Multimodality Imaging Diagnosis of Multiple Giant Coronary Artery Aneurysms with Massive Mural Thrombosis

Technical Summary: Multimodality Imaging Diagnosis of Multiple Giant Coronary Artery Aneurysms with Massive Mural Thrombosis

Problem Statement
Giant coronary artery aneurysms (GCAA), defined as coronary dilatations with a diameter of at least 20 mm, are rare entities with an angiographic incidence of approximately 0.02–0.20%. While atherosclerosis is the primary etiology in adults, complications such as thrombosis, distal embolization, myocardial infarction, heart failure, and rupture pose significant clinical risks. The specific case presented involves an exceptionally rare presentation: multiple GCAAs affecting multivessel segments (left main, left anterior descending, and right coronary arteries) accompanied by massive mural thrombosis. The clinical challenge lies in the fact that no single imaging modality can fully characterize the complex interplay of aneurysm morphology, thrombus burden, myocardial injury, ventricular function, and coronary hemodynamics required for accurate risk stratification and management.

Methodology
The study employs a multimodality imaging approach to diagnose and characterize a complex case of a 64-year-old male patient with a 13-year history of coronary ectasia who presented with recurrent chest pain and worsening heart failure. The diagnostic workflow integrated four distinct imaging modalities:

1. Transthoracic Echocardiography (TTE): Performed at the bedside as the initial screening tool to assess cardiac chamber size, ventricular function, and detect pericardial mass-like lesions.
2. Coronary Computed Tomography Angiography (CCTA): Utilized for high-resolution, non-invasive 3D anatomical mapping to measure aneurysm dimensions, characterize wall calcification, and delineate intraluminal thrombus.
3. Cardiac Magnetic Resonance (CMR): Employed to evaluate myocardial tissue characterization (specifically late gadolinium enhancement for prior infarction) and quantify ventricular function without ionizing radiation.
4. Selective Coronary Angiography (CAG): Conducted to provide dynamic evaluation of lumen anatomy, contrast clearance, flow stasis, occlusion status, and collateral circulation.

Key Results
The multimodality approach yielded a comprehensive diagnostic profile:

• TTE Findings: Rapidly identified irregular dilatation of proximal coronary segments and multiple mass-like pericardial lesions. The largest lesion, located anterior to the right ventricle, measured approximately 92 x 72 mm, exhibited a markedly thinned wall (minimum thickness ~1.0 mm), and contained irregular hypoechoic mural thrombus. It also revealed left ventricular enlargement with impaired global and regional systolic function.
• CCTA Findings: Confirmed multiple GCAAs involving the left main, left anterior descending (LAD), and right coronary arteries (RCA). The largest aneurysm (proximal LAD) measured 91.0 mm in diameter, showing extensive calcification and a large volume of heterogeneous intraluminal material consistent with thrombus. 3D volume-rendered images successfully delineated the spatial relationship between the aneurysms and adjacent myocardium.
• CMR Findings: Demonstrated patchy late gadolinium enhancement in the anterolateral left ventricular wall, consistent with prior myocardial infarction. Quantitative analysis confirmed reduced left ventricular systolic function with a Left Ventricular Ejection Fraction (LVEF) of approximately 40%.
• CAG Findings: Revealed giant aneurysms at the left coronary ostium and proximal RCA, with occlusion of the mid-RCA. Dynamic angiography showed delayed contrast clearance and impaired distal perfusion, indicating flow stasis, while collateral vessels provided retrograde filling to the posterior descending territory.

Conclusion and Management
Based on the integrated imaging data, the patient was diagnosed with multiple GCAAs with mural thrombosis, coronary atherosclerotic heart disease, unstable angina, previous myocardial infarction, acute left-sided heart failure, and persistent atrial fibrillation. Due to the massive aneurysm size, multivessel involvement, heavy thrombus burden, and high operative risk, surgical intervention was deemed too hazardous. The patient was managed with intensified medical therapy, including anticoagulation, antiplatelet therapy, diuretics, and guideline-directed heart failure treatment, resulting in clinical improvement and stable discharge.

Significance and Claims
The paper asserts that multimodality imaging is essential for the management of complex GCAA cases where a single test is insufficient. The authors claim that:

• TTE serves as a critical first-line tool for rapid detection of large proximal aneurysms and thrombus, guiding subsequent imaging.
• CCTA provides the most complete non-invasive anatomical assessment, defining 3D relationships and thrombus burden.
• CMR offers superior tissue characterization for myocardial injury and precise ventricular function quantification.
• CAG remains indispensable for dynamic flow assessment and evaluating the feasibility of revascularization.

The study concludes that integrating these modalities is crucial for defining aneurysm anatomy, assessing thrombus burden, evaluating myocardial injury, and planning individualized treatment strategies for patients with complex, life-threatening coronary artery aneurysms.