Blocked Arteries Might Affect Rx Effects

Statin medications to lower cholesterol may not work as well in patients with blocked arteries

(RxWiki News) When statin medications don’t work, check the arteries. They may not work because the arteries are blocked.

New research found that when patients don’t respond to statins, it may be because they have more blocked arteries than people who do respond. A clot in an artery can lead to a stroke or heart attack, so this lack of response could indicate serious problems.

The authors of this study found that men were more likely than women to not respond and said patients on statins should have regular lab tests to check low-density lipoprotein (LDL) cholesterol levels.

Stephen J. Nicholls, PhD, deputy director of the South Australian Health & Medical Research Institute, led this study.

“To lower their cardiovascular risk, it is essential to monitor LDL levels in patients with established heart disease who are receiving ongoing statin treatment,” Dr. Nicholls said in a press release.

LDL cholesterol can contribute to plaque buildup — a thick, hard coating — in the arteries. One of the ways doctors know statins (brand names Lipitor, Crestor and Zocor) are effective is that the LDL in the circulating blood decreases.

Sarah Samaan, MD, a cardiologist at the Baylor Heart Hospital in Plano, TX, told dailyRx News that “The latest guidelines suggest that lipids be treated not on the basis of LDL numbers, but rather due to risk profile. This study emphasizes that the LDL number does matter, and that simply treating with a statin drug is not enough if we don't drop the LDL sufficiently.”

Dr. Nicholls and colleagues studied data from seven different studies on nearly 1,000 patients who were diagnosed with disease in the heart arteries.

These patients had been prescribed a statin medication to help lower cholesterol.

In 20 percent of the patients, LDL cholesterol levels either decreased only slightly, stayed the same or even increased, Dr. Nicholls and team found. They called these patients “non-responders.”

Dr. Nicholls and team stressed that their study underscored the need for careful monitoring of LDL cholesterol levels.

“In general, LDL levels are checked 6-12 weeks after starting a statin, and every 6 to 12 months thereafter," Dr. Samaan said. "This study won’t change that practice.”

Of the non-responders, 79 percent were male, Dr. Nicholls and colleagues found.

“The study doesn't explain why men are less likely to respond to treatment than women," Dr. Samaan said. "We can speculate that perhaps testosterone is a factor, since higher levels of testosterone are associated with higher LDL levels.”

Dr. Samaan added, “The take home message for people with high cholesterol and atherosclerosis, or cholesterol deposits, is that getting the LDL number down is crucial if we want to do everything we can to lower heart disease and stroke risk. Statins are the best drugs that we have, but a healthy diet, regular exercise, not smoking, and keeping body weight, blood sugar, and blood pressure normal are at least as important in prevention.”

This study was published Feb. 26 in the journal Arteriosclerosis, Thrombosis and Vascular Biology.

Dr. Nicholls and team disclosed no funding sources. Some study authors received funding from pharmaceutical companies like Pfizer, Roche, AstraZeneca, Merck and Eli Lilly, among others.

Review Date: 
February 25, 2015