Sports·In Depth

Blood clot issues put star athletes Stamkos, Bosh in doubt

Two high-profile active pro athletes are currently dealing with serious blood clot issues. As Steven Stamkos, Chris Bosh and their doctors try to figure out how to deal with their ailments, the players' health and millions of dollars are at stake.

Players' health, millions of dollars at stake

Tampa Bay Lightning star Steven Stamkos has been sidelined by a blood clot problem that could also affect his ability to cash in with a new contract in free agency this summer. (Mike Carlson/Associated Press)

NHL superstar Steve Stamkos was born with a wealth of natural talent. He was also born with a narrow artery that has only been made worse by years of practising his craft. The physical style of play in professional hockey also hasn't helped.

Now his path back to the ice, and the possibility of a lucrative free-agent contract, is cloudy

The blood clot problem in Stamkos's arm that has kept the Tampa Bay Lightning forward off the ice since March was likely inevitable, says Dr. Bill Geerts, a thrombosis specialist at Sunnybrook Hospital in Toronto. Geerts hasn't treated Stamkos, so his opinions are based only on the information that has been made public, but he says Stamkos was born with what's known as a "narrowed thoracic outlet," meaning the space between the collarbone and ribs that veins and arteries pass through is narrower than usual.

Being an NHL hockey player doesn't help with this condition.

"This issue has been there his whole life. It's been made worse by the fact that he is an elite athlete and he is much more muscular than the average person," Geerts explains. "The bigger your muscles are, the greater potential there is for that space being narrowed."

It's not just a muscular build that is working against Stamkos, a player known for working diligently on his outstanding shot, which has resulted in 312 goals in only eight NHL seasons.

"He has repeated physical activities that narrow that space even more," Geerts explains. "Activities like moving your arms back or over your head, those are the kind of activities that, even in a normal person, narrows that thoracic outlet. And if you do that repeatedly there can be damage to the vein and a clot can develop."

Geerts says this is often referred to as "effort thrombosis" and is something he has treated in elite swimmers, pitchers, weightlifters and people who paint houses for a living. All those jobs require repetitive arm action.

Athletes aren't necessarily more susceptible to blood clots, but Geerts says those who have had knee or leg surgery may be more at risk. In 2013, Stamkos suffered a broken tibia during a game that required surgery and the use of blood thinners.

NBA player Anderson Varejao has dealt with clotting issues after surgery. So has tennis star Serena Williams and former Yankees pitcher Mariano Rivera. NHLer Pascal Dupuis ended his career this season after clotting complications stemming from knee surgery.

In fact, athletes and blood clots have a long history. In the 1930s, Canadiens great Howie Morenz died in hospital before the dangers of clotting were known by doctors.

Bosh's condition resurfaces

Stamkos is one of two high-profile active pro athletes currently dealing with serious blood clot issues. The other is NBA basketball player Chris Bosh, whose situation is completely different and much more of a mystery.

During last year's all-star break, the Miami Heat forward, and former Toronto Raptor, was sidelined with blood clots that had traveled to his lungs from his leg. Then this year Bosh was forced out again, and Heat president Pat Riley confirmed last week it was a blood clot issue that kept the star forward out of the lineup for the final 29 games of the season and the playoffs, and has put his career in doubt.

"All of us — the Heat, the doctors and also Chris — are looking to proceed forward to find a way to get him back on the court," Riley said in his season-ending session with the media. "Last year, we were blindsided. This year, when it happened, we're eyes wide open with him. We all knew what the treatment was last year. It's two years in a row. We're all day-to-day in proceeding with this thing."

Doctors are unsure why this is happening to Bosh.

Dr. Geerts has not treated Bosh but says his height may be a factor.

"The blood flow through a guy who is 6-foot-11 [Bosh's listed height] is going to be a lot slower than somebody who is six feet and the distance is a lot less," Geerts says. "And the potential to compress veins in the leg and groin area is a lot less."

Bosh has been tested and does not have a condition where his blood is prone to forming clots. Also, Geerts says inherited clotting abnormalities are pretty uncommon in the African-American community. But here Bosh is again, facing the very real danger of having a clot spread to his lungs.

"Those clots in the deep veins are more likely to break off and go to the lungs," explains McMaster University's Dr. James Douketis, who specializes in blood clotting issues. "Over 95 per cent of clots that end up in the lungs originated in the legs."

The road back

Both Bosh and Stamkos are looking for a way to return to their sports. There are millions of dollars at stake. Bosh, 32, has three years left on a five-year $118-million US contract, while Stamkos, 26, has a chance to cash in as a highly sought free agent this summer, with his hometown Toronto Maple Leafs looming as a potential suitor. But there are no guarantees.

Doctors have done two different things to treat Stamkos, who has been practising with his Lightning teammates of late but has not been cleared to play.

Dr Douketis hasn't treated Stamkos but understands the player first had a clot-busting treatment, likely a medication called TPA, injected directly into his vein.

"It is very different than blood thinning treatment. It actually breaks down the clot and is associated with a higher risk of bleeding," Douketis says.

The treatment, which Douketis says breaks clost within minutes while a blood thinner can take days or weeks, is usually only used in life-threatening situations or if a limb could be lost.

"Normally we probably wouldn't have administered this kind of treatment to [a high-level athlete like Stamkos]," Douketis says.

On April 4, Stamkos had a rib removed below the collarbone to enlarge the space that his nerves and veins pass through.

'Risky' treatment

Both Bosh and Stamkos must now find the right treatment for their clots without jeopardizing their health. Not an easy task.

Geerts says Stamkos is being treated with Heparin, an injectable blood thinning medication. It's injected into the skin and lasts about a day. So if he had a game tomorrow night, he could get an injection now so the blood thinning effects would be out of his system by game time.

Dr. Geets says continued use of blood thinners by an NHL hockey player is "risky." He rarely restricts patients from physical activity but few of his patients do something as physically demanding as playing pro hockey.

Dr Douketis adds: "If you are on a blood thinner and you get injured, you can have a serious life-threatening bleed, especially if it's a head injury."

And there's the problem: Stamkos requires a blood thinner to prevent clotting, but if he's cut during game, he needs his blood to do the thing the medication is preventing: that is, to clot and stop the bleeding.

It's a difficult balance and there is no hard-and-fast rule as to when he will be ready to return.

"Generally it can be anywhere from one to three months but it's a fine line. You have to balance the risk of bleeding versus clotting," says Dr. Thomas Forbes, a vascular surgeon at the Peter Munk Cardiac Centre in Toronto. In other words, a player like Stamkos has to know that if he is cut, his blood will be able to clot. 

Bosh is attempting to treat his clots with a different drug called Xarelto. It's a relatively new oral blood thinner. You may have seen the television ad starring Bosh, golf legend Arnold Palmer, NASCAR driver Brian Vickers and comedian Kevin Nealon, all of whom have had clotting issues.

"It's a drug that has a fairly short half-life, which means you could time the dosing so you know when the drug wears off," Geerts explains. The problem with that drug is its effect in the blood is a bit longer than the injection. That makes it a little bit tricky, but maybe an athlete could be on an oral blood thinner at lower than usual doses."

As Riley said of Bosh: "We are trying to find a way over the next two or three months to find a protocol, a program that will get him back playing. That's always been our objective and we're in this together."

Unfortunately when it comes to blood clots and big-name, highly paid athletes, the road to recovery is undefined and full of unknowns. And by no means guaranteed.

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