The association between renal atherosclerotic plaque characteristics and renal function before and after renal artery intervention

OBJECTIVE: To evaluate the effect of plaque composition on renal function after renal artery intervention (RAI). PATIENTS AND METHODS: In 33 consecutive patients with atherosclerotic renal artery stenosis (enrolled between January 1, 2007, and April 30, 2009), renal angiography, pressure gradients across the lesion, and intravascular ultrasonography (IVUS) with virtual histology (VH)-derived plaque characteristics were assessed. In 25 patients who underwent RAI, estimated glomerular filtration rate (eGFR) was evaluated at baseline and at 3 months. RESULTS: Mean pressure gradients across the lesion were poorly associated with baseline eGFR (r=-0.37; P=.07). In gray scale IVUS data, only remodeling index was significantly correlated with baseline eGFR (r=-0.38; P=.03). Plaque components classified by VH-IVUS had no correlation with baseline eGFR. During follow-up of 25 patients, the improvement in eGFR after RAI was observed in 9 patients, unchanged in 3, and deteriorated in 13. Overall, follow-up eGFR (median, 49.0 mL/min/1.73 m²; interquartile range [IQR], 40.6-63.9 mL/min/1.73 m²) was unchanged compared with baseline eGFR (median, 53.8 mL/min/1.73 m²; IQR, 41.4-63.4 mL/min/1.73 m ²; P=.38). The percent change in eGFR (median, -0.2%; IQR, -16.0% to 16.0%) after RAI had a significant negative correlation with the mean percentage of necrotic core classified by VH-IVUS (r=-0.47; P=.02), and the mean percentage of necrotic core was significantly larger in patients with deterioration of eGFR than in patients without deterioration of eGFR (median, 12.7%; IQR, 9.5%-19.5%; vs median, 8.3%; IQR, 5.5%-11.6%; P=.04). CONCLUSION: In patients with atherosclerotic renal artery stenosis, the change in eGFR after RAI was related to plaque composition classified by VH-IVUS. The evaluation of plaque composition may provide more insights into the change in renal function after RAI.