Impact of type 2 diabetes mellitus on diffuse inflammatory activation of de novo atheromatous lesions: implications for systemic inflammation

Abstract

Aims: Local coronary and systemic inflammation is pronounced in patients with diabetes mellitus (DM). Intracoronary thermography detects local inflammation and C-reactive protein (CRP) is a marker of systemic inflammation. We investigated whether or not, in patients with DM, thermal heterogeneity of culprit lesions (CLs) correlates with that of non-culprit lesions (NCLs) and with systemic inflammation.

Methods: We included DM patients who had two angiographically significant lesions and were undergoing percutaneous coronary intervention. We measured the temperature difference (DeltaT) between the lesion and proximal vessel wall.

Results: We included 104 (n=208 lesions) patients: 32 (n=64 lesions) had DM and 72 (n=144 lesions) were non-DM (control group). DeltaT was increased in DM in both CLs and NCLs (CLs: DM=0.12+/-0.06 degrees C; no DM=0.06+/-0.04 degrees C; P<0.01 versus NCLs: DM=0.13+/-0.08 degrees C versus no DM=0.06+/-0.05 degrees C; P<0.01). Patients with DM had similar DeltaT in CLs and NCLs (P=0.49). A linear correlation was detected between heat production in all lesions and CRP (R=0.45; P<0.01), which was attributed to the correlation of DeltaT in lesions of patients with DM and CRP (R=0.32; P<0.01). In lesions of patients with low CRP, a greater rate of discrepancy was found, as 100% of lesions in patients with DM versus 66.1% of lesions of patients without DM had a high DeltaT in one or both lesions (P<0.01).

Conclusion: In patients with DM, local inflammatory activation is diffuse and correlates with systemic inflammation. However, low systemic inflammatory activation does not always predict an increase in local thermal heterogeneity.