Increasing the level of carbon monoxide in the bloodstream following angioplasty and stent placement in the arteries of the legs may help prevent restenosis, according to Austrian researchers. The easiest way to accomplish this? By smoking cigarettes.
Principal investigator Dr. Martin Schillinger and colleagues at the University of Vienna Medical School assessed 650 patients with peripheral artery disease who underwent angioplasty with or without stent placement. Patients were classified into groups ranging from those who had never smoked to smokers of more than 20 cigarettes a day who continued smoking even after angioplasty.
The researchers found that both habitual and heavy smokers have a lower rate of restenosis than nonsmokers. They published their findings in the June issue of Radiology.
Smokers have a higher blood concentration of carbon monoxide, an anti-inflammatory agent with a known vasodilator effect. Carbon monoxide may also inhibit the growth of smooth muscle cells within the artery wall, a key factor in the restenosis process, said Schillinger, an associate professor of internal medicine at UVMS.
Patients underwent post-treatment follow-up twice in a year. The rate of restenosis among nonsmoking patients was 28% and 45% at six and 12 months, respectively. In the heavy-smoker group -- those who smoked more than 20 cigarettes daily -- the rate was 16% and 29%, respectively.
Ironically, cigarettes may help solve a problem they originally helped create. Peripheral artery disease and smoking go hand in hand. It is a well-documented fact that smokers suffer heart attacks and strokes at a higher rate than nonsmokers.
Angioplasty and stent placement can help combat peripheral artery disease. But the restenosis rate after treatment is high, and occurrence may require a new intervention within a year. Results of this study suggest that delivering carbon monoxide to the site of the blockage could be a promising concept -- just not through cigarette smoking.
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