Long-Term Survival of Patients with a History of Venous Thromboembolism
Authors: Reitter Sylvia Elisabeth , Waldhoer Thomas , Mayerhofer Michaela , Eigenbauer Ernst , Ay Cihan , Kyrle Paul Alexander , Pabinger Ingrid 
Published: October 2019

Abstract
Abstract 3168

Background:
Only limited data are available regarding long-term survival following venous thromboembolism (VTE).

Objectives:
In our study, we aimed to evaluate the long-term mortality rate in patients having a history of deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Patients were referred to our outpatient department for thombophilia testing. We assessed long-term mortality according to the etiology of VTE (spontaneous or following a triggering event) as well as according to the site of thrombosis. In addition, we investigated the relative survival of our patients in comparison to the general Austrian population.

Patients/Methods:
In our analysis, we included patients with a history of VTE (at least 3 months after a VTE event), who were examined at our out-patient department for routine thrombophilia testing between September 1, 1994 and December 31, 2007. We were provided with information concerning mortality and causes of death of our patients from the Austrian Central Death Registry. The data supplied by Statistics Austria was compared with mortality rates of the general Austrian population, which were also obtained through Statistics Austria.

Results:
Our study covered a total of 3209 patients (mean age 46.2, range 14–89 years, 1280 men = 40%). The median time interval between the initial occurrence of VTE and study inclusion was 14 months, the median observation period was 6.6 years. During the considered time period (September 1, 1994 and December 31, 2008) a total of 169 patients (5.3%) died, 6 patients died from definite and 2 from probable PE, another 6 patients died from bleeding. The remaining patients died from cancer (34%), cardiovascular causes others than PE (27%) or other diseases (30%). The cumulative survival rate of patients was 0.97 and 0.87 after 5 and 10 years, respectively, the death rate in men was higher than that of the women and the survival of patients with idiopathic VTE was lowest in comparison to those having a triggering event. When patients were compared to the general population, the cumulative relative survival was 1.02 (95% CI 1.00–1.03). In none of the analysed subgroups a reduced cumulative relative survival rate among our patients was noted. Male patients showed a tendency for a better relative survival (1.05, 95 % CI 1.03 – 1.08), whereas that of women (1.00, 95 % CI 0.98 – 1.01) equalled that of the normal population. Duration of anticoagulation (less than 6 months in comparison to more than 18 months after first VTE) did not have an influence on the cumulative survival rates (p = 0.96).

Conclusion:
Our findings indicate that after the critical initial period, VTE does not seem to have an impact on long-term survival of outpatients with a history of VTE without active malignancy. This is most likely due to the currently prevailing improved diagnostic and treatment modalities of recurrent VTE, which have proved to be most effective and safe.

Disclosures:
No relevant conflicts of interest to declare.