ACE and Hypertension: Also, in the prospective intervention trial captopril prevention project (CAPPP) [27] and Swedish Trial in Old Patients with Hypertension-2 study (STOP-Hypertension 2) [28] the potential benefits of ACE inhibitor (captopril) in addition to a conventional antihypertensive regimen of diuretics or β-blockers was evaluated in essential hypertension patients.