Angiotensin Receptor Antagonists

Heart failure is a clinically complex syndrome that results due to the failure of the ventricles to function as pump and oxygenate end organs. The repercussions of inadequate perfusion are seen in the form of sympathetic overactivation and third spacing, leading to clinical signs of increased blood pressure, dyspnea, fatigue, palpitations, etc. This article provided a brief overview of the clinical syndrome of heart failure; its epidemiology, risk factors, symptoms, and staging; and the mechanisms involved in disease progression. This article also described several landmark trials in heart failure that tested the efficacy of first-line drugs such as beta-blockers, angiotensin receptor blockers, angiotensin-converting enzyme inhibitors, and the latest drugs in the field of heart failure: angiotensin receptor neprilysin inhibitors. Most studies described in this article were guideline-setting trials that revolutionized the practice of medicine and cardiology.

Background: Three drug classes (mineralocorticoid receptor antagonists [MRAs], angiotensin receptor-neprilysin inhibitors [ARNIs], and sodium/glucose cotransporter 2 [SGLT2] inhibitors) reduce mortality in patients with heart failure with reduced ejection fraction (HFrEF) beyond conventional therapy consisting of angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) and β blockers. Each class was previously studied with different background therapies and the expected treatment benefits with their combined use are not known. Here, we used data from three previously reported randomised controlled trials to estimate lifetime gains in event-free survival and overall survival with comprehensive therapy versus conventional therapy in patients with chronic HFrEF.

Methods: In this cross-trial analysis, we estimated treatment effects of comprehensive disease-modifying pharmacological therapy (ARNI, β blocker, MRA, and SGLT2 inhibitor) versus conventional therapy (ACE inhibitor or ARB and β blocker) in patients with chronic HFrEF by making indirect comparisons of three pivotal trials, EMPHASIS-HF (n=2737), PARADIGM-HF (n=8399), and DAPA-HF (n=4744). Our primary endpoint was a composite of cardiovascular death or first hospital admission for heart failure; we also assessed these endpoints individually and assessed all-cause mortality. Assuming these relative treatment effects are consistent over time, we then projected incremental long-term gains in event-free survival and overall survival with comprehensive disease-modifying therapy in the control group of the EMPHASIS-HF trial (ACE inhibitor or ARB and β blocker).

Findings: The hazard ratio (HR) for the imputed aggregate treatment effects of comprehensive disease-modifying therapy versus conventional therapy on the primary endpoint of cardiovascular death or hospital admission for heart failure was 0·38 (95% CI 0·30-0·47). HRs were also favourable for cardiovascular death alone (HR 0·50 [95% CI 0·37-0·67]), hospital admission for heart failure alone (0·32 [0·24-0·43]), and all-cause mortality (0·53 [0·40-0·70]). Treatment with comprehensive disease-modifying pharmacological therapy was estimated to afford 2·7 additional years (for an 80-year-old) to 8·3 additional years (for a 55-year-old) free from cardiovascular death or first hospital admission for heart failure and 1·4 additional years (for an 80-year-old) to 6·3 additional years (for a 55-year-old) of survival compared with conventional therapy.

Interpretation: Among patients with HFrEF, the anticipated aggregate treatment effects of early comprehensive disease-modifying pharmacological therapy are substantial and support the combination use of an ARNI, β blocker, MRA, and SGLT2 inhibitor as a new therapeutic standard.

Funding: None.

Summary

Background

Guideline-recommended doses of angiotensin-converting-enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs), and β blockers are similar for men and women with heart failure with reduced ejection fraction (HFrEF), even though there are known sex differences in pharmacokinetics of these drugs. We hypothesised that there might be sex differences in the optimal dose of ACE inhibitors or ARBs and β blockers in patients with HFrEF.

Methods

We did a post-hoc analysis of BIOSTAT-CHF, a prospective study in 11 European countries of patients with heart failure in whom initiation and up-titration of ACE inhibitors or ARBs and β blockers was encouraged by protocol. We included only patients with left ventricular ejection fraction less than 40%, and excluded those who died within the first 3 months. Primary outcome was a composite of time to all-cause mortality or hospitalisation for heart failure. Findings were validated in ASIAN-HF, an independent cohort of 3539 men and 961 women with HFrEF.

Findings

Among 1308 men and 402 women with HFrEF from BIOSTAT-CHF, women were older (74 [12] years vs 70 [12] years, p<0·0001) and had lower bodyweights (72 [16] kg vs 85 [18] kg, p<0·0001) and heights (162 [7] cm vs 174 [8] cm, p<0·0001) than did men, although body-mass index did not differ significantly. A similar number of men and women reached guideline-recommended target doses of ACE inhibitors or ARBs (99 [25%] vs 304 [23%], p=0·61) and β blockers (57 [14%] vs 168 [13%], p=0·54). In men, the lowest hazards of death or hospitalisation for heart failure occurred at 100% of the recommended dose of ACE inhibitors or ARBs and β blockers, but women showed approximately 30% lower risk at only 50% of the recommended doses, with no further decrease in risk at higher dose levels. These sex differences were still present after adjusting for clinical covariates, including age and body surface area. In the ASIAN-HF registry, similar patterns were observed for both ACE inhibitors or ARBs and β blockers, with women having approximately 30% lower risk at 50% of the recommended doses, with no further benefit at higher dose levels.

Interpretation

This study suggests that women with HFrEF might need lower doses of ACE inhibitors or ARBs and β blockers than men, and brings into question what the true optimal medical therapy is for women versus men.

Funding

European Commission.