Elevated levels of C-reactive protein at discharge in patients with unstable angina predict recurrent instability
L M Biasucci1, G Liuzzo, R L Grillo
1Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy. biasucci@pelagus.it
Insights
Persistent elevation of C-reactive protein (CRP) after unstable angina discharge indicates higher risk for recurrent instability. This marker may persist for months and is linked to Chlamydia pneumoniae infection.
Area of Science:
- Cardiology
- Biomarkers
- Inflammation
Background:
- Unstable angina is a critical cardiovascular condition.
- Assessing post-discharge inflammatory markers is crucial for risk stratification.
Purpose of the Study:
- To determine if C-reactive protein (CRP) levels remain elevated at discharge in unstable angina patients.
- To investigate the association between persistent CRP elevation and recurrent cardiovascular events.
Main Methods:
- Measured CRP, SAA, fibrinogen, cholesterol, and antibodies to H. pylori and C. pneumoniae in 53 unstable angina patients.
- Collected blood samples on admission, at discharge, and 3 months post-discharge.
- Followed patients for 1 year to track readmissions for instability or myocardial infarction.
Main Results:
- 49% of patients had elevated CRP (>3 mg/L) at discharge.
- Elevated discharge CRP was significantly associated with higher rates of readmission (69% vs. 15%).
- Higher CRP levels correlated with increased risk of recurrent instability and were linked to C. pneumoniae titers.
Conclusions:
- Elevated CRP post-unstable angina discharge suggests ongoing inflammation and predicts recurrent instability.
- Persistent inflammation, potentially linked to chronic infections like C. pneumoniae, may be a hallmark of subclinical instability.
- C-reactive protein and serum amyloid A protein are valuable prognostic markers in unstable angina.
Background:
In a group of patients admitted for unstable angina, we investigated whether C-reactive protein (CRP) plasma levels remain elevated at discharge and whether persistent elevation is associated with recurrence of instability.
Methods And Results:
We measured plasma levels of CRP, serum amyloid A protein (SAA), fibrinogen, total cholesterol, and Helicobacter pylori and Chlamydia pneumoniae antibody titers in 53 patients admitted to our coronary care unit for Braunwald class IIIB unstable angina. Blood samples were taken on admission, at discharge, and after 3 months. Patients were followed for 1 year. At discharge, CRP was elevated (>3 mg/L) in 49% of patients; of these, 42% had elevated levels on admission and at 3 months. Only 15% of patients with discharge levels of CRP <3 mg/L but 69% of those with elevated CRP (P<0.001) were readmitted because of recurrence of instability or new myocardial infarction. New phases of instability occurred in 13% of patients in the lower tertile of CRP (/=8.7 mg/L, P<0.001). The prognostic value of SAA was similar to that of CRP; that of fibrinogen was not significant. Chlamydia pneumoniae but not Helicobacter pylori antibody titers significantly correlated with CRP plasma levels.
Conclusions:
In unstable angina, CRP may remain elevated for at >/=3 months after the waning of symptoms and is associated with recurrent instability. Elevation of acute-phase reactants in unstable angina could represent a hallmark of subclinical persistent instability or of susceptibility to recurrent instability and, at least in some patients, could be related to chronic Chlamydia pneumoniae infection.
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