Profile of sacubitril/valsartan in the treatment of heart failure: patient selection and perspectives

With an estimated prevalence of 5.8 million in the USA and over 23 million people worldwide, heart failure (HF) is growing in epidemic proportions. Despite the use of guideline-directed medical therapies such as angiotensin-converting enzyme inhibitors, beta-adrenergic blockers, angiotensin receptor blockers, and mineralocorticoid receptor antagonists for chronic systolic HF for almost two decades, HF remains a leading cause of morbidity, mortality, and health care expenditures. The Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor with Angiotensin-Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial provided compelling evidence for the cardiovascular and mortality benefit of sacubitril/valsartan when compared to enalapril in patients with heart failure and reduced ejection fraction (HFrEF). Sacubitril/valsartan performed better than enalapril across various HFrEF patient characteristics and showed substantial benefit in patients with other common comorbidities. Following the trial, the US Food and Drug Administration approved this drug for the treatment of HF. Various international HF consensus guidelines endorse sacubitril/valsartan as a class I recommendation for the management of symptomatic HFrEF. Although this high-quality clinical study is the largest and the most globally represented trial in HFrEF patients, concerns have been raised regarding the generalizability of the trial results in real-world HF population. The gaps in US Food and Drug Administration labeling and guideline recommendations might lead to this medication being used in a larger population than it was studied in. In this review, we will discuss the current role of sacubitril/valsartan in the management of HF, concerns related to PARADIGM-HF and answers, shortcomings of this novel drug, effects on patient characteristics, real-world eligibility, and the role of ongoing and further investigations to clarify the profile of sacubitril/valsartan in the management of HF.

New medications for heart failure

Heart failure is common and results in substantial morbidity and mortality. Current guideline-based therapies for heart failure with reduced ejection fraction, including beta blockers, angiotensin converting enzyme (ACE) inhibitors, and aldosterone antagonists aim to interrupt deleterious neurohormonal pathways and have shown significant success in reducing morbidity and mortality associated with heart failure. Continued efforts to further improve outcomes in patients with heart failure with reduced ejection fraction have led to the first new-in-class medications approved for heart failure since 2005, ivabradine and sacubitril/valsartan. Ivabradine targets the If channels in the sinoatrial node of the heart, decreasing heart rate. Sacubitril/valsartan combines a neprilysin inhibitor that increases levels of beneficial vasodilatory peptides with an angiotensin receptor antagonist. On a background of previously approved, guideline-directed medical therapies for heart failure, these medications have shown improved clinical outcomes ranging from decreased hospitalizations in a select group of patients to a reduction in all-cause mortality across all pre-specified subgroups. In this review, we will discuss the previously established guideline-directed medical therapies for heart failure with reduced ejection fraction, the translational research that led to the development of these new therapies, and the results from the major clinical trials of ivabradine and sacubitril/valsartan.

The neprilysin pathway in heart failure: a review and guide on the use of sacubitril/valsartan

Inhibition of neurohumoural pathways such as the renin angiotensin aldosterone and sympathetic nervous systems is central to the understanding and treatment of heart failure (HF). Conversely, until recently, potentially beneficial augmentation of neurohumoural systems such as the natriuretic peptides has had limited therapeutic success. Administration of synthetic natriuretic peptides has not improved outcomes in acute HF but modulation of the natriuretic system through inhibition of the enzyme that degrades natriuretic (and other vasoactive) peptides, neprilysin, has proven to be successful. After initial failures with neprilysin inhibition alone or dual neprilysin-angiotensin converting enzyme (ACE) inhibition, the Prospective comparison of angiotensin receptor neprilysin inhibitor (ARNI) with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure trial (PARADIGM-HF) trial demonstrated that morbidity and mortality can be improved with the angiotensin receptor blocker neprilysin inhibitor sacubitril/valsartan (formerly LCZ696). In comparison to the ACE inhibitor enalapril, sacubitril/valsartan reduced the occurrence of the primary end point (cardiovascular death or hospitalisation for HF) by 20% with a 16% reduction in all-cause mortality. These findings suggest that sacubitril/valsartan should replace an ACE inhibitor or angiotensin receptor blocker as the foundation of treatment of symptomatic patients (NYHA II–IV) with HF and a reduced ejection fraction. This review will explore the background to neprilysin inhibition in HF, the results of the PARADIGM-HF trial and offer guidance on how to use sacubitril/valsartan in clinical practice.

[Study PARADIGM-HF - a paradigm shift in the treatment of chronic heart failure]

Chronic heart failure is a crucial problem of current cardiology. Despite that, no major development has occurred in the therapy in recent years. In this regard, first results of studies with ARNI inhibitors (angiotensin-receptor neprilysin inhibitors) may be considered hopeful. Dual inhibition of AT1 receptors and neprilysin blocks renin-angiotensin-aldosteron (RAS) axis and concurrently supports natural vasodilatory and diuretic effect of natriuretic peptides. Large-scale prospective randomized multicenter trial PARADIGM-HF with more than 8000 individuals with stabilized chronic heart failure with systolic dysfunction (LV EF 40%, later 35%), mostly in functional class NYHA II-III with elevated BNP/NT-pro BNP has shown 20% decrease in primary endpoint (cardiovascular death or hospitalization for heart failure) in a group treated by ARNI (LCZ696; sacubiltril - valsartan). Beneficial effect of ARNI was consistent also for total and cardiovascular mortality, for hospitalization for heart failure and in other pre-specified subgroup analyses, including quality of life. The treatment was safe, typical adverse event was hypotension, however without a need to interrupt the treatment. Dual RAS and neprilysin inhibition might thus after long time become a change in stable chronic heart failure with systolic dysfunction treatment "paradigm". Czech Republic significantly contributed to this study and all study sites should be congratulated and thanked for their high-quality work provided.

Angiotensin-neprilysin inhibition versus enalapril in heart failure

BACKGROUND

We compared the angiotensin receptor-neprilysin inhibitor LCZ696 with enalapril in patients who had heart failure with a reduced ejection fraction. In previous studies, enalapril improved survival in such patients.

METHODS

In this double-blind trial, we randomly assigned 8442 patients with class II, III, or IV heart failure and an ejection fraction of 40% or less to receive either LCZ696 (at a dose of 200 mg twice daily) or enalapril (at a dose of 10 mg twice daily), in addition to recommended therapy. The primary outcome was a composite of death from cardiovascular causes or hospitalization for heart failure, but the trial was designed to detect a difference in the rates of death from cardiovascular causes.

RESULTS

The trial was stopped early, according to prespecified rules, after a median follow-up of 27 months, because the boundary for an overwhelming benefit with LCZ696 had been crossed. At the time of study closure, the primary outcome had occurred in 914 patients (21.8%) in the LCZ696 group and 1117 patients (26.5%) in the enalapril group (hazard ratio in the LCZ696 group, 0.80; 95% confidence interval [CI], 0.73 to 0.87; P<0.001). A total of 711 patients (17.0%) receiving LCZ696 and 835 patients (19.8%) receiving enalapril died (hazard ratio for death from any cause, 0.84; 95% CI, 0.76 to 0.93; P<0.001); of these patients, 558 (13.3%) and 693 (16.5%), respectively, died from cardiovascular causes (hazard ratio, 0.80; 95% CI, 0.71 to 0.89; P<0.001). As compared with enalapril, LCZ696 also reduced the risk of hospitalization for heart failure by 21% (P<0.001) and decreased the symptoms and physical limitations of heart failure (P=0.001). The LCZ696 group had higher proportions of patients with hypotension and nonserious angioedema but lower proportions with renal impairment, hyperkalemia, and cough than the enalapril group.

CONCLUSIONS

LCZ696 was superior to enalapril in reducing the risks of death and of hospitalization for heart failure. (Funded by Novartis; PARADIGM-HF ClinicalTrials.gov number, NCT01035255.).

Efficacy and safety of LCZ696, a first-in-class angiotensin receptor neprilysin inhibitor, in Asian patients with hypertension: a randomized, double-blind, placebo-controlled study

LCZ696 (Japanese adopted name: sucabitril valsartan sodium hydrate), a first-in-class angiotensin receptor neprilysin inhibitor, concomitantly inhibits neprilysin and blocks angiotensin type 1 receptor. This randomized, double-blind, placebo-controlled study, the first in Asia for this drug, evaluated the dose-related efficacy and safety of LCZ696 in patients with hypertension using 24-hour ambulatory blood pressure (BP) monitoring. Asian patients aged ≥18 years (n=389) with hypertension were randomized to receive LCZ696 100 mg (n=100), 200 mg (n=101), 400 mg (n=96), or placebo (n=92) for 8 weeks. The primary end point was mean difference across the 3 single-dose pairwise comparisons of LCZ696 versus placebo in clinic diastolic BP after 8-week treatment. Key secondary efficacy variables included changes in clinic systolic BP and pulse pressure and changes in 24-hour, daytime, and nighttime ambulatory BPs and pulse pressure. Safety assessments included recording all adverse events and serious adverse events. A total of 362 patients completed the study. Reductions in clinic systolic BP, diastolic BP (P<0.0001), and pulse pressure (P<0.001) were significantly greater with all doses of LCZ696 than with placebo. There were also significant reductions in 24-hour, daytime, and nighttime ambulatory systolic BP, diastolic BP, and pulse pressure for all doses of LCZ696 compared with placebo (P<0.0001). LCZ696 was well tolerated, and no cases of angioedema were reported. In conclusion, LCZ696 is effective for the treatment of hypertension in Asian population and, in general, is safe and well tolerated. Clinical Trial Information- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01193101.

Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada

Pesticides associated to genetically modified foods (PAGMF), are engineered to tolerate herbicides such as glyphosate (GLYP) and gluphosinate (GLUF) or insecticides such as the bacterial toxin bacillus thuringiensis (Bt). The aim of this study was to evaluate the correlation between maternal and fetal exposure, and to determine exposure levels of GLYP and its metabolite aminomethyl phosphoric acid (AMPA), GLUF and its metabolite 3-methylphosphinicopropionic acid (3-MPPA) and Cry1Ab protein (a Bt toxin) in Eastern Townships of Quebec, Canada. Blood of thirty pregnant women (PW) and thirty-nine nonpregnant women (NPW) were studied. Serum GLYP and GLUF were detected in NPW and not detected in PW. Serum 3-MPPA and CryAb1 toxin were detected in PW, their fetuses and NPW. This is the first study to reveal the presence of circulating PAGMF in women with and without pregnancy, paving the way for a new field in reproductive toxicology including nutrition and utero-placental toxicities.

A double-blind trial with baclofen (Lioresal) and diazepam in spasticity due to multiple sclerosis

In 17 in-patients suffering from spasticity due to multiple sclerosis, the effect and tolerability periods were 4 weeks each. As to efficacy, the variables: spasticity, clonus, flexor spasms, gait and bladder function were evaluated clinically. No significant difference was found between the two drugs. As far as side-effects are concerned, sedation was specifically inquired about. Apart from that, spontaneoulsy reported side-effects were recorded. Sedation was more often seen during treatment with diazepam, while the side-effects during baclofen treatment were more varied. The total number and severity of side-effects were equal in the two treatment groups. A preference for one of the two treatment periods was stated by the investigator before the code was broken. A significant difference (p less than 0.001) in favor of Lioresal was found. This is discussed in the light of the fact that no significant difference was found for the individual symptoms or side-effects.