Objective performance goals of safety and blood pressure efficacy for clinical trials of renal artery bare metal stents in hypertensive patients with atherosclerotic renal artery stenosis.

Rocha-Singh, Krishna J; Novack, Victor; Pencina, Michael; D'Agostino, Ralph; Ansel, Gary; Rosenfield, Kenneth; Jaff, Michael R

OBJECTIVE To provide safety and performance goals for prospective single-arm trials of bare metal renal artery stenting in patients with resistant hypertension associated with high grade atherosclerotic renal artery stenosis. BACKGROUND To date, there have been no US Pre-Market Approval (PMA) bare metal renal stent device trials which have focused on improvement of blood pressure control as a primary effectiveness endpoint. METHODS Analysis of subject-level data from three large industry sponsored pre-market approval (PMA) trials was performed. Hypertensive patients (≥ 155 mmHg) with a ≥ 50% atherosclerotic renal artery stenosis were included. Thirty day and 9-month systolic and diastolic blood pressure measurements, renal function and 9-month duplex ultrasound assessment of renal artery patency were analyzed. RESULTS Initial data analysis of 600 patients from the 3 PMA trials identified 286 patients who met inclusion criteria. The mean baseline systolic blood pressure was 177.8 ± 19.3 mmHg with a mean 68.1% diameter renal artery stenosis. Nine months after successful stenting, the mean SBP was 156.7 ± 24.1 mmHg; the 9 month restenosis rate was 14.4%. CONCLUSION Based on the statistical modeling of these data and a priori established performance criteria, the co-primary endpoints of 9 month reduction in blood pressure and in-stent restenosis are proposed. The reduction in blood pressure will be analyzed as a continuous variable and will be compared to this performance goal.