Relation between high-sensitivity C-reactive protein and coronary plaque components in patients with acute coronary syndrome: virtual histology-intravascular ultrasound analysis

Background and objectives: We used virtual histology-intravascular ultrasound (VH-IVUS) to evaluate the relationship between high-sensitivity C-reactive protein (hs-CRP) levels and plaque components in 279 acute coronary syndrome (ACS) patients.

Subjects and methods: We divided patients into three groups according to their hs-CRP levels {lowest tertile <0.07 mg/dL (n=93), middle tertile ≥0.07, <0.4 mg/dL (n=93), and highest tertile ≥0.4 mg/dL (n=93)}. Thin-cap fibroatheroma (TCFA) was defined as focal, necrotic core (NC)-rich (≥10% of the cross-sectional area) plaques in contact with the lumen in a plaque burden ≥40%.

Results: The highest tertile group was mostly diabetics (20%, 27%, 40%, p=0.009), and had the greatest plaque plus media volume (163±139/mm(3) vs. 201±155/mm(3) vs. 232±176/mm(3), p=0.013). The highest tertile group had the greatest absolute and % NC volumes (13.6±15.1 mm(3) vs. 14.8±14.2 mm(3) vs. 23.7±24.3 mm(3), p<0.001, and 14.9±8.7% vs. 16.0±8.7% vs. 19.5±10.2%, p=0.024, respectively). The culprit lesion TCFA was observed most frequently in the highest tertile group (28% vs. 35% vs. 55%, p=0.006). By multivariable analysis, absolute NC volume was an independent predictor of hs-CRP elevation {odds ratio (OR); 1.03, 95% confidence interval (CI)=1.06-1.21, p=0.004}, and hs-CRP was an independent predictor of TCFA (OR; 1.86, 95% CI=1.11-2.90, p=0.010).

Conclusion: VH-IVUS analysis has demonstrated that ACS patients with elevated hs-CRP have more vulnerable plaque component (NC-rich plaques and higher frequency of culprit lesion TCFA), compared with ACS patients with normal hs-CRP.