Cognitive Impairment After Coronary Bypass Surgery

Coronary artery disease occurs when the arteries of the heart become constricted. When the arteries narrow, angina pectoris, arrhythmias, heart failure and/or myocardial infarction can result. Coronary artery disease affects more than 13 million people in the United States and is responsible for almost 75% of all deaths from cardiovascular disease.

Coronary artery bypass surgery is one of the most common treatments for coronary artery disease. According to the American Heart Association, 467,000 Americans had coronary artery bypass surgery in 2003, the latest year for which statistics are available. Of people having coronary artery bypass surgery every year, a majority, ranging from 50% according to the American Heart Association to much as 82% according to some researchers, will experience cognitive impairment after surgery.

Unfortunately, many surgeons are reluctant to discuss the high risk of cognitive impairment after coronary bypass surgery with their patients. Sometimes labeled a "neurocognitive defect", the risk of cognitive impairment is so well known to surgeons that it has earned the nickname "pump head". Pump head refers to the theory that blood clots, air bubbles or other debris travel to the brain when the patient's heart is stopped for surgery and the patient's blood is being pumped through a heart-lung machine.

Cognitive impairment occurs when memory-related thinking abilities are adversely affected. People experiencing cognitive impairment can cope with everyday activities, such as dressing, bathing and eating, but experience memory-related difficulties. Remembering people's names, participating in the flow of a conversation and frequently misplacing items are examples of memory-related functions that deteriorate when an individual experiences cognitive impairment.

Several factors contribute to cognitive impairment after coronary bypass surgery. First, cardiovascular disease affects the brain as well as the heart, meaning cognitive decline can occur even before bypass surgery. Another major factor is the surgery itself. Minimizing trauma to the aorta during surgery has been shown to minimize cognitive impairment after surgery as well. People with high fevers after surgery also experience more cognitive impairment. Age is another factor. Elderly people may have experienced cognitive decline well before undergoing bypass surgery.

Other health issues, including high blood pressure and low immunity to common gastrointestinal bacteria, are also linked to cognitive impairment, perhaps through causing abnormalities in the white matter of the brain. Heredity plays a part also. People carrying a gene called apoliprotein E4 (about 25% of the population) may have more cognitive impairment than people who don't carry the gene. Finally, low educational levels also impact cognitive impairment after coronary artery bypass surgery.
If you or a loved one has coronary artery disease, thoroughly research all of the treatment options. Be sure to get a second opinion, particularly if coronary bypass surgery is recommended.

If you or a loved one requires coronary bypass surgery, ask your doctor about measures that can be taken to protect the brain. Research indicates that antioxidants may be helpful. Memantine, a drug developed by Merck Pharmaceuticals that's shown to be effective in helping to slow the progression of Alzheimer's disease, may be available to you. Other neuroprotective drugs are currently in development, so ask your doctor for advice.