High-sensitivity C-reactive protein and the risk of chronic kidney disease progression or acute kidney injury in post-myocardial infarction patients

Abstract Background Persistent, low-grade inflammation likely participates in the pathophysiology of both atherosclerosis and kidney disease. While high-sensitivity C-reactive protein (hsCRP) predicts future cardiovascular risk in patients with chronic kidney disease (CKD), it is unknown whether hsCRP levels predict adverse renal outcomes in patients with cardiovascular disease. Methods We studied all myocardial infarction (MI) survivors undergoing hsCRP testing >30 days after their MI during routine healthcare in Stockholm, Sweden (2006–2011) with available information on estimated glomerular filtration rate (eGFR). HsCRP tests measured during hospitalization/emergency room visits, followed by antibiotics or indicative of acute illness, were excluded, together with patients with ongoing/recent cancer, chronic infections or immunosuppression. Inflammation was defined over a 3-month baseline window. Study outcomes were chronic kidney disease (CKD) progression (composite of doubling plasma creatinine, renal replacement therapy or renal death) and acute kidney injury (AKI, acute creatinine peaks according to KDIGO criteria). Multivariable Cox regression was used to adjust for age, sex, eGFR, hemoglobin, time since MI, comorbidities, undertaken procedures and medications. Results Total 12,905 patients (62% men, mean age 73 years and 3 years since MI) were included, of whom 35% had an eGFR 2 . The mean (SD) hsCRP was 3.0 (4.4) mg/L. Baseline hsCRP levels were increasingly higher across lower eGFR categories. During a median follow-up of 3.2 years, 1019 CKD progression and 1481 AKI events were recorded. Patients with hsCRP≥2 mg/L were at higher risk of both CKD progression (adjusted hazard ratio 1.42; 95% CI 1.21–1.66) and AKI (1.29; 1.13–1.47) compared to those with hsCRP 10 mg/L). Results were robust across subgroups of patients and after exclusion of events occurring during the first 6–12 months. Conclusions In post-MI patients undergoing routine healthcare, elevated hsCRP was associated with subsequent risk of AKI and progression of CKD, irrespective of baseline kidney function.