Massive hypercoagulable state despite full-dose anticoagulant treatment in a patient with occult malignancy: considerations concerning chemotherapy without definitive diagnosis.

A 55-year-old female patient presented with recurrent deep venous thrombosis and pulmonary embolism while on oral anticoagulant treatment using the vitamin K antagonist phenprocoumon. Hypercoagulable state was regarded to be paraneoplastic, but no underlying malignancy could be identified despite extensive screening for cancer, including gastroscopy and colonoscopy, a bone marrow biopsy, thoracoabdominal CT scans with subsequent biopsies of possibly malignant findings, octreotide scintigraphy, skeletal scintigraphy and gynaecological screening. In the course of her hospital stay she developed progressive right cardiac insufficiency due to the formation of new thromboses despite aggressive anticoagulant treatment and died of right-sided heart failure. The autopsy showed a poorly differentiated adenocarcinoma in the middle lobe of the right lung. In addition, pulmonary lymphangiosis carcinomatosa, pleural and pericardial carcinosis, and lymph node metastases and osteoblastic vertebral body metastases were shown.

How useful is determination of anti-factor Xa activity to guide bridging therapy with enoxaparin? A pilot study.

Low-molecular-weight heparins (LMWH) are commonly used as peri-procedural bridging anticoagulants. The usefulness of measurement of anti-factor Xa activity (anti-Xa) to guide bridging therapy with LMWH is unknown. It was the objective of this study to determine levels of anti-Xa during standard bridging therapy with enoxaparin, and to examine predictors for residual anti-Xa. Consecutive patients receiving enoxaparin at a dosage of 1 mg/kg body weight/12 hours for temporary interruption of phenprocoumon were prospectively enrolled to the study. Blood-samples were obtained 14 hours after LMWH-application immediately pre- procedurally. Procedural details, clinical and demographic data were collected and subsequently analyzed. Seventy patients were included (age 75.2 +/- 10.8 years, Cr Cl 55.7 +/- 21.7ml/min, body mass index [BMI] 27.1 +/- 4.9). LMWH- therapy was for a mean of 4.2 +/- 1.6 days; overall anti-Xa was 0.58 +/- 0.32 U/ml. In 37 (52.8%) of patients anti-Xa was > or U/ml, including 10 (14.3%) patients with anti-Xa > 1U/ml. Linear regression analysis of single variables and logistic multivariable regression analysis failed to prove a correlation between anti-Xa and single or combined factors. No major bleeding, no thromboembolism and four (5.7%) minor haemorrhages were observed. When bridging OAC with therapeutic doses of enoxaparin a high percentage of patients undergo interventions with high residual anti-Xa. The levels of anti-Xa vary largely and are independent of single or combined clinical variables. Since the anti-Xa-related outcome of patients receiving bridging therapy with LMWH is not investigated, no firm recommendation on the usefulness of monitoring of anti-Xa can be given at this stage.