Early verification of myocardial ischemia with a novel biomarker of acute tissue damage: C-reactive protein fractional forms

Department of Hospital Laboratories, UMass Memorial Medical Center, One Biotech Park, 365 Plantation Street, Worcester, MA 01605, USA.
Clinica chimica acta; international journal of clinical chemistry (Impact Factor: 2.76). 06/2012; 413(19-20):1536-41. DOI: 10.1016/j.cca.2012.06.023
Source: PubMed

ABSTRACT We evaluated the utility of an independent biomarker of early ischemic cellular damage-circulating fractional forms of C-reactive protein (fracCRP), to verify the diagnostic relevance of low Troponin I (TnI) values within the context of a workup for Acute Coronary Syndrome (ACS).
On a semi-preparative scale, the molecular characteristics of fracCRP were established by electron microscopy and Western Blot, using isolates captured from patient serum on phosphorylcholine beads and purified by size exclusion high-pressure liquid chromatography (SE-HPLC). Captured on an analytical scale, the diagnostic utility of fracCRP was evaluated in first-draw plasma specimens (total CRP not exceeding 6 mg/l) recovered from 300 cardiac emergency patients with final discharge diagnoses of ACS ruled out (N=132) or ruled in (N=168).
At a cutoff value chosen for 97.7% test specificity, the test metric (fracCRP×TnI) identified in the first blood draw 39.9% of all emergency patients ultimately diagnosed with ACS, and 17.9% of ultimately diagnosed patients who arrived with TnI values within the normal reference range (0.01-0.04 ng/ml).
These findings suggest that the fracCRP test metric could serve as a rule-in test for ACS in a significant proportion of low to moderate risk emergency patients.