NEW YORK, Mar 19 (Reuters Health) - Diabetics with several blocked heart arteries who have bypass surgery live longer than those who undergo the artery-clearing procedure balloon angioplasty, researchers report.
Diabetes increases the risk of heart disease, but the best way to clear clogged heart arteries in people with the disease has been controversial. After a study found that diabetics fared better after bypass surgery than after angioplasty, the National Heart, Lung and Blood Institute (NHLBI) said that bypass surgery is the preferred treatment for diabetic patients who had more than one blocked heart artery. But several other researchers have failed to replicate the findings of the study.
Now, Dr. Nathaniel W. Niles, of Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire, and colleagues provide evidence supporting the advantages of bypass surgery. In a sample of more than 2,700 diabetic patients with multiple diseased arteries, they found patients treated with angioplasty or bypass surgery had similar survival rates during the first 3 to 4 months after treatment.
But after this time, the odds of survival declined in patients who had undergone angioplasty, the researchers report in the March 15th issue of the Journal of the American College of Cardiology. Patients treated with angioplasty were 49% more likely to die during the 5-year study than patients who had bypass surgery, the report indicates.
The study "supports the recommendation of the initial NHLBI clinical alert" recommending bypass surgery for diabetics with two or three blockages in coronary arteries, Niles and his colleagues conclude.
Recently, however, stents--wire mesh tubes used to keep arteries open after angioplasty--and other technological advances have been used more frequently than they were at the time of the study. Even though there is little evidence that stents and other advances in angioplasty techniques improve the survival of diabetic patients, the effects of these improvements need to be measured in future studies, according to the researchers.
"Overall, the vote is in and the winner has been declared," according to Dr. Spencer B. King III, of Emory University in Atlanta, Georgia.
"Surgery...is superior to angioplasty in the broad population of patients with diabetes and multivessel disease," he writes in an editorial that accompanies the study. He points out, however, that patients in the study who had just two blocked arteries did not fare any worse with angioplasty. Only those with three or more blockages clearly benefited from bypass versus angioplasty.
The study did not examine why people with diabetes tended to do better after bypass surgery, but more rapid progression of artery disease in diabetics may have played a role, King said in an interview with Reuters Health.
By "putting in more conduits" through which blood can pass, bypass surgery may make it easier for blood to keep flowing to the heart, according to King.
"You've got more options on how to get blood to the heart," he said.
The main challenge, however, according to King, is to prevent blockages from developing in the first place by modifying risk factors such as high blood pressure and high cholesterol and by keeping diabetes under control.
Bypass surgery involves taking veins, and sometimes arteries, from other parts of the body and grafting them to bypass the blocked vessel. In contrast, during angioplasty, a balloon-tipped catheter is threaded into a blocked artery and inflated, flattening fatty plaques against the artery wall. |
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