Health Care

Medical experts weigh in on Miami Heat star Chris Bosh’s second bout with blood clot

Miami Heat forward Chris Bosh reportedly is being treated with blood thinners for the second time in a year. Medical experts say it's not unusual for blood clots to reappear.
Miami Heat forward Chris Bosh reportedly is being treated with blood thinners for the second time in a year. Medical experts say it's not unusual for blood clots to reappear.

One year after he was hospitalized with blood clots in his lungs, the Miami Heat’s Chris Bosh reportedly is back on medication to treat a new clot in his left leg — casting doubt on the All-Star player’s ability to return for the remainder of the NBA season.

Bosh, who turns 32 next month, and Heat officials did not comment publicly on initial reports that he is expected to meet with doctors in Miami on Thursday to diagnose blood clotting in his left calf.

With the Heat clinging to the fifth seed in the Eastern Conference, and the team set to open the second half of the NBA season Friday in Atlanta, Bosh — the team’s leading scorer and the centerpiece of the franchise — is key to Miami’s playoff hopes.

Last season, Bosh missed the second half of the NBA season after a blood clot traveled from his leg to his lungs, requiring hospitalization and several months of therapy with blood thinners while avoiding contact sports.

If Bosh developed a new blood clot in his leg, he likely will have to take blood thinners and avoid contact sports for about three to six months, said Dr. Robert Myerburg, a physician and expert on athletes and cardiology at the University of Miami Health System or UHealth.

“The problem is if you’re on blood thinners and have trauma, say you get hit in the head, that could end up being fatal or disabling,” Myerburg said. “There’s a lot of precautions about this. … The one we worry about most is bleed in the brain.”

Blood clots can form in people who have a genetic predisposition for them, but most commonly they are provoked by long periods of immobility resulting from injury or travel, or from a traumatic injury, typically to the leg, said Dr. Terry King, a vascular surgeon with Cleveland Clinic Florida in Weston.

Professional athletes are at greater risk for developing blood clots, known as deep vein thrombosis, due to hours of immobility during long flights to games or while recovering from injuries, hard blows to the legs from contact sports and dehydration from physical exertion.

More than 600,000 Americans are diagnosed with deep vein thrombosis each year, according to the Cleveland Clinic, and about 30 percent of those patients develop a recurrence within 10 years.

Bosh’s condition last year was diagnosed as a pulmonary embolism, which is a clot that breaks free, typically from veins in the legs or pelvis, and travels to the lungs, where it might block blood flow and force the heart to work harder.

This could cause the heart to become enlarged, or in a worst-case scenario, lead to heart failure. According to Cleveland Clinic, pulmonary embolisms killed about 200,000 Americans in 2010 — more than breast cancer, AIDS and highway fatalities combined.

But less than 50 percent of blood clots ever break free from a vein and travel to organs, King said.

Blood clots can be asymptomatic, but most of the time people will feel some discomfort, such as heaviness in the leg or foot, swelling and sometimes bluish skin tone.

King said blood clots can be absorbed by the body, reduced with medication or removed surgically — but they almost always leave lasting damage to veins and arteries, which increases the chances of a recurrence in patients.

“A lot of times there’s residual damage,” he said. “The vein doesn’t return to totally normal function.”

King said clots often leave residue in the lining of the affected vein, increasing the risk of another clot developing in the same place.

“So if you have another long plane ride, time spent sitting, you’re sick with the flu in bed for a week, that area is more susceptible,” he said.

After returning from his season-ending blood clot last year, Bosh said he learned a lot about the condition, including that he did not have the hereditary gene that increases the risk for recurring episodes.

The 11-time All-Star and father of three, whose wife, Adrienne, is set to give birth to twins in the coming months, said he would take precautions, such as getting up to walk during long flights, stretching his legs, wearing compression socks and taking Aspirin.

He also became a pitchman for Xarelto, a prescription blood thinner, sharing his story.

This season, Bosh was returning to form, developing his three-point shot and leading the team in scoring.

He missed the Feb. 14 All-Star Game with a strained calf, and told reporters that he was “pretty optimistic” that his injury was not related to blood clots but that he intended to see a physician this week.

Miami Herald staff writer Barry Jackson contributed to this report.

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