Urinary Proteomics and Outcomes in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Although several studies have addressed plasma proteomics in heart failure with preserved ejection fraction, limited data are available on the prognostic value of urinary proteomics. The objective of our study was to identify urinary proteins/peptides associated with death and heart failure admission in patients with heart failure with preserved ejection fraction. METHODS AND RESULTS: The study population included participants enrolled in TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist Trial). The relationship between urine protein levels and the risk of death or heart failure admission was assessed using Cox regression, in both nonadjusted analyses and adjusting for urine creatinine levels, and the MAGGIC (Meta-Analysis Global Group in Chronic Heart Failure) score. A total of 426 (12.4%) TOPCAT participants had urinary protein data and were included. There were 40 urinary proteins/peptides significantly associated with death or heart failure admission in nonadjusted analyses, 21 of which were also significant adjusted analyses. Top proteins in the adjusted analysis included ANGPTL2 (angiopoietin-like protein 2) (hazard ratio [HR], 0.5731 [95% CI, 0.47-0.7]; P=3.13E-05), AMY2A (α amylase 2A) (HR, 0.5496 [95% CI, 0.44-0.69]; P=0.0001), and DNASE1 (deoxyribonuclease-1) (HR, 0.5704 [95% CI, 0.46-0.71]; P=0.0002). Higher urinary levels of proteins involved in fibrosis (collagen VI α-1, collagen XV α-1), metabolism (pancreatic α-amylase 2A/B, mannosidase α class 1A member 1), and inflammation (heat shock protein family D member 1, inducible T cell costimulatory ligand) were associated with a lower risk of death or heart failure admission. CONCLUSIONS: Our study identifies several novel associations between urinary proteins/peptides and outcomes in heart failure with preserved ejection fraction. Many of these associations are independent of clinical risk scores and may aid in risk stratification in this patient population.

Post-diuretic spot urine sodium assessment in acute heart failure: a retrospective analysis.

AIMS: To provide real-world data on post-diuretic spot urine sodium concentration (UNa) assessment in acute heart failure (AHF) and its implications for treatment. METHODS AND RESULTS: Automated query of the electronic medical record identified patients admitted to the cardiac intensive care unit of a single tertiary care hospital between November 2018 and December 2021, who received intravenous loop diuretics. Detailed manual chart review confirmed the AHF diagnosis. Stratification was performed based on whether post-diuretic UNa was assessed within 24 h of admission. AHF was confirmed in 340/380 identified patients. Post-diuretic UNa was assessed in 117 (34%), more frequently when ejection fraction was reduced and heart failure more advanced. Patients with versus without post-diuretic UNa assessment received higher doses of intravenous loop diuretics and more frequently acetazolamide and thiazide-like diuretics (p < 0.001 for all), resulting in similar urine output despite more advanced heart failure [2,488 mL (1,740-4,033 mL) vs. 2,400 mL (1,553-3,250 mL), respectively; p = 0.170]. Diuretic therapy remained more intense at discharge in the post-diuretic UNa group, with also a higher prescription rate of angiotensin-neprilysin inhibitors (p = 0.021). Serum creatinine increases/decreases were similarly frequent irrespectively from UNa assessment, with more dynamic changes observed in patients with UNa ≤ 80 mmol/L versus ≥ 81 mmol/L. After adjustments for baseline characteristics, the risk for death or heart failure readmission was similar in patients with versus without UNa assessment [HR (95%CI) = 1.43 (0.88-2.32); p = 0.150]. CONCLUSION: Post-diuretic UNa assessment in AHF was associated with more intense diuretic regimens, preserving urine output despite its use in a sicker population.

Urinary Cell Cycle Arrest Biomarkers and Diuretic Efficiency in Acute Heart Failure.

INTRODUCTION: This study aimed to evaluate the association between the NephroCheck® test AKIRisk® score, diuretic efficiency (DE), and the odds of worsening kidney function (WKF) within the first 72 h of admission in patients hospitalized for acute heart failure (AHF). METHODS: The study prospectively enrolled 125 patients admitted with AHF. NephroCheck® test was obtained within the first 24 h of admission. DE was defined as net fluid urine output per 40 mg of furosemide equivalents. RESULTS: The median AKIRisk® score was 0.11 (IQR 0.06-0.34), and 38 (30.4%) patients had an AKIRisk® score >0.3. The median cumulative DE at 72 h was 1,963 mL (IQR 1317-3,239 mL). At 72 h, a total of 10 (8%) patients developed an absolute increase in sCr ≥0.5 mg/dL (WKF). In a multivariable setting, there was an inverse association between the AKIRisk® score and DE within the first 72 h. In fact, the highest the AKIRisk® score (centered at 0.3), the higher the likelihood of poor DE (below the median) and WKF at 72 h (odds ratio [OR] 2.04; 95%; CI: 1.02-4.07; p = 0.043, and OR 3.31, 95% CI: 1.30-8.43; p = 0.012, respectively). CONCLUSION: In patients with AHF, a higher NephroCheck® AKIRisk® score is associated with poorer DE and a higher risk of WKF at 72 h. Further research is needed to confirm the role of urinary cell cycle arrest biomarkers in the AHF scenario.

The impact of urinary albumin-creatinine ratio and glomerular filtration rate on long-term mortality in patients with heart failure: The National Health and Nutrition Examination Survey 1999-2018.

BACKGROUND AND AIMS: The urinary albumin‒creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) are important markers of renal dysfunction, but few studies have simultaneously examined their impact on long-term mortality in patients with heart failure (HF). METHODS AND RESULTS: This study included patients with HF from the National Health and Nutrition Survey from 1999 to 2018. The fully adjusted Cox proportional risk model was adopted, and propensity score matching (PSM) was also used for risk adjustment. Among 988 patients, a median follow-up of 7.75 years was recorded. A higher UACR corresponded to a higher risk of cardiovascular death (P < 0.001 for trend). No statistically significant difference was found in the trend of eGFR risk stratification on the risk of cardiovascular death (P = 0.09 for trend). After PSM, the results showed that when grouped by UACR, the high-risk group had a higher risk of cardiovascular death regardless of a cutoff value of 30 or 300 mg/g (all P < 0.05). When grouped by eGFR, regardless of a cutoff value of 45 or 30 mL/min/1.73 m2, compared to the low-risk group, the high-risk group did not have a statistically significant increase in cardiovascular death (P = 0.086 and P = 0.093, respectively). The subgroup analysis of the main outcome showed an interaction between the UACR and eGFR (P = 0.044). CONCLUSIONS: Both the UACR and eGFR are markers for predicting the progression of HF, but the UACR may be a more important indicator than the eGFR, and they synergistically and complementarily reflect the long-term cardiovascular risk of HF patients.

Trajectory of Urine Albumin-Creatinine Ratio in Patients with Acute Heart Failure.

INTRODUCTION: Albuminuria is prevalent in patients with chronic heart failure and is a risk factor for disease progression. However, its clinical meaning in acute heart failure remains elusive. This study analyzed the trajectory of urine albumin to creatinine ratio (UACR) between admission and discharge and its association with decongestion. METHODS: In this prospective observational study, 63 patients were enrolled. UACR, B-type natriuretic peptide (BNP), and clinical congestion score (CCS) were obtained at admission and discharge. We used linear mixed regression analysis to compare changes in the natural logarithm of UACR (logUACR) and its association with changes in markers of decongestion. Estimates were reported as least squares mean with their respective 95% CIs. RESULTS: The median age of the study population was 87 years, 68.5% were women, and 69.8% had a left ventricular ejection fraction >50%. LogUACR at discharge significantly decreased in the overall population compared to admission (Δ -0.47, 95% CI: -0.78 to -0.15, p value = 0.003). The magnitude of UACR drop at discharge was associated with changes in surrogate markers of decongestion. Patients who showed a greater reduction in BNP at discharge exhibited a greater reduction in UACR (p = 0.016). The same trend was also found with clinical decongestion, as assessed by changes in CCS, however, without achieving statistical significance (p = 0.171). UACR change at discharge was not associated with changes in serum creatinine (p value = 0.923). CONCLUSION: In elderly patients with AHF and volume overload, the level of UACR significantly decreased upon discharge compared to admission. This reduction in UACR was closely linked to decreases in BNP.

Urinary Proteomic Signature in Acute Decompensated Heart Failure: Advances into Molecular Pathophysiology.

Acute decompensated heart failure (ADHF) is a life-threatening clinical syndrome involving multi-organ function deterioration. ADHF results from multifaceted, dysregulated pathways that remain poorly understood. Better characterization of proteins associated with heart failure decompensation is needed to gain understanding of the disease pathophysiology and support a more accurate disease phenotyping. In this study, we used an untargeted mass spectrometry (MS) proteomic approach to identify the differential urine protein signature in ADHF patients and examine its pathophysiological link to disease evolution. Urine samples were collected at hospital admission and compared with a group of healthy subjects by two-dimensional electrophoresis coupled to MALDI-TOF/TOF mass spectrometry. A differential pattern of 26 proteins (>1.5-fold change, p < 0.005), mostly of hepatic origin, was identified. The top four biological pathways (p < 0.0001; in silico analysis) were associated to the differential ADHF proteome including retinol metabolism and transport, immune response/inflammation, extracellular matrix organization, and platelet degranulation. Transthyretin (TTR) was the protein most widely represented among them. Quantitative analysis by ELISA of TTR and its binding protein, retinol-binding protein 4 (RBP4), validated the proteomic results. ROC analysis evidenced that combining RBP4 and TTR urine levels highly discriminated ADHF patients with renal dysfunction (AUC: 0.826, p < 0.001) and significantly predicted poor disease evolution over 18-month follow-up. In conclusion, the MS proteomic approach enabled identification of a specific urine protein signature in ADHF at hospitalization, highlighting changes in hepatic proteins such as TTR and RBP4.

Identifying Candidate Protein Markers of Acute Kidney Injury in Acute Decompensated Heart Failure.

One-quarter of patients with acute decompensated heart failure (ADHF) experience acute kidney injury (AKI)-an abrupt reduction or loss of kidney function associated with increased long-term mortality. There is a critical need to identify early and real-time markers of AKI in ADHF; however, to date, no protein biomarkers have exhibited sufficient diagnostic or prognostic performance for widespread clinical uptake. We aimed to identify novel protein biomarkers of AKI associated with ADHF by quantifying changes in protein abundance in the kidneys that occur during ADHF development and recovery in an ovine model. Relative quantitative protein profiling was performed using sequential window acquisition of all theoretical fragment ion spectra-mass spectrometry (SWATH-MS) in kidney cortices from control sheep (n = 5), sheep with established rapid-pacing-induced ADHF (n = 8), and sheep after ~4 weeks recovery from ADHF (n = 7). Of the 790 proteins quantified, we identified 17 candidate kidney injury markers in ADHF, 1 potential kidney marker of ADHF recovery, and 2 potential markers of long-term renal impairment (differential abundance between groups of 1.2-2.6-fold, adjusted p < 0.05). Among these 20 candidate protein markers of kidney injury were 6 candidates supported by existing evidence and 14 novel candidates not previously implicated in AKI. Proteins of differential abundance were enriched in pro-inflammatory signalling pathways: glycoprotein VI (activated during ADHF development; adjusted p < 0.01) and acute phase response (repressed during recovery from ADHF; adjusted p < 0.01). New biomarkers for the early detection of AKI in ADHF may help us to evaluate effective treatment strategies to prevent mortality and improve outcomes for patients.

Characterization of Circulating and Urinary Biomarkers in the Fontan Circulation and Their Correlation With Cardiac Imaging.

Several circulating biomarkers have been found to play a role in the surveillance and risk stratification of heart failure without congenital heart disease, but these have not been widely studied in patients with single ventricles palliated with a Fontan operation. Imaging predictors of worse outcomes in this population include ventricular dilation and dysfunction. Patients who weighed >30 kg with a Fontan circulation referred for cardiac magnetic resonance imaging were invited to participate in the study. Blood and urine samples were obtained at the time of imaging and multiple conventional and novel biomarkers were measured. A total of 82 patients with a median age of 18 years were enrolled. Among the novel biomarkers, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin T had the strongest correlation with ventricular dilation and dysfunction. NT-ProBNP >100 pg/ml has a sensitivity of 91% for the detection of significant ventricular dilation (end-diastolic volume >120 ml/body surface area1.3) and 82% for detection of ejection fraction <50%. The urinary neutrophil gelatinase-associated lipocalin-2 to creatinine ratio correlated with ejection fraction and estimated glomerular filteration rate. In conclusion, abnormalities in biomarkers of heart failure are common in ambulatory, largely asymptomatic patients with Fontan circulation. NT-ProBNP may serve as a sensitive marker for the identification of patients with significant ventricular dilation or dysfunction. Further work is needed to understand how these easily measured circulating biomarkers may be integrated into clinical care.

Nutritional and Non-Nutritional Predictors of Low Spot Urinary Creatinine Concentration in Patients with Heart Failure.

Low spot urinary creatinine concentration (SUCR) is a marker of muscle wasting and clinical outcome. The risk factors for low SUCR in heart failure (HF) remain poorly understood. We explored the risk factors for low SUCR related to poor outcomes. In 721 HF patients (age: 52.3 ± 11 years, female: 14%, NYHA: 2.7 ± 0.7) SUCR and Dexa body composition scans were performed. BMI prior HF-onset, weight loss, and appendicular muscle mass were obtained. Each patient was classified as malnutrition or normal by GLIM criteria and three other biochemical indices (CONUT, PNI, and GRNI). Sarcopenia index (SI) as creatinine to cystatin C ratio was also calculated. Within 1 year, 80 (11.1%) patients died. In ROC curve we identified a SUCR value of 0.628 g/L as optimally discriminating surviving from dead. In low SUCR group more advanced HF, higher weight loss and catabolic components of weight trajectory (CCWT), more frequent under-nutrition by GLIM, and lower SI were observed. In multivariate analysis the independent predictors of low SUCR were SI, CCWT, and GNRI score. In conclusion: the risk of low SUCR was associated with a worse outcome. Low SUCR was associated with greater catabolism and sarcopenia but not with biochemical indices of malnutrition.

Relationship Between HbA1c Level and Effectiveness of SGLT2 Inhibitors in Decompensated Heart Failure Patients with Type 2 Diabetes Mellitus.

The DAPA-HF trial demonstrated that sodium-glucose cotransporter 2 inhibitors (SGLT2i) reduced worsening heart failure (HF) events in chronic HF patients with or without type 2 diabetic mellitus (T2DM). However, it remains unclear whether the effectiveness of SGLT2i is also observed in patients with decompensated HF irrespective of HbA1c level. Eighty-one T2DM patients hospitalized due to decompensated HF were enrolled and divided into 2 groups according to their HbA1c levels (group H, HbA1c 6.9-13.0%, n = 41; group L, HbA1c < 6.9%, n = 40). After the initial management of HF, one of the SGLT2i (canagliflozin 100 mg/day or dapagliflozin 5 mg/day or empagliflozin 10 mg/day) was non-randomly administered, and clinical parameters associating with HF and T2DM were followed for 7 days. No symptomatic hypoglycemia was observed in any patient. In both groups, urine glucose excretion was increased significantly after the administration of SGLT2i. However, its amount was greater in group H than group L. Urine volume was increased significantly at day 1 in both groups. Urine volume returned to the baseline after one week in group L. In contrast, the increase in urine volume persisted at least for one week in group H. Of note, a decrease in B-type natriuretic peptide levels after the initiation of SGLT2i was observed in both groups similarly despite differences in urine output and excretion of urine glucose. In conclusion, SGLT2i can improve decompensated HF in patients with T2DM irrespective of the HbA1c level.

Urinary Levels of the Acrolein Conjugates of Carnosine Are Associated with Cardiovascular Disease Risk.

Carnosine is a naturally occurring dipeptide (ß-alanine-L-histidine) which supports physiological homeostasis by buffering intracellular pH, chelating metals, and conjugating with and neutralizing toxic aldehydes such as acrolein. However, it is not clear if carnosine can support cardiovascular function or modify cardiovascular disease (CVD) risk. To examine this, we measured urinary levels of nonconjugated carnosine and its acrolein conjugates (carnosine-propanal and carnosine-propanol) in participants of the Louisville Healthy Heart Study and examined associations with indices of CVD risk. We found that nonconjugated carnosine was significantly associated with hypertension (p = 0.011), heart failure (p = 0.015), those categorized with high CVD risk (p < 0.001), body mass index (BMI; p = 0.007), high sensitivity C-reactive protein (hsCRP; p = 0.026), high-density lipoprotein (HDL; p = 0.007) and certain medication uses. Levels of carnosine-propanal and carnosine-propanol demonstrated significant associations with BMI, blood glucose, HDL and diagnosis of diabetes. Carnosine-propanal was also associated with heart failure (p = 0.045) and hyperlipidemia (p = 0.002), but no associations with myocardial infarction or stroke were identified. We found that the positive associations of carnosine conjugates with diabetes and HDL remain statistically significant (p < 0.05) in an adjusted, linear regression model. These findings suggest that urinary levels of nonconjugated carnosine, carnosine-propanal and carnosine-propanol may be informative biomarkers for the assessment of CVD risk-and particularly reflective of skeletal muscle injury and carnosine depletion in diabetes.

Comparing Diuresis Patterns in Hospitalized Patients With Heart Failure With Reduced Versus Preserved Ejection Fraction: A Retrospective Analysis.

BACKGROUND: Congestion predominates in exacerbations of heart failure with reduced ejection fraction (HFrEF) or preserved ejection fraction (HFpEF), but evidence suggests that excess volume may be distributed differently in these 2 subgroups. METHODS AND RESULTS: In this retrospective study, diuretic efficiency (DE, or net urine output per 40-mg of intravenous furosemide equivalent) during the first 72 hours was compared between patients hospitalized with HFrEF (n = 121) versus HFpEF (n = 120). Multivariate analysis was used to compare the 2 groups based on expected baseline differences (e.g., demographics, heart failure etiology, concomitant therapy). During the first 72 hours, mean daily diuretic doses were higher in patients with HFpEF versus HFrEF (172.0 vs. 159.9 mg, respectively, P = 0.026) but urine output was not significantly different (2603.3 mL vs. 2667.5 mL, respectively, adjusted P = 0.100). Similarly, mean cumulative DE did not differ (-673.5 vs. -637.8 mL/40-mg in the HFrEF and HFpEF groups, respectively, adjusted P = 0.884). An exploratory analysis of propensity-matched cohorts yielded similar findings. Correlations between the components of DE varied considerably and only became weak to moderately correlated toward the end of the observation period. CONCLUSIONS: Although cumulative DE did not differ between patients with HFrEF and HFpEF, variable correlations in the components of DE suggest there may be differences in diuretic response that warrant future analysis.

Time Course Changes in Urinary Angiotensinogen and Circulating N-Terminal Pro-B-Type Natriuretic Peptide in Patients Hospitalized with Acute Heart Failure.

Objective Home care is important in patients with heart failure (HF) in order to maintain their quality of life. A biomarker that can be measured noninvasively is needed to optimize the home care of patients with HF. Urinary angiotensinogen (uAGT) is an indicator of the intrarenal renin-angiotensin system activity, which may be augmented in HF. We hypothesized that uAGT might be a urinary biomarker in HF. Methods We measured uAGT by an enzyme-linked immunosorbent assay and uAGT normalized by urinary creatinine (uCr)-designated uAGT/uCr-at admission and discharge in 45 patients hospitalized for HF. Results We found that both uAGT/uCr [median (interquartile range): 65.5 (17.1-127.7) µg/g Cr at admission; 12.1 (6.0-37.0) µg/g Cr at discharge; p<0.01] and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels [5,422 (2,280-9,907) pg/mL at admission; 903 (510-1,729) pg/mL at discharge; p<0.01] significantly decreased between admission and discharge along with an improvement in patient's clinical status [New York Heart Association scores: 3 (3-4) at admission; 1 (1-1) at discharge; p<0.01]. The generalized least squares model revealed that the time course changes in uAGT/uCr also correlated with those in NT-proBNP levels between admission and readmission in five patients readmitted for HF. Conclusion The results indicated that the time course changes in uAGT/uCr correlated with those in the NT-proBNP levels in patients with HF who showed a clinical improvement. Further investigation and development of a kit for the rapid measurement of uAGT are needed to evaluate the clinical utility of uAGT as a biomarker in HF.

Higher urinary nitrate was associated with lower prevalence of congestive heart failure: results from NHANES.

BACKGROUND: Some studies have reported that nitrate intake from vegetables was inversely associated with many vascular diseases, but few studies have paid attention to the relationship between urinary nitrate and cardiovascular diseases (CVDs). This cross-sectional study aimed to explore the connections between urinary nitrate and prevalence of CVDs. METHODS: The data of this study was collected from National Health and Nutrition Examination Survey (NHANES). Finally, several years' data of NHANES were merged into 14,894 observations. Logistic regression models were used to examine the associations between urinary nitrate and CVDs by using the "survey" package in R software (version 3.2.3). RESULTS: In the univariable logistic analysis, significant association was discovered between urinary nitrate and congestive heart failure, coronary heart disease, angina pectoris, myocardial infarction (all P < 0.001). By adjusting related covariates, the multivariable logistic analysis showed that the significant association only existed between urinary nitrate and congestive heart failure (OR = 0.651, 95% CI 0.507-0.838, P < 0.001). Compared to Q1 urinary nitrate level as reference, the risk for prevalent heart failure diminished along with increasing levels of urinary nitrates, (OR of Q2 level = 0.633, 95% CI 0.403-0.994), (OR of Q3 level = 0.425, 95% CI 0.230-0.783), (OR of Q4 level = 0.375, 95% CI 0.210-0.661), respectively. Moreover, urinary nitrate levels were associated with congestive heart failure in a dose-dependent manner in both 20-60 years group, 60+ years group and male, female group (P < 0.001, P = 0.011 and P = 0.009, P = 0.004). CONCLUSIONS: Independent of related covariates, higher urinary nitrate was associated with lower prevalent congestive heart failure.

Renal and Cardiovascular Effects of SGLT2 Inhibition in Combination With Loop Diuretics in Patients With Type 2 Diabetes and Chronic Heart Failure: The RECEDE-CHF Trial.

BACKGROUND: SGLT2 (sodium-glucose cotransporter-2) inhibitors improve heart failure-associated outcomes in patients with type 2 diabetes. In patients with heart failure, SGLT2 inhibitors will likely be coprescribed with a loop diuretic, but this combined effect is not well-defined. Our aim was to assess the diuretic and natriuretic effect of empagliflozin in combination with loop diuretics. METHODS: The RECEDE-CHF trial (SGLT2 Inhibition in Combination With Diuretics in Heart Failure) was a randomized, double-blind, placebo-controlled, crossover trial of patients with type 2 diabetes and heart failure with reduced ejection fraction taking regular loop diuretic who were randomized to empagliflozin 25 mg once daily or placebo for 6 weeks with a 2-week washout period. The primary outcome was change in 24-hour urinary volume from baseline to week 6. RESULTS: Twenty-three participants (mean age, 69.8 years; 73.9% male; mean furosemide dose, 49.6±31.3 mg/d; mean HbA1c, 7.9±3.8%) were recruited. Compared with placebo, empagliflozin caused a significant increase in 24-hour urinary volume at both day 3 (mean difference, 535 mL [95% CI, 133-936]; P=0.005) and week 6 (mean difference, 545 mL [95% CI, 136-954]; P=0.005) after adjustment for treatment order, baseline 24-hour urine volume, and percentage change in loop diuretic dose. At 6 weeks, empagliflozin did not cause a significant change in 24-hour urinary sodium (mean difference, -7.85 mmol/L [95% CI, -2.43 to 6.73]; P=0.57). Empagliflozin caused a nonsignificant increase in fractional excretion of sodium at day 3, which was absent at week 6 (mean difference day 3, 0.30% [95% CI, -0.03 to 0.63]; P=0.09; week 6, 0.11% [95% CI, -0.22 to 0.44]; P>0.99), and a significant increase in electrolyte-free water clearance at week 6 (mean difference, 312 mL [95% CI, 26-598]; P=0.026) compared with placebo. Empagliflozin also caused significant reductions in body weight and serum urate at week 6. CONCLUSIONS: Empagliflozin caused a significant increase in 24-hour urine volume without an increase in urinary sodium when used in combination with loop diuretic. Registration: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT03226457.

Heart Failure Disturbs Gut-Blood Barrier and Increases Plasma Trimethylamine, a Toxic Bacterial Metabolite.

Trimethylamine (TMA) is a gut bacteria product oxidized by the liver to trimethylamine-N-oxide (TMAO). Clinical evidence suggests that cardiovascular disease is associated with increased plasma TMAO. However, little headway has been made in understanding this relationship on a mechanistic and molecular level. We investigated the mechanisms affecting plasma levels of TMAO in Spontaneously Hypertensive Heart Failure (SHHF) rats. Healthy Wistar Kyoto (WKY) and SHHF rats underwent metabolic, hemodynamic, histopathological and biochemical measurements, including tight junction proteins analysis. Stool, plasma and urine samples were evaluated for TMA and TMAO using ultra performance liquid chromatography-mass spectrometry. SHHF presented disturbances of the gut-blood barrier including reduced intestinal blood flow, decreased thickness of the colonic mucosa and alterations in tight junctions, such as claudin 1 and 3, and zonula occludens-1. This was associated with significantly higher plasma levels of TMA and TMAO and increased gut-to-blood penetration of TMA in SHHF compared to WKY. There was no difference in kidney function or liver oxidation of TMA to TMAO between WKY and SHHF. In conclusion, increased plasma TMAO in heart failure rats results from a perturbed gut-blood barrier and increased gut-to-blood passage of TMAO precursor, i.e., TMA. Increased gut-to-blood penetration of bacterial metabolites may be a marker and a mediator of cardiovascular pathology.

Empagliflozin in Heart Failure: Diuretic and Cardiorenal Effects.

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors improve heart failure-related outcomes. The mechanisms underlying these benefits are not well understood, but diuretic properties may contribute. Traditional diuretics such as furosemide induce substantial neurohormonal activation, contributing to the limited improvement in intravascular volume often seen with these agents. However, the proximal tubular site of action of the sodium-glucose cotransporter-2 inhibitors may help circumvent these limitations. METHODS: Twenty patients with type 2 diabetes mellitus and chronic, stable heart failure completed a randomized, placebo-controlled crossover study of empagliflozin 10 mg daily versus placebo. Patients underwent an intensive 6-hour biospecimen collection and cardiorenal phenotyping at baseline and again after 14 days of study drug. After a 2-week washout, patients crossed over to the alternate therapy with the above protocol repeated. RESULTS: Oral empagliflozin was rapidly absorbed as evidenced by a 27-fold increase in urinary glucose excretion by 3 hours (P<0.0001). Fractional excretion of sodium increased significantly with empagliflozin monotherapy versus placebo (fractional excretion of sodium, 1.2±0.7% versus 0.7±0.4%; P=0.001), and there was a synergistic effect in combination with bumetanide (fractional excretion of sodium, 5.8±2.5% versus 3.9±1.9%; P=0.001). At 14 days, the natriuretic effect of empagliflozin persisted, resulting in a reduction in blood volume (-208 mL [interquartile range, -536 to 153 mL] versus -14 mL [interquartile range, -282 to 335 mL]; P=0.035) and plasma volume (-138 mL, interquartile range, -379 to 154±453 mL; P=0.04). This natriuresis was not, however, associated with evidence of neurohormonal activation because the change in norepinephrine was superior (P=0.02) and all other neurohormones were similar (P<0.34) during the empagliflozin versus placebo period. Furthermore, there was no evidence of potassium wasting (P=0.20) or renal dysfunction (P>0.11 for all biomarkers), whereas both serum magnesium (P<0.001) and uric acid levels (P=0.008) improved. CONCLUSIONS: Empagliflozin causes significant natriuresis, particularly when combined with loop diuretics, resulting in an improvement in blood volume. However, off-target electrolyte wasting, renal dysfunction, and neurohormonal activation were not observed. This favorable diuretic profile may offer significant advantage in the management of volume status in patients with heart failure and may represent a mechanism contributing to the superior long-term heart failure outcomes observed with these agents. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03027960.

Evaluating the confounding effects of medical therapies on potassium intake assessment in patients with heart failure.

BACKGROUND AND AIMS: Potassium-wasting (loop diuretics [LD]) and potassium-sparing (spironolactone) medications used for heart failure (HF) may alter renal potassium handling and confound the use of twenty-four-hour (24-h) urine collections as a surrogate marker for potassium intake, an effect that has been observed with dietary sodium assessment. The objective was to determine the strength of association between 24-h urine collections and weighed food records in assessing potassium intake in HF patients stratified by LD usage and spironolactone usage. METHODS AND RESULTS: Stable outpatients with HF simultaneously completed two 24-h urine collections and two weighed food records on consecutive days. Analyses compared patients stratified by LD and/or spironolactone use. Pearson's correlation and the Bland-Altman method of agreement assessed the relationship between the techniques. Overall, 109 patients (61 ± 11 yrs, 74% male) were included. The mean difference in dietary potassium estimated between 24-h urine collections and food records was -353 ± 1043 mg (p < 0.01) for all patients, with no differences between measures among subgroups. The association between the two methods was r = 0.551 (95% CI, 0.373 to 0.852, p < 0.001) for LD users; r = 0.287 (95% CI, 0.01 to 0.570, p = 0.050) for LD non-users; r = 0.321 (95% CI, 0.13 to 0.798, p = 0.043) for spironolactone users, and; r = 0.534 (95% CI, 0.331 to 0.747, p < 0.001) for spironolactone non-users. There were no significant mean biases identified as part of the Bland-Altman analysis. CONCLUSION: Among HF patients, potassium-wasting and potassium-sparing medications do not influence the agreement between the two methods in the assessment of potassium intake.