Characterization of individuals with atherosclerotic cardiovascular disease, with and without chronic kidney disease: results from a UK electronic health record database
Authors: Sattar N , Muhammad I F , Plunde O , Reuter S B , Shen Z , Tarp-Johansen M J , Tokgozoglu L , Khunti K 
Published: October 2024

Abstract

Introduction
Elevated C-reactive protein (CRP) levels are often present in individuals with atherosclerotic cardiovascular disease (ASCVD), including in those who also have chronic kidney disease (CKD), and are associated with an increased risk of major adverse cardiovascular events (MACE). To understand unmet needs in the identification and management of at-risk individuals, we characterized patients with ASCVD in a UK database, according to CKD stage and CRP levels.

Methods
This study comprised separate retrospective cross-sectional and longitudinal cohort analyses of patients in the Clinical Practice Research Datalink (CPRD) Aurum database, a representative UK database of anonymized primary care records. In the cross-sectional analysis, CPRD Aurum was linked with Hospital Episode Statistics (HES) and Index of Multiple Deprivation data to assess patient characteristics on 1 Jan 2021 (defined as index date). In the cohort analysis, CPRD Aurum was linked with HES and Office for National Statistics mortality data to determine the incidence of 3-point MACE (3P-MACE) over approximately 5 years of follow-up (index date: 1 Jan 2016). Both analyses included individuals ≥ 18 years old with an ASCVD diagnosis in both primary and secondary care in the 5 years pre-index. Data were analysed using descriptive statistics. Patient characteristics were assessed by CKD stage; for individuals with CKD stage 3–4, characteristics were also assessed by CRP levels.

Results
In total, 225,767 and 230,055 individuals were included in the cross-sectional and cohort analyses, respectively. The prevalence of CKD stage 3–4 among individuals with ASCVD was 24.3% (Table 1). The proportion of individuals with elevated CRP (CRP ≥ 2 mg/L) and anaemia increased for successively higher CKD severity groups; in addition, glycated haemoglobin (HbA1c) ≥ 7% and elevated blood pressure were generally more frequently observed in individuals with CKD than in those without (Table 1). Individuals with ASCVD, CKD stage 3–4 and elevated CRP had higher HbA1c and total cholesterol levels and a greater proportion had obesity, anaemia and elevated blood pressure, compared with individuals with CRP &lt; 2 mg/L (Table 2). Over 5 years’ follow-up, the incidence of 3P-MACE increased with CKD severity (Table 1) and with increasing CRP levels in individuals with ASCVD and CKD stage 3–4 (Table 2). However, only 28% of individuals with ASCVD and CKD stage 3–4 had CRP measurements.

Conclusion
Adults with ASCVD, CKD and elevated CRP identified from primary and secondary UK care records had a higher disease burden than individuals with CRP levels &lt; 2 mg/L. In the UK, testing CRP levels is not routinely recommended, resulting in a high proportion of missing CRP measurements in this study. Routine testing of CRP may help in identifying patients with residual cardiovascular risk and has the potential to support risk assessment and management of patients with ASCVD and CKD.