hsCRP Level and the Risk of Death or Recurrent Cardiovascular Events in Patients With Myocardial Infarction: a Healthcare-Based Study

Abstract

Background: Beyond the controlled setting of trials, scarce information exists on the burden, predictors, and outcomes associated with elevated hsCRP (high-sensitivity C-reactive protein) in “real-world” patients with myocardial infarction (MI). Methods and Results: We included all-coming MI survivors undergoing hsCRP testing >30 days after an MI during routine health care in Stockholm, Sweden (2006–2011). hsCRP tests measured during hospitalization/emergency department 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 and associated with subsequent death and major adverse cardiovascular events (composite of MI, ischemic stroke, or cardiovascular death). Included were 17 464 patients (63% men; mean age, 72.6 years) with a median hsCRP level of 2.2 (interquartile range, 1.0–6.0) mg/L and a median of 2.2 (interquartile range, 0.8–4.9) years since their MI. Most (66%) had hsCRP ≥2 mg/L, and 40% had hsCRP >3 mg/L. Lower hemoglobin, lower estimated glomerular filtration rate, and comorbidities (eg, heart failure, peripheral vascular disease, stroke, atrial fibrillation, diabetes mellitus, and rheumatoid diseases) were associated with higher odds of hsCRP ≥2 mg/L. Conversely, previous percutaneous coronary intervention, ongoing renin-angiotensin blockade, and statins were associated with lower hsCRP ≥2 mg/L odds. Patients with hsCRP ≥2 mg/L were at higher risk of major adverse cardiovascular events (n=3900; adjusted hazard ratio, 1.28; 95% CI, 1.18–1.38) and death (n=4138; adjusted hazard ratio, 1.42; 95% CI, 1.31–1.53). Results were robust across subgroups of patients and after exclusion of events occurring during the first 6 to 12 months. On a continuous scale, the association between hsCRP and outcomes was linear until hsCRP >5 mg/L, plateauing thereafter. Conclusions: Most patients with MI exhibit elevated hsCRP levels. Besides identifying populations at high-inflammatory risk, this study extends the prognostic validity of this biomarker from trial evidence to real-world healthcare settings.