Evaluation of the clinical effectiveness of ACEI or ARB in hypertension using plasma renin activity/plasma aldosterone concentration ratio

Abstract

Renin-angiotensin system (RAS) modulation is considered a cornerstone of hypertension therapy and ACE inhibitors and angiotensin receptor (AR) blockers are among the most widely used anti-hypertensive drugs. The expected effects on the RAS are an increase in plasma renin activity (PRA) together with a reduction of plasma aldosterone concentration (PAC), proportional to the efficacy of ACE or AR blockade. Aim: evaluation of real-life clinical-practice efficacy of stable therapies based on ACE or AR blockers, using PRA / PAC ratio values. We studied 184 essential hypertensives (59.2 11.9 years, 63% males) in stable treatment for at least three months with an ACEI or ARB as part of the treatment. PRA was expressed as ng/ml and PAC as ng/dl, then the ratio was multiplied by 100. Tertiles of PRA/PAC ratio were considered for the analysis. ABPM was performed to evaluate the BP control. Tertiles of PRA/PAC: 1st 0.2 to 5.7; 2nd 5.9 to 28.4; 3rd 29.4 to 509.8. There was no difference by age, sex, BMI and eGFR between PRA/PAC tertiles. A significant reduction in 24hour, daytime and nighttime BP values was associated with increasing PRA/PAC tertiles (all p<0.05). An increase of PRA/ PAC tertiles was associated with a higher prevalence of controlled patients during the nighttime period (1st: 14.5%; 2nd: 43.3%; 3rd: 45.9%; p<0.001 for trend). PRA/PAC ratio was also a predictor of nighttime BP control, as shown by ROC curve (AUC: 0.664, 95% CI: 0.582-0.745; p<0.001). An increasing PRA/PAC ratio reflects, in most cases, reduced values of PAC despite higher values of PRA as expression of a more effective RAS blockade by ACEIs or ARBs. These findings are associated with lower BP values and better BP control, especially in nighttime period, highlighting the effectiveness and compliance to the anti-hypertensive therapy with ACEI or ARB. Therefore, PRA/PAC ratio may be not only a useful biomarker of effective treatment based on ACEI or ARB, but also it can be used as an indirect index of drug intake and therapy compliance.