Venous thromboembolism and mortality in a multiethnic population: a report from the Birmingham Black Country VTE registry (BBC-VTE Investigators)

Abstract

Abstract Background Most epidemiological studies into venous thromboembolism (VTE) are based on the white Caucasian population and unrepresentative of VTE outcomes in non-white ethnicities. Purpose Our VTE registry aims to get an insight into the outcomes of VTE patients as applicable to a developed world population with a multi-ethnic background. This will guide clinicians to make appropriate decisions with regards to management and prognosis. Methods The Birmingham Black Country VTE Registry (BBC-VTE) is a multi-ethnic cohort of patients in the West Midlands region of the United Kingdom, who suffered a first episode of VTE. In this study we compared baseline characteristics, treatment patterns and outcomes, and secondly, compared these among the different ethnic groups in this region. Results Between the years 2012–2014 there was a total of 1615 patients (mean age 65.5; 53.1% female) admitted with a first episode of VTE of whom, 134 (8.3%) were Asian, 92 (5.7%) Black, and 1213 (75.1%) White. Asian patients were younger (mean age 54, SD 19.3) vs Black patients (59, SD 19.7) and White patients (68, SD 17.4); and were less often female (50.7% vs. 55.4% and 53.8%) for Black and White patients respectively. The initial VTE event was a DVT in 680 (42.1%) and a PE±DVT in 935 patients (57.9%). Below-knee and above-knee DVT occurred in 95 (5.9%) and 585 (36.2%) patients respectively. Recurrent DVT occurred in 3.2% of those with an initial below-knee DVT and 12.5% of those with an initial above-knee DVT. Recurrent PE was also more common in those with an initial above knee DVT (4.8%) compared to those with below-knee DVT (3.2%). After the initial VTE event, 1269 (78.6%) were started on long-term anticoagulation for the prevention of recurrent VTE. Of those, 65.1% stayed on anticoagulation for up to 6 months after the initial VTE event, and 34.9% continued for longer than 6 months, including those on lifelong anticoagulation. Bleeding and major bleeding occurred in 6.8% and 2.5% respectively in those on anticoagulation for 6 or less months, vs. 10.4% and 3.5% in those anticoagulated for longer than 6 months. The most common site of bleeding was gastrointestinal in 42.3% of all bleeds and this site was also responsible for 54.3% of major bleeds. From evaluating the odds ratio for VTE mortality (see Fig. 1), ethnicity did not have a significant impact. Older age; the presence of diabetes mellitus; history of malignancy; as well as admission laboratory results for C-reactive protein and neutrophil count were all significantly associated with higher odds of mortality in this patient cohort. Conclusion BBC-VTE is a contemporary multi-ethnic cohort of patients providing insights into the risk factors among multi-ethnic patients that have developed VTE. Ethnicity did not emerge as an independent risk for VTE mortality. Funding Acknowledgement Type of funding sources: None.