Researchers have found that high levels of an enzyme called PLTP significantly increased the risk of heart attack in the subset of patients taking statins, according to a study of more than 1,000 patients with coronary artery disease (CAD) in the April issue of the Journal of Lipid Research.
PLTP (phospholipid transferprotein) is involved in the metabolism of cholesterol-containing molecules like LDL and HDL, and therefore has been associated with atherosclerosis and heart disease. However, the authors noted that the exact role of PLTP in cardiovascular health remains debated, which led Axel Schlitt, MD, from the department of medicine at Martin Luther University in Halle-Wittenberg, Germany, and colleagues measured PLTP levels in 1,085 patients with CAD. They then tracked how PLTP related to clinical outcome.
During the follow-up period (about 5.1 years), the researchers said that 156 of the trial subjects suffered a fatal or non-fatal MI, including 47 individuals who were taking statins (out of 395 total statin patients).
The investigators found that in this statin subset, PLTP levels were a significant predictor of cardiovascular outcome. In the total cohort, PLTP levels and outcome were not associated.
While the statin patients experienced a lower overall rate of heart MI (12 vs. 15 percent-which the researchers noted it is not statistically significant), some individuals taking these drugs are at higher risk than normal, according to the authors.
Based on their findings, Schlitt and colleagues hypothesize that the high PLTP levels may blunt the beneficial effects of statins, though additional studies will certainly be needed.
The authors noted that while follow-up studies will be needed to tease out the exact connection between PLTP and statins, the connection does suggest levels of PLTP in the blood should be a consideration for potential statin treatment.