Safety of antithrombotic therapy in subjects with hereditary hemorrhagic telangiectasia: prospective data from a multidisciplinary working group.

Subjects with the rare autosomal dominant disease Hereditary Hemorrhagic Telangiectasia (HHT) may develop medical conditions that require antithrombotic therapy (AT). However, safety of AT is uncertain in these patients and the only data currently available derive from retrospective analyses of registries and/or databases. At the HHT Centre of the 'Fondazione Policlinico Universitario A. Gemelli IRCCS' (Rome, Italy), a prospective study is currently ongoing to evaluate the safety of AT in subjects affected by HHT. The study is enrolling subjects with a definite diagnosis of HHT who receive an AT prescription by one of the physicians of the HHT Centre. The primary outcome is the number of hemorrhagic events, distinguished in major, clinically relevant non-major (CRNM), and minor bleedings, according to the criteria of the International Society on Thrombosis and Hemostasis (ISTH). Another primary outcome is worsening of epistaxis upon initiation of AT, assessed using the internationally accepted Epistaxis Severity Score (ESS). Additional outcomes are changes in hemoglobin levels and changes in the need of blood transfusion after initiation of AT. Here, we present the results of an interim analysis, conducted on the 12 HHT subjects that have been enrolled so far. After a mean follow-up of 6.5 ± 0.8 months, no major bleedings, no CRNM bleedings, and no minor bleedings different from epistaxis were recorded. Worsening of epistaxis upon initiation of AT was documented only in one patient, but did not require discontinuation of AT. There were no significant changes in the mean ESS measured before and after initiation of AT. There were no significant changes in hemoglobin levels and need for blood transfusion after initiation of AT. Although preliminary, these are the first prospective data on the safety of AT in HHT patients. Our interim analysis suggests that, when prescribed by experienced physicians in a multidisciplinary setting, AT is well tolerated by HHT patients. More patients and a longer follow-up are needed to confirm these findings.

Differences in Clinical Presentation, Rate of Pulmonary Embolism, and Risk Factors Among Patients With Deep Vein Thrombosis in Unusual Sites.

Unusual site deep vein thrombosis (USDVT) is an uncommon form of venous thromboembolism with heterogeneous signs and symptoms, unknown rate of pulmonary embolism (PE), and poorly defined risk factors. We conducted a retrospective analysis of 107 consecutive cases of USDVTs, discharged from our University Hospital over a period of 2 years. Patients were classified based on the site of thrombosis and distinguished between patients with cerebral vein thrombosis, jugular vein thrombosis, thrombosis of the deep veins of the upper extremities, and abdominal vein thrombosis. We found statistically significant differences between groups in terms of age (P < .0001) and gender distribution (P < .05). We also found that the rate of symptomatic patients was significantly different between groups (P < .0001). Another interesting finding was the significant difference between groups in terms of rate of PE (P < .01). Finally, we found statistically significant differences between groups in terms of risk factors for thrombosis, in particular cancer (P < .01). Unprovoked cases were differently distributed among groups (P < .0001). This study highlights differences between patients with USDVT, which depend on the site of thrombosis, and provides data which might be useful in clinical practice.