Congenital atresia of the left main coronary artery ostium

Incidental finding and conservative management of left main coronary atresia in an adult patient: a case report

Background

Left main (LM) coronary atresia (LMCA) is a rare coronary anomaly where the LM is congenitally absent and a variable clinical spectrum can follow. The diagnosis of LMCA is generally made in youth because of the development of symptoms, but very rarely in adulthood. In symptomatic patients, surgical revascularization is recommended, whereas, in asymptomatic patients with LMCA and without inducible myocardial ischaemia, preventive surgical treatment is controversial.

Case summary

A 58-year-old male patient with aortic ectasia detected during an echocardiogram performed to evaluate a hypertension-related preclinical cardiac damage and, due to this finding, an echocardiographic follow-up was suggested. Three years later, he was admitted to undergo coronary angiography (CA) after the computed tomography finding of a suspected occlusion of the LM with collateral circulation from right coronary artery (RCA) to left anterior descending and circumflex arteries. CA confirmed an LMCA and the RCA provided blood supply to the left coronary artery through collaterals whose calibre was similar to that of the target left-sided vessels. No obstructive coronary artery disease was detected. In order to detect potential myocardial ischaemia, a technetium-tetrofosmin cardiac single-photon emission computed tomography during maximal exercise-stress test was performed and it did not show a perfusion defect. Medical management with scheduled follow-up visits was deemed to be the best therapeutic option.

Discussion

LMCA is a rare anomaly where LM is absent and the RCA provides collateral circulation for left coronary artery. In asymptomatic patients, preventive surgical treatment is controversial.

Sudden cardiac arrest of a 16-year-old boy with left main coronary artery atresia: a case report

Background

In many cases, the cause of exercise-induced cardiopulmonary arrest in young persons is thought to be fatal arrhythmia, and one of the causes is ischaemic heart disease. Left main coronary artery atresia (LMCAA) is an extremely rare disease in which there is a congenital defect of the left main coronary artery, causing heart failure and exercise-induced angina attacks at a young age. Thus, it is disease that should be differentiated when examining young persons with chest pain.

Case summary

A 16-year-old boy experienced sudden cardiopulmonary arrest during soccer practice, was brought to our hospital for emergency treatment after return of spontaneous circulation. Elective coronary angiography revealed findings indicating an osmium defect in the left coronary artery (LCA) and blood flow via collateral circulation from the right coronary artery. Contrast-enhanced coronary computed tomography (CT) angiography showed a defect in the LCA ostium and LMCAA was diagnosed in the patient. After coronary artery bypass grafting was performed, but the patient was discharged in an ambulatory state with a wearable cardiac defibrillator. Postoperative course has been favourable.

Discussion

Left main coronary artery atresia is an extremely rare disease in which there is a congenital defect of the left main trunk of the coronary artery and should be differentiated when encountering cases of heart failure or exercise-induced angina/arrhythmia attacks in young persons who are not at risk for atherosclerosis. Exercise electrocardiogram may show a false negative result, and therefore coronary CT is useful for diagnosis.

A case series of left main coronary artery ostial atresia and a review of the literature

Left main coronary artery ostial atresia (LMCAOA) is a rare congenital anomaly of the coronary arteries. The published literature regarding the current diagnostic and management recommendations are limited. We present three case series of LMCAOA from our institution, including one with a unique association with anomalous origin of left coronary artery (LCA) from pulmonary artery. In addition, this report includes a review of 50 pediatric and 43 adult cases from literature. The majority of the patients were symptomatic. Sudden cardiac death occurred in 10% of pediatric patients and 7% of adult patients. Almost half of pediatric patients had additional cardiac lesions. At the time of diagnosis, 82% of patients had abnormal exercise stress test and 73% had abnormal myocardial perfusion imaging (MPI). The diagnosis of LMCAOA was suspected by echocardiography in 47% of pediatric patients, while 26% were initially misdiagnosed as anomalous origin of LCA from pulmonary artery. Coronary angiography confirmed the diagnosis in most cases and 70.5% of pediatric patients had small collaterals, while 80.5% of adult patients had large collaterals. Nine pediatric patients had no revascularization surgery with five deaths. Revascularization surgery was performed in 39 pediatric patients with four deaths. After 2005, there is a gradual shift toward performing coronary osteoplasty rather than coronary artery bypass grafting. Eighteen adult patients had revascularization surgery and all survived. Fifteen adult patients had no revascularization surgery, of which there were five deaths. In patients with LMCAOA, revascularization surgery is currently recommended in the presence of symptoms, ischemic changes on electrocardiogram or exercise stress test, myocardial perfusion defect on MPI, global left ventricular systolic dysfunction on echocardiogram, severe mitral regurgitation, or small-sized collaterals in coronary angiography. Short-term and mid-term outcomes are encouraging.

Coronary Artery Anomalies and Associated Radiologic Findings

Coronary anomalies occur in about 1% of the general population and in severe cases can lead to sudden cardiac death. Coronary computed tomography angiography and magnetic resonance imaging have been deemed appropriate for the evaluation of coronary anomalies by accurately allowing the noninvasive depiction of coronary artery anomalies of origin, course, and termination. The aim of this article is to describe and illustrate a comprehensive array for the classification of coronary artery anomalies.

True congenital atresia of the left main coronary ostium: delayed presentation

Congenital atresia of the left main coronary ostium is a rare coronary anomaly presenting in adulthood. A 48-year-old man presented with unstable angina. Coronary angiography showed an absent left coronary ostium with a super-dominant right coronary artery retrogradely filling the left system. Computed tomography-angiography with 3-dimensional reconstruction confirmed the absence of the left main coronary artery. In view of ongoing chest pain, the patient was offered coronary artery bypass surgery. Total arterial revascularization was performed with a left internal mammary artery-left radial artery Y-graft.

Severe congenital stenosis of the left coronary artery ostium and its possible pathogenesis according to current knowledge on coronary artery development

We report a 72-year-old woman with severe congenital stenosis of the left coronary artery orifice and clinically significant atherosclerotic changes in both the right and left coronary arteries. The stenotic ostium was located at the point at which the left and posterior aortic valve leaflets joined to form the left commissure, just at the distal vertex of the left interleaflet triangle, between the left and posterior aortic sinuses. The right coronary artery was more developed in size than usual, whereas the left coronary artery consisted of a short left main coronary trunk that bifurcated into left anterior descending and left circumflex arteries. The left coronary artery system was filled retrogradely through two vessels proceeding from the right coronary artery, namely, the conal artery and a well-developed branch that ran across the interventricular septum. This abnormal arrangement of the coronary arteries showed striking functional similarities with atresia of the left main coronary artery. Current knowledge on the morphogenesis of the coronary arteries suggests that the present anomalous coronary artery pattern resulted from the penetration of the anticipated left coronary artery system into the aorta at a totally erroneus site. This hindered the normal development of the ostium, which subsisted as a punctiform, practically nonfunctional opening.

Connecting the coronaries: how the coronary plexus develops and is functionalized

The establishment of the coronary circulation is one of the final critical steps during heart development. Despite decades of research, our understanding of how the coronary vasculature develops and connects to the aorta remains limited. This review serves two specific purposes: it addresses recent advances in understanding the origin of the coronary endothelium, and it then focuses on the last crucial step of coronary vasculature development, the connection of the coronary plexus to the aorta. The chick and quail animal models have yielded most of the information for how these connections form, starting with a fine network of vessels that penetrate the aorta and coalesce to form two distinct ostia. Studies in mouse and rat confirm that at least some of these steps are conserved in mammals, but gaps still exist in our understanding of mammalian coronary ostia formation. The signaling cues necessary to guide the coronary plexus to the aorta are also incompletely understood. Hypoxia-inducible transcription factor-1 and its downstream targets are among the few identified genes that promote the formation of the coronary stems. Together, this review summarizes our current knowledge of coronary vascular formation and highlights the significant gaps that remain. In addition, it highlights some of the coronary artery anomalies known to affect human health, demonstrating that even seemingly subtle defects arising from incorrect coronary plexus formation can result in significant health crises.

Congenital atresia of the left main coronary artery in an infant

Congenital atresia of the left main coronary artery is a rare occurrence, and surgical revascularization-bypass graft is required. We here report a rare case of congenital coronary anomaly in an infant. A 10-month-old male infant was admitted to the hospital with heart failure symptoms. Echocardiographic examinations revealed mitral valve regurgitation and ischemic changes of the anterolateral papillary muscle and chordae. Coronary angiography showed atresia of the left main coronary artery with a severe hypoplastic left anterior descending artery and a circumflex coronary artery. Unfortunately, sudden cardiac arrest occurred after catheterization and the infant did not recover despite of immediate cardiopulmonary resuscitation. Further studies are needed to find a newer diagnostic method to detect coronary anomaly in an infant, and coronary angiography, if necessary, has to be performed very carefully.

Left main coronary artery atresia: extremely rare coronary anomaly in an asymptomatic adult and an adolescent soccer player

Left main coronary artery atresia is a very rare coronary anomaly with only 33 cases reported in the literature, of whom only 1 patient is asymptomatic. Pediatric patients are usually very symptomatic early in life (dyspnea, syncope, failure to thrive, ventricular tachycardia, and sudden death), whereas adult patients begin showing symptoms (angina or sudden death) only at an advanced age. Given the high risk related to the presence of left main coronary artery atresia, and in view of the good results obtained by coronary artery bypass surgery, coronary artery revascularization should always be considered as the possible treatment of choice for establishing adequate myocardial blood flow.

Left main coronary artery atresia: literature review and therapeutical considerations

OBJECTIVE

Left main coronary artery atresia is a rare coronary anomaly in which there is no left coronary ostium, the proximal left main trunk ends blindly, blood flows from the right coronary artery to the left via small collateral arteries and retrogradely in at least one of the left-sided arteries. Since published case reports are few and rather scattered, no comprehensive information about this uncommon anomaly is available.

METHODS

A through search for published cases of left main coronary atresia was performed in the major medical journals by electronic (MEDLINE and INTERNET) and hand-scanning.

RESULTS

The authors found 28 cases of left main atresia (including two from their own experience), 15 of which were pediatric; five of these cases had associated cardiac anomalies. While pediatric patients were usually overtly symptomatic early in their life (syncope, dyspnea, sudden death, failure to thrive, infarction, ventricular tachycardia), adult patients began showing symptoms (angina, dyspnea, sudden death) only at an advanced age; associated coronary atherosclerosis seemed to be uncommon, though (2/13 adult patients, 15%). We know of only one asymptomatic patient, a 76-year old lady who had died of unrelated causes; in her case left main atresia was an unforeseen autopsy finding. Four untreated patients had died suddenly; most of the others were highly symptomatic and required surgical therapy, usually as direct coronary artery revascularization via one or more saphenous vein or mammary artery grafts to the left-sided arteries; all revascularized patients were reported to be alive and well; in one pediatric case the left main coronary artery was reconstructed using an aortic wall baffle, with a good result. In contrast, the outcome of patients who did not receive revascularization has been poor.

CONCLUSION

In light of the favorable results obtained by surgical therapy, the authors endorse prompt coronary artery revascularization for all patients with left main coronary artery atresia.

Expanding indications for pediatric coronary artery bypass

Pediatric coronary artery bypass has been done mostly for ischemic complications of Kawasaki disease. We reviewed our clinical experience between 1987 and 1994 with internal thoracic artery-coronary artery bypass in one infant and five children for varying indications. Indications for coronary bypass included Kawasaki disease (2), congenital left main coronary ostial stenosis, iatrogenic coronary cameral fistula, anomalous origin of the left coronary artery from the pulmonary artery, and single coronary artery traversing between the great arteries in a patient after cardiac transplantation. An additional cohort of 34 control patients of various ages and weights (1 day to 16.1 years, 2.6 kg to 62 kg) had angiographic measurements of the right coronary, left coronary, and left internal thoracic arteries with respect to the feasibility of performing coronary artery bypass. All six patients survived internal thoracic artery-left anterior descending coronary artery bypass without evidence of perioperative myocardial infarction. Postoperative angiographic studies in five and color Doppler echocardiography in one showed graft patency. Retrospective angiographic measurements in the 34 control patients showed that internal thoracic and coronary arteries are proportionately quite large in neonates and infants compared with those in older children and adolescents. Internal thoracic artery-coronary artery bypass should be considered for the expanding indications presented herein and when emergency intraoperative life-threatening situations present themselves. Long-term patency and reoperation rates have yet to be determined.

Isolated congenital atresia of the left main coronary artery and atherosclerosis

Successful surgical revascularization in an adult with isolated congenital atresia of the left main coronary artery with coexistent two-vessel atherosclerosis is described. This extremely rare anomaly must be differentiated from single right coronary artery and acquired occlusion of the left main coronary artery. Symptomatic myocardial ischemia in patients surviving to adulthood is an indication for surgical revascularization in them.

Congenital atresia of left main coronary artery: proposed mechanism for severe disabling angina in a patient with non-atherosclerotic single right coronary artery--a case report

A patient with progressive disabling angina was found to have a single right coronary artery with atresia of the left main coronary artery, and absence of any obstructive coronary disease. The patient required aortocoronary by-pass surgical reconstruction of a left main coronary artery to control her angina. Possible mechanisms for the development of her anginal pain are briefly discussed.

Complete left main coronary artery occlusion: angiographic evaluation of collateral vessel patterns and assessment of hemodynamic correlates

An angiographic study of eight patients with total occlusion of the left main coronary artery identified six patients with chronic occlusion and two with acute complete occlusion. In each of six patients, there were two to six different intercoronary collateral pathways. Altogether, a total of 13 specific collateral channels were recognized. One patient had evidence of unique homocollaterals represented by enlarged vasa vasorum, which created a vascular cuff that surrounded a totally obstructed left main artery. The ventricular function and hemodynamic parameters in these patients not only depend on the collateral vessels but may also be affected by the severity of coronary artery disease in the artery that supplies collaterals.

Survival after myocardial infarction caused by acute left main coronary artery occlusion: case report and review of the literature

We report a 44-year-old white male presenting with an acute anterior myocardial infarction. Cardiac catheterization at 2 weeks postinfarction revealed total occlusion of the left main coronary artery. There was a normal dominant right coronary artery supplying moderate collaterals to the left coronary system. The patient was managed with conservative therapy and was N.Y.H.A. functional class II on followup 2 years later. A review of the literature relative to myocardial infarction caused by acute left main coronary artery occlusion is presented, and unique features of these cases are described.

Normal and anomalous coronary arteries: definitions and classification

Results of a comprehensive survey of the literature concerning coronary artery anatomy, embryology, and pathophysiology show the lack of an adequate definition of normal coronary arteries. To fill this gap, the present review considers the available data concerning the embryogenesis of the coronary arteries and proposes a new definition of normality that refers to essential anatomic features. The concepts of normal variant versus anomaly are introduced, based on a statistical definition of the normal range (99% of the presentations observed in a normal, unselected population). Coronary anomalies are defined as those patterns found in less than 1% of the cases. The wide spectrum of coronary abnormalities is then organized according to a comprehensive classification scheme. For clinical purposes the conceptual difference between anatomic and pathophysiologic anomalies is stressed. The current paucity of experimental studies concerning normal and abnormal embryogenesis of the coronary arteries is found to be the major limitation to an understanding of this subject.

Congenital atresia of the left coronary ostium: diagnosis and surgical treatment

An 11-year-old girl with congenital atresia of the left coronary ostium underwent coronary artery bypass grafting using the internal mammary artery. Before surgery, the patient complained of syncope on exertion. Exercise electrocardiogram (ECG), two-dimensional echocardiogram, and 201Tl myocardial scintigram were useful in establishing the diagnosis. Selective coronary angiograms showed typical findings. Postoperative recovery was uneventful; exercise ECG and stress 201Tl myocardial scintigram demonstrated improvement. Internal mammary artery graft is probably better than a saphenous vein graft as a coronary artery bypass graft in childhood and adolescence because of the long-term patency of this type of graft.

Congenital atresia of left coronary ostium

A two-year-old girl, who presented with congestive heart failure and an extensive anterolateral infarction, was thought to have anomalous origin of the left coronary artery from the pulmonary artery. She improved rapidly and remained symptom free until 13 years of age, when she died suddenly. At necropsy the right coronary artery was found to be normal but in the left aortic sinus a dimple was the only remnant of the left coronary ostium. The proximal segment of the left long term follow-up of a patient with this rare anomaly.