Hospital‐related first venous thromboembolism and risk of recurrence

Abstract

Background Hospitalization is a well-established risk factor for first venous thromboembolism (VTE), but the risk of recurrence, particularly in patients hospitalized for conditions other than cancer or surgery, has scarcely been investigated. The cumulative incidence of recurrence in hospital-related VTE may be influenced by the competing risk of death. Objectives To investigate the risk of recurrence and mortality among patients with a first hospital-related VTE in models with and without death as a competing event. Methods Information on hospital-related risk factors was collected in 822 patients with a first-lifetime VTE derived from the Tromsø study. Recurrent VTEs and deaths were recorded during follow-up (1994-2012). Results During a median of 2.79 years of follow-up, 132 patients experienced a recurrent VTE. Stratification on hospital-related factors revealed considerable differences in recurrence risk. The 5-year cumulative incidence of recurrence was 27.4%, 11.0% and 20.1% in patients with incident VTEs related to cancer, surgery or other medical illness, respectively, and 18.4% in patients with a non-hospital-related first VTE. The mortality rates were high for all subgroups of hospital-related VTE, except for surgery-related events. Consequently, the cumulative incidence of recurrence dropped in the competing risk analyses, showing a 5-year cumulative incidence of 14.4%, 11.7% and 9.7% in patients with a first VTE related to hospitalization for other medical illness, cancer or surgery, respectively. Conclusions Our findings suggest that patients with incident VTEs related to hospitalization for medical illness other than cancer or surgery have a high recurrence-risk, even in the presence of competing risk of death.