Benazepril-amlodipine offers no antihypertensive benefit over benazepril-hydrochlorothiazide
MedWire News: Findings from a subanalysis of the ACCOMPLISH trial suggest that combination therapy using benazepril plus amlodipine (B+A) results in similar 24-hour blood pressure (BP) control as with combined benazepril and hydrochlorothiazide (B+H).
This, say the researchers, supports "the interpretation that the difference in cardiovascular (CV) outcomes favoring a renin angiotensin system (RAS) blocker [like benazepril] combined with amlodipine rather than hydrochlorothiazide shown in the ACCOMPLISH trial was not caused by differences in BP, but instead intrinsic properties (metabolic or hemodynamic) of the combination therapies."
The main ACCOMPLISH (Avoiding Cardiovascular Events through Combination Therapy in Patients Living with Systolic Hypertension) study involved the analysis of clinical BP readings obtained from 11,506 patients. It was terminated early after a mean follow-up of 3 years, due to the superior efficacy of B+A in reducing CV events compared with B+H.
To assess the clinical relevance of the initial study findings, Kenneth Jamerson (University of Michigan Health System, Ann Arbor, USA) and colleagues analyzed the 24-hour ambulatory BP measurements (ABPM) of a subset of 573 original study participants during the second year of the study.
"Twenty-four-hour ABPM contributes more measurements and information than clinic readings and thus is a better reflection of true overall BP," say Jamerson et al in explanation of the method of BP monitoring used in the subanalysis.
The findings, reported in the journal Hypertension, show no significant difference in mean 24-hour, daytime, and nighttime BP levels between treatment groups at the end of the second study year, with respective BP levels of 123.9, 125.9, and 118.1 mmHg among patients in the B+A group, compared with 122.3, 124.1, and 116.9 mmHg in the B+H group.
Rates of controlled BP (defined as ABMP <135/85 mmHg) at 2 years were also similar, at 81.3% and 84.9% in the B+A and B+H groups, respectively.
"The combination of amlodipine with blockade of the RAS could emerge as a leading strategy for both control of BP and reduction of CV events," say Jamerson and team.
They add: "The fact that over 80% of patients achieved ABPM control in both arms demonstrates that combination therapy is effective in getting patients to the goal.
"Ultimately, however, we find no evidence to support the recommendation to prefer a diuretic-based combination regime as initial therapy in the treatment of high-risk hypertension."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Lauretta Ihonor