Length Of Left Main Coronary Artery Research Articles

Left main coronary artery dimension and variation in Thai population

Abstract Funding Acknowledgements Type of funding sources: None. Objectives The aim of our study was to determine the length, proximal and distal dimension of the left main coronary artery (LMCA) in Thai population with normal LMCA, from coronary computed tomography angiography (CCTA). Background The dimensions and length of the coronary artery are important to treatment planning and outcome prediction after revascularization. The previous studies showed that coronary artery dimensions are influenced by age, sex and BSA which may be effected by race. Recently, very limited data about coronary artery dimensions in general Thai population are available. Methods 560 patients who have undergone CCTA at a Thai hospital with normal coronary angiogram of LMCA and no history of previous percutaneous coronary interventions and coronary artery bypass graft surgery were included in the study. The LMCA cross-sectional dimensions were obtained at two points of each vessel: ostium and distal. The length of LMCA was studied. The baseline characteristics data of participants such as age, body weight, height body surface area (BMI) and body surface area (BSA) and the other findings of CCTA on the LMCA dimensions and length were evaluated. Results This study showed that the mean cross-sectional dimensions of the proximal and distal of LMCA were 3.89 ± 0.76 mm. and 3.4 ± 0.67 mm. respectively. The mean length of LMCA was 8.66 ± 3.69 mm. The dimension of vessels in males were significantly larger in size than females. The proximal and distal LMCA dimensions in males were 3.98 ± 0.81 mm. and 3.8 ± 0.69 mm. respectively. And the proximal and distal LMCA dimensions in females were 3.51 ± 0.72 mm. and 3.27 ± 0.59 mm. respectively. The factors of significant correlations were found with sex, height, weight, BMI, BSA, left dominant vessel and coronary artery calcium scores (CACs) on the proximal and distal dimensions of LMCA. In multivariate analysis, BSA and dominant system were showed significant correlation to the proximal dimension of LMCA, and BSA was showed significant correlation to the distal dimension of LMCA. The influences on length of LMCA were height, weight, BMI, BSA, right dominant vessel and CACs but no factors were significant correlation by multivariate analysis. Conclusions The length, proximal and distal dimensions of LMCA in general Thai population were differences from the previous studies which were studied in other nations. The influences on the dimensions of LMCA were sex, height, weight, BMI, BSA, left dominant vessel, and CACs. And the influences on the length of LMCA were height, weight, BMI, BSA, right dominant vessel and CACs.

Abstract 13174: Coronary Origin Patterns: Utility in Echocardiographic Diagnosis of Forme Fruste Right-left Bicuspid Aortic Valve

Introduction: Bicuspid aortic valve (BAV) is a common congenital heart defect associated with coronary artery (CA) variants, including higher incidence of left CA dominance and shorter left main CA length. In patients with right-left fusion (R/L) BAV, we observed that the origins of left and right coronaries are in closer proximity than in normal patients. ‘Forme fruste’ types of R/L BAV are subtle and difficult to diagnose, hence this coronary pattern can aid in diagnosis. We defined intercoronary distance as the angle separating the left and right coronary ostia relative to the aortic valve center. Hypothesis: The coronary angle is more acute in R/L BAV than in normal aortic valves. Methods: A retrospective review of pediatric echocardiograms with R/L BAV at a single institution (12/2010-11/2018) was performed; coronary angles were measured and compared to age-matched controls. Those with inadequate images or anomalous coronary origins were excluded. Results: We identified 193 patients with R/L BAV (64% male) and 136 patients with normal aortic valves (57% male). Coronary angle was significantly more acute in R/L BAV than in controls (117.7°±16.8° vs 139.0°±10.1°, p<0.0001). This was independent of age, gender, or other cardiac defects. This relationship remained when BAV patients with abnormal aortic Z-scores were removed from analysis (119.2°±15.3° vs 139.0°±10.1°, p<0.0001), ruling out an effect of abnormal aortic annulus or root. Conclusions: Coronary origins are in closer proximity in R/L BAV independent of annulus/root geometry, associated cardiac defects, age, or gender. This new finding may assist in echocardiographic diagnosis of subtle subtypes of BAV.

Effect of Coronary Artery Bifurcation Angle on Atherosclerotic Lesion Localization Distance to the Bifurcation Site.

ObjectivesAlthough percutaneous coronary interventions become a common treatment modality for coronary artery diseases, lesion localization make these procedures more complex. As the lesion localizes near to the bifurcation site, more complex PCI procedures, overqualified equipments are needed and complication risk increases. Previous studies have demonstrated the strong correlation between wide angulation and significant coronary stenosis. However, a paucity of data exists about the association between bifurcation angle and lesion localization distance. In this study we analysed the effect of coronary bifurcation angle and left main coronary artery length on the atherosclerotic lesion localization.MethodsPatients, who underwent coronary angiography between 01.01.2017- 31.12.2019 were scanned. Patients having atherosclerotic lesions causing more than 50% luminal narrowing and Medina classification score (0,0,0) were evaluated. After exclusion, 467 patients were included. 5 bifurcation subgroups (LAD-CX, LAD-Dx, CX-OM, RCA-RV, RPD-RPL) were formed. Distance of lesion to the bifurcation site, bifurcation angle and left main coronary artery length were analysed by 2 experienced cardiologists with invasive quantitaive coronary angiography (QCA) by using “extreme angio and cardiac pacs” software system.ResultsThere was a strong inverse correlation between bifurcation angle and lesion localization distance to the bifurcation site (r = −0.706; p < 0.0001). There was a nonsignificant negative correlation between Left-main coronary artery length and lesion localization. Regression analysis revealed that bifurcation angle is an independent risk factor for predicting the localization of an atheroslerotic lesion in 5 mm length from the point of bifurcation site (β = −0.074, p < 0.0001). A cut-off value of 80.5° coronary bifurcation angle was found to have 84.1% sensitivity and 81.3% specificity in prediction of atherosclerotic lesion localization in 5 mm length from the point of bifurcation site.ConclusionIn this study we showed that as the bifurcation angle increases, atherosclerotic lesions tend to approach to the bifurcation site. Since invertentions encompassing bifurcation sites are more complex, lesions with increased angulation may need extra care as they are more likely to present with further complications. Furthermore, bifurcation angle is an independent risk factor for lesion localization.

Effect of left coronary bifurcation angle and left main coronary artery length on coronary artherosclerotic plaque burden

Effect of left coronary bifurcation angle and left main coronary artery length on coronary artherosclerotic plaque burden

References for left main stem dimensions: A cross sectional intravascular ultrasound analysis

Angiographic assessment of left main coronary artery (LMCA) lesions remains challenging and limited data is available on reference diameters and length of nonobstructive LMCA dimensions. Our aim was to provide insights in the dimensions of nonobstructive LMCA and to find a possible correlation with gender and patient habitus. This retrospective single center study was performed in a consecutive cohort of patients who underwent Intravascular Ultrasound (IVUS) guided percutaneous coronary interventions of the left coronary system including complete pullbacks of a non-obstructive LMCA (n = 254). Mean LMCA length as measured with IVUS was 7.37 ± 4.2 mm and mean lumen area (LA) was 15.63 ± 4.76 mm2 corresponding to a mean lumen diameter (LD) of 4.41 ± 0.67 mm. An IVUS derived mean LD of >4 mm was present in 71.7%, >4.5 mm in 43% and > 5 mm in 19% of patients. LMCA mean LA was significantly smaller in women as compared to men (14.1 ± 4.1 mm2 and 16.2 ± 4.8 mm2 , P < 0.01). Multivariable analysis identified weight of the patient as the sole significant predictor for LMCA length while height of the patient and LMCA length were predictors of LMCA mean LA. Correlation coefficients of determination for all independent predictors were low (R2 < 0.1 for all). This study demonstrated that the mean LD of a non-obstructive LMCA is 4 mm or greater in the majority of patients, with a mean LMCA length of 7.4 mm. Women have smaller luminal dimension than men. No clinically relevant predictors were found for both LMCA length and mean LA.

Anatomic assessment of the left main bifurcation and dynamic bifurcation angles using computed tomography angiography.

An understanding of the left main coronary artery (LMCA) anatomy is important for accurate diagnosis and therapy. We aimed to investigate LMCA anatomy via 128-multisliced coronary computed-tomography-angiography (CCTA) in patients with normal LMCA. A total of 201 CCTA studies were included in this study. Anatomical features of LMCA including cross-sectional areas of the LMCA ostial, LMCA distal, left anterior descending artery (LAD) ostial and left circumflex artery (LCX) ostial, and degree of tapering and LMCA bifurcation angles (BA) in the form of LMCA-LCX BA, LMCA-LAD BA, LAD-LCX BA at end-diastole and end-systole. The mean age was 55 ± 11; 55.7% of patients were males. Right coronary artery was dominant in 173 (86.1%) patients. Mean LMCA length was 10.0 ± 4.5 mm. The mean values of LMCA ostial, LMCA distal, LAD ostial and LCX ostial areas were 18.2 ± 5.1 mm², 13.2 ± 4.0 mm², 9.0 ± 3.2 mm² and 7.6 ± ± 2.8 mm², respectively. LMCA ostial-distal area, LMCA distal-LAD ostial area and LMCA distal-LCX ostial area ratios were ≥ 1.44 - < 1.69 in 47 (23.4%), 53 (26.4%), 47 (23.4%) patients, respectively, and were ≥ 1.69 - < 1.96 in 19 (9.5%), 24 (11.9%), 40 (19.9%) patients respectively. Systolic motion modifies LMCA BAs; systolic motion begets an increment of LMCA-LAD angle in 72.6% of patients and decrement of LAD-LCX angle in 75.6% of patients. Patients with T-shaped LAD-LCX BA was shown to have significantly longer LMCA, larger LAD ostial area, larger LCX ostial area and higher diastolic-to-systolic range (DSR) of LAD-LCX BA compared to patients with Y-shaped LAD-LCX BA. LMCA with T-shaped distal BA was found to have significantly longer LMCA, larger LAD ostial area, larger LCX ostial area and higher DSR of distal BA compared to patients with Y-shaped distal BA. These findings may provide useful information for LMCA bifurcation stenting or designing dedicated stents for LMCA.

Bypass to the left coronary artery system may accelerate left main coronary artery negative remodeling and calcification

This study aimed to use intravascular ultrasound (IVUS) data to reveal the mechanism of lesion progression in the native coronary circulation proximal to bypass grafts after coronary artery bypass grafting (CABG). We reviewed IVUS images in 86 patients with an angiographically significant left main coronary artery (LMCA) stenosis. Overall, 41 patients underwent CABG more than 6 months (mean 8.2 ± 6.1 years) previously and had at least one patent graft to the left coronary artery system. The number of patent grafts to the left coronary artery was 1.4 ± 0.7. Comparing patent graft vs. non-CABG groups, external elastic membrane and lumen areas and remodeling index at the minimum lumen area (MLA) site trended smaller with no difference in the plaque & media area. In addition, patients in the patent graft group had more LMCA calcium whether defined by cross-sectional (arc at the MLA site of 141 ± 109° vs. 88 ± 108°, P = 0.025) or longitudinal measurements (calcium length index, calculated as LMCA calcium length divided by total LMCA length, 0.69 ± 0.38 vs. 0.50 ± 0.42, P = 0.035). Negative remodeling may be the main mechanism of lesion progression proximal to a patent bypass graft, and more calcium was found in LMCA after CABG compared with non-CABG patients.

Intravascular Ultrasound Comparison of Left Main Coronary Artery Disease Between White and Asian Patients

We assessed the ethnic differences in coronary atherosclerosis lesion morphology between white and Asian patients. Our hypothesis was that left main coronary artery (LMCA) disease was more focal and less complex in Asian than in Western white patients. We studied 99 Asian patients (Japan and South Korea) and 99 matched control United States white patients with a stable clinical presentation and >30% LMCA angiographic diameter stenosis by visual estimation. The matching parameters included age, gender, and diabetes mellitus. The vessel and lumen areas and calcium arc were analyzed every 0.5 mm and normalized for analysis length. Overall, 75.1% of the patients were men and 34.1% had diabetes. The patient age was 68.0 ± 10 years, with no differences between the Asian and white patients. The Asian patients had a lower prevalence of hyperlipidemia than the white patients (41.4% vs 81.8%; p <0.0001) and were smaller in size, and the white patients were more obese (body mass index 23.7 ± 2.6 vs 27.6 ± 4.1 kg/m(2), p <0.0001). The Asian patients had a smaller lumen area (5.2 ± 1.8 vs 6.2 ± 14 mm(2); p <0.0001), larger vessel area (20.0 ± 4.9 vs 18.4 ± 4.4 mm(2); p <0.0001), and larger plaque burden (72 ± 10 vs 64 ± 12%: p <0.0001) at the minimum lumen site and over the entire LMCA length. The white patients had more calcification, whether assessed by the maximum arc (82° ± 74° vs 49° ± 45°; p <0.0001) or total length (3.6 ± 3.2 vs 2.1 ± 2.1 mm; p <0.0001). In conclusion, after matching well-known risk factors, there appeared to be ethnic differences in coronary atherosclerosis morphology between Asian and white patients, at least as it affected LMCA morphology.

Review of the literature: The longest documented left main coronary artery

Fig. 1. Coronary angiography in right cranial position. The left main coronary artery (LMCA) ranges from 3 to 6 mm in diameter and may be up to 10 to 15 mm in length in human.We report a casewith the longest angiographically documented LMCA (44 mm) in a patient with stable angina pectoris. And additionally, we aim to review the literature about the longest LMCA. The LMCA arises from the superior portion of the left aortic sinus and courses behind the right ventricular outflow tract and usually bifurcates into two terminal branches: LAD and LCx branches. Rarely the LMCA is absent and the LAD and LCX originated directly from the aortic sinus [1]. The LMCA is generally considered to be between 5 and 15 mm. Reig andPetit [2], in their anatomical study (one-hundred human hearts taken from autopsies), reported that the longest leftmain trunk was 23 mm long and the average length was 10.8±5.5 mm. In addition, they found a case with a LMCA length of 39 mm, but it had originated in the right aortic sinus and had a retroaortic course. Recently, it was reported three cases with long LMCA in our country [3–5]. A 61-year-old woman was presented to our hospital with stable angina pectoris. Her ECG was consistent left anterior hemi-block and T wave inversion on lateral derivation. The patient had been taking two anti-hypertensive (ACE inhibitor and beta-blocker) drug and statin treatment. There was non-specific ST segment depression in exercise testing and anterior reversible perfusion defect was found inmyocardial perfusion imaging. Coronary angiography was performed in Avrupa Safak hospital. Non-critically stenoses at LCx and RCA were found. LAD was normal. But, LMCA was strikingly lengthy (44 mm). (Figs. 1 and 2). Maximal medical treatment was planned for our patient. Although a short LMCA has been considered a risk factor in the development of coronary arteriosclerosis, no relationship has been described

Remodeling is a more important determinant of lumen size than atheroma burden in left main coronary artery disease

Left main coronary artery (LMCA) disease influences survival; however, the predictors of LMCA changes over time are incompletely understood. Paired intravascular ultrasound (IVUS) and core laboratory analyses were performed in a standardized fashion in 207 subjects (mean +/- SD age 58 +/- 10 years, 80% men). The average follow-up duration was 18 months (range 12-24 months). The IVUS measurements were first obtained at the smallest lumen area and the largest plaque area at follow-up and the corresponding positions in the LMCA were then measured at baseline. The LMCA percentage of atheroma area at baseline was 38.2% +/- 11.8%, and 133 patients (64%) experienced an increase in percentage of atheroma area. Change in lumen area correlated positively with change in total vessel area (R = 0.85, P < .0001) and negatively with change in percentage of atheroma area (R = -0.58, P < .0001). Change in plaque area correlated well with change in total vessel area (R = 0.64, P < .0001) but only weakly with change in lumen area (r = 0.14, P = .039). Although LMCA length correlated negatively with baseline lumen area and total vessel area, it did not correlate with their changes over time. On multivariable analyses, current smoking predicted an increase in percentage of atheroma area (P = .0013) and plaque area (P = .0041). Height negatively predicted change in percentage of atheroma area (P = .001). The LMCA lumen dimensions are more tightly linked with remodeling than with atheroma progression/regression.

Intravascular Ultrasound Classification of Plaque Distribution in Left Main Coronary Artery Bifurcations

Background— Angiographic classifications of the location and severity of disease in the main vessel and side branch of coronary artery bifurcations have been proposed and applied to distal left main coronary artery (LMCA) bifurcation. Methods and Results— We reviewed 140 angiograms of distal LMCA and ostial left anterior descending (LAD) and left circumflex (LCX) artery lesions with preintervention intravascular ultrasound (IVUS) of both the LAD and LCX arteries as well as the LMCA. Of 140 patients, 92.9% had at least 1 cross section with ≥40% IVUS plaque burden versus 57.2% of patients with an angiographic diameter stenosis ≥50%. Contrary to angiographic classifications, IVUS showed that bifurcation disease was rarely focal and that both sides of the flow divider were always disease-free. Continuous plaque from the LMCA into the proximal LAD artery was seen in 90%, from the LMCA into the LCX artery in 66.4%, and from the LMCA into both the LAD and LCX arteries in 62%. Plaque localized to either the LAD or LCX ostium and not involving the distal LMCA was seen in only 9.3% of LAD arteries and 17.1% of LCX arteries. Plaque distribution was not influenced by the LAD/LCX angiographic angle, lesion severity, LMCA length, or remodeling. We proposed an IVUS classification for bifurcation lesions illustrating longitudinal and circumferential spatial plaque distribution. Conclusions— Angiographic classification of LMCA bifurcation lesions is rarely accurate. IVUS shows that the carina is always spared and that the disease is diffuse rather than focal. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180466.

Anatomic assessment of the bifurcation of the left main coronary artery using multidetector computed tomography

Multiple techniques for stenting left main coronary artery (LMCA) bifurcation lesions exist, and an accurate understanding of normal LMCA anatomy is essential for proper diagnosis and therapeutic intervention for these lesions. The purpose of this paper is to identify various anatomic LMCA characteristics at the point of bifurcation and draw relevant clinical lessons from these characteristics. Two independent observers analyzed 105 cardiac dual-source computed tomography images recording LMCA length, angle of bifurcation, and cross-sectional area of the LMCA, left circumflex artery (LCX), and anterior interventricular artery (AIVA) at the point of LMCA bifurcation. Frequency of left dominance, right dominance, and codominance, as well as LMCA trifurcation was also noted. Average LMCA length was 9.9±4.15 (range 2-21mm). Average angle of bifurcation between LCX and AIVA was found to be 69.3°±33.3° (range 14°-200°). The most frequent division of the LMCA is a bifurcation into the terminal LCX and AIVA. In 20/105 cases (19.0%) a trifurcation pattern was identified. Average cross-sectional areas at point of LMCA bifurcation were as follows for LMCA, LCX, and AIVA respectively: 12.4±4.4 mm(2)(range 2.3-25.9mm(2)), 7.4±3.5mm(2) (range 1.2-23mm(2)), 8.5±3.5mm(2) (range 1.3-25.9mm(2)). Frequency of heart dominance was as follows for right dominant, left dominant, and codominant 85.7, 9.5, and 4.8%, respectively. Accurate knowledge of the in vivo anatomy of the area of bifurcation of the LMCA is essential for avoiding the misdiagnoses of diseases and for proper stent placement during percutaneous intervention in the area of bifurcation.

Stenotic Lesions and the Bifurcation Angle of Coronary Arteries in the Young.

To determine the genesis of the high incidence of stenotic lesions of the left anterior descending artery (LAD) in the young, we have investigated the anatomical characteristics of coronary arteries in the following 3 groups; young (less than or equal to 40 yr) myocardial infarction (MI) patients with LAD lesions, young (less than or equal to 40 yr) patients without coronary stenosis and aged (greater than or equal to 60 yr) MI patients. The angle between the left main coronary artery (LMT) and the LAD in the young MI patient group (146.7 +/- 7.4 degrees) was significantly wider than those of the young normal (126.0 +/- 13.4 degrees) or the aged MI patient groups (127.1 +/- 18.6 degrees) (p less than 0.01, p less than 0.02, respectively). The angle between the LMT and the left circumflex artery (LCX), and the angle between the LAD and the LCX were not significantly different among the 3 groups. The LMT length in the young MI patient group was 18.3 +/- 4.7 mm, which was not significantly longer than those of the young normal (12.7 +/- 6.9 mm) or the aged patient groups (14.8 +/- 6.0 mm). The internal diameter ratio of the LAD and LCX was also not significantly different among the 3 groups. These results suggest that the angle between the LMT and LAD was significantly wider in young MI patients, and should be regarded as an inherited characteristic influencing the development of coronary atherosclerosis of the LAD, particularly in young MI patients.