There is also some evidence that direct renin inhibition may improve renal function in patients with heart failure by improving effective renal plasma flow (ERPF). In a normotensive population, direct renin inhibition has been shown to have stronger beneficial effects on renal hemodynamics in comparison with ACEi [94]. There was also an increase in ERPF observed in patients with diabetes type I treated with direct renin inhibitors [95]. Whether these results can be achieved in patients with heart failure and decreased renal function is currently under investigation in the ARIANA-CHF-RD trial (clinicaltrials.gov id NCT00881439). As mentioned above, the reactive rise of PRC in patients on direct renin inhibition raises some concern. Its effects, however, are unknown, since medication specifically lowering TPRC is missing.