Finerenone in Heart Failure with Mildly Reduced or Preserved Ejection Fraction.

BACKGROUND: Steroidal mineralocorticoid receptor antagonists reduce morbidity and mortality among patients with heart failure and reduced ejection fraction, but their efficacy in those with heart failure and mildly reduced or preserved ejection fraction has not been established. Data regarding the efficacy and safety of the nonsteroidal mineralocorticoid receptor antagonist finerenone in patients with heart failure and mildly reduced or preserved ejection fraction are needed. METHODS: In this international, double-blind trial, we randomly assigned patients with heart failure and a left ventricular ejection fraction of 40% or greater, in a 1:1 ratio, to receive finerenone (at a maximum dose of 20 mg or 40 mg once daily) or matching placebo, in addition to usual therapy. The primary outcome was a composite of total worsening heart failure events (with an event defined as a first or recurrent unplanned hospitalization or urgent visit for heart failure) and death from cardiovascular causes. The components of the primary outcome and safety were also assessed. RESULTS: Over a median follow-up of 32 months, 1083 primary-outcome events occurred in 624 of 3003 patients in the finerenone group, and 1283 primary-outcome events occurred in 719 of 2998 patients in the placebo group (rate ratio, 0.84; 95% confidence interval [CI], 0.74 to 0.95; P = 0.007). The total number of worsening heart failure events was 842 in the finerenone group and 1024 in the placebo group (rate ratio, 0.82; 95% CI, 0.71 to 0.94; P = 0.006). The percentage of patients who died from cardiovascular causes was 8.1% and 8.7%, respectively (hazard ratio, 0.93; 95% CI, 0.78 to 1.11). Finerenone was associated with an increased risk of hyperkalemia and a reduced risk of hypokalemia. CONCLUSIONS: In patients with heart failure and mildly reduced or preserved ejection fraction, finerenone resulted in a significantly lower rate of a composite of total worsening heart failure events and death from cardiovascular causes than placebo. (Funded by Bayer; FINEARTS-HF ClinicalTrials.gov number, NCT04435626.).

Vericiguat in heart failure with reduced ejection fraction: hope or solid reality?

In recent years, thanks to the advent of new classes of drugs (ARNI and SGLT2-i), the prognosis of patients suffering from heart failure with reduced ejection fraction (HFrEF) has gradually improved. Nonetheless, there is a residual risk that is not targeted by these therapies. Currently, it is recognized that vericiguat, an oral stimulator of soluble guanylate cyclase (sGC), can restore the NO-sGC-cGMP pathway, through stimulation and activation of sGC, aiming to increase cGMP levels with a reduction in heart failure-related oxidative stress and endothelial dysfunction. Even though the Victoria trial demonstrated that HFrEF patients in treatment with vericiguat showed a 10% reduction in the composite of cardiovascular mortality and rehospitalization for heart failure, statistically significantly reducing heart failure hospitalization, the international guidelines limit its use as a second-line drug for patients with worsening symptomatology despite optimized medical therapy. Furthermore, vericiguat has proved to be a valid therapeutic ally especially in those patients with comorbidities such that they cannot receive the classic four-pillar therapy of HF (in particular renal failure). In this review, the authors report on randomized clinical trials, substudies, and meta-analysis about vericiguat in HFrEF, emphasizing the strengths that would suggest the possible role of vericiguat as the fifth pillar of the HFrEF treatment, acknowledging that there are still gaps in the evidence that need to be clarified.

Redefining diabetes mellitus treatments according to different mechanisms beyond hypoglycaemic effect.

Early epidemiologic studies in type 2 diabetes suggested that the long-term risk of microvascular and macrovascular complications increase progressively as glucose concentrations rise, inspiring the pursuit of near euglycaemia as a means of preventing these complications in type 1 and type 2 diabetes. Evidence emerging over the past decade, however, showed that the aggressive efforts often needed to achieve low HbA1c levels can ultimately lead to worse clinical outcomes, greater risk of severe hypoglycaemia, and higher burden of treatment. The acknowledgment of the disappointing results obtained with therapies aimed exclusively at improving glycaemic control has led in recent years to a substantial paradigm shift in the treatment of the diabetic patient. The results obtained first with GLP-1RAs and more recently even more with SGLT2i on mortality and CV events have made it clear how other mechanisms, beyond the hypoglycaemic effect, are at the basis of the benefits observed in several cardiovascular outcome trials. And as evidence of the great revolution of thought we are experiencing, there is the recognition of gliflozins as drugs for the treatment not only of diabetic patients but also of non-diabetic patients suffering from HF, as reported in the latest ESC/HFA guidelines. Surely, we still have a lot to understand, but it is certain that this is the beginning of a new era.

Direct oral anticoagulants across the heart failure spectrum: the precision medicine era.

Heart failure (HF) is characterized by a pro-thrombotic state, which might aggravate its morbidity and, consequently, mortality. Several and commonly observed comorbidities, such as coronary artery disease, atrial fibrillation (AF), renal dysfunction, and diabetes often complicate HF, increasing the thromboembolic risk. In the past decade, direct oral anticoagulants (DOACs) have been approved for the treatment and prevention of stroke and embolic events in patients with nonvalvular AF. Due to their lower bleeding risk, these drugs are frequently used instead of warfarin; however, some controversies exist on their use in HF patients with or without comorbidities. Indeed, the management of anticoagulation in HF patients with underlying conditions is poorly investigated since these patients are underrepresented or excluded from randomized controlled trials. The aim of this research is to review current evidence on the use of DOACs in HF patients, also discussing their specific use in different clinical scenarios. Graphical abstract.

Paradigm shift in heart failure treatment: are cardiologists ready to use gliflozins?

Despite recent advances in chronic heart failure (HF) therapy, the prognosis of HF patients remains poor, with high rates of HF rehospitalizations and death in the early months after discharge. This emphasizes the need for incorporating novel HF drugs, beyond the current approach (that of modulating the neurohumoral response). Recently, new antidiabetic oral medications (sodium-glucose cotransporter 2 inhibitors (SGLT2i)) have been shown to improve prognosis in diabetic patients with previous cardiovascular (CV) events or high CV risk profile. Data from DAPA-HF study showed that dapaglifozin is associated with a significant reduction in mortality and HF hospitalization as compared with placebo regardless of diabetes status. Recently, results from EMPEROR-Reduced HF trial were consistent with DAPA-HF trial findings, showing significant beneficial effect associated with empagliflozin use in a high-risk HF population with markedly reduced ejection fraction. Results from the HF with preserved ejection fraction trials using these same agents are eagerly awaited. This review summarizes the evidence for the use of gliflozins in HF treatment.

ß-Blockers and Erectile Dysfunction in Heart Failure. Between Myth and Reality.

Erectile dysfunction (ED) is a major concern in heart failure (HF) due its high prevalence as well as its negative impact on the quality of life, this condition being usually unrecognized and thus untreated. A number of possible causes might contribute to the above mentioned tight association, i.e., shared risk factors, comorbidities and several physiologic HF abnormalities such as impaired exercise tolerance, psychogenic factors and neurohumoral, metabolic and vascular changes. Medications have been blamed for playing also a pivotal role in the ED occurrence and, particularly, the ß -blockers. Remarkably, the underlying mechanisms have not been fully identified. All the available scientific literature dealing with this topic derives from studies not addressing this issue in HF, but in other settings, (e.g., arterial hypertension) and are also characterized by important methodological flaws. Thus, given the solid evidences arguing in favor of ß -blockers in HF in terms of morbidity, mortality and quality of life, ß -blockers at the maximal tolerated dosage in this patients' category should be recommended, regardless of ED. However, the ED-related issues should not be neglected, and adequate psychological counseling and management should be provided, pursuing the correction of risk factors, the choice of more suitable medications and, in selected cases, adopting specific drugs or devices. The purpose of this narrative review is to highlight the close relationship between ED and HF and, specifically, to focus on a possible ß -blockers' role in determining or, at least, worsening this condition.

Vericiguat for Heart Failure with Reduced Ejection Fraction.

PURPOSE OF REVIEW: The nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway plays an important role in the regulation of cardiovascular function, and it is disrupted in heart failure (HF), resulting in decreased protection against myocardial injury. Impaired NO-sGC-cGMP signaling in HF is secondary to reduced NO bioavailability and altered redox state of sGC, which becomes less responsive to NO. The sGC activator cinaciguat increases cGMP levels by direct NO-independent activation of sGC and may be particularly effective in conditions of increased oxidative stress and endothelial dysfunction, and therefore reduced NO levels, at the expense of a greater risk of hypotension. Conversely, sGC stimulators (riociguat and vericiguat) enhance sGC sensitivity to endogenous NO, thus exerting a more physiological action. RECENT FINDINGS: Clinical trials have suggested the benefit of vericiguat in patients with high-risk HF; in particular, a lower incidence of death from cardiovascular causes or HF hospitalization. Adding vericiguat may be considered in individual patients with HF, and reduced left ventricular ejection fraction (HFrEF) particularly those at higher risk of HF hospitalization.

Reduction of hospitalizations for myocardial infarction in Italy in the COVID-19 era.

AIMS: To evaluate the impact of the COVID-19 pandemic on patient admissions to Italian cardiac care units (CCUs). METHODS AND RESULTS: We conducted a multicentre, observational, nationwide survey to collect data on admissions for acute myocardial infarction (AMI) at Italian CCUs throughout a 1 week period during the COVID-19 outbreak, compared with the equivalent week in 2019. We observed a 48.4% reduction in admissions for AMI compared with the equivalent week in 2019 (P < 0.001). The reduction was significant for both ST-segment elevation myocardial infarction [STEMI; 26.5%, 95% confidence interval (CI) 21.7-32.3; P = 0.009] and non-STEMI (NSTEMI; 65.1%, 95% CI 60.3-70.3; P < 0.001). Among STEMIs, the reduction was higher for women (41.2%; P = 0.011) than men (17.8%; P = 0.191). A similar reduction in AMI admissions was registered in North Italy (52.1%), Central Italy (59.3%), and South Italy (52.1%). The STEMI case fatality rate during the pandemic was substantially increased compared with 2019 [risk ratio (RR) = 3.3, 95% CI 1.7-6.6; P < 0.001]. A parallel increase in complications was also registered (RR = 1.8, 95% CI 1.1-2.8; P = 0.009). CONCLUSION: Admissions for AMI were significantly reduced during the COVID-19 pandemic across Italy, with a parallel increase in fatality and complication rates. This constitutes a serious social issue, demanding attention by the scientific and healthcare communities and public regulatory agencies.

Characteristics and outcomes of patients hospitalized for COVID-19 and cardiac disease in Northern Italy.

AIMS: To compare demographic characteristics, clinical presentation, and outcomes of patients with and without concomitant cardiac disease, hospitalized for COVID-19 in Brescia, Lombardy, Italy. METHODS AND RESULTS: The study population includes 99 consecutive patients with COVID-19 pneumonia admitted to our hospital between 4 March and 25 March 2020. Fifty-three patients with a history of cardiac disease were compared with 46 without cardiac disease. Among cardiac patients, 40% had a history of heart failure, 36% had atrial fibrillation, and 30% had coronary artery disease. Mean age was 67 ± 12 years, and 80 (81%) patients were males. No differences were found between cardiac and non-cardiac patients except for higher values of serum creatinine, N-terminal probrain natriuretic peptide, and high sensitivity troponin T in cardiac patients. During hospitalization, 26% patients died, 15% developed thrombo-embolic events, 19% had acute respiratory distress syndrome, and 6% had septic shock. Mortality was higher in patients with cardiac disease compared with the others (36% vs. 15%, log-rank P = 0.019; relative risk 2.35; 95% confidence interval 1.08-5.09). The rate of thrombo-embolic events and septic shock during the hospitalization was also higher in cardiac patients (23% vs. 6% and 11% vs. 0%, respectively). CONCLUSIONS: Hospitalized patients with concomitant cardiac disease and COVID-19 have an extremely poor prognosis compared with subjects without a history of cardiac disease, with higher mortality, thrombo-embolic events, and septic shock rates.

Effects of Elamipretide on Left Ventricular Function in Patients With Heart Failure With Reduced Ejection Fraction: The PROGRESS-HF Phase 2 Trial.

BACKGROUND: Elamipretide, a novel mitochondrial modulating agent, improves myocardial energetics; however, it is unknown whether this mechanistic benefit translates into improved cardiac structure and function in heart failure (HF) with reduced ejection fraction (HFrEF). The objective of this study was to evaluate the effects of multiple subcutaneous doses of elamipretide on left ventricular end systolic volume (LVESV) as assessed by cardiac magnetic resonance imaging. METHODS: We randomized 71 patients with HFrEF (LVEF ≤ 40%) in a double-blind, placebo-controlled trial in a 1:1:1 ratio to receive placebo, 4 mg or 40 mg elamipretide once daily for 28 consecutive days. RESULTS: The mean age (standard deviation) of the study population was 65 ± 10 years, 24% were females, and the mean EF was 31% ± 7%. The change in LVESV from baseline to week 4 was not significantly different between elamipretide 4 mg (89.4 mL to 85 mL; difference, -4.4 mL) or 40 mg (77.9 mL to 76.6 mL; difference, -1.2 mL) compared with placebo (77.7 mL to 74.6 mL; difference, -3.8 mL) (4 mg vs placebo: difference of means, -0.3; 95% CI, -4.6 to 4.0; P = 0.90; and 40 mg vs placebo: difference of means, 2.3; 95% CI, -1.9 to 6.5; P  =  0.28). Also, no significant differences in change in LVESV and LVEF were observed between placebo and either of the elamipretide groups. Rates of any study drug-related adverse events were similar in the 3 groups. CONCLUSIONS: Elamipretide was well tolerated but did not improve LVESV at 4 weeks in patients with stable HFrEF compared with placebo.

Redefining biomarkers in heart failure.

Heart failure (HF) is the end result of many different cardiac and non-cardiac abnormalities leading to a complex clinical entity. In this view, the use of biomarkers in HF should be deeply reconsidered; indeed, the same biomarker may carry a different significance in patients with preserved or reduced EF. The aim of this review is to reconsider the role of biomarkers in HF, based on the different clinical characteristics of this syndrome. The role of cardiac and non-cardiac biomarkers will be reviewed with respect of the different clinical manifestations of this syndrome.

Identification, prevention and management of cardiovascular risk in chronic myeloid leukaemia patients candidate to ponatinib: an expert opinion.

Ponatinib (Iclusig, ARIAD Pharmaceuticals-Incyte Co.) is a third-generation structure-guided tyrosine kinase inhibitor that is approved for treatment of Philadelphia chromosome-positive leukaemias resistant or intolerant to other inhibitors. The clinical use of ponatinib is complicated by the possible development of cardiovascular events, primarily hypertension and arterial or venous thrombotic events. The US Food and Drug Administration and the European Medicine Agency recommend that the cardiovascular profile of patients candidate for ponatinib should be carefully evaluated. For patients deemed to carry a high risk of cardiovascular events, other life-saving therapeutic options should be considered. When alternative options are not available, treatment with ponatinib is indicated but requires that haematologists and cardiologists collaborate and identify modalities of surveillance and risk mitigation in the best interest of the patient. This article reports on the expert opinion provided by a panel of Italian haematologists, cardiologists and clinical pharmacologists. It summarises suggestions that may help to improve the therapeutic index of ponatinib, primarily in the settings of chronic-phase chronic myeloid leukaemia.

Site selection in global clinical trials in patients hospitalized for heart failure: perceived problems and potential solutions.

There are over 1 million hospitalizations for heart failure (HF) annually in the United States alone, and a similar number has been reported in Europe. Recent clinical trials investigating novel therapies in patients with hospitalized HF (HHF) have been negative, and the post-discharge event rate remains unacceptably high. The lack of success with HHF trials stem from problems with understanding the study drug, matching the drug to the appropriate HF subgroup, and study execution. Related to the concept of study execution is the importance of including appropriate study sites in HHF trials. Often overlooked issues include consideration of the geographic region and the number of patients enrolled at each study center. Marked differences in baseline patient co-morbidities, serum biomarkers, treatment utilization and outcomes have been demonstrated across geographic regions. Furthermore, patients from sites with low recruitment may have worse outcomes compared to sites with higher enrollment patterns. Consequently, sites with poor trial enrollment may influence key patient end points and likely do not justify the costs of site training and maintenance. Accordingly, there is an unmet need to develop strategies to identify the right study sites that have acceptable patient quantity and quality. Potential approaches include, but are not limited to, establishing a pre-trial registry, developing site performance metrics, identifying a local regionally involved leader and bolstering recruitment incentives. This manuscript summarizes the roundtable discussion hosted by the Food and Drug Administration between members of academia, the National Institutes of Health, industry partners, contract research organizations and academic research organizations on the importance of selecting optimal sites for successful trials in HHF.

Climate change versus Mediterranean diet: A hazardous struggle for the women's heart.

Climate change impacts food systems, causing nutritional deficiencies and increasing cardiovascular diseases (CVD). Regulatory frameworks like the European Farm-to-Fork Strategy aim to mitigate these effects, but current EU food safety regulations inadequately address health risks from poor diet quality and contaminants. Climate change adversely affects food quality, such as nutrient depletion in crops due to higher CO2 levels, leading to diets that promote chronic diseases, including CVD. Women, because of their roles in food production and their unique physiological responses to nutrients, face distinct vulnerabilities. This review explores the interplay between climate change, diet, and cardiovascular health in women. The review highlights that sustainable diets, particularly the Mediterranean diet, offer health benefits and lower environmental impacts but are threatened by climate change-induced disruptions. Women's adherence to the Mediterranean diet is linked to significant reductions in CVD risk, though sex-specific responses need further research. Resilient agricultural practices, efficient water management, and climate-smart farming are essential to mitigate climate change's negative impacts on food security. Socio-cultural factors influencing women's dietary habits, such as traditional roles and societal pressures, further complicate the picture. Effective interventions must be tailored to women, emphasizing education, community support, policy changes, and media campaigns promoting healthy eating. Collaborative approaches involving policymakers, health professionals, and the agricultural sector are crucial for developing solutions that protect public health and promote sustainability. Addressing the multifaceted challenges posed by climate change to food quality and cardiovascular health in women underscores the need for integrated strategies that ensure food security, enhance diet quality, and mitigate environmental impacts.

Distinct Profiles and New Pharmacological Targets for Heart Failure with Preserved Ejection Fraction.

Background: Heart failure with preserved ejection fraction (HFpEF) is a multifactorial condition with a variety of pathophysiological causes and morphological manifestations. The inclusion criteria and patient classification have become overly simplistic due to the customary differentiation regarding the ejection fraction (EF) cutoff. EF is considered a measure of systolic function; nevertheless, it only represents a portion of the true contractile state and has been shown to have certain limits due to methodological and hemodynamic irregularities. Methods: As a result, broader randomized clinical trials have yet to incorporate the most recent criteria for HFpEF diagnosis, leading to a lack of data consistency and confusion in interpreting the results. The primary variations between the bigger clinical trials published in this context concerning patient selection and echocardiographic characteristics were analyzed. For all these reasons, we aim to clarify the main features and clinical impact of HFpEF in a study combining imaging, bio-humoral analysis, and clinical history to identify the specific subgroups that respond better to tailored treatment. Results: Disparate clinical characteristics and a lack of uniform diagnostic standards may cause suboptimal therapeutic feedback. To optimize treatment, we suggest shifting the paradigm from the straightforward EF measurement to a more comprehensive model that considers additional information, such as structural traits, related disorders, and biological and environmental data. Therefore, by evaluating certain echocardiographic and clinical factors, a stepwise diagnostic procedure may be useful in identifying patients at high risk, subjects with early HFpEF, and those with evident HFpEF. Conclusions: The present assessment underscores the significance of the precision medicine approach in guaranteeing optimal patient outcomes by providing the best care according to each distinct profile.

The Impact of Stress and Social Determinants on Diet in Cardiovascular Prevention in Young Women.

The prevention of cardiovascular diseases is a fundamental pillar for reducing morbidity and mortality caused by non-communicable diseases. Social determinants, such as socioeconomic status, education, neighborhood, physical environment, employment, social support networks, and access to health care, play a crucial role in influencing health outcomes and health inequities within populations. Social determinants and stress in women are interconnected factors that can significantly impact women's health and well-being. Pregnancy is a good time to engage young women and introduce them to beneficial behaviors, such as adopting essential life skills, especially diet, and learning stress management techniques. Stress influences diet, and women are more likely to engage in unhealthy eating behaviors such as emotional eating or coping with stress with food. Strong action is needed to improve women's lifestyle starting at a young age considering that this lays the foundation for a lower cardiovascular risk in adults and the elderly. The objective of this review is to examine cardiovascular primary prevention in young healthy women, focusing particularly on unresolved issues and the influence of social determinants, as well as the correlation with stressors and their influence on diet.

[SIC Position paper: Treat to prevent the first event - intensive LDL cholesterol lowering in patients at very high cardiovascular risk without a previous cardiovascular event. From ESC guidelines to clinical practice]. / Position paper SIC: Trattare per prevenire ­ la riduzione intensiva del colesterolo LDL nel paziente a rischio cardiovascolare molto alto senza pregresso evento. Dalle linee guida ESC alla pratica clinica.

Cardiovascular (CV) diseases account for over 4 million deaths every year in Europe and over 220 000 deaths in Italy, representing the leading cause of morbidity and mortality worldwide. The European Society of Cardiology (ESC) guidelines have visionary included in the at very high CV risk group patients without previous acute ischemic events, such as those with subclinical atherosclerosis, chronic coronary syndrome or peripheral arterial disease, familial hypercholesterolemia, diabetes mellitus with target organ damage or multiple associated risk factors, and those with high calculated CV risk score, recommending to consider them and to achieve the same LDL-cholesterol targets as for secondary prevention patients. The aim of this position paper is to provide an updated overview of ESC guidelines that focuses on these patient categories to raise awareness within the clinical community regarding CV risk reduction in this specific epidemiological context.

Maternal-fetal dyad beyond the phenomenology of pregnancy: from primordial cardiovascular prevention on out, do not miss this boat!

Pregnancy represents a stress test for every woman's cardiovascular (CV) system, and a pre-existing maternal unfavorable cardio-metabolic phenotype can uncover both adverse pregnancy outcomes and the subsequent development of cardiovascular disease (CVD) risk factors during and after pregnancy. Moreover, the maternal cardiac and extracardiac environment can affect offspring's cardiovascular health through a complex mechanism called developmental programming, in which fetal growth can be influenced by maternal conditions. This interaction continues later in life, as adverse developmental programming, along with lifestyle risk factors and genetic predisposition, can exacerbate and accelerate the development of CV risk factors and CVD in childhood and adolescence. The aim of this narrative review is to summarize the latest evidences regarding maternal-fetal dyad and its role on primordial, primary and secondary CV prevention.

Right ventricular dysfunction in chronic heart failure: clinical laboratory and echocardiographic characteristics. (the RIVED-CHF registry).

BACKGROUND: Right ventricular dysfunction (RVD) and pulmonary hypertension have been recognized as two important prognostic features in patients with left side heart failure. Current literature does not distinguish between right heart failure (RHF) and RVD, and the two terms are used indiscriminately to describe pulmonary hypertension and RVD as well as clinical sign of RHF. Therefore, the right ventricle (RV) adaptation across the whole spectrum of left ventricular ejection fraction (LVEF) values has been poorly investigated. METHODS: This is a multicenter observational prospective study endorsed by the Italian Society of Cardiology aiming to analyze the concordance between the signs and symptoms of RHF and echocardiographic features of RVD. The protocol will assess patients affected by chronic heart failure in stable condition regardless of the LVEF threshold by clinical, laboratory, and detailed echocardiographic study. During the follow-up period, patients will be observed by direct check-up visit and/or virtual visits every 6 months for a mean period of 3 years. All clinical laboratory and echocardiographic data will be recorded in a web platform system accessible for all centers included in the study. RESULTS: The main study goals are: to investigate the concordance and discordance between clinical signs of RHF and RVD measured by ultrasonographic examination; to evaluate prognostic impact (in terms of cardiovascular mortality and heart failure hospitalization) of RVD and RHF during a mean follow-up period of 3 years; to investigate the prevalence of different right ventricular maladaptation (isolated right ventricular dilatation, isolated pulmonary hypertension, combined pattern) and the related prognostic impact. CONCLUSIONS: With this protocol, we would investigate the three main RVD patterns according to heart failure types and stages; we would clarify different RVD and pulmonary hypertension severity according to the heart failure types. Additionally, by a serial multiparametric analysis of RV, we would provide a better definition of RVD stage and how much is it related with clinical signs of RHF (ClinicalTrials.gov Identifier: NCT06002321).

Deceived by the Fick principle: blood flow distribution in heart failure.

AIMS: The Fick principle states that oxygen uptake (V̇O2) is cardiac output (Qc)*arterial-venous O2 content difference [ΔC(a-v)O2]. Blood flow distribution is hidden in Fick principle and its relevance during exercise in heart failure (HF) is undefined.To highlight the role of blood flow distribution, we evaluated peak-exercise V̇O2, Qc and ΔC(a-v)O2, before and after HF therapeutic interventions. METHODS: Symptoms-limited cardiopulmonary exercise tests with Qc measurement (inert-gas-rebreathing) was performed in 234 HF patients before and 6 months after successful exercise training, cardiac-resynchronization therapy or percutaneous-edge-to-edge mitral valve repair. RESULTS: Considering all tests (n=468) a direct correlation between peakV̇O2 and peakQc (R2=0.47) and workload (R2=0.70) were observed. Patients were grouped according to treatment efficacy in group 1 (peakV̇O2 increase >10%, n=93), group 2 (peakV̇O2 change between 0 and 10%, n=60) and group 3 (reduction in peakV̇O2, n=81). Post-treatment peakV̇O2 changes poorly correlated with peakQc and peakΔC(a-v)O2 changes. Differently, post-procedures peakQc vs. peakΔC(a-v)O2 changes showed a close negative correlation (R2=0.46), becoming stronger grouping patients according to peakV̇O2 improvement (R2=0.64, 0.79 and 0.58 in group 1, 2 and 3, respectively). In 76% of patients peakQc and ΔC(a-v)O2 changes diverged regardless of treatment. CONCLUSION: The bulk of these data suggests that blood flow distribution plays a pivotal role on peakV̇O2 determination regardless of HF treatment strategies. Accordingly, for assessing HF treatment efficacy on exercise performance the sole peakV̇O2 may be deceptive and the combination of V̇O2, Qc and ΔC(a-v)O2, must be considered.

This study aimed to understand how oxygen uptake during exercise is affected by heart failure therapeutic intervention. We evaluated 234 heart failure patients before and after treatments such as exercise training, cardiac resynchronization therapy, or mitral valve repair, finding that changes in oxygen uptake were poorly correlated with changes in cardiac output and oxygen content difference between arteries and veins. However, we observed a strong negative correlation between changes in cardiac output and oxygen content difference, especially in patients with significant improvement in oxygen uptake. This suggests that blood flow distribution is crucial for oxygen uptake during exercise, regardless of treatment. Therefore, relying solely on oxygen uptake may not accurately assess treatment effectiveness, and considering a combination of oxygen uptake, cardiac output, and oxygen content difference is important. Oxygen uptake during exercise was strongly related to cardiac output and workload.Changes in cardiac output and oxygen content difference were closely related after treatments, especially in patients with significant improvement in oxygen uptake.