Cardiac Involvement in a Patient With Aortic Aneurysm, Familial Thoracic-8.

BACKGROUND: Aortic aneurysm, familial thoracic-8 (AAT-8) is a rare genetic aortopathy caused by mutations in PRKG1. Cardiac involvement has not been previously reported. CASE SUMMARY: We report the case of a young man who was diagnosed with Stanford type B aortic dissection, later diagnosed as AAT-8, at age 11 years. At age 24 years, he developed severe heart failure and was found to have diffuse coronary artery ectasia. An endomyocardial biopsy was nonspecific. Three months later, he experienced an ST-segment elevation myocardial infarction due to thrombotic occlusion within an ectatic coronary artery. After intervention, his left ventricular ejection fraction remained severely reduced, and he has been referred for advanced heart failure therapies. DISCUSSION: The severe cardiomyopathy and coronary ectasia seen in this case represent novel cardiac manifestations of AAT-8. The underlying PRKG1 gain-of-function mutation, known to affect smooth muscle cell relaxation, likely predisposed the patient to both vasculopathy and cardiomyocardiopathy. TAKE-HOME MESSAGE: Clinicians should be aware that AAT-8 can present with severe cardiomyopathy and coronary ectasia.