Cardiovascular Health

Atherosclerosis – when vascular health fails

Atherosclerosis (Greek: Athero = gruel or porridge, Sclerosis = toughening or hardening) is the irreversible and progressive build up of plaque in the arteries. It is a complex process originated by endothelial dysfunction, and includes the accumulation of cholesterol inside the arterial wall, with local inflammation and coagulation reactions, oxidative processes, and many other conditions, which contribute together to plaque growth.

There are many risk factors related to cardiovascular disease, which cause people to be more susceptible to atherosclerotic plaque formation and the resultant cardiovascular disease. These risk factors include smoking, Diabetes, high blood pressure, age, genetics, high LDL levels (“bad” cholesterol), low HDL levels (“good” cholesterol), sedentary lifestyle, and several others.

Subclinical atherosclerosis is divided into several stages; the earliest is known as the “fatty streak”. In this stage, the plaque continues to build up over time, transforming from a quiescent subclinical phase (see above) to a clinical phase. Plaque in the coronary circulation will predispose people to angina pains, heart attacks and heart failure, altogether can be referred as characteristics of a cardiovascular disease. Plaque in the neck and head increases the risk of dementia and strokes. Plaque can also form in the arteries, supplying blood to the limbs, causing claudication, while in the penile circulation it is the cause of erectile dysfunction. Plaque also leads to blood clots which may detach, and cause embolisms.

Vulnerable Plaque – acute danger

When plaques form in small increments, they can lead to heart attacks and strokes. In these cases, plaques are at a higher risk of rupturing, which leads to an acute and catastrophic cascade of events. When a plaque ruptures it causes immediate coagulation and a concomitant constriction of the artery, blocking off the blood supply to downstream tissues, which causes ischemia and then necrosis. This is the most common mechanism of heart attacks and strokes. As a result, these unstable plaques have been nicknamed “vulnerable plaques”. While they usually account for about 10-20% of the plaques, they cause around 80-90% of the acute events. In the USA alone there are about 1.5 million heart attacks every year.

Stable Plaque – chronic disease

When the plaques mature and stabilize, they begin to slowly occlude the blood vessel. Natural collateral blood vessels can form to supply the tissues suffering from lack of oxygen due to the blockage. Often these collaterals are insufficient and during times of exertion patients feel pain due to ischemia. This is the typical case of Angina Pectoris (Greek: Angina = pain, Pectoris = Chest).