Heart failure (HF) is generally observed as clinical observation caused by different kinds of cardiac diseases . The prevalence of HF has steadily been increasing in recent years and this trend is expected to continue due to a growing aging population with more cardiovascular risk factors  . Heart failure with reduced ejection fraction responsible for 50% of the conditions  is complicated by means of considerable morbidity and mortality  . Previously, a lot of clinical trials were conducted with the pharmacological treatments including β blockers  calcium-channel blockers  angiotensin-converting enzyme inhibitors (ACEi)  and angiotensin receptor blockers (ARBs) . But it was not able to demonstrate absolute benefit as expected.
For patients with HF with reduced ejection fraction (HFrEF), no therapy has proven to be effective at reducing morbidity and mortality . Consequently, there is an urgent need for new safe therapies to prevent and treat HFrEF. Angiotensin receptor neprilysin inhibitor (ARNi) is the new drug class and unprecedented scientifically which forms one compound with molecular moieties of the neprilysin (neutral endopeptidase 24)  inhibitor prodrug AHU377 and the ARB valsartan . Enzymatic cleavage absorbs AHU377 to sacubitril at (LBQ657), the active inhibitor of neprilysin.
Except for biologically inactive NT-proBNP, biologically active natriuretic peptides as well as atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and C-type natriuretic peptide are degraded by Neprilysin . Assays for BNP and NT-proBNP which are both natriuretic peptide biomarkers, have been used increasingly to establish the presence and severity of HF. proBNP (108 amino acid) cleavage into NT-proBNP (76 amino acid) & BNP (32 amino acid). Notably, BNP but not NT-proBNP, is a substrate for Neprilysin; therefore, ARNi increases BNP level but not NT pro-BNP level. In two studies with ARNi, NT-proBNP level was reduced. With the reduction of NT-pro-BNP in one study had associated with an improved clinical outcome. New data suggest that natriuretic peptide biomarkers screening and early intervention may prevent heart failure   .
The Dual inhibition of ACE and neprilysin was connected with serious angioedema   . LCZ696 which consists of the neprilysin inhibitor Sacubitril (AHU 377) and the ARB was designed to minimize the risk of serious angioedema and fully additive reduction of blood pressure  . There are no head to head comparisons of an ARB versus ARNi for HF. The current study will evaluate whether the short-term effects of ARNi on morbidity and mortality were superior to those of Valsartan in patients with chronic heart failure with reduced ejection fraction.
2. Methods and Materials
2.1. Study Design and Patient’s Selection
We conducted a single-blind randomized controlled trial at the Department of Cardiology, Rangpur Medical College Hospital, Rangpur, Bangladesh. In this trail, the patients were unaware of the treatment but researchers are aware of it, where 100 patients were randomly assigned comparative treatment arms ARNi and Valsartan to know the efficacy of the study drug. A total of 242 patients were screened between May 10, 2018 and December 3, 2018. Out of which 142 patients were excluded due to not meeting inclusion and exclusion criteria, withdrawal of consent or adverse events (Figure 1). Exclusion Criteria:
Figure 1. Sampling technique.
• Any prior measurement of LVEF < 40%.
• Acute coronary syndrome (including MI), cardiac surgery, other major CV surgery within 3 months, or urgent percutaneous coronary intervention within 3 months or and elective PCI within 30 days prior to entry.
• Any clinical event within the 6 months prior to entry could have reduced the LVEF (e.g., MI, CABG), unless an echo measurement performed after the event confirms a LVEF ≥ 45%.
• Current acute decompensated HF requiring therapy.
• Patients who require treatment with 2 or more of the following: an angiotensin converting enzyme inhibitor (ACEI), an angiotensin receptor blocker (ARB) or a renin inhibitor.
In this single-blind trial, the patients were enrolled with chronic HF aged on or above 40 years, considering based on NYHA class II - IV and LVEF 40% or less. Moreover, NT-proBNP was required to have 400 pg/ml or larger among the patients. In view of inclusion and exclusion criteria, 100 patients with heart failure were randomly assigned 1:1 to the treatment arms either angiotensin receptor neprilysin inhibitor (ARNi) or valsartan through purposive sampling technique and followed for a median of 88 days. The study was approved by ERC (Ethical Research Committee) and IRB (Institutional Review Board) of Rangpur Medical College authority, Rangpur, Bangladesh. The study was approved in April, 2018. All of the subjects were required to receive written informed consent prior to be included in the study. Each patient was prospectively included in the intention-to-treat analysis and study ended on March 3, 2019.
Subsequent to randomization, the patients were underwent angiotensin receptor neprilysin inhibitor (ARNi) 50 mg and titrated to their final dose of 100 mg twice a day or valsartan 40 mg and titrated to the final dose of 80 mg twice a day to identify the effect of angiotensin receptor neprilysin inhibitor (ARNi) on cardiac status compared to valsartan in patients with chronic heart failure with reduced ejection fraction. Prior to be enrolled in the study, each of total of 100 patients was discontinued on their background treatments (ACE-I or ARB) 24 hour earlier.
Transthoracic echocardiography (LA diameter, LVIDD, LVIDS and left ventricular ejection fraction) test was performed at baseline, 30 days and 90 days or end of the study. All the echocardiographys were performed in the Department of Cardiology, Rangpur Medical College Hospital, Rangpur, Bangladesh. Measurement is made in accordance with the recommendation of the American society of Echocardiography. Echo was performed by using Philip iE-33 echo machine. NT-proBNP was measured at screening/baseline and 90 days or at early termination of visits by Getein 1100 immunofluorescence Quantitative Analyzer. Level of blood sugar, serum creatinine, eGFR (estimated glomerular filtration rate) and level of serum electrolytes were also examined at baseline, 30 days and 90 days or at early termination of visit or end of the study . To define the functional capacity, the New York Heart Association (NYHA) functional classiﬁcation (I, II, III, IV) was used.
Based on New York Heart Association (NYHA) Classification:
1) Class I—No symptoms and no limitation in ordinary physical activity, e.g. shortness of breath when walking, climbing stairs etc.
2) Class II—Mild symptoms (mild shortness of breath and/or angina) and slight limitation during ordinary activity.
3) Class III—Marked limitation in activity due to symptoms, even during less-than-ordinary activity, e.g. walking short distances (20 - 100 m). Comfortable only at rest.
4) Class IV—Severe limitations. Experiences symptoms even while at rest. Mostly bedbound patients.
5) No NYHA class listed or unable to determine.
The clinical composite assessment was done in accordance with the NYHA functional classiﬁcation, patient-reported outcomes (PROs) or major adverse clinical events (or both) . The patients were considered as improved based on improvement in NYHA functional classiﬁcation or patient-reported outcomes (PROs) and no major cardiovascular event was reported. In contrast, at the endpoint of follow up, the patients who did have a major cardiovascular event or deteriorating of their NYHA class or patient-reported outcomes (PROs) during this single-blind treatment were adjudicated to be inferior. The primary outcome was mode of cardiovascular death and rate of hospitalization for heart failure or overall mortality.
2.3. Statistical Analysis
A total 100 patients were randomly assigned through system generated block randomization into two comparison treatment arms, considering 80% power and at 5% level of significance, to perceive 25% in the ratio of the NT-proBNP at a median of 88 days over baseline between ARNi and valsartan group, we used a two-sided t-test on the logarithm of this ratio (Table 1).
Table 1. Demographic characteristics and clinical profile at baseline.
No significant difference was found to have between two groups. Plus-minus values indicate mean ± SD. IQR denotes interquartile range. The body-mass index is the weight in kilograms divided by the square of the height in meters.
We used statistical software STATA (version 13.0) for all of analysis according to intent-to-treat. For the primary endpoint of the single-blind trial, we performed Cox-proportional hazards models and Kaplan-Meier estimates for comparing time-to-event cardiovascular deaths and rehospitalization due to heart failure between the treatment arms. We then adjusted the effect of all prespecified subgroups with dichotomas variables through Cox-proportional hazards models as well. To compare the occurrence of adverse event for undergoing both treatments, we performed Fisher’s exact test.
3.1. Patient’s Demographic Information and Clinical Profiles
Finally, a total of 100 patients with chronic heart failure were recruited to equally distributed between two groups. The patients were predominantly male (67%). The majority of patients reclined in the age group of (61 - 70) years (32%). The most collective symptom was found to have shortness of breath (83%) followed by chest pain (61%). The trial found tobacco smoking/chewing (30%) as the major risk factor followed by hypertension and diabetes (25% each). The both treatment arms were well-adjusted with reference to patient’s baseline characteristics.
3.2. Study Outcome
The primary endpoints, occurrence of cardiovascular deaths occurred 4 (8%) in the ARNi treatment arm, while 11 (22%) in the valsartan treatment arm with significant hazard ratio in the ARNi group [Hazard Ratio = 0.37; 95% CI: 0.34, 0.64; p = 0.042] during a median of 88 days of follow up period (Table 2(a) and Figure 2). 2 (4%) of the patients from the ARNi treatment arm were hospitalized due to HF, while in the valsartan treatment arm, 10 (20%) patients were hospitalized due to HF followed by receiving treatment respectively with hazard ratio in the ARNi group [Hazard Ratio = 0.80; 95% CI: 0.57, 0.92; p < 0.037] (Table 2(a)). The secondary outcomes of the trial were to examine the differences of ejection fraction, NT-proBNP and e-GFR between two groups.
A significant effect was found to have in both ejection fraction and NT-proBNP at 95% confidence interval (p < 0.05). These effects resulted from somewhat increased in ejection fraction (30.4% ± 6.7% to 38.8% ± 8.1%) and intensely decreased in NT-proBNP (3066.5 ± 1882.1 pg/ml to 808.2 ± 592.5 pg/ml) in the ARNi group, as compared to valsartan group in LVEF (30.6% ± 6.0% to 35% ± 7.9%) and in NT-proBNP (3488.2 ± 2912.2 pg/ml to 1886.4 ± 1017.8 pg/ml) respectively (Table 2(b)).
But no evidence of differences was found to have between the ARNi and valsartan groups with respect to the other echocardiography measurements (LA Diameter, p-value 0.53; LVIDD. p-value 0.78; LVIDS and p-value 0.50) except ejection fraction at a median of 88 days of follow up (Table 3). Similarly, the ARNi and valsartan groups did not differ with regard to the blood sugar (p-value = 0.38), potassium (K) (p-value = 0.23) and chloride (Cl) (p-value = 0.68) but sodium (Na) (p-value = 0.028) of serum electrolytes demonstrated the significance difference between ARNi and valsartan groups.
Table 2. Primary and secondary outcomes.
EF denotes ejection fraction, e-GFR denotes estimated glomerular filtration rate and NT-proBNP denotes N-terminal prohormone of brain natriuretic peptide.
Table 3. Changes in echocardiographic measures and serum electrolytes at 90 days.
Figure 2. Kaplan-Meier mortality curves.
3.3. Adverse Event during Treatment
In the ARNi group, 2 patients (4%) were re-hospitalized followed by receiving treatment while ratio of re-hospitalized increased to a greater extent in the valsartan group, 10 patients (20%) (p-value = 0.014). No adverse effect was found in the ARNi group 0 (0%) with respect to renal impairment but in the valsartan group 4 patients (10.26%) did have the abnormal (≥2.5 mg/dl) level of serum creatinine (p-value = 0.026) (Table 5). The number of patients with elevated potassium or elevated blood sugar did not diﬀer between the groups.
The study revealed that participated patients with chronic heart failure by means of reduced ejection fraction, the angiotensin receptor neprilysin inhibitor (ARNi) was to a greater extent effective in dropping the risk of cardiovascular deaths and re-hospitalization resulting from heart failure than did valsartan followed by a median of 88 days. ARNi was also found as superior in powerfully reducing NT-proBNP and increasing ejection fraction compared to valsartan which was consistent with a few studies previously conducted  . The results of these extensive benefits of angiotensin receptor neprilysin inhibitor compared to valsartan were found to have a strong significant effect. In the ARNi group, improvement of NYHA class was significant compared to valsartan. To inhibit deteriorating of clinical condition in patients with heart failure, previously conducted few trials have reported advances in exercise tolerance or functional class or reductions in the risk of hospitalization for heart failure  . In accordance with these generated findings, this trial recommends that the patients of heart failure with reduced ejection fraction have a greater chance of having a beneficial effect who receive ARNi. In patients with this disorder, further testing of this composite could be justified. Current treatment of heart failure with reduced ejection fraction is continued through both symptom-based and empiric without acceptance of specific treatment for this indication . Even though ACE inhibitors and ARBs have the evidence improving the symptoms, increasing the functional capacity and reduction of hospitalization in patients with this condition  . Existing guidelines announced that to decrease morbidity or mortality, current treatment could not show the credibility .
Our study aimed to reveal the credible evidence in management of cardiovascular diseases with ARNi in adding with existing treatment. This study observed a benefit with regard to reduce cardiovascular mortality, was one of our primary endpoints which were met by the study (Table 4).
The patients who received ARNi did have consistently much lower levels of NT-proBNP (reflecting reduced cardiac wall stress) all over the trial in comparison with valsartan which is consistent with the evidence previously reported . NT-proBNP is an indicator of left ventricular tension and decreases in NT-proBNP were associated with better-quality outcomes in patients with heart failure, which was our secondary outcome and achieved expectedly.
Table 4. Sub group analysis with multiple adjustments for all variables shown in Cox proportional Hazards Models with time dependent coverable.
ARNi was found sound endurable as a whole and its adverse-eﬀect proﬁle was less frequent in comparison with valsartan in this study. Fewer patients of the study participants underwent the adverse events in the ARNi with respect to re-hospitalization and no adverse event was found in regard to renal impairment while in the valsartan group, significant increase in the level of serum creatinine (≥2.5 mg/dl) and re-hospitalization was more frequent (Table 5).
Table 5. Adverse events during treatment.
This outcome of ARNi on renal impairment is found consistent in the experimental studies  . Biomarkers and substitute endpoints were the major determinants for this result of the study, whether the experimental outcomes will interpret into better clinical consequences need to conduct further prospective testing in an appropriately sampled outcomes study.
Limitation of the Study: The study had a limitation on sample size. Based on geographic consideration and traditional perspective, study sample size was limited.
Chronic treatment with the angiotensin receptor neprilysin inhibitor (ARNi) significantly decreases the progressive NT-proBNP, slightly changes sodium (Na) and e-GFR levels . ARNi also increases ejection fraction including decreasing the risks and rates of a number of indicators of clinical worsening of enduring patients with heart failure compared to valsartan. As a result, ARNi has a greater impact on reducing morbidity and mortality in patients with chronic heart failure than valsartan. Besides the treatment effect of ARNi, it steady the progression of heart failure is likely to have significant effect for quality of life in this disorder.
General Pharmaceuticals Limited, Bangladesh.
 Ho, K.K.L., Pinsky, J.L., Kannel, W.B. and Levy, D. (1993) The Epidemiology of Heart Failure: The Framingham Study. Journal of the American College of Cardiology, 22, 6A-13A.
 Go, A.S., et al. (2013) Heart Disease and Stroke Statistics 2013 Update: A Report from the American Heart Association. Circulation, 127, e6-e245.
 Fonarow, G.C., et al. (2007) Characteristics, Treatments, and Outcomes of Patients with Preserved Systolic Function Hospitalized for Heart Failure: A Report from the OPTIMIZE-HF Registry. Journal of the American College of Cardiology, 50, 768-777.
 Bhatia, R.S., Tu, J.V., Lee, D.S., Austin, P.C., Fang, J., Haouzi, A., et al. (2006) Outcome of Heart Failure with Preserved Ejection Fraction in a Population-Based Study. The New England Journal of Medicine, 355, 260-269.
 Owan, T.E., Hodge, D.O., Herges, R.M., Jacobsen, S.J., Roger, V.L. and Redfield, M.M. (2006) Trends in Prevalence and Outcome of Heart Failure with Preserved Ejection Fraction. The New England Journal of Medicine, 355, 251-259.
 Aronow, W.S., Ahn, C. and Kronzon, I. (1997) Effect of Propranolol versus No Propranolol on Total Mortality plus Nonfatal Myocardial Infarction in Older Patients with Prior Myocardial Infarction, Congestive Heart Failure, and Left Ventricular Ejection Fraction ≤ 40% Treated with Diuretics plus Angiot. American Journal of Cardiology, 80, 207-209.
 Setaro, J.F., Zaret, B.L., Schulman, D.S., Black, H.R. and Soufer, R. (1990) Usefulness of Verapamil for Congestive Heart Failure Associated with Abnormal Left Ventricular Diastolic Filling and Normal Left Ventricular Systolic Performance. American Journal of Cardiology, 66, 981-986.
 Cleland, J.G.F., Tendera, M., Adamus, J., Freemantle, N., Polonski, L. and Taylor, J. (2006) The Perindopril in Elderly People with Chronic Heart Failure (PEP-CHF) Study. European Heart Journal, 27, 2338-2345.
 Yusuf, S., Pfeffer, M.A., Swedberg, K., Granger, C.B., Held, P., McMurray, J.J.V., et al. (2003) Effects of Candesartan in Patients with Chronic Heart Failure and Preserved Left-Ventricular Ejection Fraction: The CHARM-Preserved Trial. The Lancet, 362, 777-781.
 Members, A.F., McMurray, J.J.V., Adamopoulos, S., Anker, S.D., Auricchio, A., Bohm, M., et al. (2012) ESC Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure 2012: The Task Force for the Diagnosis and Treatment of Acute and Chronic Heart Failure 2012 of the European Society of Cardiology. Developed in Collaboration with the Heart. European Heart Journal, 33, 1787-1847.
 Gu, J., Noe, A., Chandra, P., Al-Fayoumi, S., Ligueros-Saylan, M., Sarangapani, R., et al. (2010) Pharmacokinetics and Pharmacodynamics of LCZ696, a Novel Dual-Acting Angiotensin Receptor-Neprilysin Inhibitor (ARNi). The Journal of Clinical Pharmacology, 50, 401-414.
 Martinez-Rumayor, A., Richards, A.M., Burnett, J.C. and Januzzi, J.L. (2008) Biology of the Natriuretic Peptides. American Journal of Cardiology, 101, 3-8.
 Potter, L.R., Abbey-Hosch, S. and Dickey, D.M. (2006) Natriuretic Peptides, Their Receptors, and Cyclic Guanosine Monophosphate-Dependent Signaling Functions. Endocrine Reviews, 27, 47-72.
 Gardner, D.G., Chen, S., Glenn, D.J. and Grigsby, C.L. (2007) Molecular Biology of the Natriuretic Peptide System: Implications for Physiology and Hypertension. Hypertension, 49, 419-426.
 Fryer, R.M., Segreti, J., Banfor, P.N., Widomski, D.L., Backes, B.J., Lin, C.W., et al. (2008) Effect of Bradykinin Metabolism Inhibitors on Evoked Hypotension in Rats: Rank Efficacy of Enzymes Associated with Bradykinin-Mediated Angioedema. British Journal of Pharmacology, 153, 947-955.
 Kostis, J.B., Packer, M., Black, H.R., Schmieder, R., Henry, D. and Levy, E. (2004) Omapatrilat and Enalapril in Patients with Hypertension: The Omapatrilat Cardiovascular Treatment vs. Enalapril (OCTAVE) Trial. American Journal of Hypertension, 17, 103-111.
 Ruilope, L.M., Dukat, A., Böhm, M., Lacourcière, Y., Gong, J. and Lefkowitz, M.P. (2010) Blood-Pressure Reduction with LCZ696, a Novel Dual-Acting Inhibitor of the Angiotensin II Receptor and Neprilysin: A Randomised, Double-Blind, Place-bo-Controlled, Active Comparator Study. The Lancet, 375, 1255-1266.
 Nishimura, R.A., Otto, C.M., Bonow, R.O., Carabello, B.A., Erwin, J.P., Fleisher, L.A., et al. (2017) AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients with Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Journal of the American College of Cardiology, 70, 252-289.
 Packer, M. (2001) Proposal for a New Clinical End Point to Evaluate the Efficacy of Drugs and Devices in the Treatment of Chronic Heart Failure. Journal of Cardiac Failure, 7, 176-182.
 Swedberg, K. and Kjekshus, J. (1988) Effects of Enalapril on Mortality in Severe Congestive Heart Failure: Results of the Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS). American Journal of Cardiology, 62, 60A-66A.
 Brown, E.J., Chew, P.H., MacLean, A., Gelperin, K., Ilgenfritz, J.P. and Blumenthal, M. (1995) Effects of Fosinopril on Exercise Tolerance and Clinical Deterioration in Patients with Chronic Congestive Heart Failure Not Taking Digitalis. American Journal of Cardiology, 75, 596-600.
 Rogers, J.K., et al. (2012) Eplerenone in Patients with Systolic Heart Failure and Mild Symptoms: Analysis of Repeat Hospitalizations. Circulation, 126, 2317-2323.
 McMurray, J.J., Adamopoulos, S., Anker, S.D., et al. (2012) ESC Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure 2012: The Task Force for the Diagnosis and Treatment of Acute and Chronic Heart Failure 2012 of the European Society of Cardiology. Developed in Collaboration with the Heart Failure Association (HFA) of the ESC. European Heart Journal, 33, 1787-1847.
 Alehagen, U., Svensson, E. and Dahlström, U. (2007) Natriuretic Peptide Biomarkers as Information Indicators in Elderly Patients with Possible Heart Failure Followed over Six Years: A Head-to-Head Comparison of Four Cardiac Natriuretic Peptides. Journal of Cardiac Failure, 13, 452-461.
 Rademaker, M.T., Charles, C.J., Espiner, E.A., Nicholls, M.G., Richards, A.M. and Kosoglou, T. (1998) Combined Neutral Endopeptidase and Angiotensin-Converting Enzyme Inhibition in Heart Failure: Role of Natriuretic Peptides and Angiotensin II. Journal of Cardiovascular Pharmacology, 31, 116-125.
 Packer, M., et al. (2002) Comparison of Omapatrilat and Enalapril in Patients with Chronic Heart Failure: The Omapatrilat versus Enalapril Randomized Trial of Utility in Reducing Events (OVERTURE). Circulation, 106, 920-926.
 Damman, K., Gori, M., Claggett, B., Jhund, P.S., Senni, M., Lefkowitz, M.P., et al. (2018) Renal Effects and Associated Outcomes during Angiotensin-Neprilysin Inhibition in Heart Failure. JACC: Heart Failure, 6, 489-498.