Cardiologists' excitement over an absorbable, dissolvable stent that hit the market last year is fading a bit. A study by the U.S. Food and Drug Administration shows that patients with the stent have higher rates of heart attack and thrombosis.
A doctor in Los Angeles is standing by the new technology when it's used by the right practitioners in the right patients.
Sixty-three-year-old Charles Tasso was at his dialysis center when his heart went into atrial fibrillation.
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"I mean, I thought it was an elephant sitting on my chest. That's the first time I had experienced any pain," Tasso explained.
Dr. Michael Chan, an interventional cardiologist at St. Joseph Hospital in Orange, Calif., used the Absorb stent for Tasso, who already has traditional metal stents. It's made of polylactide, which is similar to what's in dissolvable stitches. The stent dissolves in three years, so the artery is flexible again.
"It allows us to theoretically have less inflammation. Because of that, it also reduces the risk of clot formation that can form late on stents because of that metal exposure," Chan said.
But an FDA review showed an 11-percent rate of cardiac problems like heart attack and a 1.9-percent rate of blood clots after two years with the Absorb stent. This compares with 7.9 percent and 0.8 percent with a metal stent.
Abbott labs, which produces the stent, and Chan, say the right implantation technique and the right patients minimize risk.
"I think that if it's not used in the proper setting, then the risks are higher. We've seen that in smaller vessels that the heart attack risk as you mentioned, and risks of clotting are higher," Chan said.
Nineteen percent of people in the study had arteries that are too small for the device under usage guidelines. Removing their results equalizes findings.
"As technology evolves, there are many in our field that feel like this will be the next generation," Chan said.
Chan said he will keep using the Absorb stent on patients who fit the stricter criteria, while the FDA completes more study.
In May, Abbott laboratories restricted use of the Absorb stent to clinical use at select sites while it monitors implantation techniques and training. Some cardiac care facilities in the U.S. have stopped using the stent until more study is done. Chan has no financial interest in the stent or Abbott labs.