Renal denervation using carbon dioxide renal angiography in patients with uncontrolled hypertension and moderate to severe chronic kidney disease

Chronic kidney disease (CKD) is the most common cause of secondary hypertension. More than half of the patients have uncontrolled hypertension (≥140/90 mmHg on three or more antihypertensive agents at optimum doses). Renal sympathetic denervation (RSDN) has been shown to reduce blood pressure (BP) in patients with resistant hypertension. Although patients with CKD have high sympathetic drive, all major clinical trials have excluded patients with estimated glomerular filtration rates (eGFRs) <45 mL/min/1.73m2 for risk of contrast-induced nephropathy. In this pilot study, carbon dioxide (CO2) was used as the sole contrast agent to carry out renal angiography and RSDN in patients with moderate to severe CKD (eGFR 15–44 mL/min/1.73m2) and uncontrolled hypertension. Eleven patients (eight males) underwent RSDN. The median age was 57 years [interquartile range (IQR) 49–66]. The median number of antihypertensives being taken at baseline was 4 (IQR 3–4). No statistically significant difference was observed in serum creatinine in the serial follow-ups until at 6 months[median difference 0.25 mg/dL (IQR 0.09–0.53); P = 0.008]. There was a non-significant reduction in median clinic BP from baseline to 6 months [−14 mmHg (IQR −24–5)] and a significant increase in daytime ambulatory systolic BP [7 mmHg (IQR −2–12); P= 0.045]. A trend towards a serial reduction in albuminuria was observed. Procedure-related complications included a groin haematoma (n = 1) and reported flank (n = 1) and groin pain (n = 1). This pilot study shows that CO2 renal angiography can be used to perform RSDN in patients with significant renal impairment and may lead to associated improvements in clinic BP and albuminuria.