Study suggests 1% risk of DVT for long-distance air travellers

December 18, 2003

Results of a study from New Zealand in this week's issue of THE LANCET suggest that the frequency of symptomatic venous thromboembolism (deep-vein thrombosis [DVT] or pulmonary embolism) could be around 1% for long-distance air travellers. This rate was found in a study of over 800 frequent long-haul air travellers identified as being at low to moderate risk-many of whom wore compression stockings or took aspirin as precautionary measures to prevent possible blood clots.

The true frequency of symptomless and symptomatic venous thromboembolism for long-haul air travellers is not known; a previous study (Lancet 2001; 357: 1485-89) suggested that symptomless DVT could occur in up to 10% of long-haul fliers. Richard Beasley from the Medical Research Institute of New Zealand and colleagues did a prospective study of long-haul air travelers to determine the frequency of symptomatic DVT and pulmonary embolism.

Volunteers were given a D-dimer blood test before flying; increases in D-dimer concentrations were used to identify individuals who may have developed thromboembolism. Overall, 878 people undertook long-haul flights (minimum duration four hours) over a six-week period. Those who became D-dimer positive or developed high clinical probability symptoms during the 3 months after travel were investigated with ultrasound and pulmonary angiography.

All participants travelled for at least 10 hours, with an average total duration of 39 hours travel over six weeks. 17% of travellers wore compression stockings and 31% took aspirin to reduce thrombosis risk. 112 patients with positive D-dimer results after flying were referred for radiological assessment. Frequency of venous thromboembolism associated with travel was 1% (9 out of 878), which included four cases of pulmonary embolism and five of deep venous thrombosis. Six patients with venous thromboembolism had pre-existing clinical risk factors, two had a recognised thrombophilic risk factor, two travelled exclusively in business class, five used aspirin, and four wore compression stockings.

Richard Beasley comments: "Our results suggest an association between multiple long distance air flights and venous thromboembolism, even in individuals at low to moderate risk. The role of traditional risk factors and prophylactic measures in air travel-related venous thromboembolism needs further investigation."

The study also shows that thrombosis may also occur for air travellers in Business Class as well as among those travelling in Economy Class. Professor Beasley adds: "The term 'Economy Class syndrome' is now redundant, with a better term being 'air-traveller's thrombosis'."
-end-
Lancet 2003; 362: 2039-44

Contact:
Professor Richard Beasley,
Medical Research Institute of New Zealand,
PO Box 10055, 3rd Floor, 99 The Terrace,
Wellington, New Zealand;
T) 64-21-403060;
F) 64-4-472-9224;
E) richard.beasley@mrinz.ac.nz

NB: Professor Beasley will be available for media contact/interview on the telephone number above at the following times (all GMT):
Wednesday 17 December 1800-2100
Thursday 18 December 0600-0900 and 1800-2100
Friday 19 December 0600-0900

Lancet

Related Aspirin Articles from Brightsurf:

An aspirin a day keeps the bowel doctor away
A regular dose of aspirin to reduce the risk of inherited bowel cancer lasts at least 10 years after stopping treatment, research has revealed.

What are the risks and benefits of low-dose aspirin?
Low-dose aspirin significantly lowers cardiovascular disease risk but increases the risk of bleeding, according to a review published in the British Journal of Clinical Pharmacology.

Benefit seen for ticagrelor alone, without aspirin, in patients with ACS
The research was presented at the American College of Cardiology's Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC).

Study: An aspirin a day does not keep dementia at bay
Taking a low-dose aspirin once a day does not reduce the risk of thinking and memory problems caused by mild cognitive impairment or probable Alzheimer's disease, nor does it slow the rate of cognitive decline, according to a large study published in the March 25, 2020, online issue of Neurology®, the medical journal of the American Academy of Neurology.

Aspirin's health benefits under scrutiny
Taking a baby aspirin every day to prevent a heart attack or stroke should no longer be recommended to patients who haven't already experienced one of these events.

Aspirin may no longer be effective as cardiovascular treatment
A new paper in Family Practice, published by Oxford University Press, found that the widespread use of statins and cancer screening technology may have altered the benefits of aspirin use.

Migraine headaches? Consider aspirin for treatment and prevention
Evidence from 13 randomized trials of the treatment of migraine in 4,222 patients and tens of thousands of patients in prevention of recurrent attacks supports the use of high dose aspirin from 900 to 1,300 milligrams to treat acute migraine as well as low dose daily aspirin from 81 to 325 milligrams to prevent recurrent attacks.

Aspirin use after biliary tract cancer diagnosis
Researchers in this observational study examined if aspirin use after a diagnosis of a biliary tract cancer, which includes gallbladder cancer, was associated with reduced risk of death among nearly 3,000 patients.

Aspirin may prevent air pollution harms
A new study is the first to report evidence that nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin may lessen the adverse effects of air pollution exposure on lung function.

Aspirin should not be recommended for healthy people over 70
Low-dose aspirin does not prolong disability-free survival of healthy people over 70, even in those at the highest risk of cardiovascular disease.

Read More: Aspirin News and Aspirin Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.