C-Reactive Protein Concentrations and Angiographic Characteristics of Coronary Lesions Demosthenes Katritsis, 1,3 Socrates Korovesis, 1 Eleftherios Giazitzoglou, 1 John Parissis, 1 Pericles Kalivas, 1 Michael M. Webb-Peploe, 3 John P.A. Ioannidis, 4,5 and Alexander Haliassos 2* Background: C-Reactive protein (CRP) is a strong pre- dictor of clinical outcome in coronary artery disease (CAD), and inflammation has been implicated in the process. We aimed to evaluate whether CRP concen- trations measured with a new, automated particle- enhanced immunoturbidimetric method for high- sensitivity CRP may be related to specific high-risk angiographic features of coronary lesions. Methods: In a cross-sectional study, we examined 103 consecutive patients undergoing cardiac catheterization for suspected CAD. We assessed the association of preprocedural CRP concentrations with clinical presen- tation (unstable angina) and angiographic features of coronary lesions. Results: Twenty patients had unstable angina. Indepen- dent predictors of unstable angina included increased CRP [odds ratio (OR), 2.93 per 10-fold increase in CRP; 95% confidence interval (CI), 1.28 – 6.69; P  0.01] and the presence of macroscopic thrombus (OR, 7.08; 95% CI, 1.33–37.8; P  0.02). Thirty-two culprit lesions had macroscopic thrombus or eccentric/irregular discrete morphology without total occlusion. Increased CRP was the strongest predictor of such features (OR, 2.04 per 10-fold increase in CRP; 95% CI, 1.03– 4.04; P  0.04), and the effect was independent of the presence of unstable angina. Conclusions: Among patients with suspected CAD un- dergoing coronary angiography, increased CRP is strongly associated with unstable angina and with spe- cific high-risk features of the culprit coronary lesions. © 2001 American Association for Clinical Chemistry There is increasing evidence that inflammation plays an important role in the pathophysiology of acute coronary syndromes. In particular, increased C-reactive protein (CRP), 6 an acute phase reactant, has been associated with unstable angina (1) and unfavorable short- and long-term clinical outcomes in patients with coronary artery disease (CAD) (2–5 ). Definition of unstable angina depends on the presence of one or more of the following three historical features: (a) crescendo angina (more severe, prolonged, or frequent) superimposed on a preexisting pattern or relatively stable, exertion-related angina pecto- ris; (b) angina pectoris of new onset (usually within 1 month), which is brought on by minimal exertion; or (c) angina pectoris at rest as well as with minimal exertion. The mechanisms underlying these associations are uncer- tain (6–9). Infectious pathogens, including Chlamydia pneumoniae and cytomegalovirus (CMV), have been im- plicated as mediators of coronary inflammation, but the data are controversial (7–9 ). In addition to the specific triggering agent or event, an important question is whether increased CRP reflects specific high-risk features of the culprit coronary lesions. To answer this question, we examined the relationship between preprocedural CRP and angiographic features in 103 consecutive pa- tients undergoing cardiac catheterization for suspected CAD with a new, particle-enhanced immunoturbidimet- ric method for high sensitivity CRP. 1 Department of Cardiology and 2 Central Laboratories, Athens Euroclinic, Athens 11521, Greece. 3 Department of Cardiology, St. Thomas’ Hospital, London SE1 7EH, United Kingdom. 4 Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina, School of Medicine, Ioannina 45110, Greece. 5 Department of Medicine, Tufts University, School of Medicine, Boston, MA 02111. *Address correspondence to this author at: Central Laboratories, Athens Euroclinic, 9 Athanassiadou St., Athens 11521, Greece. Fax 30-1-6416555; e-mail haliassos@moleculardiagnostics.gr. Received September 22, 2000; accepted March 1, 2001. 6 Nonstandard abbreviations: CRP, C-reactive protein; CAD, coronary artery disease; CMV, cytomegalovirus; ACC/AHA, American College of Cardiology/American Heart Association; TnI, troponin I; OR, odds ratio; and CI, confidence interval. Clinical Chemistry 47:5 882– 886 (2001) Enzymes and Protein Markers 882 Downloaded from https://academic.oup.com/clinchem/article/47/5/882/5639192 by guest on 16 February 2022