Vascular Health Vital to Optimal Heart and Brain Function

Treating hypertension and atherosclerosis may help prevent stroke and dementia.

Controlling your risk of heart disease may control your risk of dementia, too. That’s the finding of a pair of studies that focus on the heart-brain connection.

The first is an American Heart Association statement that atherosclerosis can result in age-related vascular cognitive impairment. Experts who drafted this statement believe that cerebrovascular disease and Alzheimer’s disease may work together to cause dementia, and that this may be a very common source of dementia in older adults. The statement was published in the July 22 issue of the journal Stroke.

In the second study, researchers from University of California-Davis found that cardiovascular risk factors such as hypertension, diabetes or obesity in midlife can lead to an increase in the rate of brain atrophy linked to dementia within 10 years. The study, which appeared in the Aug. 2 issue of Neurology, found that the association of hypertension and brain aging begins early in adulthood. Researchers say that protecting brain tissue is one more reason to treat high blood pressure.

Cleveland Clinic cardiologist Christopher T. Bajzer, MD, explains that high blood pressure can eventually damage brain tissue, resulting in several brain function symptoms, such as dementia.

“Hypertension alone, with its many small areas of intra-brain bleeds, gradually and progressively results in the loss of enough neurons and neuronal function to cause a similar constellation of clinical symptoms,” he says. “Sadly, once the loss of neuronal function is evident to family, friends and health professionals, the damage is done and treatment has limited effect. This is where prevention—the earlier the better—is the best intervention. Control your blood pressure.”

Heart-Brain Connection
Treating atherosclerosis is also vital to preserve brain and heart health, because clogged coronary arteries can lead to heart attacks and clogged cerebral arteries can cause brain tissue damage due to the reduction of oxygen-rich blood flowing to the brain. Plaque buildup can also rupture in any artery, resulting in a blood clot that can cause a stroke if it prevents blood from reaching the brain.

“In the brain, atherosclerosis can cause similar problems of reduced blood flow, and can slow brain cell metabolic processes and repair processes,” Dr. Bajzer says. “The unstable plaque in the arteries within the skull can rupture. Clot formation occludes the artery, resulting in a stroke. Also, atherosclerosis in larger arteries leading to the skull (carotid arteries, vertebral arteries, aorta) can become unstable and plaque can rupture. The result is embolization of either atheromatous debris or thrombotic debris or both. And again the bloodstream would carry the debris to a small branch artery within the brain and cause stroke or a transient ischemic attack (TIA, an event in which stroke-like symptoms occur, but no permanent damage is done).”

He also explains that the consequences of a heart attack can be decreased pump function and/or rhythm abnormalities. Both of these conditions can result in clots forming within the chambers of the heart. “Such a clot can dislodge,” Dr. Bajzer says. “Even a particle the size of a head of a pin can freely float in the bloodstream. In the worst case, it ends up lodging within a small branch artery within the brain, causing a stroke or a TIA.”

He adds that a TIA is often kept from becoming a stroke because the body dissolves the particle on its own.

Coordinated Care
Strokes are sudden events that are treated, optimally, within a few hours. Stroke rehabilitation follows, ranging from minor physical therapy to help restore full limb function to more complicated rehab to help patients with speech, balance, strength and even memory or cognitive function.

But a patient starting to develop dementia due to insufficient blood flow to the brain may require the coordinated involvement of a neurologist and cardiologist, and possibly other specialists.

“Patients should seek out cardiologists with strong interest in brain vascular health,” Dr. Bajzer says. “Likewise there are neurologists that specialize in dementias and brain vascular disease and health and psychiatrists that specialize in treating dementing illnesses and importantly helping family and friends cope with loved ones with dementing illness. Large integrated health care centers like the Cleveland Clinic have all of these specialists available.”

He adds that if there is concern about cognition by a patient or more importantly by a spouse, family or friends, then this deserves an evaluation by a skilled neurologist.

“The ‘latent period’ of many dementing processes—that is, the period of time where damage is occurring to the brain completely without any symptoms—can be many years to decades,” Dr. Bajzer says. “This is the reason why control of blood pressure, diabetes, cholesterol, and stopping smoking is so vitally important. The focus must be on controlling the risk factors—now—with no symptoms.”

Your Health and Mine