C-reactive protein, clinical presentation, and ischemic activity in patients with chest pain and normal coronary angiograms

Objectives We sought to investigate the relationship among C-reactive protein (hs-CRP), clinical characteristics, exercise stress test responses, and ST-segment changes during daily life in patients with typical chest pain and normal coronary angiograms (CPNCA). Background Patients with CPNCA have coronary microvascular endothelial dysfunction and myocardial ischemia. Elevated hs-CRP levels have been related to atherogenesis and endothelial dysfunction. The relationship between hs-CRP and disease activity has not been previously investigated in CPNCA patients. Methods We studied 137 consecutive CPNCA patients (mean age, 57 ± 9; 33 men). All completed standardized angina questionnaires, underwent exercise stress testing, 24-h ambulatory electrocardiogram (ECG) monitoring (Holter), and hs-CRP measurements at study entry. Results C-reactive protein levels (mg/l) were higher in patients with frequent (2.9 ± 3.3) and prolonged (3.9 ± 4.1) chest pain episodes, and in those with ST-segment depression on exercise testing (2.6 ± 2.8) and Holter monitoring (3.4 ± 3.1) compared with patients with occasional (1.3 ± 1.2; P = 0.002) or shorter chest pain (1.5 ± 1.3; p < 0.001) episodes, negative exercise stress testing (1.1 ± 1.1; p < 0.001), and no ST-segment shifts on Holter monitoring (0.9 ± 0.7; p < 0.001). Moreover, we found a correlation between hs-CRP concentration and number of ischemic episodes during Holter monitoring (r = 0.65; p < 0.001) and with the magnitude of ST-segment depression on exercise testing (r = −0.43; p < 0.001). The hs-CRP was the only independent variable (multivariate logistic regression) capable of predicting positive findings on Holter monitoring (odds ratio [OR], 3.8; confidence interval [CI], 2.3 to 6.2) and exercise testing (OR, 1.7; CI, 1.2 to 2.2). Conclusions The hs-CRP correlates with symptoms and ECG markers of myocardial ischemia in CPNCA patients. Whether hs-CRP is related to the pathogenesis of angina in these patients deserves further investigation.