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Abstract: SA-PO323

Windkessel Modeling-Based Estimation of Intraglomerular Pressure Using Invasively Measured Renal Arterial Pressure and Flow Velocity in Humans

Session Information

Category: Hypertension and CVD

  • 1403 Hypertension and CVD: Mechanisms

Authors

  • Collard, Didier, University Medical Centers Amsterdam, Amsterdam, Netherlands
  • van Brussel, Peter Mathijs, University Medical Centers Amsterdam, Amsterdam, Netherlands
  • Van de velde, Lennart, University Medical Centers Amsterdam, Amsterdam, Netherlands
  • Vogt, Liffert, University Medical Centers Amsterdam, Amsterdam, Netherlands
  • Van den born, Bert-jan, University Medical Centers Amsterdam, Amsterdam, Netherlands
Background

Glomerular hyperfiltration due to a combination of failed autoregulation and progressive glomerulosclerosis is important in the pathogenesis of chronic kidney disease (CKD). Although prevention is widely recommend in current guidelines, up to now it is only possible to measure intraglomerular pressure (Pglom) directly in animal models. We hypothesized that renal arterial compliance and Pglom can be estimated from proximal renal arterial measurements.

Methods

Pressure and flow velocity were recorded in patients with a clinical indication for either coronary or renal angiography. The data was acquired under baseline conditions and after hyperemia induced by dopamine 30 μg/kg intrarenal. This was further analyzed using an adapted 3-element Windkessel model, consisting of compliance, impedance, afferent resistance and Pglom.

Results

We included 33 subjects with a median age of 58 years (IQR 52-65), eGFR of 85.9 ml/min/1.73m2, 31% had microalbuminuria. In 4 patients, a renal artery stenosis was found. The model showed a mean Pglom of 47.7 mmHg at baseline. After induction of hyperemia, flow increased by 90 (95%CI 66-133)%. This resulted in a 172 (95%CI 81-309)% increase in compliance and a decrease of Pglom of 12.6 (95%CI 9.5-15.7) mmHg. Patients with diabetes had a significantly higher Pglom of 10.8 (95%CI 5.3-15.5) mmHg, after correction for a significant positive association with BMI (0.81, 95%CI 0.37-1.59) and renal perfusion pressure (0.40, 95%CI 0.22-0.59).

Conclusion

The model enables determination of parameters for the renal macro- and microcirculation using proximal pressure and flow measurements, which could be useful to identify patients at risk for CKD.