High Levels of Cholesterol Contribute to Heart Failure

Stop for a moment, especially if you’re about to take a big bite of chocolate cake, and think about what happens to your kitchen drain pipes when you pour meat grease or chicken fat down the sink. Over time, this sludge builds up in the pipes, causing them to drain slower or blocking them completely. The same thing can happen to our blood vessels when they are exposed to high levels of cholesterol. LDL slowly builds up in artery walls, causing a thick plaque that can narrow arteries, restrict blood flow, and lead to blood clots. A blocked blood vessel in the brain can trigger a stroke. If the coronary arteries of the heart become blocked, a heart attack occurs. Heart attack is a major risk factor for heart failure, a condition in which damaged or weakened heart muscle is unable to pump enough blood to meet the body’s needs for blood and oxygen. But a new study shows that high levels of cholesterol may significantly raise the risk of heart failure, even for people who never have a heart attack.

Heart failure is a very common condition, affecting about 5 million Americans. Each year in the United States, it results in about 300,000 deaths and is responsible for more hospitalizations than all forms of cancer combined. The most common causes of heart failure are coronary artery disease (CAD), high blood pressure, and diabetes. Treating these underlying problems can prevent or improve heart failure. For instance, drugs called ACE inhibitors lower blood pressure and reduce strain on the heart and beta blockers slow the heart rate and lower blood pressure to decrease the heart’s workload. In trials, cholesterol-lowering drugs called statins were also shown to reduce the incidence of heart failure, but it has been unclear whether the reduction was due to abnormal lipids or a benefit of the reduction in heart attacks.

To investigate the relationship between lipid levels and heart failure, researchers at the National Heart, Lung and Blood Institute analyzed data on 6,860 participants in the Framingham Heart Study, none of whom had heart disease when they were enrolled. The group had an average age of 44 at the beginning of the study, and 54 percent were women. After an average 26 years of follow-up, 680 had developed heart failure. The incidence of heart failure was:

• 12.8 percent in those with low levels of high-density lipoprotein (HDL), the “good” cholesterol, but only 6.1 percent in those with desirable HDL levels.
• 13.8 percent in those with high levels of low-density lipoprotein (LDL), the “bad” cholesterol, compared to 7.9 percent in those with desirable levels of LDL.