Plasma Renin test-guided drug treatment algorithm for correcting patients with treated but uncontrolled hypertension: a randomized controlled trial

Abstract

Background: Undefined pathophysiologic mechanisms likely contribute to unsuccessful antihypertensive drug therapy. The renin test-guided therapeutic (RTGT) algorithm is based on the concept that, irrespective of current drug treatments, subnormal plasma renin activity (PRA) (<0.65 ng/ml/h) indicates sodium-volume excess "V" hypertension, whereas values >or=0.65 indicate renin-angiotensin vasoconstriction excess "R" hypertension.

Methods: The RTGT algorithm was applied to treated, uncontrolled hypertensives and compared to clinical hypertension specialists' care (CHSC) without access to PRA. RTGT protocol: "V" patients received natriuretic anti-"V" drugs (diuretics, spironolactone, calcium antagonists, or alpha(1)-blockers) while withdrawing antirenin "R" drugs (converting enzyme inhibitors, angiotensin receptor antagonists, or beta-blockers). Converse strategies were applied to "R" patients. Eighty-four ambulatory hypertensives were randomized and 77 qualified for the intention-to-treat analysis including 38 in RTGT (63.9 +/- 1.8 years; baseline blood pressure (BP) 157.0 +/- 2.6/87.1 +/- 2.0 mm Hg; PRA 5.8 +/- 1.6; 3.1 +/- 0.3 antihypertensive drugs) and 39 in CHSC (58.0 +/- 2.0 years; BP 153.6 +/- 2.3/91.9 +/- 2.0; PRA 4.6 +/- 1.1; 2.7 +/- 0.2 drugs).

Results: BP was controlled in 28/38 (74% (RTGT)) vs. 23/39 (59% (CHSC)), P = 0.17, falling to 127.9 +/- 2.3/73.1 +/- 1.8 vs. 134.0 +/- 2.8/79.8 +/- 1.9 mm Hg, respectively. Systolic BP (SBP) fell more with RTGT (-29.1 +/- 3.2 vs. -19.2 +/- 3.2 mm Hg, P = 0.03), whereas diastolic BP (DBP) declined similarly (P = 0.32). Although final antihypertensive drug numbers were similar (3.1 +/- 0.2 (RTGT) vs. 3.0 +/- 0.3 (CHSC), P = 0.73) in "V" patients, 60% (RTGT) vs. 11% (CHSC) of "R" drugs were withdrawn and BP medications were reduced (-0.5 +/- 0.3 vs. +0.7 +/- 0.3, P = 0.01).

Conclusions: In treated but uncontrolled hypertension, RTGT improves control and lowers BP equally well or better than CHSC, indicating that RTGT provides a reasonable strategy for correcting treated but uncontrolled hypertension.