Tim Russert Teaches Us We Still Have Work To Do

Which news is worse: that a) there is atherosclerotic disease in your coronary arteries that has led to a ‘lot’ of blockage or b) similar disease that has resulted in 'minimal' blockage? While neither option is particularly attractive, if you chose to have minimal blockage, you may have also selected sharing Tim Russert’s fate.

Even though the heart is a muscle that pumps blood, it does not receive its blood supply from the blood going through the heart. Rather, there are a separate set of arteries that wrap around the outside of the heart muscle. When those arteries start becoming blocked by cholesterol plaque, the result is coronary artery disease. While having a big bulky blockage results in decreased blood flow to the heart muscle, it turns out that the composition of the plague also matters a lot.

It turns out large 'hard' plagues that result in gradually severe narrowing of the coronary arteries rarely cause the kind of abrupt blockage leading to a sudden stoppage of blood flow with the death of heart tissue a.k.a. heart attack. Instead, most large heart attacks are the result of 'soft' plaques that are only mildly obstructive. It turns out these kind of 'thin' plaques are filled with a mix of cholesterol and other substances that expand outward. This expansion can vary and be unpredictable. Local inflammation seems to play a key role (aspirin may do more than just thin blood). If the expansion reaches a point where there is a large rupture, an exposed flap of tissue can block the artery. Shut down of blood flow is further aided by the accumulation of clots around that exposed flap.

Plague rupture probably accounts for two thirds of death from acute coronary artery disease. Identifying plaques that are prone to rupture ahead of time is very difficult. Since they are not causing any blockages prior to rupture, patients may have no symptoms. Like Tim Russert, they can go through stress tests with flying colors one day and collapse the next.

Unfortunately, the types of interventions promoted by disease management, such as exercising regularly, eating 'right,' taking aspirin, using cholesterol lowering medicines and treating high blood pressure all only imperfectly lower the risk of death from coronary artery disease. Those of us in health care still have a lot of work to do.