Plasma renin activity and potential of indapamide retard to improve control of hypertension

Purpose: to study plasma renin activity (PRA) as a predictor of antihypertensive response to addition of diuretic to combination of angiotensinconverting enzyme inhibitor (ACEI) and calcium antagonist (CA). Material and methods: The study included 72 patients (39% men, mean age 62.0+8.3 years) with uncontrolled despite use of ACEI and CA arterial hypertension (AH) without overt associated clinical conditions (AH criteria of national guidelines, 2010). After 4 weeks of therapy with ACE inhibitor (quadropril 6 mg/day) and CA (felodipine 5 mg/day) in all patients who did not reach target level of blood pressure (BP) (clinical BP ≥ 40/90 mm Hg, daytime BP according to ambulatory BP monitoring [ABPM] > 135/85 mm Hg) indapamide retard (1.5 mg/day) was added to combination therapy for 6 months. Examination included measurement of baseline and on treatment PRA and repetitive ABPM. Results: More pronounced antihypertensive response was observed in the group of patients with volume dependent AH. Baseline BP was 156.6±14.1/86.7±1.5 and 151.9±17.1/78.0±7.8 mm Hg, on treatment level of clinical BP -126.2 ± 10.6/72.5 ± 11.6 and 132.2±9.1/71.9±7.2 mm Hg (p<0.05) in patients with volume dependent and renin dependent AH, respectively. Target clinical BP was achieved in 95 and 80% of patients, respectively (χ2 = 10.3; p< 0.05). According to ABPM both daytime and nighttime on treatment BP was lower in the group of patients with volume dependent AH (130.0±11.0/74.1±9.9 vs. 136.5 ± 7.3/78.8 ± 8.2 mm Hg, p<0.05; and 127.9 ± 15.8/71 ± 13.5 vs. 132.6 ± 13.0/74.5 ± 10.2 mm Hg, p<0.05). Conclusion: PRA is an independent predictor of antihypertensive response to addition of a diuretic to combination therapy with ACEI and CA.