Two important findings from a medical journal show that if you have a high risk of blood clots you should
This is obviously good advice for everyone but when you read some of the statistics from the article it will emphasis the importance if you’re at high clot risk.
- The risk of having a PE was 2.9 times higher in obese women than those of an ideal weight
- Smokers had a 1.9 times risk than never-smokers (3.3 times if they smoked more than 35 a day)
- The lowest risk of clots was in people eating four or more servings of fruit and vegetables a day, and fish once or more a week
People at high risk who receive anticoagulant prophylaxis (a smaller dose of anticoagulant than you’d have for treatment of a clot) have a 40% smaller risk of developing a clot than those who don’t.
highest risk factors in hospital include having
- Age 75 +
- Major surgery
- Congestive heart failure
- Chronic obstructive pulmonary disease
- Chronic kidney disease, especially nephrotic syndrome
Samuel Goldberg has written a wonderful paper about clot risks which you can access in full here. We are going to use it as the springboard for a series about risk factors.
Where’s the study from?
The study is from Harvard Medical School and was published in the journal of the American College of Cardiology in 2010.
What happened in the study?
Samuel Goldhaber reviewed data from some of the largest registries of patients, to identify important risk factors for venous thrombo-embolism, VTE, (DVTs and pulmonary emboli). This data had been collected over several years from Europe and North America on more than 20,000 patients with VTE, including the RIETE registry of 15,000 patients with VTE, the female nurses’ health study of 112,000 women and a meta-analysis of 63,000 patients from 21 cohort studies.
What were the results?
The author discovered many risk factors which he divided into four groups
- Risks in hospital – included major surgery, cancer and heart failure
- Risks in the community – included trauma, pregnancy and advancing age
- Potentially modifiable risks – included obesity, diabetes, smoking, hypertension and stress
- Risks for recurrent thrombosis – included male gender, obesity and incomplete lysis of the original thrombosis
He concluded that, until now, most attention has been given to risks in hospital, but suggest the greatest reduction in VTEs may occur if health providers concentrate on the lifestyle and modifiable risk factors. He noted that many of the potentially modifiable risk factors for VTE are similar to risk factors for ischaemic heart disease, so that lifestyle advice given to prevent heart attacks may also prevent VTEs.
This study revealed some interesting and alarming results, for example a quarter of patients with a cancer related blood clot had died within 28 days of their clot. Many of the identified risk factors are well known such as surgery and cancer, but the more surprising findings are that there appears to be a clear link between the well-known risk factors for heart disease and venous thrombosis. Previously the expert opinion has largely believed that obesity, high blood pressure and diabetes had little influence on the risk of VTE. This is important for patients as many ask me if they can do anything to prevent a second blood clot. In the past I have said that there is largely little they can do, but the stronger evidence supporting a link between modifiable risk factors means that patients can make life-style changes to reduce their risk of another clot. The authors emphasise the importance of patient education to address these risks.
What’s the study reference?
Risk Factors for Venous Thromboembolism