Fighting Coronary Bypass Mental Decline

ByAvis Favaro

T O R O N T O, June 26, 2001 -- Jim Chapman relies on quick wit and a keen memoryto host his radio show.

But since an emergency heart bypass operation, the host of CJBK-AM Radio's Talk of the Town in London, Ontario, noticed memory loss andmental lapses he has never had before.

"There would be moments when I would forget what to say," Chapman says. "Iknow how the streets run in the city but I can no longer remember theirnames."

He shared his complaint with listeners and found many bypass patients withthe same problem. Recent research has confirmed what Chapman and othershave experienced. Now doctors are trying to prevent the problem.

Research Documents Mental Decline After Bypass

A study in the New England Journal of Medicine in February found that asmany as 42 percent of patients who undergo a bypass may be expected toperform significantly poorer on tests of mental ability five years later.Other effects are personality changes, memory problems and irritability.

The cause is believed to be the tool that allowed the bypass operation sosuccessful.

Doctors stop the heart during surgery and the blood is rerouted through aheart-lung machine. "There is clear evidence that neurological damage occursafter the use of the heart-lung machine," says Dr. Douglas Boyd, a cardiothoracic surgeon at the London Health Sciences Center. "It cannot be ignored by anyone in the field of heart surgery."

When the pump is connected to the patient it can dislodge plaque that hasbuilt up in the arteries, some doctors say.

"If we shower the brain with thousands of these tiny particles, patients maynot have a full stroke, but they may not be as sharp as they once were,"says Dr. John Murkin, an anesthetist at the London Health Sciences Center in Ontario.

Not all surgeons agree that bypass is to blame.

"Remember, these are people who already, before they come to heart surgeryhave some changes in the brain circulation because of atherosclerosis," saysDr. Hugh Scully, a cardiothoracic surgeon of University Health Network inToronto.

Doctors are hoping to develop methods to prevent the mental losses.

Trapping the Problem

Murkin is trying to measure particles that may be moving into the brain bytrapping them on a filter that sits on the aorta. The filter, he says,collects plaque and stroke causing clots before they reach the brain.

Ottawa researchers are trying to protect the brain by cooling the patientduring the procedure. Less damage occurs to tissue under cooler conditions.

"We found that when we did the cognitive testing, the [cooler] patients didbetter," says Dr. Howard Nathanson, an anesthetist with the Ottawa Heart Institute. "There was a 25 percent reduction in the incident of deficits anddegree of problems was much less."

Others are trying to avoid the use of the heart-lung machine altogether.Early findings suggest that the number of patients suffering mental declinegoes from 30 percent to 5 percent.

More than 50 percent of bypasses in the United States are done off-pump, but inCanada the number is only 5 percent.

Benefits of Bypass Outweigh Risks

The benefits of bypass, doctors and patients agree, outweigh the risks tomemory loss. Doctors say no patient should cancel a surgery based on themental concerns.

"I would definitely go through with the surgery even though I had a strokeas well as memory loss," says Gunar Liepins, a bypass patient whose life wasin danger before the surgery.

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