Unravelling the Mechanisms Behind Exercise Intolerance and Recovery in Long COVID.

BACKGROUND: Patients suffering from long COVID may exhibit autonomic dysregulation. However, the association between autonomic dysregulation and exercise intolerance and the impact of therapeutic interventions on its modulation remain unclear. This study investigated the relationship between heart rate recovery at the first minute (HRR1), a proxy for autonomic imbalance, and exercise intolerance in patients with long COVID. Additionally, the study aimed to assess the effects of a 12-week home-based inspiratory muscle training program on autonomic modulation in this patient population. METHODS: This study is a post hoc subanalysis of a randomized trial in which 26 patients with long COVID were randomly assigned to receive either a 12-week inspiratory muscle training program or usual care alone (NCT05279430). The data were analyzed using Pearson's correlation and linear mixed regression analysis. RESULTS: The mean age was 50.4±12.2 years, and 11 (42.3%) were women. Baseline HRR1 was significantly correlated with maximal functional capacity (peakVO2) (r=0.402, p=0.041). Patients with lower baseline HRR1 (≤ 22 bpm) exhibited higher resting heart rates and lower peakVO2. Inspiratory muscle training led to a more substantial increase in peakVO2 in patients with lower HRR1 at baseline (p=0.019). Additionally, a significant improvement in HRR1 was observed in the IMT group compared to the usual care group after 12-week (Δ +9.39, 95% CI=2.4-16.4, p=0.010). CONCLUSION: Lower baseline HRR1 is associated with exercise intolerance in long COVID patients and may serve as a valuable criterion for identifying individuals likely to benefit more from a home-based inspiratory muscle training program.

Being fit in the COVID-19 era and future epidemics prevention: Importance of cardiopulmonary exercise test in fitness evaluation.

Endurance and resistance physical activity have been shown to stimulate the production of immunoglobulins and boost the levels of anti-inflammatory cytokines, natural killer cells, and neutrophils in the bloodstream, thereby strengthening the ability of the innate immune system to protect against diseases and infections. Coronavirus disease 19 (COVID-19) greatly impacted people's cardiorespiratory fitness (CRF) and health worldwide. Cardiopulmonary exercise testing (CPET) remains valuable in assessing physical condition, predicting illness severity, and guiding interventions and treatments. In this narrative review, we summarize the connections and impact of COVID-19 on CRF levels and its implications on the disease's progression, prognosis, and mortality. We also emphasize the significant contribution of CPET in both clinical evaluations of recovering COVID-19 patients and scientific investigations focused on comprehending the enduring health consequences of SARS-CoV-2 infection.

Morbimortalidad no cardiovascular en función de la fracción de eyección del ventrículo izquierdo tras una hospitalización por insuficiencia cardiaca / Noncardiovascular morbidity and mortality across left ventricular ejection fraction categories following hospitalization for heart failure

Introducción y objetivos Los eventos no cardiovasculares son una importante causa de morbimortalidad en pacientes con insuficiencia cardiaca (IC), pero parece que su riesgo difiere en función de la fracción de eyección del ventrículo izquierdo (FEVI). Nuestro objetivo es evaluar el riesgo de mortalidad y hospitalizaciones no cardiovasculares totales en función de la FEVI tras una hospitalización por IC. Métodos Se evaluó en retrospectiva a una cohorte multicéntrica de 4.595 pacientes tras una hospitalización por IC. Se evaluó la FEVI como variable continua y estratificada en 4 categorías (FEVI ≤ 40%, 41%-49%, 50-59% y ≥ 60%). Los objetivos fueron los riesgos de muerte no cardiovascular y de hospitalizaciones recurrentes por causas no cardiovasculares según la FEVI. Resultados Tras una mediana de seguimiento de 2,2 [intervalo intercuartílico, 0,76-4,8] años, se registraron 646 muertes y 4.014 episodios de rehospitalización por causas no cardiovasculares. En el análisis multivariante, que incluía el riesgo de evento cardiovascular como evento adverso competitivo, se halló relación directa entre la FEVI y el riesgo de muerte o rehospitalización no cardiovascular (p<0,001). En comparación con la FEVI ≤ 40%, la FEVI del 51-59% y especialmente la ≥ 60% se asociaron de manera significativa con un mayor riesgo de muerte no cardiovascular (respectivamente, HR=1,31; IC95%, 1,02-1,68; p=0,032; y HR=1,47; IC95%, 1,15-1,86; p=0,002) y de rehospitalizaciones no cardiovasculares (IRR=1,17; IC95%, 1,02-1,35; p=0,024; IRR=1,26; IC95%, 1,11-1,45; p=0,001). Conclusiones Tras una hospitalización por IC, la FEVI tiene relación directa con el riesgo de morbimortalidad no cardiovascular. Los pacientes con FEVI conservada tienen un riesgo significativamente mayor de muerte y hospitalizaciones por causas no cardiovasculares, fundamentalmente si la FEVI es ≥ 60%. (AU)

Introduction and objectives Noncardiovascular events represent a significant proportion of the morbidity and mortality burden in patients with heart failure (HF). However, the risk of these events appears to differ by left ventricular ejection fraction (LVEF) status. In this study, we sought to evaluate the risk of noncardiovascular death and recurrent noncardiovascular readmission by LVEF status following an admission for acute HF. Methods We retrospectively assessed a cohort of 4595 patients discharged after acute HF in a multicenter registry. We evaluated LVEF as a continuum, stratified in 4 categories (LVEF ≤ 40%, 41%-49%, 50%-59%, and ≥ 60%). Study endpoints were the risks of noncardiovascular mortality and recurrent noncardiovascular admissions during follow-up. Results At a median follow-up of 2.2 [interquartile range, 0.76-4.8] years, we registered 646 noncardiovascular deaths and 4014 noncardiovascular readmissions. After multivariable adjustment including cardiovascular events as a competing event, LVEF status was associated with the risk of noncardiovascular mortality and recurrent noncardiovascular admissions. When compared with patients with LVEF ≤ 40%, those with LVEF 51%-59%, and especially those with LVEF ≥ 60%, were at higher risk of noncardiovascular mortality (HR, 1.31; 95%CI, 1.02-1,68; P=.032; and HR, 1.47; 95%CI, 1.15-1.86; P=.002; respectively), and at higher risk of recurrent noncardiovascular admissions (IRR, 1.17; 95%CI, 1.02-1.35; P=.024; and IRR, 1.26; 95%CI, 1.11-1.45; P=.001; respectively). Conclusions Following an admission for HF, LVEF status was directly associated with the risk of noncardiovascular morbidity and mortality. Patients with HFpEF were at higher risk of noncardiovascular death and total noncardiovascular readmissions, especially those with LVEF ≥ 60%. (AU)

ß-Blocker Withdrawal and Functional Capacity Improvement in Patients With Heart Failure With Preserved Ejection Fraction.

Importance: Increasing the patient's heart rate (HR) has emerged as a therapeutic option in patients with heart failure with preserved ejection fraction (HFpEF). However, the evidence is conflicting, and the profile of patients who benefit most from this strategy remains unclear. Objective: To assess the association of ß-blocker treatment withdrawal with changes in the percentage of predicted peak oxygen consumption (VO2) across indexed left ventricular diastolic (iLVEDV) and indexed left ventricular systolic volumes (iLVESV), and left ventricular ejection fraction (LVEF) in patients with HFpEF and chronotropic incompetence. Design, Setting, and Participants: This post hoc analysis was conducted using data from the investigator-blinded multicenter, randomized, and crossover clinical trial, PRESERVE-HR, that took place from October 1, 2018, through December 31, 2020, to investigate the short-term effects (2 weeks) of ß-blocker withdrawal on peak oxygen consumption (peak VO2). Patients with stable HFpEF (New York Heart Association functional class II to III) receiving treatment with ß-blocker and chronotropic incompetence were included. Intervention: Participants in the PRESERVE-HR trial were randomized to withdraw vs continue with ß-blocker treatment. After 2 weeks, they were crossed over to receive the opposite intervention. This crossover randomized clinical trial examined the short-term effect of ß-blocker withdrawal on peak VO2. Main Outcomes and Measures: The primary outcome was to evaluate the association between ß-blocker withdrawal and short-term changes in percentage of peak VO2 across iLVEDV, iLVESV, and LVEF in patients with HFpEF and chronotropic incompetence treated with ß-blocker. Results: A total of 52 patients (mean age, 73 [SD, 13] years; 60% female) were randomized. The mean resting HR, peak HR, peak VO2, and percentage of peak VO2 were 65 (SD, 9) beats per minute (bpm), 97 (SD, 15) bpm, 12.4 (SD, 2.9) mL/kg per minute, and 72.4% (SD, 17.7%), respectively. The medians (minimum-maximum) of iLVEDV, iLVESV, and LVEF were 44 mL/m2 (IQR, 19-82), 15 mL/m2 (IQR, 7-32), and 64% (IQR, 52%-78%), respectively. After stopping ß-blocker treatment, the median increase in peak HR was plus 30 bpm (95% CI, 25-35; P < .001). ß-Blocker cessation was differentially associated with change of percentage of peak VO2 across the continuum of iLVESV (P for interaction = .02), indicating a greater benefit in those with lower iLVESV. Conclusions and Relevance: In this study, results showed that in patients with HFpEF and chronotropic incompetence receiving treatment with ß-blocker, lower iLVESV may identify those with a greater short-term improvement in maximal functional capacity after stopping ß-blocker treatment. Further studies are warranted for further investigation. Trial Registration: ClinicalTrials.gov (NCT03871803).

Exercise training response according to baseline ferrokinetics in heart failure with preserved ejection fraction: A substudy of the TRAINING-HF trial.

BACKGROUND: Iron deficiency (ID) is associated with impaired functional capacity in patients with heart failure (HF), even in those with preserved ejection fraction (HFpEF). This study aimed to evaluate the effect of baseline ferrokinetics on peak oxygen consumption (peakVO2) improvement after a 12-week physical therapy programme in patients with stable HFpEF. METHODS: This study is a post-hoc sub-analysis of a randomized clinical trial in which 59 stable patients with HFpEF were randomized to receive a 12-week programme of inspiratory muscle training (IMT), functional electrical stimulation (FES), IMT + FES or usual care (UC) to evaluate change in peakVO2 (NCT02638961). Serum ferritin and transferrin saturation (TSAT) determinations were assessed at baseline. ID was defined as ferritin <100 ng/mL and/or TSAT <20% if ferritin was within 100-299 ng/mL. We used a linear mixed regression model to analyse between-treatment changes in peakVO2 across ferrokinetics status at 12 and 24 weeks. RESULTS: The mean age was 74 ± 9 years, and 36 (61%) had ID. The mean of peakVO2 was 9.9 ± 2.5 mL/kg/min. The median of ferritin and transferrin saturation (TSAT) was 91 (50-181) ng/mL and 23% (16-30), respectively. A total of 52 patients completed the trial (13 patients per arm). Compared with those patients on UC, patients allocated to any of the active arms showed less improvement in peak VO2 when they showed ID (P-value for interaction <0.001), lower values of ferritin (P-value for interaction <0.001), or TSAT (P-value for interaction <0.001). CONCLUSIONS: Ferrokinetics status plays an essential role in modifying the aerobic capacity response to physical therapies in patients with HFpEF. Further studies are required to confirm these findings.

Noncardiovascular morbidity and mortality across left ventricular ejection fraction categories following hospitalization for heart failure.

INTRODUCTION AND OBJECTIVES: Noncardiovascular events represent a significant proportion of the morbidity and mortality burden in patients with heart failure (HF). However, the risk of these events appears to differ by left ventricular ejection fraction (LVEF) status. In this study, we sought to evaluate the risk of noncardiovascular death and recurrent noncardiovascular readmission by LVEF status following an admission for acute HF. METHODS: We retrospectively assessed a cohort of 4595 patients discharged after acute HF in a multicenter registry. We evaluated LVEF as a continuum, stratified in 4 categories (LVEF ≤ 40%, 41%-49%, 50%-59%, and ≥ 60%). Study endpoints were the risks of noncardiovascular mortality and recurrent noncardiovascular admissions during follow-up. RESULTS: At a median follow-up of 2.2 [interquartile range, 0.76-4.8] years, we registered 646 noncardiovascular deaths and 4014 noncardiovascular readmissions. After multivariable adjustment including cardiovascular events as a competing event, LVEF status was associated with the risk of noncardiovascular mortality and recurrent noncardiovascular admissions. When compared with patients with LVEF ≤ 40%, those with LVEF 51%-59%, and especially those with LVEF ≥ 60%, were at higher risk of noncardiovascular mortality (HR, 1.31; 95%CI, 1.02-1,68; P=.032; and HR, 1.47; 95%CI, 1.15-1.86; P=.002; respectively), and at higher risk of recurrent noncardiovascular admissions (IRR, 1.17; 95%CI, 1.02-1.35; P=.024; and IRR, 1.26; 95%CI, 1.11-1.45; P=.001; respectively). CONCLUSIONS: Following an admission for HF, LVEF status was directly associated with the risk of noncardiovascular morbidity and mortality. Patients with HFpEF were at higher risk of noncardiovascular death and total noncardiovascular readmissions, especially those with LVEF ≥ 60%.

Effect of paced heart rate on quality of life and natriuretic peptides for stage B or C heart failure with preserved ejection fraction: A secondary analysis of the myPACE trial.

AIM: Emerging evidence suggests a beneficial effect of higher heart rates in some patients with heart failure with preserved ejection fraction (HFpEF). This study aimed to evaluate the impact of higher backup pacing rates in HFpEF patients with preexisting pacemaker systems that limit pacemaker-mediated dyssynchrony across left ventricular (LV) volumes and LV ejection fraction (LVEF). METHODS AND RESULTS: This is a post-hoc analysis of the myPACE clinical trial that evaluated the effects of personalized accelerated pacing setting (myPACE) versus standard of care on changes in Minnesota Living with Heart Failure Questionnaire (MLHFQ) score, N-terminal pro-brain natriuretic peptide (NT-proBNP), pacemaker-detected activity levels, and atrial fibrillation (AF) burden in patients with HFpEF with preexisting pacemakers. Between-treatment comparisons were performed using linear regression models adjusting for the baseline value of the exposure (ANCOVA design). This study included 93 patients with pre-trial transthoracic echocardiograms available (usual care n = 49; myPACE n = 44). NT-proBNP levels and MLHFQ scores improved in a higher magnitude in the myPACE group at lower indexed LV end-diastolic volumes (iLVEDV) (NT-proBNP-iLVEDV interaction p = 0.006; MLHFQ-iLVEDV interaction p = 0.068). In addition, personalized accelerated pacing led to improved changes in activity levels and NT-proBNP, especially at higher LVEF (activity levels-LVEF interaction p = 0.009; NT-proBNP-LVEF interaction p = 0.058). No evidence of heterogeneity was found across LV volumes or LVEF for pacemaker-detected AF burden. CONCLUSIONS: In the post-hoc analysis of the myPACE trial, we observed that the benefits of a personalized accelerated backup pacing on MLHFQ score, NT-proBNP, and pacemaker-detected activity levels appear to be more pronounced in patients with smaller iLVEDV and higher LVEF.

La reducción temprana del filtrado glomerular se asocia con aumento de la hemoglobina tras el inicio de dapagliflozina en la insuficiencia cardiaca con fracción de eyección reducida / Early glomerular filtration rate decline is associated with hemoglobin rise following dapagliflozin initiation in heart failure with reduced ejection fraction

Introducción y objetivos: Los inhibidores del cotransportador 2 de sodio-glucosa (iSGLT2) inducen cambios a corto plazo en la función renal y la hemoglobina y su fisiopatología se comprende de manera incompleta. Nuestro objetivo es evaluar la relación entre los cambios de la tasa de filtrago glomerular estimado (TFGre) y la hemoglobina tras el inicio de dapagliflozina en pacientes estables con insuficiencia cardiaca y fracción de eyección reducida (IC-FEr). Métodos: Este análisis post hoc de un ensayo clínico aleatorizado evaluó el efecto de la dapagliflozina sobre el consumo máximo de oxígeno a 1 y 3 meses en pacientes ambulatorios con IC-FEr estable (ensayo DAPA-VO2, NCT04197635). Se utilizó un análisis de regresión lineal mixta para evaluar la relación entre los cambios en la TFGe y la hemoglobina a 1 y 3 meses. Resultados: Se evaluó a 87 pacientes. La media de edad era 67,0±10,5 años, y 21 pacientes (24,1%) eran mujeres. Las medias basales de TFGe y hemoglobina fueron de 66,9±20,7ml/min/1,73 m2 y 14,3±1,7g/dl respectivamente. En comparación con el placebo, la TFGe no cambió significativamente en el grupo de dapagliflozina, pero la hemoglobina aumentó significativamente a 1 y 3 meses. A 1 mes, el aumento de la hemoglobina se relacionó con la disminución de la TFGe solo en el grupo de dapagliflozina (p <0,001). A los 3 meses no había asociación significativa (p=0,123). Los cambios de la TFGe a 1 y 3 meses no se asociaron con cambios en el consumo pico de oxígeno, la calidad de vida o los péptidos natriuréticos. Conclusiones: En pacientes con IC-FEr estable, los cambios en la TFGe a 1 mes inducidos por la dapagliflozina están en relación inversa con cambios en la hemoglobina. Esta asociación no se observa a los 3 meses. (AU)

Introduction and objectives: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) induce short-term changes in renal function and hemoglobin. Their pathophysiology is incompletely understood. We aimed to evaluate the relationship between 1- and 3-month estimated glomerular filtration rate (eGFR) and hemoglobin changes following initiation of dapagliflozin in patients with stable heart failure with reduced ejection fraction (HFrEF). Methods: This is a post hoc analysis of a randomized clinical trial that evaluated the effect of dapagliflozin on 1- and 3-month peak oxygen consumption in outpatients with stable HFrEF (DAPA-VO2 trial, NCT04197635). We used linear mixed regression analysis to assess the relationship between eGFR and hemoglobin changes across treatment arms. Results: A total of 87 patients were evaluated in this substudy. The mean age was 67.0± 10.5 years, and 21 (24.1%) were women. The mean baseline eGFR and hemoglobin were 66.9±20.7mL/min/1.73m2 and 14.3±1.7g/dL, respectively. Compared with placebo, eGFR did not significantly change at either time points in the dapagliflozin group, but hemoglobin significantly increased at 1 and 3 months. At 1 month, the hemoglobin increase was related to decreases in eGFR only in the dapagliflozin arm (P <.001). At 3 months, there was no significant association in either treatment arms (P=.123). Changes in eGFR were not associated with changes in peak oxygen consumption, quality of life, or natriuretic peptides. Conclusions: In patients with stable HFrEF, 1-month changes in eGFR induced by dapagliflozin are inversely related to changes in hemoglobin. This association was no longer significant at 3 months. (AU)

Short-Term Changes in Peak VO2 After Initiation of Dapagliflozin in Heart Failure Across Iron Status.

BACKGROUND: Some studies have indicated that sodium-glucose cotransporter-2 (SGLT2) inhibitors promote an increase in cell iron use. OBJECTIVES: The aim of this study was to examine, in patients with stable heart failure with reduced left ventricular ejection fraction (HFrEF), the effect of dapagliflozin on ferrokinetic parameters and whether short-term changes in peak oxygen consumption (Vo2) after dapagliflozin treatment are influenced by baseline and serial ferrokinetic status. METHODS: This was an exploratory analysis of a randomized, double-blind clinical trial that evaluated the effect of dapagliflozin vs placebo on peak Vo2 in patients with HFrEF (NCT04197635) and included 76 of the 90 patients initially enrolled in the trial. Changes in peak Vo2 at 1 and 3 months were explored according to baseline and longitudinal ferrokinetic parameters (natural logarithm [ln] ferritin, transferrin saturation index [TSAT], soluble transferrin receptor, and hepcidin). Linear mixed-effect regression was used for the analyses. RESULTS: Compared with placebo, dapagliflozin led to a significant decrease in 3-month ln ferritin (P = 0.040) and an increase in 1-month ln soluble transferrin receptor (P = 0.023). Between-treatment comparisons revealed a stepwise increase in peak Vo2 in the dapagliflozin group at 1 and 3 months, which was especially apparent at lower baseline values of TSAT and ferritin (P < 0.05). Lower time-varying values of TSAT (1 and 3 months) also identified patients with greater improvements in peak Vo2. CONCLUSIONS: In patients with stable HFrEF, treatment with dapagliflozin resulted in short-term increases in peak Vo2, which were most marked in patients with surrogates of greater iron deficiency at baseline and during treatment. (Short-Term Effects of Dapagliflozin on Peak Vo2 in HFrEF [DAPA-VO2]; NCT04197635).

Short-term changes in klotho and FGF23 in heart failure with reduced ejection fraction-a substudy of the DAPA-VO2 study.

The klotho and fibroblast growth factor 23 (FGF-23) pathway is implicated in cardiovascular pathophysiology. This substudy aimed to assess the changes in klotho and FGF-23 levels 1-month after dapagliflozin in patients with stable heart failure and reduced ejection fraction (HFrEF). The study included 29 patients (32.2% of the total), with 14 assigned to the placebo group and 15 to the dapagliflozin, as part of the double-blind, randomized clinical trial [DAPA-VO2 (NCT04197635)]. Blood samples were collected at baseline and after 30 days, and Klotho and FGF-23 levels were measured using ELISA Kits. Between-treatment changes (raw data) were analyzed by using the Mann-Whitney test and expressed as median (p25%-p75%). Linear regression models were utilized to analyze changes in the logarithm (log) of klotho and FGF-23. The median age was 68.3 years (60.8-72.1), with 79.3% male and 81.5% classified as NYHA II. The baseline medians of left ventricular ejection fraction, glomerular filtration rate, NT-proBNP, klotho, and FGF-23 were 35.8% (30.5-37.8), 67.4 ml/min/1.73 m2 (50.7-82.8), 1,285 pg/ml (898-2,305), 623.4 pg/ml (533.5-736.6), and 72.6 RU/ml (62.6-96.1), respectively. The baseline mean peak oxygen uptake was 13.1 ± 4.0 ml/kg/min. Compared to placebo, patients on dapagliflozin showed a significant median increase of klotho [Δ+29.5, (12.9-37.2); p = 0.009] and a non-significant decrease of FGF-23 [Δ-4.6, (-1.7 to -5.4); p = 0.051]. A significant increase in log-klotho (p = 0.011) and a decrease in log-FGF-23 (p = 0.040) were found in the inferential analysis. In conclusion, in patients with stable HFrEF, dapagliflozin led to a short-term increase in klotho and a decrease in FGF-23.

Índice cronotrópico y eventos adversos a largo plazo en insuficiencia cardiaca con fracción de eyección conservada / Chronotropic index and long-term outcomes in heart failure with preserved ejection fraction

Introducción y objetivos: Poco se sabe sobre la utilidad de la respuesta de la frecuencia cardiaca (FC) al ejercicio para la estratificación del riesgo en la insuficiencia cardiaca con fracción de eyección conservada (ICFEc). El objetivo de este estudio fue evaluar la asociación entre la respuesta de la FC al ejercicio y el riesgo de episodios de descompensación por insuficiencia cardiaca (DIC) en pacientes sintomáticos estables con ICFEc. Métodos: Se trata de un estudio unicéntrico que incluyó a un total de 133 pacientes con ICFEc (NYHA II-III) tras la realización de una prueba de esfuerzo cardiopulmonar máxima. La respuesta de la FC al ejercicio se evaluó mediante la fórmula del índice cronotrópico (IxC). Para el análisis se utilizó un método de regresión binomial negativa. Resultados: La edad media fue de 73,2±10,5 años, el 56,4% eran mujeres y el 51,1% estaban en fibrilación auricular. La mediana de IxC fue de 0,4 (0,3-0,55). Tras una mediana de seguimiento de 2,4 (1,6-5,3) años, se registraron un total de 146 DIC en 58 pacientes y 41 (30,8%) muertes. El IxC no se asoció con eventos adversos (muerte, p=0,319, y DIC, p=0,573) cuando se analizó de forma conjunta toda la muestra. Sin embargo, se encontró un efecto diferencial en función del ritmo electrocardiográfico para DIC (p para interacción=0,002). El IxC se asoció inversa y linealmente con el riesgo de DIC en aquellos pacientes con ritmo sinusal y de forma lineal y positiva con aquellos en fibrilación auricular. Conclusiones: En pacientes con ICFEc, el IxC se asoció diferencialmente con el riesgo de DIC en función del ritmo electrocardiográfico. Un Ixc más bajo surgió como un factor de riesgo para predecir un mayor riesgo de DIC en pacientes en ritmo sinusal. Por el contrario, un IxC más alto identificó un mayor riesgo en aquellos pacientes en fibrilación auricular. (AU)

Introduction and objectives: Little is known about the usefulness of heart rate (HR) response to exercise for risk stratification in heart failure with preserved ejection fraction (HFpEF). Therefore, this study aimed to assess the association between HR response to exercise and the risk of total episodes of worsening heart failure (WHF) in symptomatic stable patients with HFpEF. Methods: This single-center study included 133 patients with HFpEF (NYHA II-III) who performed maximal cardiopulmonary exercise testing. HR response to exercise was evaluated using the chronotropic index (CIx) formula. A negative binomial regression method was used. Results: The mean age of the sample was 73.2± 10.5 years; 56.4% were female, and 51.1% were in atrial fibrillation. The median for CIx was 0.4 [0.3-0.55]. At a median follow-up of 2.4 [1.6-5.3] years, a total of 146 WHF events in 58 patients and 41 (30.8%) deaths were registered. In the whole sample, CIx was not associated with adverse outcomes (death, P=.319, and WHF events, P=.573). However, we found a differential effect across electrocardiographic rhythms for WHF events (P for interaction=.002). CIx was inversely and linearly associated with the risk of WHF events in patients with sinus rhythm and was positively and linearly associated with those with atrial fibrillation. Conclusions: In patients with HFpEF, CIx was differentially associated with the risk of total WHF events across rhythm status. Lower CIx emerged as a risk factor for predicting higher risk in patients with sinus rhythm. In contrast, higher CIx identified a higher risk in those with atrial fibrillation. (AU)

Dapagliflozin and short-term changes on circulating antigen carbohydrate 125 in heart failure with reduced ejection fraction.

Circulating antigen carbohydrate 125 (CA125) has emerged as a proxy of fluid overload in heart failure. This study aimed to evaluate the effect of dapagliflozin on short-term CA125 levels in patients with stable heart failure with reduced ejection fraction (HFrEF) and whether these changes mediated the effects on peak oxygen consumption (peakVO2). This study is a post-hoc sub-analysis of a randomized, double-blinded clinical trial in which 90 stable patients with HFrEF were randomly assigned to receive either dapagliflozin or placebo to evaluate change in peakVO2 (NCT04197635). We used linear mixed regression analysis to compare changes in the natural logarithm of CA125 (logCA125) and percent changes from baseline (Δ%CA125). We used the "rwrmed" package to perform mediation analyses. CA125 was available in 87 patients (96.7%). LogCA125 significantly decreased in patients on treatment with dapagliflozin [1-month: Δ - 0.18, (CI 95% = - 0.33 to - 0.22) and 3-month: Δ - 0.23, (CI 95% = - 0.38 to - 0.07); omnibus p-value = 0.012]. Δ%CA125 decreased by 18.4% and 31.4% at 1 and 3-month, respectively (omnibus p-value = 0.026). Changes in logCA125 mediated the effect on peakVO2 by 20.4% at 1 month (p < 0.001). We did not find significant changes for natural logarithm of NTproBNP (logNT-proBNP) [1-month: Δ - 0.03, (CI 95% = - 0.23 to 0.17; p = 0.794), and 3-month: Δ 0.73, (CI 95% = - 0.13 to 0.28; p-value 0.489), omnibus p-value = 0.567]. In conclusion, in patients with stable HFrEF, dapagliflozin resulted in a significant reduction in CA125. Dapagliflozin was not associated with short-term changes in natriuretic peptides. These changes mediated the effects on peakVO2.

Early glomerular filtration rate decline is associated with hemoglobin rise following dapagliflozin initiation in heart failure with reduced ejection fraction.

INTRODUCTION AND OBJECTIVES: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) induce short-term changes in renal function and hemoglobin. Their pathophysiology is incompletely understood. We aimed to evaluate the relationship between 1- and 3-month estimated glomerular filtration rate (eGFR) and hemoglobin changes following initiation of dapagliflozin in patients with stable heart failure with reduced ejection fraction (HFrEF). METHODS: This is a post hoc analysis of a randomized clinical trial that evaluated the effect of dapagliflozin on 1- and 3-month peak oxygen consumption in outpatients with stable HFrEF (DAPA-VO2 trial, NCT04197635). We used linear mixed regression analysis to assess the relationship between eGFR and hemoglobin changes across treatment arms. RESULTS: A total of 87 patients were evaluated in this substudy. The mean age was 67.0± 10.5 years, and 21 (24.1%) were women. The mean baseline eGFR and hemoglobin were 66.9±20.7mL/min/1.73m2 and 14.3±1.7g/dL, respectively. Compared with placebo, eGFR did not significantly change at either time points in the dapagliflozin group, but hemoglobin significantly increased at 1 and 3 months. At 1 month, the hemoglobin increase was related to decreases in eGFR only in the dapagliflozin arm (P <.001). At 3 months, there was no significant association in either treatment arms (P=.123). Changes in eGFR were not associated with changes in peak oxygen consumption, quality of life, or natriuretic peptides. CONCLUSIONS: In patients with stable HFrEF, 1-month changes in eGFR induced by dapagliflozin are inversely related to changes in hemoglobin. This association was no longer significant at 3 months.

A model-driven transformation approach for the modelling of processes in clinical practice guidelines.

Clinical Practice Guidelines (CPGs) include recommendations aimed at optimising patient care, informed by a review of the available clinical evidence. To achieve their potential benefits, CPG should be readily available at the point of care. This can be done by translating CPG recommendations into one of the languages for Computer-Interpretable Guidelines (CIGs). This is a difficult task for which the collaboration of clinical and technical staff is crucial. However, in general CIG languages are not accessible to non-technical staff. We propose to support the modelling of CPG processes (and hence the authoring of CIGs) based on a transformation, from a preliminary specification in a more accessible language into an implementation in a CIG language. In this paper, we approach this transformation following the Model-Driven Development (MDD) paradigm, in which models and transformations are key elements for software development. To demonstrate the approach, we implemented and tested an algorithm for the transformation from the BPMN language for business processes to the PROforma CIG language. This implementation uses transformations defined in the ATLAS Transformation Language. Additionally, we conducted a small experiment to assess the hypothesis that a language such as BPMN can facilitate the modelling of CPG processes by clinical and technical staff.

Short-term Changes in Hemoglobin and Changes in Functional Status, Quality of Life and Natriuretic Peptides After Initiation of Dapagliflozin in Heart Failure With Reduced Ejection Fraction.

BACKGROUND: We aimed to evaluate the effect of dapagliflozin on short-term changes in hemoglobin in patients with stable heart failure with reduced ejection fraction (HFrEF) and whether these changes mediated the effect of dapagliflozin on functional capacity, quality of life and NT-proBNP levels. METHODS: This is an exploratory analysis of a randomized, double-blinded clinical trial in which 90 stable patients with HFrEF were randomly allocated to dapagliflozin or placebo to evaluate short-term changes in peak oxygen consumption (peak VO2) (NCT04197635). This substudy evaluated 1- and 3-month changes in hemoglobin levels and whether these changes mediated the effects of dapagliflozin on peak VO2, Minnesota Living-With-Heart-Failure test (MLHFQ) and NT-proBNP levels. RESULTS: At baseline, mean hemoglobin levels were 14.3 ± 1.7 g/dL. Hemoglobin levels significantly increased in those taking dapagliflozin (1 month: + 0.45 g/dL (P = 0.037) and 3 months:+ 0.55 g/dL (P = 0.012)]. Changes in hemoglobin levels positively mediated the changes in peak VO2 at 3 months (59.5%; P < 0.001). Changes in hemoglobin levels significantly mediated the effect of dapagliflozin in the MLHFQ at 3 months (-53.2% and -48.7%; P = 0.017) and NT-proBNP levels at 1 and 3 months (-68.0%; P = 0.048 and -62.7%; P = 0.029, respectively). CONCLUSIONS: In patients with stable HFrEF, dapagliflozin caused a short-term increase in hemoglobin levels, identifying patients with greater improvements in maximal functional capacity, quality of life and reduction of NT-proBNP levels.

Maximal functional capacity in subjects with isolated left bundle branch block: A pilot study.

BACKGROUND: Left bundle branch block (LBBB) has been commonly associated with adverse cardiovascular (CV) events, but the effect of an isolated LBBB on maximal functional capacity is not well characterized. OBJECTIVE: To evaluate maximal functional capacity in adults with isolated LBBB and compare it to healthy population-derived predicted values (adjusted for sex, age, weight, and height). METHODS: This descriptive pilot study included subjects with isolated LBBB derived from outpatient clinics of two academic hospitals. All subjects underwent maximal cardiopulmonary exercise testing (CPET) and a Global Physical Activity Questionnaire (GPAQ). The primary outcome was to evaluate maximal functional capacity according to population-derived predicted values of peak oxygen consumption (peakVO2 ): pp-peakVO2 . The secondary outcome was to report adverse CV events (CV deaths or hospitalizations) at follow-up. RESULTS: A total of 27 (18 women and 9 men) participants were included. The median (interquartile range) age of the sample and time to screening from the first LBBB diagnosis were 62 (51-71) and 3.4 (1.1-8.4) years, respectively. The results of the GPAQ score showed that 19 patients were highly active, and 8 were moderately active. The median of peakVO2 and pp-peakVO2 were 19.3 (15-22.5) ml/kg/min and 88% (79.3%-104.4%), respectively. There were no adverse CV events at a median follow-up after CPET of 3.1 (2.7-3.4) years. CONCLUSION: In this pilot study, adults with isolated LBBB showed reduced maximal functional capacity, despite the absence of cardiac disease and a baseline moderate to highly active lifestyle.

Chronotropic index and long-term outcomes in heart failure with preserved ejection fraction.

INTRODUCTION AND OBJECTIVES: Little is known about the usefulness of heart rate (HR) response to exercise for risk stratification in heart failure with preserved ejection fraction (HFpEF). Therefore, this study aimed to assess the association between HR response to exercise and the risk of total episodes of worsening heart failure (WHF) in symptomatic stable patients with HFpEF. METHODS: This single-center study included 133 patients with HFpEF (NYHA II-III) who performed maximal cardiopulmonary exercise testing. HR response to exercise was evaluated using the chronotropic index (CIx) formula. A negative binomial regression method was used. RESULTS: The mean age of the sample was 73.2± 10.5 years; 56.4% were female, and 51.1% were in atrial fibrillation. The median for CIx was 0.4 [0.3-0.55]. At a median follow-up of 2.4 [1.6-5.3] years, a total of 146 WHF events in 58 patients and 41 (30.8%) deaths were registered. In the whole sample, CIx was not associated with adverse outcomes (death, P=.319, and WHF events, P=.573). However, we found a differential effect across electrocardiographic rhythms for WHF events (P for interaction=.002). CIx was inversely and linearly associated with the risk of WHF events in patients with sinus rhythm and was positively and linearly associated with those with atrial fibrillation. CONCLUSIONS: In patients with HFpEF, CIx was differentially associated with the risk of total WHF events across rhythm status. Lower CIx emerged as a risk factor for predicting higher risk in patients with sinus rhythm. In contrast, higher CIx identified a higher risk in those with atrial fibrillation.