Pleiotropic effects of the acute and chronic inhibition of the renin-angiotensin system in hypertensives.

Renin-angiotensin system (RAS) inhibition may exert beneficiary pleiotropic effects on heart hemodynamics in hypertensive patients. We aimed to assess these effects on coronary flow reserve (CFR) and left ventricular (LV) filling pressure after acute and long-term treatment. Thirty-nine patients (48.4±6.8 years) with newly diagnosed, never-treated essential arterial hypertension were consecutively recruited from an outpatient hypertension clinic. CFR in the left anterior descending artery and the ratio of mitral inflow E wave to the averaged mitral annulus tissue velocity of the E waves (E/e' ratio), as an estimate of LV filling pressure, were assessed by Doppler echocardiography. In the acute phase of the study, consecutive eligible patients were assigned to receive po Quinapril (Q) 20 mg (n=15) or Losartan (L) 100 mg (n=14) or no treatment (n=10) and were reexamined 2 h post treatment. In the chronic phase of the study, the patients were reevaluated after 1 month on the assigned treatment. During the acute phase, CFR (P=0.005) was significantly improved in the RAS inhibition as compared with the control group, independently of blood pressure (BP) changes. The E/e' ratio was also marginally improved (P=0.053), but this effect was more pronounced in patients with E/e' ratio>8 (P=0.005). CFR and E/e' ratio were also improved after 1 month of treatment, particularly in responders after the acute phase. In hypertensive patients, RAS inhibition acutely improved CFR and E/e' ratio independently of BP changes. An acute positive response in these parameters was closely related to sustained improvement after 1 month of single-drug treatment. [ABSTRACT FROM AUTHOR]