Handbook of Venous Thromboembolism Ebook PDF download
Handbook of Venous Thromboembolism Ebook PDF download Large national registries for VTE patients have helped to elucidate and quantify the relative risk of individual factors. The risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE) are largely similar, as DVT and PE represent a spectrum of the same disease process. There is also some overlap between venous
and arterial thrombotic risk, with age, smoking and obesity common to both, although they are much more
important factors in arterial disease. Part of this may be an indirect association – for example, smoking
increases cancer risk, and hence VTE, while medical in‐patients with heart failure have a marked increase in
risk for pulmonary embolism. Figure 1.1 shows the increasing rate of VTE with age, from the UK VTE registry,
VERITY. Overall, the risk for VTE is increasing, with an ever aging population, receiving multiple medications
many of which increase thrombotic risk, particularly in the field of cancer medicine.
The most important risk factors for VTE are a history of previous VTE, recent surgery, hospital in‐patient stay and cancer. While there is much comment around factors such as long‐haul travel and inherited risk factors for VTE, these represent less common and less important factors. In general the more risk factors present, the greater will be the cumulative risk for VTE.
For patients with a known history of VTE, it is important to identify if the previous event was provoked, in association with temporary risk factors, or unprovoked. The risk of recurrence is less than 3% if provoked, but is near 10% in unprovoked VTE within 12 months of discontinuing anticoagulant therapy. It can be difficult to determine what is and is not provoked; for example, a DVT post orthopaedic surgery is clearly provoked, while a female on the combined pill preparation for three years without previous thrombosis is not necessarily a provoked event. A VTE within three months of starting the pill however, would be provoked.
Provoking factors can be further divided into surgical, with a recurrence rate of 1% within 12 months of treatment, and non‐surgical factors, with a 6% risk in this time period. For patients with unprovoked VTE, the risk persists with time, with 40% recurrence within ten years. For a cohort of young male patients presenting with
unprovoked PE, there is a 20% risk of recurrence of PE within 12 months which persists, making recurrence