C-reactive protein and prognosis in women and men with coronary artery disease after percutaneous coronary intervention

Background: Sex-based differences in the association between C-reactive protein (CRP) and cardiovascular events in patients with coronary artery disease (CAD) are incompletely investigated. We investigated whether there are gender differences in the association between CRP and outcome in patients with CAD after percutaneous coronary intervention (PCI). Methods: This study included 13,170 consecutive patients with CAD: 10,098 men and 3072 women. CRP was measured on admission in all patients. The primary outcome was 1-year mortality. Results: CRP level (median [25th-75th percentiles]) was higher in women than in men (3.08 [1.30-8.37] mg/L vs 2.30 [0.92-6.47] mg/L; P < 0.001). CRP was > 3 mg/L in 4250 men (42.1%) and 1554 women (50.6%; P < 0.001). One-year mortality was 4.9% (n = 641 deaths). Deaths occurred in 318 men with CRP > 3mg/L and 122 men with CRP ≤ 3 mg/L (mortality estimates 7.7% and 2.1%, P < 0.001) and in 154 women with CRP > 3 mg/L and 47 women with CRP ≤ 3 mg/L (mortality estimates 10.1% and 3.2%, P < 0.001). After adjustment in the Cox model, CRP was associated with increased risk of mortality in women (adjusted hazard ratio [HR] = 1.03, 95% confidence interval [CI] 1.01-1.04, P < 0.001 for each 5. mg/L increase) and in men (adjusted HR = 1.02 [1.01-1.03], P < 0.001, for each 5. mg/L increase). CRP predicted mortality with an area under the receiver-operating characteristic curve = 0.721, [0.683-0.760] in women and 0.732, [0.707-0.757] in men (P = 0.659). Conclusions: Elevated CRP levels provide similar prognostic information in men and women with CAD after PCI which is independent and supplementary to that provided by conventional cardiovascular risk factors.