Impact of residual platelet reactivity under clopidogrel treatment for lesions and the clinical outcome after drug-eluting stent implantation in patients with hemodialysis.

Background: Hemodialysis (HD) patients are at high risk for adverse clinical outcomes after drug-eluting stent (DES) implantation. However, the impact of residual platelet reactivity under dual anti-platelet therapy in this subset of patients remains unclear.

Methods: We enrolled 142 stable angina patients (194 lesions) treated with DES, who were taking aspirin and 75mg clopidogrel and had undergone 8-month angiography with optical coherence tomography (OCT). OCT findings and major adverse cardiac events (MACEs) at 1 year (cardiac death, acute coronary syndrome, target lesion and vessel revascularization, and stent thrombosis) were compared between 28 HD patients and 114 non-HD patients. Responsiveness to clopidogrel was assessed by measuring P2Y12 reaction unit (PRU) at 8 months.

Results: PRU was significantly higher in HD patients than in non-HD patients (p=0.006), even though proportion of cytochrome P450 2C19 genotype was equivalent. HD patients had a significantly higher rate of thrombi formation (assessed using OCT) and MACEs than non-HD patients (thrombi: p=0.001; MACEs: p=0.0001). The PRU value was independently associated with MACEs in both groups. The optimal cutoff values of PRU for predicting MACEs were 235 for HD patients and 259 for non-HD patients.

Conclusions: HD was associated with a high residual platelet reactivity, which may contribute to the higher incidence of MACEs after DES implantation in HD patients. HD may be a patient profile that merits a more potent anti-platelet regimen.