Myocardial Infarction in Polycythemia Vera and Dengue: A Case of Competing Risks

A 71-year-old male with polycythemia vera, myocardial infarction, and acute dengue infection presented with intermittent chest pain, nausea, and fever. His medical history included hypertension, dyslipidemia, chronic kidney disease, and a prior myocardial infarction of unknown localization. Electrocardiography revealed ischemic changes and troponin T was significantly elevated (965 pg/mL). Given the regional dengue epidemic, NS1 antigen testing was performed and was strongly positive (64.93 S/Co; positive ≥1.0), confirming dengue. Laboratory findings included erythrocytosis (hematocrit 70.3%), mild thrombocytopenia (100,000/mm³), and worsening renal function (creatinine 1.6 mg/dL). The patient was diagnosed with a late-presenting myocardial infarction in the context of polycythemia vera-induced hypercoagulability and dengue-associated thrombocytopenia, raising critical management challenges regarding percutaneous coronary intervention (PCI) and antithrombotic therapy. Due to spontaneous symptom resolution and high bleeding risk, an immediate invasive strategy was deferred in favor of guideline-directed medical therapy and close monitoring. Platelets declined to 24,000/mm³, requiring conservative management of thrombocytopenia, phlebotomy, and fluid replacement. A delayed coronary angiography revealed an occluded proximal right coronary artery, but PCI was not performed due to lack of persistent symptoms. This case underscores the complex interplay between thrombosis and bleeding risks in high-risk cardiovascular patients, requiring a multidisciplinary approach to optimize outcomes.