Two classes of diagnostic tests are used to investigate the presence of RAS and indirectly RVHT.
As previously discussed, since hypersecretion of renin due to renal hypoperfusion is a primary event in the pathogenesis of RVHT, it is not surprising that patients with RVHT have been found to have elevated plasma renin activity (PRA).
The first and largest prospective study that examined clinical and radiographic features of patients with RVHT was the Cooperative Study of Renovascular Hypertension.
The frequency of RVHT in patients with high-grade (grade III or IV) retinopathy has been further investigated, Of 123 patients identified with high-grade retinopathy, 93 had renal angiography, and renovascular disease was detected in 31% of these patients.
38) Only half of this population had hypertension, and none had clinically suspected RVHT.