DVT Tied to Heart Attack, Stroke Risk
Risk May Be Highest in the Year After a Deep Vein Thrombosis
Nov. 26, 2007 -- Having a DVT (deep vein thrombosis) or a pulmonary embolism
may make a
heart attack or
stroke more likely, especially in the first year after having
Danish researchers report that news in The Lancet.
is a blood clot that forms in a vein deep in the body. A pulmonary
embolism is a sudden blockage in a lung artery, usually due to a blood clot that travels from
a deep leg vein to the lungs.
Artery, Vein Clots
Heart attacks and most strokes are tied to blood clots -- but in arteries,
Arteries and veins are like one-way streets. Arteries carry blood away from
the heart. Veins bring blood back to the heart.
But the new Danish study suggests that when clots crop up in deep veins,
they can follow years later in arteries, causing heart attacks and strokes.
The study included more than 205,000 Danish adults age 40 and older.
The group included almost 26,200 DVT patients, nearly 17,000 pulmonary
embolism patients, and more than 163,000 people with no history of DVT or
Participants were followed for up to 20 years. For DVT and pulmonary
embolism patients, that period began when they left the hospital after DVT or
pulmonary embolism treatment.
DVT and Heart Attack, Stroke
During the study, heart attacks and strokes were most common among the DVT
and pulmonary embolism patients, particularly in the first year after having a
DVT or pulmonary embolism.
Compared to people who had never had a DVT or pulmonary embolism, heart
attack risk rose by 60% and stroke risk more than doubled in DVT patients in
their first year after having a DVT.
By the same comparison, heart attacks were more than twice as common and
strokes were almost three times as common in the year after pulmonary
Those risks eased over the years but remained about 20% to 40% higher than
normal, report the researchers. They included Henrik Sorensen, DMSc, of Aarhus
The findings are "surprising," writes Gordon Lowe, MD, of Scotland's
University of Glasgow, in a Lancet editorial.
Lowe notes that blood-thinning drugs are standard treatment after having a
DVT, and those drugs should make heart attacks and clot-related strokes (the
most common type of stroke) less likely.
Sorensen's team doesn't know how to connect the dots between DVT, pulmonary
embolism, stroke, and heart attack.