Despite treatment for deadly blood clots, his health was going downhill

The devotee of rugged back country skiing spent more than a year seeking an explanation for his profound weakness

(Illustration by Cam Cottrill for The Washington Post)
11 min

Mark Porter had just sat down to lunch at home when his longtime family physician called with an urgent message: Come back to the office right now. Porter, who owns an office products company in Rexburg, Idaho, had spent that November 2020 morning consulting the doctor and undergoing tests of his swollen, painful leg. He was scheduled to return at 2 p.m. to discuss the results.

Porter’s wife drove him to the doctor’s office, where they were hustled into an exam room. Their panic rose as they overheard the doctor telling someone on the phone: “He’s stable. We have an ambulance ready to transport.”

The doctor proceeded to tell Porter, then 47, that he had two life-threatening blood clots: one nestled deep in a vein in his calf and a second rare, and especially dangerous, saddle pulmonary embolism that was choking off the blood supply to his lungs. Porter needed to go straight to a hospital in Idaho Falls, about 30 miles away; doctors there were waiting for him.

“It was surreal,” recalled Porter, who was shocked, but not entirely surprised, by the news.

The discovery of blood clots, which were treated with anticoagulant medication, was just the beginning of Porter’s ordeal. The devotee of rugged back country skiing who had been in excellent health would spend the next 16 months trying to discover why he had grown so weak that he couldn’t walk across a room without stopping to rest.

“I made it,” said Porter, who underwent arduous treatment in August 2022 and said he now feels “fantastic.” He said he wishes he had sought a second opinion more quickly. Instead, he kept returning to the primary care doctor who told him he couldn’t find a reason for Porter’s shortness of breath, chest pain or worsening fatigue and did not refer him to a specialist.

“I don’t like waves and I don’t like conflict,” Porter said, who feared offending the doctor, an old family friend, whom he had seen for years.


Porter’s blood clots had likely been brewing for months. In July 2020, despite a daily exercise regimen that included weightlifting and water skiing, he began feeling increasingly short of breath. His doctor thought that Porter, who had a history of bronchitis and pneumonia, might have developed exercise-induced asthma and prescribed a steroid and an inhaler.

Neither helped. Several times Porter returned to the doctor, who didn’t recommend anything new. In early November, a few weeks before he landed in the hospital, Porter’s right calf grew so painful and swollen it was hard to walk. He didn’t remember injuring it and thought the problem might be sciatica, a pinched nerve caused by damaged disks in the lower back. When the pain worsened he turned to the internet: A search turned up deep vein thrombosis, a blood clot that develops in the leg, as a possible cause.

Alarmed, Porter quickly made an appointment with his doctor. He apologetically told the doctor he was sure he was overreacting. The physician examined his leg and immediately sent Porter for an ultrasound followed by CT scans that revealed the potentially lethal clots.

During his two-day hospitalization Porter began taking blood thinners as doctors sought to determine the cause of the clots. They were surprised when he told them he hadn’t injured his leg, taken a flight or had the coronavirus — all known triggers. And they were particularly surprised by Porter’s age, lack of risk factors and level of fitness. Many people who develop blood clots are considerably older, overweight and sedentary or have an underlying clotting disorder.

Porter was shaken by his close call. “Nurses told me that usually by the time they see a saddle PE, the patient is already dead,” he said.

Doctors told him he should recover after six months on a blood thinner.

But seven months out, he was still short of breath. By August 2021, Porter started experiencing chest pain and felt so exhausted he began taking a daily nap.

Worried that he had developed new clots, Porter returned to his primary care doctor in late November. The doctor ordered an ultrasound and CT scans along with a cardiac stress test. No new clots were detected and Porter passed the stress test, which measures heart function during exercise. The doctor, he said, told him there was nothing wrong with his heart and that he should not be feeling short of breath. His chest pain, the physician said, might be caused by acid reflux. He cleared Porter to ski.

“He got to me the way all these patients do — after a long period of misdiagnosis.”
— Allen Salem, physician

Porter, who knew what acid reflux felt like, was skeptical. But as a self-described worrier, he said he wondered whether “a lot of this was in my head.”

In late December Porter took a long-planned back country ski trip to British Columbia with one of his three sons. “I just kind of suffered through it,” he said. He struggled to breathe at times and his chest pain was so severe it woke him in the middle of the night.

Once home, he discovered that his primary care doctor was on vacation. Porter made an appointment with a new doctor who sent him to a cardiologist.

The cardiologist put him back on the blood thinner as a precaution and ordered tests, including several to detect genetic factors that contribute to the formation of blood clots (they were negative) as well as a VQ scan, a pair of nuclear medicine tests that assess the flow of air and blood in the lungs. The scan is considered essential in the detection of certain lung problems. The scan was abnormal and a right heart catheterization, which measures pressure in the heart and lungs, indicated possible pulmonary hypertension — high blood pressure that affects the lungs.

The cardiologist then referred Porter to Idaho Falls lung specialist Allen Salem, whom he saw in March 2022.

Missing the diagnosis

“He got to me the way all these patients do — after a long period of misdiagnosis,” Salem said. Like Porter, many have been mistakenly told they have asthma or heart failure or that nothing is wrong, the pulmonologist added.

Porter’s history of blood clots for no apparent reason, his continued shortness of breath and chest pain, along with the results of the VQ scan and other tests strongly suggested one diagnosis: chronic thromboembolic pulmonary hypertension (CTEPH).

This rare form of pulmonary hypertension is caused by clots that clog arteries, forming scar tissue that adheres to blood vessels in the lungs, narrowing the vessels and impeding blood flow.

Experts estimate that between 2 and 5 percent of people with blood clots will develop CTEPH, which doesn’t respond to blood thinners.

But unlike other forms of pulmonary hypertension, CTEPH can be cured by a pulmonary thromboendarterectomy (PTE), a long, complex and demanding operation to remove clots. Nonsurgical treatment involves medication, but is not curative.

“To me, this is always at the top of my mind,” said Salem, who diagnosed 10 cases of CTEPH in the past year alone. Among them was a park ranger whose sudden difficulty climbing hills had been attributed to his age and the mother of a physician who had been misdiagnosed with asthma.

“There’s a lack of awareness (among primary care doctors) of what can happen after a blood clot,” Salem said. “This disease is underdiagnosed and underappreciated.”

Some doctors, he noted, are reluctant to refer patients to lung specialists when they cannot determine why a patient continues to be short of breath. Others have never heard of CTEPH.

In Porter’s case, diagnosis was not difficult, Salem said. “He was only 49 and in very good shape, but he was more and more short of breath.”

Salem advised Porter to reduce his activity level — Porter said he wanted to stay fit so he continued doing 60 to 100 push-ups a day — and referred him to specialists at the University of California at San Diego. Surgeons at UCSD pioneered PTE surgery and have performed more than 4,000 procedures, more than any hospital in the world.

“I probably waited too long to fight for myself.”
— Mark Porter

A multiday work-up in San Diego was required to determine whether Porter was a candidate for surgery, which would be performed by Michael Madani, chief of cardiovascular and thoracic surgery, who performs about four PTE operations per week.

Porter said his initial reaction to the diagnosis was “relief. I’d had people telling me I should be fine or ‘We don’t know what’s wrong.’”

He quickly decided that he wanted surgery despite the risks, which include an overall mortality rate approaching about 5 percent. Individual centers have varying rates; Porter’s UCSD records mention an overall mortality rate of 2 percent.

The day-long operation requires a highly skilled and experienced team.

Surgeons make an incision in the chest to access the heart and lungs, then place a patient on a heart lung bypass machine that is periodically turned off to create the bloodless surgical field necessary to visualize the clots stuck to the arterial walls. To avoid damage to the brain and other organs the body is cooled to about 68 degrees, a process called circulatory arrest. After the clots have been painstakingly removed, the patient is gradually rewarmed, the chest is closed and the patient is taken to the intensive care unit.

In Porter’s case the logistics of sending his records to San Diego took about 2 1/2 months, during which he anxiously awaited an appointment. He was given a date in late August; surgery was tentatively scheduled a week later.

In July, Porter, who needed a coronavirus test performed a week before his arrival in California, contracted a mild case of covid-19. “I was really nervous” it might delay surgery, he said. Luckily, he tested negative at the requisite time.

Porter and his wife made the 1,000-mile drive to San Diego, where they have relatives. During the work-up at UCSD, which involved repeating the VQ scan and other tests, a doctor told Porter he might not be a clear-cut candidate. Would he want to undergo surgery if there was only a 50/50 chance it would work?

“I said ‘Absolutely, there’s no other option,’” Porter recalled. At that point he was able to work three hours a day at most and required a similarly long nap. “I told her I can’t continue to live like this. But I just felt really depressed that maybe they weren’t going to offer it.” His angst turned to elation the next day when he learned he had been approved.

Porter’s Aug. 30 operation, which took nine hours, went “very well,” Madani said. “He had quite a bit of obstruction in both lungs.” Porter’s heart was in very good shape, which is not true of many patients, the surgeon noted.

Although CTEPH sometimes recurs, particularly in patients with underlying clotting disorders, Madani said he does not expect that to be the case with Porter if he takes the blood thinner he will need for the rest of his life.

After four days in the ICU and another week in the hospital, Porter’s wife drove the couple home.

Recovery was tougher than Porter had expected and some pain lingered for months.

In November 2022, three months after his operation, Porter was cleared to resume weightlifting. A month later he repeated the back country ski trip — an altogether different experience without the chest pain and shortness of breath that had plagued him previously.

Looking back, Porter said he wishes he had been more assertive in pushing for an answer and less concerned about upsetting his doctor. “I probably waited too long to fight for myself,” he said.

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