Embolic Protection and Platelet Inhibition During Renal Artery Stenting

Abstract

Background-Preservation of renal function is an important objective of renal artery stent procedures. Although atheroembolization can cause renal dysfunction during renal stent procedures, whether adjunctive use of embolic protection devices or glycoprotein IIb/IIIa inhibitors improves renal function is unknown. Methods and Results-One hundred patients undergoing renal artery stenting at 7 centers were randomly assigned to an open-label embolic protection device, Angioguard, or double-blind use of a platelet glycoprotein IIb/IIIa inhibitor, abciximab, in a 2ϫ2 factorial design. The main effects of treatments and their interaction were assessed on percentage change in Modification in Diet in Renal Disease-derived glomerular filtration rate from baseline to 1 month using centrally analyzed creatinine. Filter devices were analyzed for the presence of platelet-rich thrombus. With stenting alone, stenting and embolic protection, and stenting with abciximab alone, glomerular filtration rate declined (PϽ0.05), but with combination therapy, it did not decline and was superior to the other allocations in the 2ϫ2 design (PϽ0.01). The main effects of treatment demonstrated no overall improvement in glomerular filtration rate; although abciximab was superior to placebo (0Ϯ27% versus Ϫ10Ϯ20%; PϽ0.05), embolic protection was not (Ϫ1Ϯ28% versus Ϫ10Ϯ20%; Pϭ0.08). An interaction was observed between abciximab and embolic protection (PϽ0.05), favoring combination treatment. Abciximab reduced the occurrence of platelet-rich emboli in the filters from 42% to 7% (PϽ0.01). Conclusions-Renal artery stenting alone, stenting with embolic protection, and stenting with abciximab were associated with a decline in glomerular filtration rate. An unanticipated interaction between Angioguard and abciximab was seen, with combination therapy better than no treatment or either treatment alone. (Circulation. 2008;117:2752-2760.)

Roll-in Experience from the Cardiovascular Outcomes with Renal Atherosclerotic Lesions (CORAL) Study

“…Like many other uncontrolled case series, the observation of blood pressure improvement after renal artery stenting in this series should not be interpreted as a successful outcome of the stent procedure, since it could be attributed to regression to the mean or other phenomena associated with clinical trial participation (e.g., Hawthorne effect), since randomized trials have not shown statistically significant differences in blood pressure outcomes between those treated with revascularization and those managed medically(1, 2, 8–10). In addition, we observed that the use of a distal embolic protection device (DPD) during renal artery stenting had no discernible effect on clinical outcomes (Tables 8a and 8b), which is similar to that reported in a randomized trial of DPD use(11). …”

Clinical Outcomes in Patients With Renal Artery Stenosis Treated With Stent Placement With Embolic Protection Compared With Those Treated With Stent Alone

“…17 Kidney function change after stent placement was defined as above in the GuardWire study. After stent placement, there was stabilization or improvement in kidney function in 96% of the patients with significant decrease in systolic blood pressure.…”

“…17 The primary end point was absolute change in MDRD derived eGFR and percentage change from baseline to 30 days after renal artery stenting plus abciximab, filter-based embolic protection, or both. The mean eGFRs in these patients ranged from 52 to 66 mL/min prior to the intervention, mostly stages 3A and 2.…”

Endovascular Versus Medical Therapy for Atherosclerotic Renovascular Disease

“…Interestingly, Kanjwal et al revealed that, in a prospective study of embolic protection, a surprisingly high rate of platelet-rich thrombi were recovered during renal artery stenting [44]. In a follow-up study, Cooper et al observed that a platelet glycoprotein IIb/IIIa inhibitor, abciximab, was associated with better renal function 1 month after the procedure [45]. Antiplatelet therapy is important in optimal medical therapy of ARVD and is used for all patients with ARVD.…”