Sara Novak
Doctors have long looked at certain risk factors including blood pressure, cholesterol, diabetes, smoking, and family history to predict a patient’s risk for cardiovascular disease. But increasingly, another lesser known biomarker, known as high-sensitivity C-reactive protein (hsCRP), seems to play an important role in whether a patient is at risk for a heart attack or stroke.
As a result, the American College of Cardiology recently published a report that found hsCRP strongly predicts recurrent cardiovascular events and elevated hsCRP in otherwise healthy individuals puts them into a higher-risk group, even if cholesterol levels are normal.
“High-sensitivity CRP has been shown to be an independent marker of risk in addition to and in some cases over and above all other risk factors that we typically talk about including smoking, diabetes, blood pressure, cholesterol, and weight,” said James D. Mills, MD, a cardiologist at RWJBarnabas Health in New Brunswick, New Jersey.
What is CRP?
CRP is produced by the liver when the body’s immune system is fighting infection or when chronic immune issues like rheumatoid arthritis, lupus, and heart disease cause levels to remain elevated.
Rohit Vuppuluri, MDHsCRP is a more sensitive test that’s less likely to show inflammation caused by infection or an injury because it looks for smaller increases that are the result of low grade, long-term inflammation, more likely to be caused by cardiovascular and autoimmune disease.
“The plaque in your arteries is deemed a foreign substance that doesn’t belong, which causes your own immune system to attack,” said Brett A. Sealove, MD, a cardiologist at Hackensack Meridian Health in New Jersey. He adds that this is why elevated levels are considered a sign of coronary artery disease and disease progression.
Low density lipoprotein (LDL) circulating in your blood causes plaque, and once it’s developed, inflammation can make the problem much worse. Inflammation ends up in the arteries because white blood cells release cytokines and other immune substances that cause plaque to become unstable and more likely to rupture or fissure, making it more likely to cause a heart attack, said Sealove. That’s why the hsCRP biomarker can be an important additional tool for primary care physicians in evaluating risk.
Should hsCRP Be Part of Your Annual Bloodwork Panel?
The hsCRP biomarker blood test has been around for decades. It’s a routine blood test that can provide physicians with more information regarding cardiovascular health. It should only be used when a patient isn’t ill because an infection or an autoimmune disease that’s not controlled can cause elevated immune activation.
“We’ve known for a long time that inflammation can cause heart disease, make it worse, and make it unstable and when it becomes unstable that could lead to an acute event,” said Sealove. What’s more, hsCRP tends to be a catalyst leading to the progression of atherosclerosis, the hardening of arteries due to a buildup of plaque.
Brett A. Sealove, MDAnnual physicals are an important tool for evaluating cardiovascular risk. The current testing includes a lipid panel, which is a common blood test that assesses the amount of lipids or fats in your bloodstream.
The standard lipid panel looks at LDL cholesterol, which is known to clog arteries, as well as high density lipoprotein which has a positive effect on arterial health, along with total cholesterol and triglycerides, a type of fat that comes from the foods you eat. Doctors also look at blood pressure, which is important because high blood pressure is an indication of the heart having to work harder to pump blood, which can be taxing to the cardiovascular system.
There’s still a lot of debate as to whether hsCRP should be tested in all patients. Some doctors contend that it should be part of every patient’s annual bloodwork panel because even for those at a lower risk, it’s an easy, relatively inexpensive, and reliable test that can help ensure that any potential risk isn’t missed.
A large body of research has shown that patients without a previous history of cardiovascular disease who had elevated hsCRP also had an increased risk for ischemic stroke, blood clotting that blocks arteries to the brain, as well as heart attack. CRP can also drive heart failure, which has also been shown in a wide body of evidence.
“We can’t treat what we don’t look for and that’s why we as cardiologists and our primary care colleagues need to be more attuned to the role of inflammation in cardiovascular risk,” said Jared A. Spitz, MD, a cardiologist at Inova Health System in Northern Virginia.
Still, most physicians contend that it should only be used in patients at intermediate risk, for example, those with moderately high blood pressure and elevated cholesterol who may benefit from statins but are on the line between treatment and monitoring. Additionally, it should also be used in patients who already have cardiovascular disease and are at risk for a repeat heart attack.
How to Reduce CRP in the Body
If hsCRP is elevated, there are a number of steps that patients can take to lower the numbers. Similar to cholesterol, diet, exercise, weight loss, and tobacco cessation can all reduce hsCRP numbers. Also, if a patient already has an immunologically disease which may be elevating their levels, treating these diseases first and making sure they’re under control can help.
Jared A. Spitz, MDSpitz added that we also have robust data to show that even if cholesterol is not elevated, starting a statin may be helpful. Statins reduce the liver’s production of cholesterol and help to remove LDL, known as bad cholesterol, from the blood. A study published in The New England Journal of Medicine found that statins lower the levels of both LDL cholesterol and CRP.
Primary care physicians should continue to check numbers to see if they’re improving as a result of lifestyle changes. Still, beyond statins, we don’t have very many other medication options that can be used to reduce low grade inflammation, said Rohit Vuppuluri, MD, an interventionist and vascular cardiologist at Chicago Heart and Vascular Specialists.
“This is the tricky part because we don’t have enough data for how to lower CRP beyond lifestyle so if physicians see that CRP levels are high, they might not know what to do with the information,” said Vuppuluri.
