Management and Outcome of Venous Thromboembolic Disorders Among Cancer Patients at Kenyatta National Hospital

Abstract

Background: Cancer is a well-known hypercoagulable state. Compared to patients without cancer, the incidence of venous thromboembolic events is 4 to 7 times higher among cancer patients. There is paucity of data on the assessment of the management and covariates of venous thromboembolic events (VTEs) among patients with cancer in resource constrained settings. Objective: To characterize the management and outcome of venous thromboembolic disorders among Cancer Patients at Kenyatta National hospital. Study Area and Setting: - Kenyatta National Hospital, oncology department Participants: - Cancer patients with a diagnosis of VTE Methodology: A retrospective cross-sectional design and random sampling were used to assess 250 files, which satisfied the inclusion criteria, from the health records department. Data on patient sociodemographic characteristics, types of cancer and treatment modalities, types and management patterns of VTE as well as outcomes of anticoagulation including level of anticoagulation, venous thromboembolic events recurrence and bleeding events were extracted from the files into a predesigned data collection tool. Data Analysis: Raw data was entered into Microsoft excel 2016 to created database and exported to STATA version 13 for analysis. Descriptive analysis of variables such as marital status was done and presented as percentages while continuous variables such as age were analyzed and summarized using the mean, mode, median and standard variation. Inferential statistics using the Pearson’s Chi-Square test or Fischer’s test and logistic regression was used to determine the strength of association between the sociodemographic and clinical characteristics with the type of VTE, level of anticoagulation, VTE recurrence and occurrence of major bleeding episodes. Backward stepwise model building was used to achieve the most parsimonious model that explained independent predictors of the occurrence of bleeding events and statistical significance was assumed if the p-value was less than 0.05. Results: Majority of the study participants were females (75.6%). The mean age of the participants was 54.4years (±15.4) years. Cervical cancer (30%) was the commonest malignancy and most patients (71.8%) developed VTE after 1 month of cancer diagnosis where the most prevalent thrombotic event was deep vein thrombosis, 234(93.6%). Warfarin was the principal agent prescribed for the management of the VTE (72.8%) but 5.6% patients had recurrence while 18.8% had major bleeding events. The duration of anticoagulation for most of the patients was xiii less than 3 months. Monitoring of patients was mainly through determination of INR and aPTT. Patients were poorly anticoagulated with only 33(16.6%) achieving optimal INR and only 7.6% had the aPTT values within the recommended range. The independent predictors of major bleeding events included comorbidities (AOR = 3.91; CI: 1.77- 8.63; p=0.001), gender (AOR=0.09; CI;0.02-0.04; p=0.02), history of surgery (AOR = 4.5; CI: 2.10-9.75; P <0.001) and history of radiotherapy (AOR = 6.13; CI: 2.19-17.23; P =0.001). Conclusion: Most cancer patients suffer from DVT as opposed to PEs. Warfarin is the most used anticoagulant but there is poor anticoagulation control with majority of the patients being under-anticoagulated. However, the frequency of recurrence of VTE among cancer patients is low. The frequency of major bleeding events in cancer patients receiving anticoagulation therapy was high and majorly attributed to presence of comorbidities, gender, history of surgery and history of radiotherapy. Recommendations: Anticoagulation practice among cancer patients should be improved. A specialized anticoagulation clinic that is focused solely on anticoagulation management may ensure that patients are followed up from a central place, adequate levels of anticoagulation are maintained and the negative outcomes of anticoagulation are noted earlier or prevented. A large prospective study to find out the outcomes of anticoagulation among cancer patients with VTE should be conducted so as to establish their accurate incidence rates and their associated risk factors.