Background: Recurrent myocardial ischaemia and restenosis are more common in diabetic patients treated with primary percutaneous coronary intervention (PCI) due to an acute coronary syndrome (ACS) compared to patients without diabetes. Diabetes is also associated with increased residual platelet activity during dual antiplatelet treatment. In recent reports, platelet reactivity has been linked to outcomes after ACS. Appropriate platelet inhibition might lead to improved outcomes in this patient population. To this end, newest methods to evaluate platelet function may prove helpful.
Aim: To evaluate 6-month outcomes in diabetic patients treated with primary PCI due to ST segment elevation myocardial infarction (STEMI) in relation to platelet reactivity evaluated at discharge.
Methods: The study included 120 diabetic patients treated with primary PCI due to STEMI. Patients received loading doses of acetylsalicylic acid (ASA, 300 mg) and clopidogrel (600 mg) on admission, and later were treated with maintenance doses of 75 mg of ASA and clopidogrel. Blood for platelet aggregation testing was collected at discharge. We used whole blood impedance aggregometry using the Multiplate aggregometer with arachidonic acid (AA), adenosine diphosphate (ADP), collagen, and thrombin receptor peptide agonist (TRAP) as agonists. Six-month follow-up was based on telephone contact and hospital discharge summaries if hospitalisation occurred. The primary combined endpoint included recurrent ACS and restenosis.
Results: The primary combined endpoint occurred in 28 (23%) patients. Among patients with the primary endpoint, we found significantly higher platelet reactivity as evaluated by aggregation testing using AA and TRAP at discharge following the initial infarction compared to patients without the primary endpoint (area under aggregation curve 1137.4 ± 198.5 vs 833.5 ± 253.4; p = 0.013 for TRAP-induced aggregation, and 333.0 ± 263.8 vs 186.9 ± 105.4; p = 0.019 for AA-induced aggregation). We found no relationship between ADP- and collagen-induced aggregation at discharge and the occurrence of the primary endpoint.
Conclusions: Increased platelet reactivity evaluated by TRAP-induced aggregation is related to a higher rate of restenosis and recurrent ACS during a 6-month follow-up of diabetic STEMI patients treated with PCI.
Kardiol Pol 2011; 69, 6: 531–537