Plasma renin activity to plasma aldosterone concentration ratio correlates with night-time and pulse pressures in essential hypertensive patients treatedwith angiotensin-converting enzyme inhibitors/AT1 blockers

Objectives: Angiotensin-converting enzyme inhibitors (ACE-I) and AT1 blockers (ARB) are commonly used antihypertensive drugs, but several factors may affect their effectiveness. We evaluated the associations between ambulatory blood pressure (BP) monitoring (ABPM) parameters and plasma renin activity (PRA)-to-plasma aldosterone concentration (PAC) ratio (RAR) to test reninangiotensin-aldosterone system inhibition in essential hypertensive patients treated with ACE-I or ARB for at least 12 months. Methods: We evaluated 194 consecutive patients referred to our Hypertension Centre. ABPM, PRA and PAC tests were performed without any changes in drug therapy. RAR, PRA and PAC tertiles were considered for the analyses. Results: Mean age: 57.4 +/- 12.0 years; male prevalence: 63.9%. No differences between RAR tertiles regarding the use of ACE-I or ARB (P = 0.385), as well as the other antihypertensive drug classes, were found. A reduction of all ABPM values considered (24-h BP, daytime BP and night-time BP and 24-h pulse pressure (PP), daytime PP and night-time PP) and a better BP control were observed at increasing RAR tertiles, with an odds ratio = 0.12 to be not controlled during night-time period for patients in the third tertile compared with patients in the first tertile (P<0.001). This association remained significant even after adjusting for 24-h BP control. All the associations were also confirmed for PRA tertiles, but not for PAC tertiles. Conclusion: Higher RAR values indicate effective renin-angiotensin- aldosterone system inhibition and lower nighttime and pulse pressures in real-life clinical practice. It could be a useful biomarker in the management of essential hypertensive patients treated with ACE-I or ARB.