Abstract 2406: C-Reactive Protein in Essential Hypertension: Association with Left Ventricular Mass Index and Risk of Cardiovascular Disease
Objectives: An elevated plasma level of C-reactive protein (CRP) is frequently encountered in individuals with hypertension, and is associated with the increased risk of cardiovascular disease (CVD). However, whether the relationship between CRP and CVD events is circumstantial or causal remains to be answered. We examined the association between CRP and left ventricular mass index (LVMI), and investigated prospectively whether the combination of CRP and LVMI can predict the incidence of CVD in asymptomatic subjects with essential hypertension.
Methods and Results: A total of 570 subjects (mean age 62 years, 52% female) free of prior CVD were included in this study. In cross-sectional analysis at baseline, serum CRP level was categorized according to the American Heart Association/Centers for Disease Control and Prevention clinical guidelines; i.e., <1, 1 to 3, and >3 mg/L. In multivariate analysis, LVMI increased in a stepwise gradient with increasing categories of CRP level in both men (126.0±2.7, 132.6±3.4, 140.3±4.9 g/m2; F=3.73, p=0.0253) and women (119.2±3.4, 127.4±3.9, 131.3±5.7 g/m2; F=3.36, p=0.0361). During follow-up (mean 33 months), 32 subjects (12 female) developed CVD including myocardial infarction, angina pectoris, congestive heart failure, cerebral infarction, and peripheral arterial occlusive disease. Kaplan-Meier curves showed a significantly poorer survival rate in the group with elevated CRP level (≥1 mg/L) (log-rank χ2=10.61, p<0.01), whereas the independence of CRP as a predictor of CVD events was lost after multivariate Cox-regression analysis. After participants had been divided into four groups on the basis of CRP level (<1 or ≥1 mg/L) and the absence or presence of left ventricular hypertrophy (LVH), the risk factor-adjusted hazard ratios were as follows: non-LVH/CRP <1, 1.0; non-LVH/CRP ≥1, 1.02; LVH/CRP <1, 1.49; LVH/CRP ≥1 mg/L, 2.32 (χ2=9.45, p=0.02).
Conclusions: Our findings demonstrate that CRP categories are independently associated with LVMI, and suggest that the combination of high CRP combined with LVH is a powerful independent predictor of CVD. Thus, measurement of CRP may provide clinically important prognostic information in patients with LVH.