Elevated high-sensitivity C-reactive protein and the risk for cardiovascular events in chronic cardiac disease

Abstract Background High sensitivity C-reactive protein (hs-CRP) is a biomarker used for risk prediction for cardiovascular disease by assessing low concentration of inflammation. This study aims to assess the event-free time for the composite outcome between patients of different hs-CRP risk groups and the possible predictive value of hs-CRP for event occurrence in patients with chronic cardiac disease. Methods Data from 607 consecutive patients referred for cardiovascular risk assessment with hs-CRP from November 2017 to October 2018 were reviewed retrospectively. Routine peripheral venous blood samples were taken on the day of study inclusion and sent to the local laboratory, where laboratory parameters were analyzed and processed in accordance with local laboratory standards. 570 patients who had hs-CRP measurement by immunoturbidimetric assay were included in the analysis and classified into three (low-, medium- and high-risk) groups (hs-CRP cut-off: <1, 1–3, >3 mg/L). Association between hs-CRP and occurrence of the composite outcome (acute myocardial infarction, stroke, coronary intervention (percutaneous coronary intervention or bypass surgery) or death) was determined with Cox regression analysis and visualized with Kaplan Meier curves. Results In total, 570 patients from our cardiology outpatient clinic were included in this study. Cohorts were formed according to hs-CRP risk groups, 209 (36.7%), 226 (39.6%) and 135 (23.7%) patients were classified as low-, medium- and high-risk, respectively. The composite endpoint occurred in 93 (19.1%) of the 486 patients with available follow-up. Events occurred in 29 (16.3%), 30 (15.7%), 34 (29.1%) patients of the low-, medium- and high-risk group, respectively (p=0.016). There was a significant difference in the event-free survival time patients of the low- and medium-risk groups compared with patients in the high-risk group (p=0.015). The difference between groups is shown by the Kaplan-Meier plot (log rank test, p=0.01) (Figure 1). Univariate Cox proportional-hazard analysis identified age, hs-CRP risk group, hypertension, diabetes, hyperlipidemia, coronary artery disease, peripheral artery disease, cerebrovascular disease log(NT-proBNP) and creatinine as significant predictors for the primary study outcome. In multivariable analysis coronary artery disease and age were found to be highly significant predictors for the occurrence of an composite event during follow-up, while patients categorized in the low- and medium-risk groups appeared to predict a lower likelihood for events (Table 1). Conclusions Cardiovascular events were more likely to occur in patients who were older, with hs-CRP >3 mg/L and a history of coronary artery disease. However, assessment of inflammation markers alone may play a secondary role compared to other established cardiovascular risk factors, elevated CRP appears helpful to detect higher risk and in prediction of further cardiovascular events and mortality. Funding Acknowledgement Type of funding sources: None.