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Factor XI deficiency is associated with decreased risk for cardiovascular and venous thromboembolism events

Factor XI deficiency is one of the rare inherited coagulation factor deficiencies. However, its incidence is high within the Ashkenazi Jewish community. Because factor XI displays both procoagulant and antifibrinolytic activities, it has been postulated that an underlying cardiovascular benefit may exist with factor XI deficiency. This historical cohort study was performed using the electronic database of Clalit Health Services, the largest health care provider in Israel. All adults tested for factor XI activity between 2002 and 2014 were included in the study. Factor XI activity was classified into 3 categories: normal (activity >50%), mild deficiency (activity = 30%-50%), and moderate-severe deficiency (activity ≤30%). The cohort was followed until 31 December 2015 for incidence of cardiovascular events (composite of myocardial infarction, stroke, and transient ischemic attack) and venous thromboembolism (VTE). Of the 10 193 included patients, 8958 (88.9%) had normal factor XI activity, 690 (6.8%) had mild deficiency, and 542 (5.3%) had moderate-severe deficiency. Compared with individuals with normal activity, the adjusted hazard ratio (HR) for cardiovascular events was 0.52 (95% confidence interval [CI], 0.31-0.87) in those with mild deficiency, and 0.57 (95% CI, 0.35-0.93) in those with moderate-severe factor XI deficiency. The incidence of VTE was lower in those with factor XI deficiency (activity <50%) compared with those with normal activity; adjusted HR = 0.26 (95% CI, 0.08-0.84). In summary, factor XI deficiency is associated with decreased incidence of cardiovascular events and VTE.

Engineering blood vessels by gene and cell therapy.

Cardiovascular-related syndromes are the leading cause of morbidity and mortality worldwide. Arterial narrowing and blockage due to atherosclerosis cause reduced blood flow to the brain, heart and legs. Bypass surgery to improve blood flow to the heart and legs in these patients is performed in hundreds of thousands of patients every year. Autologous grafts, such as the internal thoracic artery and saphenous vein, are used in most patients, but in a significant number of patients such grafts are not available and synthetic grafts are used. Synthetic grafts have higher failure rates than autologous grafts due to thrombosis and scar formation within graft lumen. Cell and gene therapy combined with tissue engineering hold a great promise to provide grafts that will be biocompatible and durable. This review describes the field of vascular grafts in the context of tissue engineering using cell and gene therapies.

Association of factor V activity with risk of venous thromboembolism and atherothrombotic cardiovascular events: A retrospective population-based cohort study

INTRODUCTION Factor V (FV) deficiency is a rare inherited coagulation disorder associated with bleeding tendency. As a result, it has been postulated that decreased FV activity may confer protection against venous thromboembolism and atherothrombotic cardiovascular events. MATERIALS AND METHODS Using the electronic database of the largest health care provider in Israel, we identified all adult individuals who were tested for FV activity between January 2004 and June 2017. Subjects with liver cirrhosis or FV Leiden mutation were excluded. FV activity was classified into three predefined categories; FV activity >50%, FV activity 30-50%, and FV activity ≤30%. Patients were followed from January 2004 to June 2017 for new atherothrombotic cardiovascular events (composite of myocardial infarction, stroke, and TIA) and venous thromboembolism (VTE). RESULTS Overall 2021 individuals were included; 83.2% had FV activity >50%, 9.6% FV activity 30-50%, and 7.2% had FV activity ≤30%. Compared to individuals with FV activity >50% the adjusted HR for atherothrombotic cardiovascular events was 1.10 (95% CI, 0.63-1.90) in those with FV activity 30-50%, and 0.95 (0.49-1.8) in those with FV activity ≤30%. None of the patients with FV activity 30-50% had VTE during follow-up; therefore those with FV activity ≤50% were classified into one group. VTE incidence was lower in those with FV activity ≤50% compared to those with FV >50% activity; adjusted HR = 0.28 (0.09-0.91). CONCLUSION This study suggests that decreased FV activity might be associated with decreased incidence of VTE. No significant association appears to exist between FV activity and atherothrombotic cardiovascular events.