Homocysteine and coronary plaque

If you’ve watched the news over the past year, you know that doubt has been cast over the idea that reducing homocysteine blood levels with high doses of B vitamins (B6, B12, and folic acid, or B9) results in reduced risk for heart attack.

Is the homocysteine concept dead? Shall we empty our bottles of costly B vitamins into the trash and move on?

I don’t think so. As detailed in one of our Track Your Plaque Special Reports from a few months ago, I think the homocysteine issue still deserves lots of respect and further investigation. After all, hundreds of clinical studies have connected higher homocysteine levels with greater risk for heart disease, stroke, and aneurysm. Numerous studies, for example, have repeatedly and consistently demonstrated a tripling of heart attack risk when homocysteine levels exceed 14 ?mol/l. Can we dismiss this association because several more recent studies—NORVIT, HOPE, and VISP—suggested that, when starting homocysteine levels are 12.5, that B vitamin supplementation does not reduce heart attack risk?

I think there’s lots more to know about the homocysteine connection. That said, I have never seen a patient who I thought had heart disease strictly because homocysteine was increased.

I believe that we can at least use homocysteine as an index of lifestyle: the higher the homocysteine, the poorer the diet, or the less effective the absorption of B vitamins (especially vitamins B12 and folic acid). Homocysteine levels of <9 micromol/l suggest both adequate intake and absorption of these B vitamins.

If homocysteine is tightly connected with risk for heart disease, yet supplementation of B vitamins fails to reduce risk, might there be another means of connection? Or, could both homocysteine and heart disease be connected in some way that has nothing to do with B vitamins?

Don’t close the book on homocysteine. Just because conventional experience fails to draw connection does not necessarily mean that none exists. If it’s any consolation, taking B vitamins has been correlated with better memory, concentration, and other health benefits, even if no reduction in heart disease develops.

Big heart scan scores drop

Most Heart Scan Blog readers already know:

Your doctor has been brainwashed by the pharmaceutical industry.

Your doctor more than likely has spent the better part of his or her career in the Guantanamo Bay of healthcare, water-boarded by seductive sales representatives, enticed with promises of fame and riches, threatened with ostracism from the clubby internal halls of healthcare if--gasp!--he or she didn't subscribe to the "rule" that only drugs are good, anything else is bad.

The same FDA-approval-is-necessary-to-be-good brand of nonsense is gaining popularity among my colleagues who, having caught some mention (on the Today Show, Oprah, or similar source of medical information), hope to join the vitamin D hoopla.

People will proudly declare that they are taking a high dose of vitamin D: 50,000 units once per week.

No. They are taking a barely useful form: D2, ergocalciferol.

Studies examining the reliability of the D2 form differ:

There's the Heaney study suggesting that D2 is less effective than D3:
Vitamin D2 is much less effective than vitamin D3 in humans

Then there's the Holick study showing they are equivalent:
Vitamin D2 is as effective as vitamin D3 in maintaining circulating concentrations of 25-hydroxyvitamin D.

My experience is more in line with the Heaney study: Little or no real effect with D2.

One particularly illustrative case I witnessed was a woman who was mistakenly prescribed D2 at 50,000 units per day. She told me that she'd been taking it for a year. I fully expected to see clear-cut signs of toxicity (e.g., high blood calcium levels). Curiously, she showed no signs of toxicity. Nor did she show any vitamin D at all in her blood: 25-hydroxy D level of zero--literally zero.

I've witnessed similar phenomena several times: plenty of vitamin D2 . . . very little vitamin D in the blood.

All in all, I suppose that D2 is better than No-D at all. But you are far better off joining the ranks of the pharmaceutically challenged and go with the stuff that really works: D3.

D3, or cholecalciferol, yields confident increases in blood levels. It is inexpensive, safe, and an exact copy of the human form of vitamin D. (Of course, gelcap or drops only, NEVER tablets.)

There is absolute NO reason to take vitamin D2, the form that sometimes works, sometimes doesn't, the facsimile plant form issued by the drug industry.

Why don't stents prevent heart attack?



No study has ever documented that stents prevent future heart attack. But, in day-to-day practice, stents are frequently implanted for just this reason.

A little clarification. Stents do prevent heart attack--if the heart attack is already underway, either as an "acute myocardial infarction" or "unstable angina."

In other words, a plaque in a coronary artery can rupture just like a little volcano. Rather than spewing lava, the underlying plaque contents--fibrous tissue, inflammatory cells, cholesterol crystals, fatty material, debris--are exposed to flowing blood and trigger spasm of the artery and blood clot formation. A ruptured plaque is typically found in people who go to the emergency room with severe chest pain or have difficulty breathing.

A heart catheterization is performed, a severe (e.g., 90-100%--completely closed) is found. A stent in this situation is of clear-cut benefit.

What is not clearly beneficial is someone with no symptoms, symptoms only with physical activity that has been present for at least several months, or someone with a high heart scan score and no symptoms. In these circumstances, stent implantation does not reduce risk for future heart attack.

Why?



Take a look at this angiogram of a right coronary artery. You can seen plaque all along the artery (represented by areas that appear pinched off. There are at least 4 visible.)

Putting one 15 millimeter stent in the artery will only affect the area of artery stented. (Stents vary in length, but typically are 12-18 millimeters in length.) The right coronary artery is about 10 times or more this length. There are also two other arteries of similar length. A stent at one location will do nothing to affect the potential for rupture in any of the other plaque-laden areas.

Say a stent is implanted in the "worst" blockage in this right coronary artery, the plaque located at around 9 o'clock. What about all the other plaques? They can still rupture.

Why not put in many stents, say, 4 or 5, and stent all the visible plaques?

Two reasons: 1) Plaque you can't even see on an angiogram can still rupture, and 2) it is very costly (easily $30,000 at the very least), 3) incurs greater procedural risk, and 4) messes up the artery for future procedures, since a steel-lined artery that develops more disease in future will be more difficult to re-implant stents, bypass, or perform other procedural manipulations.

The point: Putting in stents does not reduce potential for plaque rupture in the entire artery.

What can prevent plaque rupture? That's the whole point of following an effective prevention program: prevent plaque rupture.

(Of course, this discussion cannot encompass the wide variety of potential situations that may cause your doctor to individualize your approach. Nonetheless, when advised to have an elective heart procedure, a healthy dose of skepticism and is clearly a good practice.)

Top image courtesy National Heart, Lung, and Blood Institute.