Aims/hypothesis Clot properties are altered in acute coronary syndromes (ACS). However, data on clot properties and the impact of concomitant disease and medication in patients with diabetes in ACS are incomplete. Therefore, the present study investigates clot parameters in stable and unstable coronary artery disease (SCAD and UCAD respectively).

Methods Hundred-eighty patients were included in a consecutive manner based on their diabetes and CAD status between March 2012 and December 2014. Clot properties were determined by a turbidimetric assay in 90 controls (noCAD N=39; SCAD N=29;, UCAD N=22) and 90 patients with diabetes (noCAD N=21; SCAD N=41; UCAD N=28).

Results Clot structure was not affected by CAD status. However, clot lysis time was significantly increased in UCAD compared to SCAD and absence of CAD in control patients (1414 ± 703, 915 ± 461 and 1069 ± 414 respectively; p = 0.003). In contrast, in patients with DM clot lysis time did not differ between UCAD, SCAD and absence of CAD (1260 ± 649, 1304 ± 658 and 1318 ± 675 respectively; p = 0.947). Interestingly, clot lysis time in diabetes patients without CAD was comparable to UCAD control patients (p = 0.654). In an adjusted multiple regression model clot lysis time was significantly predicted by PAI-1 (p = 0.023), CRP (p = 0.042) and presence of UCAD (NSTEMI p = 0.010, STEMI p = 0.002) in control patients. Strikingly, in diabetes patients solely PAI-1 (p = 0.004) predicted clot lysis time.

Conclusions Unstable coronary artery disease leads to an increase in clot lysis time in control patients. In contrast, clot lysis time in patients with diabetes is not affected by UCAD. Strikingly, clot lysis time in diabetes patients without CAD is comparable to control patients with UCAD indicating their increased prothrombotic risk already present in a stable situation.