CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 4, July/August 2022 AFRICA 187 warfarin for the treatment of DVT and PE.7 In the RE-MEDY trial, the efficacy of dabigatran was comparable to that of warfarin, with much fewer bleeding events for extended treatment of VTE.8 The phase 3 EINSTEIN-DVT study showed that major bleeding occurred less often with rivaroxaban and with less severity than with low-molecular weight heparin (LMWH)/ vitamin K antagonist (VKA) therapy,3 and it was equally as efficacious in the treatment of VTE.6,7 In the AMPLIFY trial of apixaban use in VTE, apixaban was found to be non-inferior to conventional therapy in the treatment of VTE, and the rate of major bleeding was significantly lower in the apixaban group.9 XALIA, a large-scale, prospective study of rivaroxaban in patients with VTE, showed a low rate of major bleeding (0.8 vs 2.1%) and recurrent VTE in the treatment of DVT.4 Similar real-world studies including from the European PREFER and the REMOTEV study showed low rates of major bleeding. The major and clinically relevant bleeding rate was 5.4% (15/280) in the rivaroxaban group, 9.4% (9/96) in the VKA group and 7.2% (5/69) in the heparin/fondaparinux group.10,11 These results are consistent with those of the phase 3 EINSTEIN-DVT and -PE trials,3 and confirm that the results of these studies can be translated to patients typically treated in routine clinical practice. XALIA-LEA was conducted in regions not included in the XALIA study (Latin America, Eastern Europe, the Middle East, Africa and the Asia–Pacific) and enrolled patients with isolated PE. It included 12 patients on rivaroxaban from Kenya.12 This study reaffirmed the findings of XALIA. ETNA-VTE Europe, a prospective, non-interventional study conducted in eight European countries assessed the real-world benefits and risks of edoxaban for the treatment of VTE during the first three months. The rate of major bleeding was low, occurring in 0.97% of the patients. This study further reaffirms the safety of NOACs in contemporary clinical practice.13 NOACs have a higher incidence of gastrointestinal bleeding compared to VKAs.14 In the RE-LY trial, dabigatran at 150 mg twice a day was associated with a higher incidence of gastrointestinal bleeding compared with warfarin (1.51 vs 1.02%). Holster et al.15 summarised the risk of gastrointestinal bleeding associated with NOACs in a meta-analysis and noted 1.5% gastrointestinal bleeding events, with 89% being major gastrointestinal bleeding [defined by the International Society on Thrombosis and Haemostasis (ISTH) criteria]. Methods This was a single-centre, retrospective cohort study of patients diagnosed with VTE and treated with NOACs. The diagnosis of PE was confirmed by either computed tomography pulmonary angiogram or a ventilation-perfusion lung scan. DVT was confirmed by ultrasonography. The patients had to be on treatment with rivaroxaban, apixaban or dabigatran. The index date of diagnosis was defined as the date of the first prescription of the NOAC. Patients were followed from the index date to the first major or first CRNM bleeding event, date of discontinuation of NOAC, date of a switch to VKA (commonly warfarin) or LMWH, end of the study period or interruption in continuous enrolment, which ever occurred earlier. A hospital database medical chart search of patients with VTE was carried out. Files for patients with VTE diagnosed between January 2014 and December 2019 were retrieved. All eligible patients were assessed for inclusion. The observation period ended three months from the date of the final patient enrolment, which ensured that each patient was followed up for at least three months. Demographic and clinical characteristics, and relevant concomitant medication were obtained from the medical records. Co-morbidities, including heart failure, acute coronary syndromes, peripheral vascular disease, hypertension, renal insufficiency, cancer, stroke, and alcohol and tobacco use were identified based on the diagnosis. A questionnaire was used to record data on bleeding, which was obtained from medical records and telephone interviews. Patients were advised to seek medical attention if they developed any bleeding complications. The main outcome was minor, major or CRNM bleeding as per the ISTH criteria.16 Ethical approval was sought from the Aga Khan University Research Ethics Committee before conducting the study. Verbal consent was obtained from all participants before initiating the telephone interview. Statistical analysis Categorical data are presented as frequencies and percentages, and continuous data as means and standard deviations (SD) or medians and interquartile ranges (IQR). Unadjusted rates of the first major bleeding event or CRNM bleeding are reported as the number of bleeding events per 100 person-years. Univariate analyses were performed using the Kruskal–Wallis test for continuous variables and Fisher’s exact test for categorical variables. A p-value < 0.05 was considered significant. Results A total of 608 patients were assessed for eligibility; 288 did not meet the inclusion criteria and 320 were enrolled, of whom 77 were excluded (unavailable or declined to participate). A total of 243 patients was included in the final analysis, as shown in Fig. 1. Among 243 eligible patients, 222 (91.4%) were initiated on rivaroxaban, 12 (4.9%) on dabigatran and nine (3.7%) on apixaban, with a median follow up of 213 (IQR: 119–477) days. The median age of the patients was 57 (IQR: 45–71) years and the mean age was 57.9 (16.1) years. Of the co-morbidities investigated, hypertension, diabetes mellitus, dyslipidaemia, cancer and renal dysfunction affected 608 patients were assessed for eligibility 320 enrolled Eligible patients for analysis (n = 243) Fig. 1. Study flow diagram.
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