In traditional bypass surgery, doctors stop the patient's heart during bypass surgery and hook up the patient to a heart-lung bypass machine during the operation. But during beating heart bypass (also called "off-pump" bypass), doctors operate on the patient's beating heart without using a heart-lung machine.
Heart bypass is done when coronary arteries, which supply blood to heart muscle, are blocked. During heart bypass, surgeons take a blood vessel from the patient's chest, legs, or arms and graft it onto the heart to bypass the coronary blockage.
Past studies have suggested that traditional bypass surgery might boost the odds of mental decline. Those findings had raised interest in beating heart bypass. Both procedures are major surgery, and certain risk factors may rule out beating heart bypass for some patients.
The new study comes from Dutch doctors including Diederik van Dijk, M.D., Ph.D., of the anesthesiology department of University Medical Center Utrecht in Utrecht, the Netherlands.
They randomly assigned 281 low-risk bypass patients to get beating heart bypass or traditional bypass. The patients were 61 years old, on average.
Before surgery, the patients took tests of mental skills, including attention, memory, and manual dexterity.
Five years after surgery, 260 of the patients repeated the mental skills test. Half of the patients in both groups showed a 20 percent decline in their mental skills test scores.
Those declines weren't necessarily due to the bypass surgeries. Simply getting older might have been responsible, the doctors note.
The study also shows that a similar percentage of patients in both groups — 30 patients in the beating heart bypass group (21 percent) and 25 patients in the traditional bypass group (18 percent) — had a heart attack, stroke, heart-related death, or more heart surgery during the five-year follow-up period.
The use of beating heart bypass instead of traditional bypass "had no effect on cognitive or cardiac outcome five years after the procedure" in these low-risk patients, the researchers conclude.
The study appears in The Journal of the American Medical Association.
By Miranda Hitti
Reviewed by Louise Chang, M.D.
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