Sequential Nephron Blockade Best Strategy in Resistant Hypertension
Sequential nephron blockade (SNB) promotes greater reductions in blood pressure and left ventricular mass (LVM) than sequential combined renin-angiotensin system blockade (SRASB) for patients with resistant hypertension, new research suggests.
This echocardiographic substudy of the PHARES trial was presented by Michel Azizi, MD, of Paris-Descartes University, Paris, France, here on April 29 at the Annual Congress of the European Society of Hypertension (ESH).
?Resistant hypertension is associated with high cardiovascular risk, and also with high risk of having target agent damage, one of which is left ventricular hypertrophy,? he explained.
The researchers investigated 2 step-care strategies: SNB – aldosterone blockade combined with diuretics targeted to different renal tubule sites; and SRASB – angiotensin-converting-enzyme inhibitor combined with a beta blocker.
Patients on standard treatment (hydrochlorothiazide 12.5 mg, irbesartan 300 mg, amlodipine 5 mg) were randomised to 1 of 2 target-driven, add-on strategies (2x 4-week + 2× 2-week): ? SNB (n = 85): add spironolactone 25 mg; add on furosemide 20 mg; up-titrate furosemide 40 mg; add on amiloride 5 mg; or ? SRASB (n = 82): add ramipril 5 mg; up-titrate ramipril 10 mg; add on bisoprolol 5 mg; up-titrate bisoprolol 10 mg.
Transthoracic echocardiography was also performed, with measurements performed according to the American Society of Echocardiography criteria.
After 12 weeks, mean daytime ambulatory systolic/diastolic blood pressures showed a greater reduction with SNB than SRASB (12 mm Hg, P
<.0001; 5 mm Hg, P =.0027).
For the LVM index, SRASB showed no change from baseline, whereas by contrast, SNB showed a significant decrease of 8.5 g/m2 (P=.0326).
There was also a significant positive correlation between changes in LVM index and daytime ambulatory systolic blood pressures (R =.27; P =.0110).
No changes or differences between SNB and SRASB were observed for end-diastolic interventricular septum thickness, end-diastolic left ventricular internal diameter, or left ventricular ejection fraction. However, SNB showed a small but significant reduction over SRASB (which remained unchanged) for end-diastolic posterior wall thickness (0.7 mm; P =.0450).
Likewise, left atrial area and mitral valve lateral E/E? ratio were unchanged with SRASB, but were significantly reduced with SNB: 2.2 cm2 (P =.0028) and 8.5 (P =.0326), respectively.
?In patients with resistant hypertension, this treatment strategy based on aldosterone blockade is more efficient to decrease both blood pressure and left ventricular mass than a strategy based on combined renin-angiotensin system blockade,? Dr Azizi said.
[Presentation title: Effects of a Treatment Strategy Based on Aldosterone Blockade vs a Strategy Based on Combined RAS Blockade on LVM in Patients With Resistant Hypertension. Abstract 9C.05]
By Chris Berrie