Acute coronary syndrome associated with probable immunoglobulin G4-related coronary periarteritis successfully treated with a drug-coated balloon.

UNLABELLED: Immunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory disorder that can rarely affect the coronary arteries, leading to acute coronary syndrome (ACS). A 68-year-old man with IgG4-RD presented with exertional chest pain. An electrocardiogram showing ST-segment elevation in II, III, aVF leads, and rising troponin levels confirmed ACS. Emergent coronary angiography (CAG) revealed right coronary artery occlusion, and intravascular ultrasound (IVUS) showed vasculitis-related coronary pathology. Based on these findings and the patient's clinical background, ACS secondary to IgG4-related coronary periarteritis (IgG4-related CP) was diagnosed. Because stent implantation for inflammation-associated lesions carries a high risk of restenosis, percutaneous coronary intervention (PCI) without stenting was performed. Plaque ablation was achieved using excimer laser coronary atherectomy, followed by angioplasty with a drug-coated balloon. Post-PCI coronary computed tomography angiography demonstrated perivascular soft tissue around the culprit lesion, suggestive of ongoing inflammation. Follow-up CAG and IVUS confirmed good patency without restenosis after intensification of steroid therapy. This case highlights the complexity of ACS secondary to IgG4-related CP. Coronary involvement in IgG4-RD remains under-recognized, necessitating a high index of suspicion and multimodal imaging for diagnosis.

LEARNING

OBJECTIVE

Although rare, immunoglobulin G4-related coronary involvement should be considered a potential cause of acute coronary syndrome. Awareness of this entity and a multidisciplinary, multimodality imaging-based approach, including serial coronary computed tomography and intravascular ultrasound to assess treatment response, are essential for optimal management. In cases with insufficient response to corticosteroids, additional immunosuppressive therapy may be required.