Impact of haemoglobinA1c on platelet reactivity and cardiovascular outcomes in patients undergoing drug-eluting stent implantation

This study investigates the impact of hemoglobin A1c on platelet reactivity and cardiovascular outcomes in patients undergoing drug-eluting stent implantation. HbA1c levels were categorized into 3 groups: < 6.5%, 6.5-8.5%, and > 8.5%. ROC (resistance to clopidogrel) and ROA (resistance to aspirin) were calculated. The primary endpoint was a composite of MACE, including all-cause mortality, nonfatal MI, and ischemia-driven revascularization. The secondary endpoints comprised individual MACE components. The incidence of ROC was 9.3% (151 of 1621), whereas that of ROA was 16.5% (268 of 1621). The ROC for each of the 3 groups significantly increased with increasing HbA1c levels [4.3% vs. 7.1% vs. 10.1%, p = 0.006]; however, the ROA did not [16.4% vs. 17.7% vs. 14.3%, P = 0.694]. HbA1c > 8.5 was significantly associated with ROC (3.356 [1.231, 9.234], p = 0.009). Compared with the HbA1c < 6.5 subgroup, the HbA1c˃8.5 subgroup was significantly associated with MACE (3.142 [2.346, 4.206], < 0.001), nonfatal MI (2.297 [1.275, 4.137], P = 0.006) and ischemia-driven revascularization (3.845 [2.082, 7.101], p < 0.001), but not all-cause mortality (2.371 [0.551, 10.190], 0.246) at the 36-month follow-up. HbA1c levels were positively correlated with ROC, but the adverse cardiovascular events were driven by elevated HbA1c, constituting an argument to intensify glycemic control in subjects with diabetes after intracoronary stent placement.