A 52-year-old male presents to the clinic for routine follow-up. As part of the evaluation, he undergoes an assessment of cardiovascular risk. His past medical history is notable for hypertension (treated) and increased cholesterol (currently untreated).
Recent testing demonstrated a total cholesterol of 203 mg/dL with an HDL of 48 mg/dL. Systolic blood pressure today is 133 mmHg. His calculated Framingham Risk Score is 12, resulting in an estimated 10 year risk of Cardiovascular disease of 10% (intermediate risk). His physician decides to measure C Reactive protein (CRP) to assist in further risk stratification.
The CRP returns at 13 mg/L. He is then referred to you for further care.
What would be your next step?
The correct answer is: 5. Repeat the CRP value 2 weeks later.
In general, cutpoints of <1.0 mg/L (low risk), 1.0 to 3.0 mg/L (average risk), and >3.0 mg/L (high risk) are used. These correspond to approximate tertiles of hs-CRP in the adult population. The high-risk tertile has an 1.5 fold increase in relative risk compared with the low-risk tertile. For patients with acute coronary syndromes, cutpoints for elevated hs-CRP different than those for prediction in asymptomatic patients may be useful (e.g., >10 mg/L).
Asymptomatic patients who have a markedly elevated CRP (defined as >10 mg/L) should generate a search for evidence of active infection, systemic inflammatory processes, or cancer. It is recommended that the value be disregarded and be repeated >2 weeks later.
In this patient, further questioning revealed that he had a chronic sinus infection with intermittent purulent drainage that was subsequently treated successfully with antibiotics. Repeat testing resulted in a value of 3.5 mg/L, and he was started on a statin.