STEMI as the Initial Presentation of Polyarteritis Nodosa Associated with Hepatitis B: A Rare Cardiovascular Manifestation

Background: Polyarteritis nodosa (PAN) is a rare necrotizing vasculitis affecting medium-sized arteries. While cardiac involvement is uncommon, it can lead to severe coronary complications. We report a case of hepatitis B virus-associated PAN (PAN-HBV) revealed by an acute ST-elevation myocardial infarction (STEMI). Case Presentation: A 49-year-old male smoker presented with anterior STEMI. Echocardiography revealed severe left ventricular dysfunction and an apical thrombus. Coronary angiography showed multiple aneurysmal dilatations and critical stenoses. Hepatitis B serology was positive, with no other infectious or autoimmune findings. PAN-HBV was diagnosed. The patient underwent percutaneous coronary intervention (PCI) and was treated with dual antiplatelet therapy, antivirals (tenofovir), and a short course of corticosteroids. Discussion: This case underscores the need to consider vasculitis in young patients with atypical coronary lesions, combining stenoses and aneurysms. The angiographic findings were key to the diagnosis. Prompt antiviral therapy and cautious immunosuppression were critical in managing both the ischemic event and underlying vasculitis. Conclusion: PAN-HBV can manifest initially as an acute coronary syndrome, particularly STEMI, without systemic features of vasculitis. Early recognition and a multidisciplinary approach are essential for optimizing outcomes in these patients.