Hypercoagulable states increasingly reflect acquired rather than inherited factors with advancing age, and myeloproliferative neoplasms are a key acquired driver of extreme, persistent thrombocytosis capable of triggering multivessel coronary thrombosis, distinguishing this presentation from reactive thrombocytosis, which rarely exceeds 1,000,000/µL. Diagnosis followed International Consensus Classification criteria: sustained platelet count above 450,000/µL, marrow megakaryocytic hyperplasia with hyperlobulated nuclei and grade 1 fibrosis, JAK2 mutation, and exclusion of reactive causes and other myeloproliferative neoplasms (polycythemia vera, chronic myeloid leukemia, primary myelofibrosis) through normal erythropoietin, cytogenetics, and marrow morphology. Platelet counts rising despite hydroxyurea prompted platelet-lowering apheresis, which lowers counts 30% to 60% per session toward a target below 600,000/µL and served as an effective bridge, allowing safe staged revascularization. Extreme thrombocytosis also unmasked acquired von Willebrand syndrome, reflected in impaired ristocetin-induced platelet aggregation and suboptimal P2Y12 inhibition, which required increasing the clopidogrel dose and underscores the paradoxical thrombotic-hemorrhagic balance inherent to this disease. The antithrombotic strategy followed a time-limited triple therapy transitioning to dual and then single antiplatelet therapy, consistent with contemporary acute coronary syndrome guidelines favoring bleeding-reduction strategies after percutaneous intervention. Evidence guiding anticoagulation duration for left ventricular thrombus is limited to expert consensus, and no dedicated data exist for essential thrombocythemia specifically, highlighting a persistent knowledge gap. This case reinforces that unexplained or refractory thrombocytosis accompanying acute coronary thrombosis warrants hematologic evaluation, and that management requires close cardiology-hematology collaboration to balance ischemic and hemorrhagic risk.