The Heart of the Matter

If there were a problem with a life-saving medical device implanted in your heart, someone would tell you, right? Tom Hatch thought so. He was wrong.

"I think what I expected was that they would have a physician, or a cardiologist or surgeon, who I would see and who would monitor my condition, at their expense, for the rest of my life," he continues. "And that they would make determinations based on the tests that they would run as to what was to be done with my heart valve. That's kind of what I thought in the back of my mind, but of course that was kind of Pollyannaish because what would it cost for them to monitor 36,000 people? They don't want to do that because we're probably talking several thousand dollars a year per person."

In the months following the recall, St. Jude volunteered to pay Hatch only the cost of diagnosing or ruling out paravalvular leak, and then only expenses not covered by insurance. A year later, St. Jude sent him a check for $1,650 to pay for the first test to see whether his valve was leaking. St. Jude had marketed the Silzone as a "premium" product at a cost of about $5,000. No refund was forthcoming.

The size of the check angered Hatch, but not as much as St. Jude's assertion that his clots weren't a side effect of the Silzone. His desire to get St. Jude to acknowledge the risk was more than symbolic. He thought Silzone bearers ought to be told to ask for the kind of monitoring he was getting. What if his own doctor hadn't gone the extra step of ordering the second test that had found his clots? "Perhaps they would have grown or dislodged without treatment," he wrote in a letter to St. Jude. "I wonder if a loose clot would have lodged in my lungs or coronary arteries or in my brain. I wonder if I would be able to write this letter today.... What are my odds? What should I tell my wife and six children?"

Raoul Benavides

After his own clots were discovered, Hatch did some research on the internet and learned that, months earlier, Great Britain had issued a warning about the Silzone based on a study by a Welsh surgeon who concluded there was an increased risk of clotting. Hatch mentioned this to the St. Jude employee coordinating his reimbursement request, but she dismissed it. Blood clots were a normal complication of heart valve replacement, she explained, and St. Jude's own research did not show a statistically significant increase in risk of clotting.

The Silzone went on the market in Europe in July 1997. Within weeks, a Welsh surgeon conducting a study of the rate of clot formation associated with several different artificial heart valves, the Cardiff Embolic Risk Factor Study, began including Silzone patients in his trial. Two years later, he reported a disturbing finding to the British agency that regulates medical devices: Seven of 51 Silzone patients in his study had clearly suffered strokes, and five more were suspected to have suffered them. Only one of the 115 patients bearing the conventional valve suffered clots.

"In my opinion," the surgeon, Eric Butchart, would later summarize his conclusions, "the large differences in thromboembolism [blood clots] are clinically significant and the incidence of thromboembolism after mitral valve replacement is so high that the Silzone valve would almost certainly not have received FDA approval if these figures had been submitted in pursuit of approval of a new prosthesis."

As a result, in November 1999, the British government issued a warning. Acting on the same report, New Zealand withdrew the valve altogether, requiring surgeons to contact each patient for monitoring. (This proved relatively easy: 28 of the 29 Silzones implanted in New Zealanders had been installed at a single facility.)

Unlike the leaking that prompted the recall, clots don't produce symptoms. Butchart asked more Silzone patients to undergo the more sophisticated test that would later find Hatch's thread-shaped formations. The TE echo found plenty of clots, he reported: "More intense surveillance using transoesophogeal echocardiography has revealed asymptomatic sewing ring thrombus in approximately 30 percent of mitral valve replacement patients and cinefluoroscopy has revealed abnormal leaflet motion of the Silzone prosthesis in approximately 27 percent of atrial valve replacement patients, raising concern about pannus [the growth of new tissue] and/or small thrombi interfering with leaflet movement."

Later, after patients claiming to be injured by the Silzone began to file suit, Butchart prepared a report at the request of several law firms pursuing the cases. His explanation for the unusually high number of thromboembolisms his study had found: He had been looking for them.

Thrombus would not have shown up in a clinical trial of the Silzone in human beings, because no such study had been carried out, just a small study of sheep and a 60-day European trial involving 38 patients. The FDA approved the device without further testing, but told St. Jude that if it wanted to claim that the silver coating combated infection, it would have to demonstrate that the improvement was effective.

To this end, St. Jude commissioned a study, dubbed AVERT, that was supposed to enroll 4,400 patients. According to St. Jude materials, AVERT participants were evaluated via regular office visits, phone calls, and mail survey. The researchers were looking for infection, not clotting.

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