Statins associated with lower risk of cardiac events for some patients, not others

Cholesterol-lowering statins were associated with lower risk for major cardiac events in some patients with preexisting ischemic heart disease but not in others, according to an article published online by JAMA Internal Medicine.

Long-term treatment with statins is recommended for patients with stable ischemic heart disease (IHD) because they are at increased risk for recurrent cardiovascular events. But there are differences among guidelines regarding the definition of appropriate targets for low-density lipoprotein cholesterol (LDL-C) levels. The American Heart Association's guidelines do not establish target LDL-C levels. However, the European Society of Cardiology recommends treatment be titrated to achieve LDL-C levels below 70 mg/dL.

Morton Leibowitz, M.D., of Clalit Research Institute, Tel Aviv, Israel, and coauthors compared the risk for major adverse cardiac events (MACEs) among patients with IHD according to LDL-C levels after at least one year of statin therapy.

The study considered low LDL-C levels to be less than or equal to 70 mg/dL; moderate levels to be 70.1 to 100 mg/dL; and high levels to be 100.1 to 130 mg/dL. MACEs included heart attack, unstable angina, stroke, angioplasty, bypass or death.

The study included 31,619 patients with IHD who were at least 80 percent adherent to their statin treatment: 9,086 (29 percent) had low LDL-C levels, 16,782 (53 percent) had moderate LDL-C levels and 5,751 (18 percent) had high LDL-C levels. There were 9,035 patients who had a MACE or who died during an average 1.6 years of follow-up.

The authors report a low LDL-C level was not significantly associated with the risk of MACE compared with patients who had moderate LDL-C levels. However, moderate LDL-C levels were associated with a lower risk of MACE for patients compared with patients who had high LDL-C levels.

The authors note a number of study limitations, including restricting the study to patients with preexisting IHD and limited generalizability.

"Our results do not provide support for a blanket principle that lower LDL-C is better for all patients in secondary prevention," the study concludes.

In a related editor's note, JAMA Internal Medicine Editor Rita F. Redberg, M.D., M.Sc., of the University of California, San Francisco, and colleagues write: "The study by Leibowitz et al adds important information to the ongoing discussion of the best statin strategy and LDL-C targets to improve outcomes with minimal harms."