Coronary Artery Variants and Anomalies in Patients With Bicuspid Aortic Valve

Patients with a Bicuspid Aortic Valve (BAV) Diagnosed with ECG-Gated Cardiac Multislice Computed Tomography-Analysis of the Reasons for Referral, Classification of Morphological Phenotypes, Co-Occurring Cardiovascular Abnormalities, and Coronary Artery Stenosis

Background/Objectives: The aim of this study was to analyze a group of patients with a bicuspid aortic valve (BAV) examined with ECG-gated cardiac CT (ECG-CT), focusing on the assessment of the clinical reasons for cardiac CT, cardiovascular abnormalities coexisting with their BAV, and coronary artery stenosis. Methods: A detailed statistical analysis was conducted on 700 patients with a BAV from a group of 15,670 patients examined with ECG-CT. Results: The incidence of a BAV in ECG-CT was 4.6%. The most common reason for examination was suspicion of coronary heart disease-31.1%. Cardiovascular defects most frequently associated with a BAV were a VSD (4.3%) and coarctation of the aorta (3.6%), while among coronary anomalies, they were high-take-off coronary arteries (6.4%) and paracommissural orifice of coronary arteries (4.4%). The analysis of the coronary artery calcium index showed significantly lower values for type 2 BAV compared to other valve types (p < 0.001), with the lowest average age in this group of patients. Moreover, the presence of a raphe between the coronary and non-coronary cusps was associated with a higher rate of significant coronary stenosis compared to other types of BAVs (p < 0.001). Conclusions: The most common reason for referral for cardiac ECG-CT in the group ≤ 40-year-olds with a BAV was the suspicion of congenital cardiovascular defects, while in the group of over 40-year-olds, it was the suspicion of coronary artery disease. The incidence of cardiovascular abnormalities co-occurring with BAV and diagnosed with ECG-CT differs among specific patient subgroups. The presence of a raphe between the coronary and non-coronary cusps appears to be a potential risk factor for significant coronary stenosis in patients with BAVs.

Coronary Artery Anomalies - State of the Art Review

Coronary artery anomalies (CAAs) comprise a wide spectrum of anatomic entities, with diverse clinical phenotypes. We present a case of an anomalous right coronary artery arising from the left aortic sinus with an interarterial course, a potentially fatal condition that can precipitate ischemia and sudden cardiac death. CAAs are increasingly detected in adults, mostly as incidental findings in the course of cardiac evaluation. This is due to the expanding use of invasive and noninvasive cardiac imaging, usually in the work-up for possible CAD. The prognostic implications of CAAs in this group of patients remain unclear. In AAOCA patients, appropriate work-up with anatomical and functional imaging should be performed for risk stratification. An individualized approach to management should be adopted, considering symptoms, age, sporting activities and the presence of high-risk anatomical features and physiologic consequences (such as ischemia, myocardial fibrosis, or cardiac arrhythmias) detected on multimodality imaging or other functional cardiac investigations. This comprehensive and up to date review seeks to crystallize current data in the recent literature, and proposes a clinical management algorithm for the clinician faced with the conundrum of managing such conditions.

Transcatheter Aortic Valve Therapy for Bicuspid Aortic Valve Stenosis

Transcatheter aortic valve implantation (TAVI) has become first-line treatment for older adults with severe aortic stenosis (AS), however, patients with bicuspid aortic valve (BAV) have been traditionally excluded from randomised trials and guidelines. As familiarity and proficiency of TAVI operators have improved, case-series and observational data have demonstrated the feasibility of successful TAVI in bicuspid aortic valve aortic stenosis (BAV-AS), however, patients with BAV-AS have several distinct characteristics that influence the likelihood of TAVI success. This review aims to summarise the pathophysiology and classification of BAV, published safety data, anatomical challenges and procedural considerations essential for pre-procedural planning, patient selection and procedural success of TAVI in BAV.

The Role of the Bicuspid Aortic Valve in Sudden Cardiac Death - Findings at Cardiac Autopsy

BACKGROUND

Bicuspid aortic valve (BAV) is the most common congenital cardiac defect in the adult population, with a prevalence of 0.5-2%. It is well recognised that aortic stenosis (AS), aortic regurgitation (AR) and aortopathy may develop by the fifth or sixth decade of life. There is a paucity of autopsy studies evaluating the hearts of subjects with BAV. The aim of this study is to help to ascertain the role of the bicuspid valve in the cause of sudden cardiac deaths.

METHODS

A database of 6325 whole hearts referred to a specialist cardiac pathology centre between 2004 and 2021 was reviewed to identify a subgroup of 91 subjects with a BAV reported. All cases had a negative full body autopsy and toxicology before being referred and subsequently underwent detailed cardiac evaluation including histological analysis by expert cardiac pathologists.

RESULTS

The mean age of death was 37±16 years (84% male). Death was attributed to aortic valve or aortic disease in 57% (n=52) of cases; AS 30% (n= 27), endocarditis 11% (n=10), aortic dissection (AD) 9% (n=8) and AR 8% (n=7). In the remaining 43% of cases, BAV was an incidental finding.

CONCLUSION

The majority of deaths in young individuals with BAV were attributed to complications related to the aortic valve or aorta indicating that BAV is not a benign condition. When a BAV is identified, individuals should be appropriately follow-up with imaging to inform the optimal timing of intervention before a complication develops that may predispose the individual to a premature death.

Coronary Artery Origins Pattern in Pediatric Patients with Right-Left Fusion Bicuspid Aortic Valve

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. We observed by transthoracic echocardiography that left and right CA origins appear closer together in pediatric patients with right-left fusion (R/L) BAV compared to patients with trileaflet aortic valves. We sought to objectively confirm this observation. A retrospective review of pediatric echocardiograms with R/L BAV at a single institution (12/2010-11/2018) was performed. The 'coronary angle' was defined as the angle between the left and right coronary artery origins in the parasternal short axis view relative to the center of the aortic valve orifice. Values were compared to age-matched controls. Patients with inadequate images, anomalous coronary origins, or predefined significant congenital heart defects were excluded. We compared 191 R/L BAV patients (64% male) to 136 controls (57% male). Coronary angle was significantly more acute in R/L BAV than in controls (117.9° ± 16.7° vs 139.0° ± 10.1°, p < 0.0001). This was independent of age and gender. The difference persisted when BAV patients with abnormal aortic annulus/root diameters were removed from analysis (119.5° ± 15.1° vs 139.0° ± 10.1°, p < 0.0001). CA origins are closer together in R/L BAV independent of age, gender, or annulus/root size. This new anatomical description may aid in the diagnosis of subtle ('forme fruste') R/L BAV, assist in interventional planning, and improve understanding of the relationship between BAV and CA development.

Concomitant cardiovascular malformations in isolated bicuspid aortic valve disease: a retrospective cross-sectional study and meta-analysis

Background

Congenital bicuspid aortic valve affects up to 2% of the general population. It occurs in complex congenital heart defects or in syndromes such as Turner, Marfan, or Loeys-Dietz. However, the majority of bicuspid aortic valves are considered to manifest as isolated malformations.

Methods

We aimed to assess retrospectively associated cardiovascular malformations in 200 individuals with bicuspid aortic valve considered to occur as an isolated manifestation. All individuals underwent transthoracic echocardiography, 164 thoracoabdominal tomographic imaging, and 84 coronary artery imaging. In addition, we also performed a meta-analysis of data from the literature to assess the occurrence of associate malformations.

Results

In our retrospective cross-sectional study collective, the mean age was 45±15 years, 154 (77%) individuals were male. Anatomy of bicuspid aortic valve according to Schaefer was type 1 in 142 (71%), type 2 in 35 (18%), type 3 in 2 (1%), unicuspid in 6 (3%), and unclassified in 15 (8%) individuals. Coarctation of the aorta had 4.2% of individuals, 3.6% had coronary anomalies. No individual had a patent ductus arteriosus, 0.5% had atrial and ventricular septal defect each, 1.5% mitral valve prolapse. No individual had a tricuspid valve prolapse. Our meta-analysis identified in cohorts with isolated bicuspid aortic valve 11.8% (95% CI: 7.7–16.0%) individuals with aortic coarctation, 3.7% (95% CI: 1.2–6.1%) with coronary anomalies, 3.3% (95% CI: 0.0–6.7%) with patent ductus arteriosus, 5.9% (95% CI: 1.3–10.5%) with ventricular septal defect and 1.6% (95% CI: 1.1–2.1%) with mitral valve prolapse.

Conclusions

Individuals with isolated bicuspid aortic valve may exhibit a variety of associated cardiovascular malformations and therefore screening for associated malformations may be warranted.

A SOX17-PDGFB signaling axis regulates aortic root development

Developmental etiologies causing complex congenital aortic root abnormalities are unknown. Here we show that deletion of Sox17 in aortic root endothelium in mice causes underdeveloped aortic root leading to a bicuspid aortic valve due to the absence of non-coronary leaflet and mispositioned left coronary ostium. The respective defects are associated with reduced proliferation of non-coronary leaflet mesenchyme and aortic root smooth muscle derived from the second heart field cardiomyocytes. Mechanistically, SOX17 occupies a Pdgfb transcriptional enhancer to promote its transcription and Sox17 deletion inhibits the endothelial Pdgfb transcription and PDGFB growth signaling to the non-coronary leaflet mesenchyme. Restoration of PDGFB in aortic root endothelium rescues the non-coronary leaflet and left coronary ostium defects in Sox17 nulls. These data support a SOX17-PDGFB axis underlying aortic root development that is critical for aortic valve and coronary ostium patterning, thereby informing a potential shared disease mechanism for concurrent anomalous aortic valve and coronary arteries.

Bicuspid Aortic Valve Stenosis: From Pathophysiological Mechanism, Imaging Diagnosis, to Clinical Treatment Methods

Bicuspid aortic valve (BAV) is the most frequent congenital anomaly and has a natural evolution toward aortic regurgitation or stenosis due to the asymmetrical valve function associated with an evolutive ascending aortopathy. Several BAV classifications exist describing the presence and number of raphe, amount and location of calcium, and the symmetry of the functional cusps. The impact of BAV morphology on transcatheter aortic valve implantation (TAVI) outcomes still remains little investigated. Pivotal randomized trials comparing TAVI with surgery have excluded BAV until yet. However, data from registries and observational studies including highly selected patients have shown promising results of TAVI in BAV. With this review, we aimed at describing anatomical and pathophysiological characteristics of BAV, discussing the main aspects to assess diagnostic imaging modalities, and giving an overview of TAVI outcomes and technical considerations specific to BAV morphology.

Congenital Left Coronary Atresia: Diagnostic Pearls and Management Challenges in Two Children Presenting with Syncope

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LMCA ostial atresia has variable clinical presentation.

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Diagnosis of LMCA ostial atresia is challenging and often requires multiple modalities.

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Coronary revascularization is possible for LMCA ostial atresia by varying surgical techniques.

Coronary Artery Anomalies

Coronary artery anomalies (CAAs) are a group of congenital conditions characterized by abnormal origin or course of any of the 3 main epicardial coronary arteries. Although CAAs have been identified as a common underlying condition in young athletes with sudden cardiac death, the widespread use of invasive and noninvasive coronary imaging has led to increased recognition of CAAs among adults. CAAS are often discovered as an incidental finding during the diagnostic workup for ischemic heart disease. The clinical correlates and prognostic implication of CAAs remain poorly understood in this context, and guideline-recommended therapeutic choices are supported by a low level of scientific evidence. Several studies have examined whether assessment of CAA-related myocardial ischemia can improve risk stratification in these patients, suggesting that multimodality imaging and functional tests may be key in the management of CAAs. The aim of this review is to outline definitions, classification, and epidemiology of the most relevant CAAs, highlighting recent advances and the potential impact of multimodality evaluation, and to discuss current therapeutic opportunities.

Left Ventricular Summit-Concept, Anatomical Structure and Clinical Significance

The left ventricular summit (LVS) is a triangular area located at the most superior portion of the left epicardial ventricular region, surrounded by the two branches of the left coronary artery: the left anterior interventricular artery and the left circumflex artery. The triangle is bounded by the apex, septal and mitral margins and base. This review aims to provide a systematic and comprehensive anatomical description and proper terminology in the LVS region that may facilitate exchanging information among anatomists and electrophysiologists, increasing knowledge of this cardiac region. We postulate that the most dominant septal perforator (not the first septal perforator) should characterize the LVS definition. Abundant epicardial adipose tissue overlying the LVS myocardium may affect arrhythmogenic processes and electrophysiological procedures within the LVS region. The LVS is divided into two clinically significant regions: accessible and inaccessible areas. Rich arterial and venous coronary vasculature and a relatively dense network of cardiac autonomic nerve fibers are present within the LVS boundaries. Although the approach to the LVS may be challenging, it can be executed indirectly using the surrounding structures. Delivery of the proper radiofrequency energy to the arrhythmia source, avoiding coronary artery damage at the same time, may be a challenge. Therefore, coronary angiography or cardiac computed tomography imaging is strongly recommended before any procedure within the LVS region. Further research on LVS morphology and physiology should increase the safety and effectiveness of invasive electrophysiological procedures performed within this region of the human heart.

Anomalous coronary artery origin from the opposite sinus in patients with bicuspid aortic valve: comparison with tricuspid aortic valve

Objective

To compare the prevalence and patterns of anomalous coronary artery origin from the opposite sinus (ACAOS) in patients with bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV).

Methods

Retrospective review of consecutive patients with surgically excised BAV and TAV was performed from 1994 to 2015. Clinical notes, echocardiograms, coronary angiograms, CT angiographies, and pathology reports were reviewed. ACAOS included right coronary artery from the left cusp, left circumflex artery from the right cusp and left main or left anterior descending artery from the right cusp.

Results

2371 (years 1994–2015) and 1679 (years 2009–2015) consecutive patients with pathology-confirmed BAV and TAV, respectively, and defined preoperative coronary anatomy were identified. A left dominant coronary circulation was present in 386 (18%) patients with BAV and 179 (11%) patients with TAV (p<0.001). ACAOS was identified in 43 (1.8%) patients with BAV and 15 (0.9%) patients with TAV, p=0.02. Among patients with BAV and ACAOS, the most common phenotype was right-left fusion (n=34, 79%) with present raphe (n=36, 84%), with no association between BAV phenotype and ACAOS type. On multivariate analysis, BAV status and size of the mid-ascending aorta were independently associated with ACAOS (OR 3.29; CI 1.26 to 8.6; p=0.02; OR 0.93; CI 0.87 to 0.98; p=0.01; respectively). Only two patients with ACAOS, one with BAV and one with TAV, had a perioperative coronary ischaemic event.

Conclusions

The prevalence of the potentially malignant ACAOS is significantly higher (threefold higher odds) in patients with BAV as compared with TAV, yet remains uncommon in absolute terms. Most patients with BAV and ACAOS had right-left cusp fusion and present raphe. Perioperative coronary events are rare in patients with ACAOS.

The impact of coronary anomalies on the outcome in aortic valve surgery: comparison of bicuspid aortic valve versus tricuspid aortic valve morphotype

OBJECTIVES

The association of anomalous anatomy of coronary arteries and bicuspid aortic valve (BAV) has been sporadically reported. Our aim was to evaluate the prevalence of coronary anomalies between BAV and tricuspid aortic valve (TAV) and to analyse their impact on major adverse cardiac events during and after aortic valve surgery.

METHODS

A total of 1099 consecutive patients who received preoperative coronary evaluation and elective aortic valve replacement/repair between January 2013 and July 2016 at our institution were involved. Based on surgical inspection at the open-heart surgery, a total of 345 (32%) patients were diagnosed with BAV, whereas the remaining 754 (68%) patients had TAV. Coronary anatomy was evaluated by preoperative coronary angiography (n = 1084) or multislice computed tomography (n = 15). The primary end-point was the prevalence of coronary anomalies in BAV versus TAV cohort. Secondary end-points included postoperative cardiac ischaemia markers, postoperative coronary artery imaging or interventions and hospital mortality.

RESULTS

A total of 46 (4%) coronary anomalies were detected and were significantly more frequent in the BAV group (7% vs 3%, P = 0.001). Postoperative markers of myocardial injury (creatine kinase/creatine kinase-MB and troponin) were increased and the need for postoperative coronary angiography/percutaneous coronary intervention was significantly higher in patients with coronary anomalies (12% vs 1%, P < 0.001).

CONCLUSIONS

Our study revealed significantly increased prevalence of coronary anomalies in BAV patients when compared with their tricuspid counterparts. Patients with diagnosed coronary anomalies had more postoperative ischaemic cardiac events that resulted in increased morbidity of this cohort.