Ask The Doctors: August 2011
I heard for a long time that raising your HDL was crucial to cardiovascular health and would help reduce the risk of heart attacks. But I recently read about research that said raising HDL may not make a difference. What do you think?
Your question is both insightful and timely. As some readers may already be aware, high-density lipoprotein (HDL) is the bodyís tool for retrieving cholesterol from arterial plaques. Imagine tiny shuttles in the bloodstream unloading cholesterol from athesclerotic plaques, and then carrying it back to the liver. The cholesterol riding on these particles is often referred to as "good cholesterol."
It was observed a long time ago that patients with low levels of HDL-cholesterol (HDL-C) were at elevated risk for developing severe coronary artery disease (CAD) and and a heart attack. As such, doctors reasonably assumed that raising a personís HDL-C would reduce the chance of such events.
But subsequent trials have yielded conflicting results. The Coronary Drug Project showed that niacin, an agent which increases HDL-C and decreases LDL-C, decreased heart attacks and saved lives. Later, the Veterans Administration HDL-C Intervention Trial (VA-HIT) showed that treatment with the drug gemfibrozil (Lopid) reduced the likelihood of MI, and this effect appeared due to its ability to increase HDL-C. Then, the HDL-Atherosclerosis Treatment Study (HATS) showed convincing evidence that, in patients with low-HDL-C, combined statin/niacin therapy caused regression of cholesterol plaques, and possibly a reduction in cardiac events.
Later, there were high hopes for drugs intended to specifically increase HDL-C, including torcetrapib. Unfortunately, this drug caused an increased number of deaths, due to a mechanism distinct from its ability to raise HDL-C. Most recently, the Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High-Triglycerides: Impact on Global Health (AIM-HIGH) trial yielded unexpected results. Addition of niacin to simvastatin (Zocor) showed no further reduction in cardiovascular events. A few more strokes were seen in the niacin-treated group, but the difference was not statistically significant.
Despite these latest findings, many cardiologists (including myself) feel that raising HDL-C may still yield benefits, and has not been shown to cause harm. We must await further studies to further delineate the most appropriate standard of care. In the meantime, I would not discourage patients from taking medications that aim to increase HDL-C, including niacin.
My cardiologist is retiring soon, and he has recommended that I start seeing a younger doctor in his practice. I donít really care for this other doctor, having had a couple of appointments with him in the past. I may look elsewhere in town. How should I handle all this?
Choosing a new physician is difficult, especially when the recommended replacement has been suggested by a highly trusted doctor. If your instincts lead you away from this younger cardiologist, it makes sense to follow them, even if the physician happens to be the hand-picked successor of your longtime cardiologist. Unless the doctor-patient relationship is based upon mutual respect and trust, it cannot succeed.
I would suggest that you investigate other practices and other providers, in order to find a physician whom you can respect and trust. Otherwise, you will not be emotionally at ease, and your heath care may be jeopardized.
Patients change doctors for a variety of reasons, so donít be self-conscious about your decision. And if you find a new doctor with whom you are comfortable, talk with him or her about what you will need to do to transfer your records to the new practice.