Predictive value of high sensitivity C-reactive protein in three-vessel disease patients with and without type 2 diabetes

Background: Diabetes mellitus (DM) and atherosclerosis are multifactorial conditions and share a common inflammatory basis. Three-vessel disease (TVD) represents a major challenge for coronary intervention. Nonetheless, the predictive value of high-sensitivity C-reactive protein (hs-CRP) for TVD patients with or without type 2 DM remains unknown. Herein, we aimed to ascertain the long-term predictive value of hs-CRP in TVD patients according to type 2 DM status from a large cohort.

Methods: A total of 2734 TVD patients with (n = 1040, 38%) and without (n = 1694, 62%) type 2 diabetes were stratified based on the hs-CRP (< 2 mg/L vs. ≥ 2 mg/L). Three multivariable analysis models were performed to evaluate the effect of potential confounders on the relationship between hs-CRP level and clinical outcomes. The Concordance index, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to assess the added effect of hs-CRP and the baseline model with established risk factors on the discrimination of clinical outcomes. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE).

Results: The median follow-up duration was 2.4 years. Multivariate Cox regression analyses showed that the incidence of MACCE (adjusted hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.01-1.35, p = 0.031) and all-cause death (HR 1.82, 95% CI 1.07-3.11, p = 0.026) were significantly higher in the diabetic group compared to the non-diabetic group. In the diabetic group, the incidence of MACCE (adjusted HR 1.51, 95% CI 1.09-2.10, p = 0.013) was significantly higher in the high hs-CRP group than in the low hs-CRP group; no significant difference was found for all-cause death (HR 1.63; 95% CI 0.58-4.58, p = 0.349). In the non-diabetic group, the prevalence of MACCE (adjusted HR 0.93, 95% CI 0.71-1.22, p = 0.613) was comparable between the two groups. Finally, the NRI (0.2074, p = 0.001) and IDI (0.0086, p = 0.003) for MACCE were also significantly increased after hs-CRP was added to the baseline model in the diabetic group.

Conclusions: Elevated hs-CRP is an independent prognostic factor for long-term outcomes of MACCE in TVD patients with type 2 diabetes but not in those without type 2 diabetes. Compared to traditional risk factors, hs-CRP improved the risk prediction of adverse cardiovascular events in TVD patients with type 2 diabetes.