Most people who suffer a heart attack maintain elevated levels of high-sensitivity C-reactive protein (hs-CRP) several years later, which can only partially be explained by traditional cardiovascular risk factors, researchers reported in the American Heart Journal.
Overall, the results suggest inflammation may independently contribute to cardiovascular disease (CVD), wrote lead researcher Neha J. Pagidipati, MD, MPH, with Duke Clinical Research Institute, and colleagues. Hs-CRP is a marker of inflammation, as well as a predictor of increased CVD risk in both primary and secondary intervention.
Pagidipati et al. studied almost 1,300 individuals from the National Health and Nutrition Examination Surveys (NHANES) who had a prior myocardial infarction and valid hs-CRP measurements. When the blood tests were conducted an average of 7.1 years after MI, 61 percent of patients had hs-CRP above 2 mg/L—a recognized cutoff for elevated levels. Nearly half had readings above 3 mg/L and the cohort’s overall average was 2.69 mg/L.
Several patient factors were associated with increasing hs-CRP, including higher body mass index, older age, hypertension and smoking. But importantly, the authors found those standard CVD risk factors only accounted for 22 percent of the variability in the hs-CRP levels.
Also, 6 percent of patients had increased inflammation levels—as evidenced by hs-CRP—but no other standard modifiable risk factor.
“In light of emerging evidence on the importance of inflammation in the pathogenesis of cardiovascular disease, the high prevalence of elevated hs-CRP in patients with prior MI in the U.S. may have public health implications,” the researchers wrote.
Pagidipati et al. acknowledged their study was limited by its observational nature and cross-sectional design. Because of this, clinical outcomes and changes in hs-CRP levels over time couldn't be assessed.
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.