DALLAS, Dec. 2 -- For people undergoing balloon angioplasty to reopen disease-clogged blood vessels to the heart, the best insurance policy against needing the more serious coronary artery bypass surgery months or years later, may be the timely insertion of small flexible metal coils called "stents," say researchers today in the American Heart Association journal Circulation.
Placing the stainless steel "Slinky"-like cylinders in blood vessels during angioplasty appears to drastically reduce the need for bypass surgery later by keeping the vessels propped open, thus reducing the likelihood that vessel blockages will return, says the study's author Issam Moussa, M.D.
The findings show that using stents as an initial strategy to treat patients with multi-vessel disease can safely be performed with "a high success rate and a low need for emergency bypass surgery," he says.
About 35-50 percent of angioplasties fail because blockages recur in the blood vessels, requiring another angioplasty, or the more serious and costly cardiac bypass surgery.
When the results of this study are compared with findings from previous investigations in which stenting was not used, the Slinky-like coil results in fewer "repeat interventions, in particular, coronary bypass surgery." However, patients who undergo angioplasty in multiple vessels have similar long-term survival, regardless of whether stenting is used.
"When large blood vessels are obstructed and the blockages are short, stents most likely will reduce the need for repeat angioplasty or bypass surgery and thereby improve their quality of life and functional status," Moussa says.
The scientists base their conclusion on a study of 100 consecutive patients who had stents placed in their coronary arteries, the blood vessels to the heart, when they underwent angioplasty at Centro Cuore Columbus, a major medical center in Milan, Italy, between 1993 and 1995. Most of the 86 men and 14 women had badly weakened hearts, due to insufficient blood supply, with either two or three diseased vessels that required reopening using balloon angioplasty.
During an average 21-month follow-up, only two (2 percent) of the stent recipients required bypass surgery because their blood vessels closed up a second time. By contrast, in earlier studies, bypass surgery was necessary during a similar follow-up period in 16 to 31 percent of angioplasty patients who had not received stents.
The fact that only two patients needed bypass surgery during follow-up "is clearly a major advantage" over angioplasty on more than one vessel without stenting, Moussa and his colleagues say in their report. Individuals getting stents had less chest pain, called angina, and were slightly less likely to need repeat angioplasty procedures.
"Stenting modestly decreases the need to come back to the hospital for further angioplasty, but it significantly reduces the need to have bypass surgery," noted Moussa who began the stent research project while he was at the Milan center. He is now assistant director of clinical research in interventional cardiology at Lenox Hill Hospital in New York City.
Thirty of the Milan stent recipients, including the two who had surgery, had to return for more treatment. But the other 28 needed only a repeat balloon procedure because blockages generally recurred in only one previously treated vessel. While this number appears high, Moussa says it underlines stenting's major advantage: that angioplasty without stents more often results in major relapses involving multiple vessels. That's a more complex problem that can be resolved only by resorting to more invasive and expensive bypass surgery.
No deaths were reported among the 100 stent recipients during the procedure. Two (2 percent) died of heart problems and two more died of unrelated causes during follow-up. In the earlier angioplasty studies, death rates during follow-up, which averaged three years, ranged from 3 to 14 percent, the researchers report.
Moussa points out that patients in the Milan study were generally much sicker than most of the earlier angioplasty recipients included in studies used for comparison. This, he says, makes the new study's positive result even more noteworthy. Compared to historical results of multiple angioplasty without stenting, patients undergoing stent implants "need fewer repeat interventions, in particular, less coronary bypass surgery and have similar long-term survival."
"The complexity of vessel blockages in this study was much greater than in the studies that have been reported in the past," he explains. "Many of these individuals had three-vessel disease and a 'bad pump,' meaning their heart muscle was not functioning very well." Some vessels were totally blocked by hardened deposits of calcium.
When angioplasty began, its use was usually limited to individuals with only one narrowed vessel, far less extensive disease than is now treated routinely in many major centers.
About one third of all angioplasty patients currently are getting stents to keep their angioplasty-treated vessels from closing again, Moussa estimates. According to the American Heart Association, some 404,000 angioplasties (called PTCA, or percutaneous transluminal coronary angioplasty) were performed in the United States in 1994, the most recent statistics available.
In all, the 100 patients in the new study had 243 diseased arteries requiring treatment. Each received three to four stents. Some were better stent candidates than others, he notes.
Randomized clinical trials that directly compare outcomes in patients who receive stents and patients who undergo bypass surgery are needed to confirm their observations.
Other co-authors of the study are Bernard Reimers, M.D.; Jeffrey Moses, M.D.; Carlos Di Mario, M.D.; Lucia Di Francesco, Ph.D.; Massimo Ferraro, R.N.; and Antonio Colombo, M.D.
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Media advisory: Dr. Moussa can be reached in New York by calling (212) 434-2606. Reporters may call (214) 706-1173 for copies of the report. (Please do not publish telephone numbers.)