterior interventricular artery and less commonly in right coronary artery, it can cause limitation in the blood flow, which leads to myocardial ischaemia. Left dominance increases cardiac mortality because of association with the congenital bicuspid aortic valve and myocardial infarction. An earlier study has shown the correlation of myocardial bridging with left coronary circulation and it is rare in relation with right coronary and left dominance. Manifestations of high takeoff of the coronary ostia are highly debatable, with varied opinions given by various authors. It has been believed that myocardial bridging is congenital and that it also causes limitation of blood flow to the myocardium. Cardiac muscles have a unique capability to adapt in response to decreased blood supply, which is in the form of coronary collateral circulation. So, is their any correlation between myocardial bridging and dominance? Herein, we are reporting an unusual autopsy case of myocardial bridging on its right main coronary artery, left coronary dominance and high take off of left main coronary artery in the same heart.

Impact of coronary dominance on in-hospital outcomes after percutaneous coronary intervention in patients with acute coronary syndrome

Objective

This study evaluated the manner in which coronary dominance affects in-hospital outcomes of acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI).

Background

Previous studies have shown that left dominant coronary anatomies are associated with worse prognoses in patients with coronary artery disease.

Methods

Data were analyzed from 4873 ACS patients undergoing PCI between September 2008 and April 2013 at 14 hospitals participating in the Japanese Cardiovascular Database Registry. The patients were grouped based on diagnostic coronary angiograms performed prior to PCI; those with right- or co-dominant anatomy (RD group) and those with left-dominant anatomy (LD group).

Results

The average patient age was 67.6±11.8 years and both patient groups had similar ages, coronary risk factors, comorbidities, and prior histories. The numbers of patients presenting with symptoms of heart failure, cardiogenic shock, or cardiopulmonary arrest were significantly higher in the LD group than in the RD group (heart failure: 650 RD patients [14.7%] vs. 87 LD patients [18.8%], P = 0.025; cardiogenic shock: 322 RD patients [7.3%] vs. 48 LD patients [10.3%], P = 0.021; and cardiopulmonary arrest: 197 RD patients [4.5%] vs. 36 LD patients [7.8%], P = 0.003). In-hospital mortality was significantly higher among LD patients than among RD patients (182 RD patients [4.1%] vs. 36 LD patients [7.8%], P = 0.001). Multivariate logistic regression analysis revealed that LD anatomy was an independent predictor for in-hospital mortality (odds ratio, 1.75; 95% confidence interval, 1.06–2.89; P = 0.030).

Conclusion

Among ACS patients who underwent PCI, LD patients had significantly worse in-hospital outcomes compared with RD patients, and LD anatomy was an independent predictor of in-hospital mortality.

The Relation between Left Coronary Dominancy and AtheroscleroticInvolvement of Left Anterior Descending Artery Origin

INTRODUCTION

Limited information is available regarding the relationship between coronary vessel dominance and atherosclerotic involvement. Rheological factors have been implicated in the pathogenesis of coronary lesions. More than 90% of the coronary blood flow enters the left coronary if it is the dominant artery. The main purpose of this study was to determine the relation between left coronary dominance and atherosclerotic involvement of left anterior descending artery (LAD) origin. In addition, the prevalence and degree of associated ischemic mitral regurgitation (MR) in these patients were assessed.

METHODS

The study included 678 consecutive patients with an indication for coronary angiography. One hundred and twenty two patients with right dominant and 61 patients with left dominant arteries were randomly selected for analysis. All demographics, risk factors, coronary dominancy and involvement, left ventricular ejection fraction (LVEF), and MR were recorded.

RESULTS

One hundred and eighty three patients (mean age of 57.7 years) were studied. The types of coronary circulation included right, left, and balanced in 78.6%, 8.9%, and 12.5%, of the patients respectively. In 64 patient with significant LAD lesions, 22 (34.9%) had ostial while the remainder had non-ostial involvement. Ischemic MR was present in 5 (2.7%) patients. There was no difference in demographics, risk factors, LVEF, MR, extent of coronary artery disease, and LAD ostial involvement between left and right dominant circulations.

CONCLUSION

In this study, left coronary dominance was not associated with atherosclerotic involvement of LAD ostium and ischemic MR.

Coronary anatomy characteristics in patients with isolated right bundle branch block versus subjects with normal surface electrocardiogram

INTRODUCTION AND OBJECTIVE

Isolated right bundle branch block is a common finding in the general population. It may be associated with variations in detailed coronary anatomy characteristics. The aim of this study was to investigate the coronary anatomy in patients with isolated right bundle branch block and to compare that with normal individuals.

METHOD

In this case-control study we investigated the coronary anatomy by reviewing angiographic films in two groups of normal coronary artery patients: patients with right bundle branch block (RBBB) (n = 92) and those with normal electrocardiograms (n = 184).

RESULTS

There was no significant difference between the two groups in terms of diminutive left anterior descending artery, dominancy, number of obtuse marginal artery, diagonal, acute marginal artery, the position of the first septal versus diagonal branch, presence of ramus artery, and size of left main artery. The number of septal branches was higher in the case group (p-value <0.001). Origination of the atrioventricular node artery from the right circulatory system was more common in both groups but cases showed more tendency to follow this pattern (p-value = 0.021). The frequency of the normal conus branch was higher in the cases versus controls (p-value = 0.009).

CONCLUSIONS

Coronary anatomy characteristics are somewhat different in subjects with RBBB compared to normal individuals.

The prevalence of coronary artery variations on coronary computed tomography angiography

BACKGROUND

Coronary computed tomography angiography (CCTA) can delineate the coronary artery anatomy precisely. Basic knowledge of the normal coronary artery anatomy and familiarity with its common variations are essential in order to assess CCTA accurately.

PURPOSE

To determine the prevalence of coronary artery variations detected by 64-slice mutidetector CT.

MATERIAL AND METHODS

CCTA images of 2096 patients were evaluated retrospectively. Relatively unusual coronary artery morphological features that were seen in greater than 1% of the study population were classified as variations.

RESULTS

Coronary artery circulation was right dominant in 86.6%, left dominant in 9.6%, and balanced in 3.8% of patients. The conus artery arose from the right coronary artery in 83%, or directly from the aorta with a separate ostium in 17% of cases which was much more common in men than women. The sinoatrial node artery originated from the right coronary artery (65.6%) or the circumflex artery (33.7%). The atrioventricular node artery originated from the right coronary artery in 86.4% or the circumflex artery in 13.6% of cases. The left main coronary artery was shorter than 0.5 cm in 4.7% of cases and trifurcated into the intermediate artery in 31.3% of cases. A myocardial bridge was observed in 21.6%, coronary ectasia-aneurysm in 2%, dual left anterior descending artery (LAD) type 1 in 1.38%, and a variant of type 1 in 0.1% of cases. The presence of coronary atherosclerosis was higher in patients with coronary ectasia-aneurysm than the patients who did not have coronary ectasia-aneurysm (90.5% vs. 72.2%, P = 0.000).

CONCLUSION

CCTA is a non-invasive imaging modality for the depiction of variations of the coronary arteries. The incidence of coronary artery variations is high and various, and readers should be familiar and looking for these conditions during interpretation of CCTA examinations.

Arterial supply of the posterior interventricular sulcus: a CT coronary angiographic study

OBJECTIVE

The objective of this study was to determine the different vascularization patterns of the posterior interventricular sulcus (PIS) with coronary CT angiography.

MATERIALS AND METHODS

Three hundred and fifty-six coronary CT angiograms (CCTA) were retrospectively analyzed in 248 men and 108 women (mean age, 54.9 years ± 13.6 [standard deviation]). The PIS was divided into three segments from the crux cordis to the notch of the cardiac apex according to the American Heart Association classification (basal, mid ventricular and apical), and the artery or arteries supplying each segment were recorded. The relative frequency of the different vascularization patterns was calculated and the distribution of dominance types was recorded.

RESULTS

Blood was supplied to the PIS by one or more branches of the right coronary artery (RCA), the left circumflex artery (LCX), or the left anterior descending artery (LAD). We observed 25 different irrigation patterns. In the most frequent pattern (31.3%), the basal and mid-ventricular segments were perfused by a single arterial branch originating from the RCA at the crux, and the apical segment was perfused by the LAD traveling beyond the notch of the cardiac apex and entering the posterior interventricular sulcus. Of the 356 cases, the circulation was right dominant in 310 (87.1%), left dominant in 34 (9.5%), and balanced in 12 (3.4%) cases. Individual segments were perfused by a single artery in 288 (80.9%) cases, and by more than one in the remainder.

CONCLUSION

CCTA allows detailed assessment of the arterial supply of the PIS, and allowed to describe 25 subtypes. This information is of potential value to both cardiac surgeons and interventional cardiologists who plan bypass surgery or angioplasty aiming at the posterior interventricular artery.