Looking for calcium in the coronary arteries of people with normal levels of “bad” cholesterol is a more accurate way to predict their risk of having a heart attack or stroke than testing their blood for a marker of inflammation, according to a new study. The findings could help physicians fine-tune important decisions about which patients need cholesterol-lowering statin medications.
The study, published online today in The Lancet, included 2083 adults with normal levels of harmful low-density lipoprotein cholesterol (LDL-C) who didn’t have cardiovascular disease. The study was designed as a kind of sequel to a 2008 study known as JUPITER, or Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvstatin.
JUPITER showed that statins reduce heart attack risks in people with normal LDL-C but high blood levels of C-reactive protein (CRP). CRP indicates the presence of inflammation, which is a risk factor for cardiovascular disease. But now investigators wanted to know whether coronary artery calcium might be a better barometer of heart attack and stroke risk in people with normal LDL-C. Coronary artery calcium is a direct measure of plaque build-up in arteries while CRP is a marker for inflammation, which could be present anywhere in the body.
After 6 years of follow-up, investigators reported that 95% of heart attacks, strokes, or heart-related deaths were in study participants who had measureable calcium in their coronary arteries. Just the presence of coronary artery calcium in coronary arteries was linked with a 4-fold increased risk of heart disease and a nearly 3-fold increase in cardiovascular disease. After accounting for risk factors including hypertension, obesity, and diabetes, investigators reported no association between CRP and heart attack or stroke risks.
“Looking for calcification in coronary vessels in certain patients makes sense in order to predict who may benefit from statin therapy,” said lead author Michael Blaha, MD, MPH, of Johns Hopkins University School of Medicine in Baltimore, Md. “The test gets right to the heart of the disease we want to treat.”