Venous thromboembolism (VTE) might be the most serious condition you’ve never heard of.
The disease starts with a blood clot, or thrombosis, that forms in a deep vein in the leg (or, less frequently, the arm). This clot is known as deep vein thrombosis. If the clot breaks off, travels through the bloodstream and lodges in a lung, it’s called a pulmonary embolism and in about a quarter of such cases causes sudden death.
Together, deep vein thrombosis and pulmonary embolism are known as VTE, a dangerous and deadly combination that can strike anyone, but is particularly problematic for those over 60 who have experienced hospital stays and/or surgeries.
Although some VTE cases are unprovoked (caused by genetic mutations that affect clotting factors in the blood or family history), many others are preventable. That’s according to Jack Ansell, an internationally recognized expert in the field of hematology and thrombosis and a member of the scientific board of the National Blood Clot Alliance.
Since about two-thirds of blood clots occur as a result of hospitalization or after hospitalization, Ansell says that many cases of VTE can be prevented if patients are proactive.
“When you enter the hospital for surgery, ask your doctor, ‘What are you going to do to prevent a blood clot in my leg?’” says Ansell. “More and more doctors are aware of the problem and are using anticoagulant therapies to prevent blood clots.”
VTE: An Underappreciated Disease
While the precise number of people affected by VTE is unknown, as many as 900,000 people could be impacted each year in the U.S., according to a report published by the Centers for Disease Control and Prevention. Up to 100,000 Americans die of VTE annually; 10 to 30 percent of them within a month of diagnosis.
A report by the World Thrombosis Day Steering Committee on common problems that stem from hospital stays found that VTE was the leading cause of death and disability in low- and middle-income countries and was the second leading cause of death in high-income countries. And while VTE per se is not listed as a leading cause of death in the U.S., Ansell cites it as an underlying specific cause of death in many cases of cancer, heart or other types of fatalities.
Despite this, awareness of VTE is woefully low, according to a 2014 global study in the Journal of Thrombosis and Haemostasis. It showed that fewer people were aware of thrombosis, deep vein thrombosis and pulmonary embolism than those aware of heart attack and stroke and health conditions such as hypertension, breast cancer, prostate cancer and AIDS. Less than half of respondents knew that blood clots were preventable or that they were associated with cancer (16 percent), hospitalization (25 percent) and surgery (36 percent).
“In the long term, we will see more cases because it is more common in older folks and the population is certainly aging,” says Gary Raskob, professor of epidemiology and dean of public health at the University of Oklahoma.
Tracking the Disease
“Blood clots work as a defense mechanism to prevent us from bleeding to death if we cut ourselves,” says Raskob, who serves as the head of World Thrombosis Day on Oct. 13, an event designed to heighten awareness of VTE. “What we’re talking about are the formation of clots inside blood vessels or veins when they shouldn’t form.”
Symptoms of deep vein thrombosis include swelling in one leg, pain or tenderness; reddish or bluish skin discoloration and warmth. Pulmonary embolism can cause sudden shortness of breath, chest pain that may get worse with deep breaths, rapid heart rate, an unexplained cough and light-headedness.
Anyone experiencing these symptoms should call his or her doctor right away or call 911 to get to an emergency room, where an ultrasound can determine the presence of a clot.
Risk Factors for Blood Clots
Three prime factors contribute to blood clot formation: “Immobility, which causes blood to pool in the veins; problems with proteins in the blood that balance bleeding and clotting and damage to a vein or blood vessel caused by injury or surgery can all spur unwanted blood clots in veins,” says Raskob, “If any two of these factors are in play, you can be in danger of developing a clot.”
In addition to hospital stays, there are a number of risk factors for developing VTE, including surgical procedures — particularly knee and hip replacements.
“After surgery you need to heal the wound and the body can’t say, ‘Put a clot here where the surgeon cut and not in the vein,’” says Raskob. “In addition, there could be damage to the vein during surgery, such as in hip replacement, where surgeons may manipulate your vein, causing it to get bent or twisted, causing a clot.”
Cancer and cancer treatments can also cause clot formation, says Raskob. They upset the delicate balance between coagulation factors that promote bleeding and those that promote clotting.
Other risk factors include taking estrogen or estrogen-blocking drugs like tamoxifen; long car rides or plane rides, family history and genetic mutations that predispose blood to clotting.
But sometimes, clots can be unprovoked, says Elaine Chiang, a hematologist at Penn Medicine. “If a person develops a clot with no risk factors, that is more concerning,” says Chiang, since they are at a higher risk for additional clots.
Although VTE is not really a “lifestyle” disease, experts suggest moving around every two or three hours if you’ve been sitting in a car, plane or train, maintaining a healthy weight and quitting or avoiding smoking.
Treatment for VTE often involves blood thinners. While older anti-coagulants required frequent tests to check if dosages were in a therapeutic range, newer drugs are more predictable and have fewer dietary restrictions, says Chiang.
“Once you have a clot, it’s important to see a hematologist — a doctor specializing in thrombosis and clotting disorders,” says Chiang. Having a blood clot is not a one and done issue, she notes. “We need to evaluate if blood thinners are doing their job and if they need to be adjusted down the road,” says Chiang.
She adds thats there are implications for family members as well. “Make sure family members tell physicians that they are related to someone who has a blood clot,” Chiang says. “If they plan for surgery or pregnancy, they need to know if there are special considerations to be made.”