Characteristics and risk factors for thrombocytopenia in malignancy patients with pulmonary embolism: a case control study

Thrombocytopenia represents a frequent yet severe complication among malignancy patients with pulmonary embolism (PE). Contrary to the assumption that low platelet counts might inhibit thrombosis, thrombocytopenia in malignancy patients poses significant challenges for anticoagulation therapy. This study aimed to investigate the clinical characteristics and identify risk factors associated with thrombocytopenia in malignancy patients complicated by PE. The findings may provide a foundation for developing targeted interventions to mitigate thrombocytopenia and guide biomarker and clinical characteristics-based management strategies. We conducted a retrospective study analyzing clinical data from malignancy patients diagnosed with PE who were admitted to the Second Affiliated Hospital of Kunming Medical University between January 2014 and June 2024. The cohort was stratified into two groups: 66 patients with thrombocytopenia and 429 patients with normal platelet counts. Clinical characteristics and potential risk factors were systematically collected and analyzed. Many clinical indicators were found to have statistically significant differences between the low platelet group and the normal platelet group (P < 0.05). Multivariable logistic regression analysis further identified coronary heart disease, right ventricular dysfunction, anticoagulant therapy, anti-tumor drug therapy, dyspnea, hemoptysis, fever(>37.3℃), neutrophil (NEUT), standard deviation in red cell distribution width (RDWSD), platelet distribution width (PDW), procalcitonin (PCT), international normalized ratio (INR), fibrinogen (FIB) were significantly associated with a 6.703, 3.335, 0.311, 4.176, 4.244, 4.533, 3.527, 0.288, 3.995, 2.616, 5.129, 2.641, 0.212 times higher risk of thrombocytopenia in malignant patients with PE respectively. Multivariate analysis identified several independent risk factors for thrombocytopenia in malignant patients with PE, including coronary heart disease, right ventricular dysfunction, anti-tumor drug therapy, dyspnea, hemoptysis, fever (> 37.3 °C), RDW-SD, PDW, PCT and INR. Conversely, anticoagulant therapy, NEUT, and FIB emerged as independent protective factors against thrombocytopenia in this patient population.