Prognostic value of plasma high-sensitivity C-reactive protein levels in Japanese patients with stable coronary artery disease: The Japan NCVC-Collaborative Inflammation Cohort (JNIC) Study

High-sensitivity C-reactive protein (hsCRP) levels can predict cardiovascular events among apparently healthy individuals and patients with coronary artery disease (CAD). However, hsCRP levels vary among ethnic populations. We previously reported hsCRP levels in Japanese to be much lower than in Western populations. We investigated the prognostic value of hsCRP levels in Japanese patients with stable CAD. The hsCRP levels were measured in 373 Japanese patients who underwent elective coronary angiography and thereafter decided to receive only medical treatment. Patients were followed up for 2.9 ± 1.5 years for major cardiovascular events (death, myocardial infarction, unstable angina, stroke, aortic disease, peripheral arterial disease, or heart failure). The median hsCRP level was 0.70 mg/l. During the follow-up, cardiovascular events occurred in 53 (14%) of the 373 patients. Compared with 320 patients without events, 53 with events had higher hsCRP levels (median 1.06 vs. 0.67 mg/l, P < 0.05). To clarify the association between hsCRP levels and cardiovascular events, the 373 study patients were divided into tertiles according to hsCRP levels: lower (<0.4 mg/l), middle (0.4-1.2 mg/l), and higher (>1.2 mg/l). The Kaplan-Meier analysis demonstrated a significant difference in the event-free survival rate between higher vs. middle or lower tertiles (P < 0.05). In multivariate Cox regression analysis, the hsCRP level of >1.0 mg/l was an independent predictor for cardiovascular events (hazard ratio, 2.0; 95%CI, 1.1-3.4; P < 0.05). Thus, in Japanese patients with stable CAD who received only medical treatment, higher hsCRP levels, even >1.0 mg/l, were found to be associated with a significantly increased risk for further cardiovascular events.