Too good to be true? New study suggests that “good cholesterol” may not always be helpful in reducing cardiovascular risk

Journal of American Cardiology - High Density Lipoprotein Apolipoproteomic Score and Coronary Artery DiseaseHigh-density lipoproteins (HDL) is sometimes called the "good" cholesterol because it helps counter the harmful role of low-density lipoproteins (LDL) cholesterol and triglycerides in heart disease. While conventional lab tests measure overall blood levels of HDL, a new study suggests that a novel lab test that analyzes specific HDL proteins may better predict risk of -- and death by -- coronary heart disease (CAD) in some patients.According the U.S. Centers for Disease Control and Prevention, CAD is the leading cause of death in the United States, often causing myocardial infarction (“heart attack”) without prior symptoms.In the study in the Journal of American College of Cardiology, researchers assessed the predictive value of a score of five HDL apolipoproteins (proteins that bind with lipids to form lipoproteins) in 943 patients without myocardial infarction referred for coronary angiography. Only about 50% had a clinical CAD diagnosis. The investigators sought to identify whether the score could predict obstructive CAD (arteries narrowing) or a cardiovascular outcome over four years.The HDL score was associated with the presence of obstructive CAD in the total population, and showed “a significant association with cardiovascular mortality” in a subgroup of 587 patients with obstructive CAD, independent of conventional measures.In an accompanying editorial, Arnold von Eckardstein, MD, of the Institute of Clinical Chemistry, University Hospital Zurich, in Switzerland, refers to the study as “a significant advance in the development of a functional HDL biomarker, which is noteworthy because of both its technological approach and the clinical validation of the association of a specific set of HDL-associated proteins with the presence and prognosis of coronary heart disease.”The study was performed by researchers at Quest Diagnostics’ Cleveland HeartLab, Massachusetts General Hospital, Harvard Medical School and other prominent research institutions. (Cleveland HeartLab is a spin out of Cleveland Clinic; Quest Diagnostics acquired the business in December 2017, and it is now Quest’s national center of excellence for cardiometabolic innovation.)