Abstract

GURFINKEL, Enrique P. et al. Value of BNP and C Reactive Protein Testing in the Differential Diagnosis between Primary Angina and Hypertension-Related Angina. Rev. argent. cardiol. [online]. 2006, vol.74, n.5, pp.268-275. ISSN 1850-3748.

Background Insufficient attention is devoted to patients who experience episodes of unstable angina, precipitated by secondary conditions, but not always easily distinguished from primary angina. In this study, we explore whether certain biomarkers can help to distinguish patients with type III A angina from patients with type III B angina, as defined by Braunwald's classification. Material and Methods A total of 64 patients were included in the study. Of them, 33 patients had a diagnosis of unstable angina secondary to hypertension, and 21 had primary angina, whereas 10 patients who had stable angina and had been referred for a scheduled coronary angiography served as controls. Serum levels of type B-atrial natriuretic peptide (BNP) and highsensitivity C Reactive Protein (hs-CRP) were measured in all patients at admission. Subsequently, angiography was performed in order to assess the atherosclerotic burden with angiographic scores. Results At angiography, patients with primary angina had higher atherosclerotic burden scores (P<0.025), more vessels involved (P=0.029) and higher percentage of stenosis (P<001) than patients with secondary angina. The BNP and hs-CRP values in control patients were 133 pg/mL (41, 224) [median (25th and 75th percentiles)[ and 1.6 mg/L (0.4, 3.6), respectively. In patients with primary angina, such values did not differ from those of controls: 129 (95, 231) and 4.0 (2.0, 5.6) for BNP and hs-CRP respectively. In patients with hypertension- related angina, values were 73 (19, 325) and 4.5 (2.2, 9.0), respectively. Differences in BNP and hs-CRP levels between patients with primary and secondary angina were not significant (p=0.458 for BNP and p=0.552 for hs-CRP). Conclusions Irrespective of the high atherosclerotic burden in patients with primary angina, serum BNP and hs-CRP levels could not accurately distinguish clinical instability caused by a plaque accident from that triggered by a secondary cause. Whether these biomarkers should be used to recognize a precise diagnosis or guide to therapy is still a matter of discussion.

Keywords : Atherosclerosis; Hypertension; Angina, unstable.