Successful Management of Early High-Risk Pulmonary Embolism Following Elective Coronary Artery Bypass Grafting (CABG) Using Intravenous Unfractionated Heparin Alone

Acute pulmonary embolism (APE) following coronary artery bypass grafting (CABG) is uncommon but may rapidly become life-threatening, particularly when it presents in the early postoperative period and is accompanied by hemodynamic instability. We report the case of an 80-year-old woman who developed high-risk APE on the second postoperative day after elective two-vessel CABG. The diagnosis was based on acute hypotension, severe hypoxemia, right ventricular (RV) failure on transthoracic echocardiography, and marked elevation of cardiac biomarkers, while computed tomography pulmonary angiography was not feasible due to profound instability. Management was complicated by recent major surgery and severe postoperative thrombocytopenia, both of which constituted strong contraindications to systemic thrombolysis. Given the prohibitive bleeding risk, the multidisciplinary team initiated continuous intravenous unfractionated heparin (UFH) at the lower therapeutic activated partial thromboplastin time range, combined with vasopressor and inotropic support. Over the following days, the patient demonstrated progressive hemodynamic, respiratory, and renal recovery without bleeding complications. Platelet count gradually normalized, allowing transition to therapeutic low-molecular-weight heparin. She was discharged in stable condition with improved RV systolic function on follow-up echocardiography. This case highlights a rare instance of successful management of early high-risk postoperative APE using UFH alone when reperfusion strategies are contraindicated. The report underscores the critical role of individualized decision-making in the postoperative period and illustrates that, in selected patients, carefully titrated UFH may serve as a lifesaving alternative in situations where thrombolysis or invasive reperfusion therapies cannot be safely performed.