Alternative RAS in Various Hypoxic Conditions: From Myocardial Infarction to COVID-19.

Alternative branches of the classical renin-angiotensin-aldosterone system (RAS) represent an important cascade in which angiotensin 2 (AngII) undergoes cleavage via the action of the angiotensin-converting enzyme 2 (ACE2) with subsequent production of Ang(1-7) and other related metabolites eliciting its effects via Mas receptor activation. Generally, this branch of the RAS system is described as its non-canonical alternative arm with counterbalancing actions to the classical RAS, conveying vasodilation, anti-inflammatory, anti-remodeling and anti-proliferative effects. The implication of this branch was proposed for many different diseases, ranging from acute cardiovascular conditions, through chronic respiratory diseases to cancer, nonetheless, hypoxia is one of the most prominent common factors discussed in conjugation with the changes in the activity of alternative RAS branches. The aim of this review is to bring complex insights into the mechanisms behind the various forms of hypoxic insults on the activity of alternative RAS branches based on the different duration of stimuli and causes (acute vs. intermittent vs. chronic), localization and tissue (heart vs. vessels vs. lungs) and clinical relevance of studied phenomenon (experimental vs. clinical condition). Moreover, we provide novel insights into the future strategies utilizing the alternative RAS as a diagnostic tool as well as a promising pharmacological target in serious hypoxia-associated cardiovascular and cardiopulmonary diseases.

Angiotensin-Neprilysin Inhibition in Heart Failure with Preserved Ejection Fraction.

BACKGROUND: The angiotensin receptor-neprilysin inhibitor sacubitril-valsartan led to a reduced risk of hospitalization for heart failure or death from cardiovascular causes among patients with heart failure and reduced ejection fraction. The effect of angiotensin receptor-neprilysin inhibition in patients with heart failure with preserved ejection fraction is unclear. METHODS: We randomly assigned 4822 patients with New York Heart Association (NYHA) class II to IV heart failure, ejection fraction of 45% or higher, elevated level of natriuretic peptides, and structural heart disease to receive sacubitril-valsartan (target dose, 97 mg of sacubitril with 103 mg of valsartan twice daily) or valsartan (target dose, 160 mg twice daily). The primary outcome was a composite of total hospitalizations for heart failure and death from cardiovascular causes. Primary outcome components, secondary outcomes (including NYHA class change, worsening renal function, and change in Kansas City Cardiomyopathy Questionnaire [KCCQ] clinical summary score [scale, 0 to 100, with higher scores indicating fewer symptoms and physical limitations]), and safety were also assessed. RESULTS: There were 894 primary events in 526 patients in the sacubitril-valsartan group and 1009 primary events in 557 patients in the valsartan group (rate ratio, 0.87; 95% confidence interval [CI], 0.75 to 1.01; P = 0.06). The incidence of death from cardiovascular causes was 8.5% in the sacubitril-valsartan group and 8.9% in the valsartan group (hazard ratio, 0.95; 95% CI, 0.79 to 1.16); there were 690 and 797 total hospitalizations for heart failure, respectively (rate ratio, 0.85; 95% CI, 0.72 to 1.00). NYHA class improved in 15.0% of the patients in the sacubitril-valsartan group and in 12.6% of those in the valsartan group (odds ratio, 1.45; 95% CI, 1.13 to 1.86); renal function worsened in 1.4% and 2.7%, respectively (hazard ratio, 0.50; 95% CI, 0.33 to 0.77). The mean change in the KCCQ clinical summary score at 8 months was 1.0 point (95% CI, 0.0 to 2.1) higher in the sacubitril-valsartan group. Patients in the sacubitril-valsartan group had a higher incidence of hypotension and angioedema and a lower incidence of hyperkalemia. Among 12 prespecified subgroups, there was suggestion of heterogeneity with possible benefit with sacubitril-valsartan in patients with lower ejection fraction and in women. CONCLUSIONS: Sacubitril-valsartan did not result in a significantly lower rate of total hospitalizations for heart failure and death from cardiovascular causes among patients with heart failure and an ejection fraction of 45% or higher. (Funded by Novartis; PARAGON-HF ClinicalTrials.gov number, NCT01920711.).

Safety, Tolerability and efficacy of Rapid Optimization, helped by NT-proBNP and GDF-15, of Heart Failure therapies (STRONG-HF): rationale and design for a multicentre, randomized, parallel-group study.

AIMS: Patients admitted for acute heart failure (HF) are at high risk of readmission and death, especially in the 90 days following discharge. We aimed to assess the safety and efficacy of early optimization of oral HF therapy with beta-blockers (BB), angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) or angiotensin receptor-neprilysin inhibitors (ARNi), and mineralocorticoid receptor antagonists (MRA) on 90-day clinical outcomes in patients admitted for acute HF. METHODS: In a multicentre, randomized, open-label, parallel-group study, a total of 900 patients will be randomized in a 1:1 ratio to either 'usual care' or 'high-intensity care'. Patients enrolled in the usual care arm will be discharged and managed according to usual clinical practice at the site. In the high-intensity care arm, doses of oral HF medications - including a BB, ACEi or ARB, and MRA - will be up-titrated to 50% of recommended doses before discharge and to 100% of recommended doses within 2 weeks of discharge. Up-titration will be delayed if the patients develop worsening symptoms and signs of congestion, hyperkalaemia, hypotension, bradycardia, worsening of renal function or significant increase in N-terminal pro-B-type natriuretic peptide between visits. The primary endpoint is 90-day all-cause mortality or HF readmission. CONCLUSIONS: STRONG-HF is the first study to assess whether rapid up-titration of evidence-based guideline-recommended therapies with close follow-up in a large cohort of patients discharged from an acute HF admission is safe and can affect adverse outcomes during the first 90 days after discharge. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03412201.

Initiation of sacubitril/valsartan in haemodynamically stabilised heart failure patients in hospital or early after discharge: primary results of the randomised TRANSITION study.

AIMS: To assess tolerability and optimal time point for initiation of sacubitril/valsartan in patients stabilised after acute heart failure (AHF). METHODS AND RESULTS: TRANSITION was a randomised, multicentre, open-label study comparing two treatment initiation modalities of sacubitril/valsartan. Patients aged ≥ 18 years, hospitalised for AHF were stratified according to pre-admission use of renin-angiotensin-aldosterone system inhibitors and randomised (n = 1002) after stabilisation to initiate sacubitril/valsartan either ≥ 12-h pre-discharge or between Days 1-14 post-discharge. Starting dose (as per label) was 24/26 mg or 49/51 mg bid with up- or down-titration based on tolerability. The primary endpoint was the proportion of patients attaining 97/103 mg bid target dose after 10 weeks. Median time of first dose of sacubitril/valsartan from the day of discharge was Day -1 and Day +1 in the pre-discharge group and the post-discharge group, respectively. Comparable proportions of patients in the pre- and post-discharge initiation groups met the primary endpoint [45.4% vs. 50.7%; risk ratio (RR) 0.90; 95% confidence interval (CI) 0.79-1.02]. The proportion of patients who achieved and maintained for ≥ 2 weeks leading to Week 10, either 49/51 or 97/103 mg bid was 62.1% vs. 68.5% (RR 0.91; 95% CI 0.83-0.99); or any dose was 86.0% vs. 89.6% (RR 0.96; 95% CI 0.92-1.01). Discontinuation due to adverse events occurred in 7.3% vs. 4.9% of patients (RR 1.49; 95% CI 0.90-2.46). CONCLUSIONS: Initiation of sacubitril/valsartan in a wide range of heart failure with reduced ejection fraction patients stabilised after an AHF event, either in hospital or shortly after discharge, is feasible with about half of the patients achieving target dose within 10 weeks. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02661217.

Unrecognised cardiovascular disease in type 2 diabetes: is it time to act earlier?

Cardiovascular disease (CVD) is the most significant prognostic factor in individuals with type 2 diabetes (T2D). However, a significant number of individuals may develop CVD that does not present with the classic angina-related or heart failure symptoms. In these cases, CVD may seem to be 'silent' or 'asymptomatic', but may be more accurately characterised as unrecognised diabetic cardiac impairment. An initial step to raise awareness of unrecognised CVD in individuals with T2D would be to reach a consensus regarding the terminology used to describe this phenomenon. By standardising the terminologies, and agreeing on the implementation of an efficient screening program, it is anticipated that patients will receive an earlier diagnosis and appropriate and timely treatment. Given the availability of anti-diabetic medications that have been shown to concomitantly reduce CV risk and mortality, it is imperative to improve early identification and initiate treatment as soon as possible in order to enable as many patients with T2D as possible to benefit.

Explaining the decline in coronary heart disease mortality rates in the Slovak Republic between 1993-2008.

OBJECTIVE: Between the years 1993 and 2008, mortality rates from coronary heart disease (CHD) in the Slovak Republic have decreased by almost one quarter. However, this was a smaller decline than in neighbouring countries. The aim of this modelling study was therefore to quantify the contributions of risk factor changes and the use of evidence-based medical therapies to the CHD mortality decline between 1993 and 2008. METHODS: We identified, obtained and scrutinised the data required for the model. These data detailed trends in the major population cardiovascular risk factors (smoking, blood pressure, total cholesterol, diabetes prevalence, body mass index (BMI) and physical activity levels), and also the uptake of all standard CHD treatments. The main data sources were official statistics (National Health Information Centre and Statistical Office of the Slovak Republic) and national representative studies (AUDIT, SLOVAKS, SLOVASeZ, CINDI, EHES, EHIS). The previously validated IMPACT policy model was then used to combine and integrate these data with effect sizes from published meta-analyses quantifying the effectiveness of specific evidence-based treatments, and population-wide changes in cardiovascular risk factors. Results were expressed as deaths prevented or postponed (DPPs) attributable to risk factor changes or treatments. Uncertainties were explored using sensitivity analyses. RESULTS: Between 1993 and 2008 age-adjusted CHD mortality rates in the Slovak Republic (SR) decreased by 23% in men and 26% in women aged 25-74 years. This represented some 1820 fewer CHD deaths in 2008 than expected if mortality rates had not fallen. The IMPACT model explained 91% of this mortality decline. Approximately 50% of the decline was attributable to changes in acute phase and secondary prevention treatments, particularly acute and chronic treatments for heart failure (≈12%), acute coronary syndrome treatments (≈9%) and secondary prevention following AMI and revascularisation (≈8%). Changes in CHD risk factors explained approximately 41% of the total mortality decrease, mainly reflecting reductions in total serum cholesterol. However, other risk factors demonstrated adverse trends and thus generated approximately 740 additional deaths. CONCLUSION: Our analysis suggests that approximately half the CHD mortality fall recently observed in the SR may be attributable to the increased use of evidence-based treatments. However, the adverse trends observed in all the major cardiovascular risk factors (apart from total cholesterol) are deeply worrying. They highlight the need for more energetic population-wide prevention policies such as tobacco control, reducing salt and industrial trans fats content in processed food, clearer food labelling and regulated marketing of processed foods and sugary drinks.

Ten-year survival and prognostic markers in one thousand patients with advanced heart failure. A single-centre analysis.

AIM: Patients with advanced heart failure (HF) represent a pool of candidates for heart transplantation and long-term mechanical circulatory support devices. The aim of our study was to determine simple and reliable markers of one-year mortality for selection of the most suitable patients for heart replacement therapy. METHODS AND RESULTS: One thousand consecutive patients with HF (mean age 49 ± 10.9 years; 86.8% males) referred to a single tertiary centre from January 1998 to January 2010 in order to assess the indication for heart transplantation were enrolled. Kaplan-Meier survival analysis was performed. Independent mortality predictors were established using logistic regression analysis. The mean follow-up was 4.3 ± 2.7 years (range 1-12 years). Cumulative survival was as follows: 1-year survival 83%, 3-year 63%, 5-year 50%, 7-year 39%, and 10-year 23%. Independent predictors of 1-year mortality included coronary artery disease, left ventricular diastolic diameter >79 mm, plasma sodium <135 mmol/L, the need for intravenous treatment at hospital admission (diuretics and/or inotropes), and furosemide dose at discharge >240 mg/day. CONCLUSIONS: Short-term prognosis of HF patient can be estimated based on simple parameters. Patients with signs of poor prognosis should be referred to tertiary centres to be considered for heart replacement therapy.

Dietary omega-3 fatty acids attenuate myocardial arrhythmogenic factors and propensity of the heart to lethal arrhythmias in a rodent model of human essential hypertension.

OBJECTIVE: Hypertension-induced myocardial remodeling is known to be associated with increased risk for malignant arrhythmias and alterations in electrical coupling protein, connexin-43 (Cx43), may be involved. We investigated whether omega-3 fatty acids intake affects abnormalities of Cx43 as well as protein kinase C (PKC) signaling and myosin heavy chain (MyHC) profile at the early and late stage of hypertension in the context of the heart's susceptibility to ventricular fibrillation and ability to restore sinus rhythm. METHODS: Untreated young and old male spontaneously hypertensive rats (SHRs) and age-matched normotensive rats were compared with animals supplemented by omega-3 (eicosapentaneoic acid + docosahexaneoic acid, 200 mg/kg body weight/day) for 2 months. Left ventricular tissues were taken for examination of subcellular integrity of gap junctions, Cx43 mRNA and protein expression, PKCε and PKCδ as well as MyHC determination. Electrically inducible ventricular fibrillation and sinus rhythm restoration (SRR) were examined on Langedorff-perfused heart preparation. RESULTS: Omega-3 intake significantly reduced cardiovascular risk factors, suppressed inducible ventricular fibrillation, and facilitated SRR in hypertensive rats. Supplementation attenuated lateralization and internalization of Cx43, suppressed elevated Cx43 mRNA, enhanced total Cx43 protein expression and/or expression of its functional phosphorylated forms as well as the expression of cardioprotective PKC-ε and suppressed pro-apoptotic PKC-δ isoform. Moreover, the omega-3 diet normalized MyHC profiles in SHR at early stage of disease and old nonhypertensive rats, but failed to do so in old SHR at late stage of disease. CONCLUSION: Findings suggest that amelioration of myocardial Cx43-related abnormalities, positive modulation of PKC pathways, and normalization of MyHC can significantly contribute to the antiarrhythmic effects of omega-3 in rat model mimicking human essential hypertension. Our results support the prophylactic use of omega-3 to minimize cardiovascular risk and sudden arrhythmic death.

The effects of phosphodiesterase 5 inhibition on hemodynamics, functional status and survival in advanced heart failure and pulmonary hypertension: a case-control study.

BACKGROUND: The goal was to examine the hemodynamic and clinical effects of long-term therapy with PDE5 inhibitor sildenafil (SILD) in patients with advanced, pre-transplant heart failure (HF) and severe pulmonary hypertension (PH), in comparison to a similar control group (CON). METHODS: In this non-randomized, retrospective case-control study, 32 middle-aged patients (81% males) with advanced systolic HF (80%≥ NYHA III, 56% ischemic) and severe pre-capillary PH (transpulmonary pressure gradient>15 mm Hg) were studied before and after initiation of SILD (dose 73 ± 25 mg/day) and were compared to 15 CON patients, matched for key clinical characteristics (including PH severity, age and co-morbidities), not exposed to SILD. Changes at 3 months and the long-term outcome were compared between groups. RESULTS: SILD significantly reduced pulmonary vascular resistance (-32% vs. baseline), transpulmonary gradient (-25%) and increased cardiac output (+15%) compared to controls, without affecting systemic or ventricular filling pressures. SILD-treated subjects experienced an improvement in NYHA class and had a steady body weight which contrasted with significant weight loss in the CON group (by -4.8%, absolutely by 4.3 ± 6 kg). During follow-up (median 349 days from baseline), 60% of patients underwent heart transplantation. Two patients in CON group had severe post-transplant failure of the right ventricle, none in SILD group. Overall pre- and peritransplant survival (censored 30 days after transplantation) was significantly better in SILD than CON group (93.7 vs 60%, p=0.0048). CONCLUSIONS: In patients with advanced HF and severe PH, SILD therapy has beneficial effects on hemodynamics, clinical status, cardiac cachexia, and contributes to improved peri-transplant survival.

Up-regulation of myocardial connexin-43 in spontaneously hypertensive rats fed red palm oil is most likely implicated in its anti-arrhythmic effects.

The purpose of this study was to test our hypothesis that red palm oil (RPO) intake may affect abnormalities of myocardial connexin-43 (Cx43) and protein kinase Cε (PKCε) signaling, and consequently the propensity of the spontaneously hypertensive rat heart (SHR) heart to arrhythmias. SHR and Wistar-Kyoto (WKY) rats fed a standard rat chow plus red palm oil (200 µL/day) for 5 weeks were compared with untreated rats. Cytosolic but not particulate PKCε expression as well as Cx43-mRNA, total Cx43 proteins, and its phoshorylated forms were increased, and disordered localization of Cx43 was attenuated in the left ventricle of RPO-fed SHR compared with untreated rats. These alterations were associated with suppression of early post-ischemic-reperfusion-related ventricular tachycardia and electrically inducible ventricular fibrillation. However, the treatment dose of RPO caused down-regulation of myocardial Cx43, but did not alter its cell membrane distribution or overall PKCε expression in WKY rats. It was, however, associated with poor arrhythmia protection, suggesting overdosing. Results indicate that SHR benefit from RPO intake, particularly because of its apparent anti-arrhythmic effects. This protection can be, in part, attributed to the preservation of cell-to-cell communication via up-regulation of myocardial Cx43, but not with PKCε activation.

Changes in gene expression of phenylethanolamine N-methyltransferase in the transplanted human heart.

Heart transplantation (HTx) is an accepted treatment for precisely defined patients with chronic congestive heart failure; however, as a result of the procedure, the graft is completely denervated. Our study focused on the catecholamine biosynthetic pathway, that is, the production of epinephrine, which is known to have positive chronotropic and inotropic effects on the heart. mRNA levels of the phenylethanolamine N-methyltransferase (PNMT), the enzyme catalyzing epinephrine synthesis in myocardial tissue, were determined in 18 patients (0 to 10 yr after HTx). Samples of myocardium were obtained from the right ventricle at the time of a routine endomyocardial biopsy performed for the diagnosis of graft rejection. Results were correlated with the following clinical parameters: heart rate, heart rate variability, blood pressure, graft systolic function, and the presence of the rejection. We observed that heart PNMT mRNA levels were significantly higher during the first 3 yr as compared to longer periods after HTx. Also, a decrease in the average heart rate and an increase in the heart rate variability were documented. Levels of the PNMT mRNA do not correlate with blood pressure, left ventricular systolic function at rest, and rejection. Thus, a gradual decrease of the heart rate and an increase in the heart rate variability after HTx is considered to be a sign of cardiac graft reinervation. We speculate that the increased PNMT transcription in human myocardium in early intervals after HTx reflects "autonomous sympathicotrophy." A decrease in the PNMT gene expression with the number of years after HTx could be a consequence of the reinnervation process.