Each year, around half a million people in the US die suddenly from a heart attack. The truly troubling thing is that around half of them had no previous symptoms of a heart problem. What a tragedy for those individuals and their families!
As a biochemist, physician, and functional medicine practitioner, I’m always interested in the “why” of all things health-related, not just the “what”. I make it a point to explain things like this to the patients that trust me with their health.
Most people understand that plaque builds up in the arteries that supply the heart muscle. If that plaque eventually obstructs the vessel, a heart attack can happen due to the lack of blood supply. Advanced technology heart scans exist that show older calcified plaque in the arteries. Routinely available are cholesterol screenings that provide information about high levels of total cholesterol, LDL “bad cholesterol”, triglycerides, and low HDL “good cholesterol” which are all valid risk factors.
However, the knowledge that many people WITHOUT high cholesterol and many people WITHOUT build up of calcified plaque shown on a heart scan STILL have heart attacks is unsettling.
So what’s the missing piece of the puzzle?
To answer that question, we have to go back…way back before there was plaque and look at what happens over time. We know that the lining inside the lumen of arteries is called endothelium. This is basically “skin” that lines the inside of the blood vessels. Just as our skin can become irritated, inflamed, and may crack, fissure or peel in response to certain triggers (sun, irritation, inflammation), so can the “skin” inside our blood vessels.
When that endothelium is in that state (inflamed, cracked, fissured), it is susceptible to cholesterol and other circulating cholesterol-containing substances called lipoproteins (i.e. LDL or “bad” cholesterol). These particles can enter the lining of the vessel. With the pressure of blood flow, the LDL and other related particles cause further inflammation, and the plaque is initiated and progresses or grows over time. The plaque can lead to a heart attacks in three potential ways:
- The plaque may grow enough to eventually cut off the oxygenated blood supply causing a heart attack.
- The presence of plaque may lead to turbulent blood flow in and around the plaque itself and a clot may form causing a heart attack.
- The plaque may become unstable and dislodge from the wall going “downstream” to a smaller vessel and cause an obstruction of blood flow leading to a heart attack.
This leads to the all important question: What causes blood vessels to become inflamed predisposing them to plaque in the first place?
The list is long of what is known to cause, contribute to, or predispose to systemic inflammation. You could probably list the top five yourself. But first and foremost, knowing IF you have chronic inflammation is key to fully understanding your risk for a sudden heart attack. A half-dozen lab tests exist, including HS-CRP, Myeloperoxidase, Lp-PLA2 to name a few, that provide more information about systemic and vascular inflammation and in turn more information about risk for heart attack.
Knowledge combined with action equals progress. First things first, knowledge. Are You at Risk for a Sudden Heart Attack? Know your inflammatory markers as well as your cholesterol.
To your health,
Brian E Lamkin DO