Prognostic performance of soluble urokinase plasminogen activator receptor for heart failure or mortality in Western and Asian patients with acute breathlessness

AIMS

The performance of circulating soluble urokinase plasminogen activator receptor (suPAR) for predicting the composite endpoint of subsequent heart failure (HF) hospitalisation and/or death at 1 year was assessed in (i) patients with undifferentiated breathlessness, and generalisability was compared in (ii) disparate Western versus Asian sub-cohorts, and in (iii) the sub-cohort adjudicated with HF.

METHODS AND RESULTS

Patients with acute breathlessness were recruited from the emergency departments in New Zealand (NZ, n = 612) and Singapore (n = 483). suPAR measured in the presentation samples was higher in patients incurring the endpoint (n = 281) compared with survivors (5.2 ng/mL vs 3.1 ng/mL, P < 0.0001). The discriminative power of suPAR for endpoint prediction was c-statistic of 0.77 in the combined population, but was superior in Singapore than NZ (c-statistic: 0.83 vs 0.71, P < 0.0001). Although the highest suPAR tertile (>4.37 ng/mL) was associated with risks of >4-fold in NZ, >20-fold in Singapore, and ≥3-fold in HF for incurring the outcome, there was no interaction between country and suPAR levels after adjustment. Multivariable analysis indicated suPAR to be robust in predicting HF/death at 1-year [hazard ratio: 1.9 (95% CI:1.7 to 2.0) per SD increase] and improved risk discrimination for outcome prediction in HF (∆0.06) and for those with NT-proBNP >1000 pg/mL (∆0.02).

CONCLUSION

suPAR is a strong independent predictor of HF and/or death at 1 year in acutely breathless patients, in both Asian and Western cohorts, and in HF. suPAR may improve stratification of acutely breathless patients, and in acute HF, for risk of later onset of heart failure or mortality.

Determination of Clinically Acceptable Analytical Variation of Cardiac Troponin at Decision Thresholds

BACKGROUND

Clinical decision-making for risk stratification for possible myocardial infarction (MI) uses high-sensitivity cardiac troponin (hs-cTn) thresholds that range from the limit of detection to several-fold higher than the upper reference limit (URL). To establish a minimum analytical variation standard, we can quantify the effect of variation on the population clinical measures of safety (sensitivity) and effectiveness [proportion below threshold, or positive predictive value (PPV)].

METHODS

From large datasets of patients investigated for possible MI with the Abbott hs-cTnI and Roche hs-cTnT assays, we synthesized datasets of 1 000 000 simulated patients. Troponin concentrations were randomly varied several times based on absolute deviations of 0.5 to 3 ng/L and relative changes of 2% to 20% around the low-risk threshold (5 ng/L) and URLs, respectively.

RESULTS

For both assays at the low-risk thresholds, there were negligible differences in sensitivity (<0.3%) with increasing analytical variation. The proportion of patients characterized as low risk reduced by 30% to 29% (Roche) and 53% to 44% (Abbott). At the URL, increasing analytical variation also did not change sensitivity; the PPV fell by less than 3%. For risk stratification, increased delta thresholds (change between serial troponin concentrations) increased sensitivity at the cost of a decreased percentage of patients below the delta threshold, with the largest changes at the greatest analytical variation.

CONCLUSIONS

At the low-risk threshold, analytical variation up to 3 ng/L minimally impacted the safety metric (sensitivity) but marginally reduced effectiveness. Similarly, at the URL even relative variation up to 25% minimally impacted safety metrics and effectiveness. Analytical variation for delta thresholds did not negatively impact sensitivity but decreased effectiveness.

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.

Mandibular Advancement vs CPAP for Blood Pressure Reduction in Patients With Obstructive Sleep Apnea

BACKGROUND

Hypertension guidelines recommend diagnosis and treatment of obstructive sleep apnea (OSA) in patients with hypertension. The mandibular advancement device (MAD) is an oral appliance therapy for patients who decline or cannot tolerate continuous positive airway pressure (CPAP).

OBJECTIVES

We compared the relative effectiveness of MAD vs CPAP in reducing 24-hour ambulatory blood pressure (BP).

METHODS

In an investigator-initiated, randomized, noninferiority trial (prespecified margin 1.5 mm Hg), 321 participants aged ≥40 years with hypertension and increased cardiovascular risk were recruited at 3 public hospitals for polysomnography. Of these, 220 participants with moderate-to-severe OSA (apnea-hypopnea index ≥15 events per hour) were randomized to either MAD or CPAP (1:1). The primary outcome was the difference between the 24-hour mean arterial BP at baseline and 6 months.

RESULTS

Compared with baseline, the 24-hour mean arterial BP decreased by 2.5 mm Hg (P = 0.003) at 6 months in the MAD group, whereas no change was observed in the CPAP group (P = 0.374). The between-group difference was -1.6 mm Hg (95% CI: -3.51 to 0.24, noninferiority P < 0.001). The MAD group demonstrated a larger between-group reduction in all secondary ambulatory BP parameters compared with the CPAP group, with the most pronounced effects observed in the asleep BP parameters. Both the MAD and CPAP improved daytime sleepiness, with the between-group difference similar (P = 0.384). There were no between-group differences in cardiovascular biomarkers.

CONCLUSIONS

MAD is noninferior to CPAP for reducing 24-hour mean arterial BP in participants with hypertension and increased cardiovascular risk. (Cardiosleep Research Program on Obstructive Sleep Apnea, Blood Pressure Control and Maladaptive Myocardial Remodeling-Non-inferiority Trial [CRESCENT]; NCT04119999).

Derivation and Validation of Thresholds Using Synthetic Data Methods for Single-Test Screening of Emergency Department Patients with Possible Acute Myocardial Infarction Using a Point-of-Care Troponin Assay

BACKGROUND

Single-sample (screening) rule-out of acute myocardial infarction (AMI) with troponin requires derivation of a single-test screening threshold. In data sets with small event numbers, the lowest one or two concentrations of myocardial infarction (MI) patients dictate the threshold. This is not optimal. We aimed to demonstrate a process incorporating both real and synthetic data for deriving such thresholds using a novel pre-production high-precision point-of-care assay.

METHODS

cTnI concentrations were measured from thawed plasma using the Troponin I Next (TnI-Nx) assay (i-STAT; Abbott) in adults on arrival to the emergency department with symptoms suggestive of AMI. The primary outcome was an AMI or cardiac death within 30 days. We used internal-external validation with synthetic data production based on clinical and demographic data, plus the measured TnI-Nx concentration, to derive and validate decision thresholds for TnI-Nx. The target low-risk threshold was a sensitivity of 99% and a high-risk threshold specificity of >95%.

RESULTS

In total, 1356 patients were included, of whom 191 (14.1%) had the primary outcome. A total of 500 synthetic data sets were constructed. The mean low-risk threshold was determined to be 5 ng/L. This categorized 38% (95% CI, 6%-68%) to low-risk with a sensitivity of 99.0% (95% CI, 98.6%-99.5%) and a negative predictive value of 99.4% (95% CI, 97.6%-99.8%). A similarly derived high-risk threshold of 25 ng/L had a specificity of 95.0% (95% CI, 94.8%-95.1%) and a positive predictive value of 74.8% (95% CI, 71.5%-78.0%).

CONCLUSIONS

With the TnI-Nx assay, we successfully demonstrated an approach using synthetic data generation to derive low-risk thresholds for safe and effective screening.

Convalescent Growth Differentiation Factor-15 and Long-Term Outcomes after an Acute Coronary Syndrome

BACKGROUND

Growth differentiation factor-15 (GDF-15) has been shown to be associated with adverse clinical outcomes in patients after an acute coronary syndrome when measured soon after an event. Although dynamic in the acute phase after myocardial injury, GDF-15 has been shown to remain stable during convalescence. In this study, we aimed to assess the value of GDF-15 as a long-term prognostic marker for clinical outcomes when measured in the convalescent phase following an acute coronary syndrome.

METHODS

GDF-15 concentrations were measured in 1945 patients who were recruited between 2002 and 2009 to the Coronary Disease Cohort Study. For this analysis, follow-up was curtailed at 10 years and association of GDF-15 with all-cause death, cardiovascular death, recurrent myocardial infarction, and heart failure hospitalizations were assessed with multivariate Cox proportional hazard regression analysis.

RESULTS

After 10 years of follow-up, there were 648 deaths (348 from cardiovascular causes), 500 admissions for myocardial infarction, and 436 for heart failure. Four-month convalescent GDF-15 demonstrated a robust independent association with all endpoints, which remained after adjustment for Global Registry of Acute Coronary Events score and other convalescent biomarkers. When compared to the lowest quartile of GDF-15 concentrations, those in the highest quartile had a 3-fold increased risk of all-cause death.

CONCLUSIONS

Convalescent plasma GDF-15 is a strong and independent predictor of 10-year all-cause death, cardiovascular death, recurrent myocardial infarction, and heart failure admission following an acute coronary syndrome.

AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY TRIAL ID

ACTRN12605000431628.

Asparagine Synthetase Marks a Distinct Dependency Threshold for Cardiomyocyte Dedifferentiation

BACKGROUND

Adult mammalian cardiomyocytes have limited proliferative capacity, but in specifically induced contexts they traverse through cell-cycle reentry, offering the potential for heart regeneration. Endogenous cardiomyocyte proliferation is preceded by cardiomyocyte dedifferentiation (CMDD), wherein adult cardiomyocytes revert to a less matured state that is distinct from the classical myocardial fetal stress gene response associated with heart failure. However, very little is known about CMDD as a defined cardiomyocyte cell state in transition.

METHODS

Here, we leveraged 2 models of in vitro cultured adult mouse cardiomyocytes and in vivo adeno-associated virus serotype 9 cardiomyocyte-targeted delivery of reprogramming factors (Oct4, Sox2, Klf4, and Myc) in adult mice to study CMDD. We profiled their transcriptomes using RNA sequencing, in combination with multiple published data sets, with the aim of identifying a common denominator for tracking CMDD.

RESULTS

RNA sequencing and integrated analysis identified Asparagine Synthetase (Asns) as a unique molecular marker gene well correlated with CMDD, required for increased asparagine and also for distinct fluxes in other amino acids. Although Asns overexpression in Oct4, Sox2, Klf4, and Myc cardiomyocytes augmented hallmarks of CMDD, Asns deficiency led to defective regeneration in the neonatal mouse myocardial infarction model, increased cell death of cultured adult cardiomyocytes, and reduced cell cycle in Oct4, Sox2, Klf4, and Myc cardiomyocytes, at least in part through disrupting the mammalian target of rapamycin complex 1 pathway.

CONCLUSIONS

We discovered a novel gene Asns as both a molecular marker and an essential mediator, marking a distinct threshold that appears in common for at least 4 models of CMDD, and revealing an Asns/mammalian target of rapamycin complex 1 axis dependency for dedifferentiating cardiomyocytes. Further study will be needed to extrapolate and assess its relevance to other cell state transitions as well as in heart regeneration.

Cardiac effects of myoregulin in ischemia-reperfusion

Myoregulin is a recently discovered micropeptide that controls calcium levels by inhibiting the intracellular calcium pump sarco-endoplasmic reticulum Ca2+-ATPase (SERCA). Keeping calcium levels balanced in the heart is essential for normal heart functioning, thus myoregulin has the potential to be a crucial regulator of cardiac muscle performance by reducing the rate of intracellular Ca2+ uptake. We provide the first report of myoregulin mRNA expression in human heart tissue, absence of expression in human plasma, and the effects of myoregulin on cardiac hemodynamics in an ex vivo Langendorff isolated rat heart model of ischemia/reperfusion. In this preliminary study, myoregulin provided a cardio-protective effect, as assessed by preservation of left ventricular contractility and relaxation, during ischemia/reperfusion. This study provides the foundation for future research in this area.

Global longitudinal strain and plasma biomarkers for prognosis in heart failure complicated by diabetes: a prospective observational study

BACKGROUND

Heart failure (HF) and diabetes are associated with increased incidence and worse prognosis of each other. The prognostic value of global longitudinal strain (GLS) measured by cardiovascular magnetic resonance (CMR) has not been established in HF patients with diabetes.

METHODS

In this prospective, observational study, consecutive patients (n = 315) with HF underwent CMR at 3T, including GLS, late gadolinium enhancement (LGE), native T1, and extracellular volume fraction (ECV) mapping. Plasma biomarker concentrations were measured including: N-terminal pro B-type natriuretic peptide(NT-proBNP), high-sensitivity troponin T(hs-TnT), growth differentiation factor 15(GDF-15), soluble ST2(sST2), and galectin 3(Gal-3). The primary outcome was a composite of all-cause mortality or HF hospitalisation.

RESULTS

Compared to those without diabetes (n = 156), the diabetes group (n = 159) had a higher LGE prevalence (76 vs. 60%, p < 0.05), higher T1 (1285±42 vs. 1269±42ms, p < 0.001), and higher ECV (30.5±3.5 vs. 28.8±4.1%, p < 0.001). The diabetes group had higher NT-pro-BNP, hs-TnT, GDF-15, sST2, and Gal-3. Diabetes conferred worse prognosis (hazard ratio (HR) 2.33 [95% confidence interval (CI) 1.43-3.79], p < 0.001). In multivariable Cox regression analysis including clinical markers and plasma biomarkers, sST2 alone remained independently associated with the primary outcome (HR per 1 ng/mL 1.04 [95% CI 1.02-1.07], p = 0.001). In multivariable Cox regression models in the diabetes group, both GLS and sST2 remained prognostic (GLS: HR 1.12 [95% CI 1.03-1.21], p = 0.01; sST2: HR per 1 ng/mL 1.03 [95% CI 1.00-1.06], p = 0.02).

CONCLUSIONS

Compared to HF patients without diabetes, those with diabetes have worse plasma and CMR markers of fibrosis and a more adverse prognosis. GLS by CMR is a powerful and independent prognostic marker in HF patients with diabetes.

Proteomic Associations of Adverse Outcomes in Human Heart Failure

BACKGROUND

Identifying novel molecular drivers of disease progression in heart failure (HF) is a high-priority goal that may provide new therapeutic targets to improve patient outcomes. The authors investigated the relationship between plasma proteins and adverse outcomes in HF and their putative causal role using Mendelian randomization.

METHODS AND RESULTS

The authors measured 4776 plasma proteins among 1964 participants with HF with a reduced left ventricular ejection fraction enrolled in PHFS (Penn Heart Failure Study). Assessed were the observational relationship between plasma proteins and (1) all-cause death or (2) death or HF-related hospital admission (DHFA). The authors replicated nominally significant associations in the Washington University HF registry (N=1080). Proteins significantly associated with outcomes were the subject of 2-sample Mendelian randomization and colocalization analyses. After correction for multiple testing, 243 and 126 proteins were found to be significantly associated with death and DHFA, respectively. These included small ubiquitin-like modifier 2 (standardized hazard ratio [sHR], 1.56; P<0.0001), growth differentiation factor-15 (sHR, 1.68; P<0.0001) for death, A disintegrin and metalloproteinase with thrombospondin motifs-like protein (sHR, 1.40; P<0.0001), and pulmonary-associated surfactant protein C (sHR, 1.24; P<0.0001) for DHFA. In pathway analyses, top canonical pathways associated with death and DHFA included fibrotic, inflammatory, and coagulation pathways. Genomic analyses provided evidence of nominally significant associations between levels of 6 genetically predicted proteins with DHFA and 11 genetically predicted proteins with death.

CONCLUSIONS

This study implicates multiple novel proteins in HF and provides preliminary evidence of associations between genetically predicted plasma levels of 17 candidate proteins and the risk for adverse outcomes in human HF.

Differential Associations of A-/B-Type Natriuretic Peptides With Cardiac Structure, Function, and Prognosis in Heart Failure

BACKGROUND

Natriuretic peptide (NP) elevations are prognostic in heart failure (HF), but relative atrial NP deficiency in acute HF has been suggested.

OBJECTIVES

The authors compared plasma concentrations and relative strength of associations of A- and B-type NPs with cardiac structure/function and clinical outcomes in HF.

METHODS

Midregional pro-atrial natriuretic peptide (MR-proANP), B-type natriuretic peptide (BNP), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured in patients with compensated HF in a prospective, multicenter study. The primary outcome was a composite of HF-hospitalization or all-cause mortality. Secondary outcomes included individual primary outcome components and cardiovascular admission.

RESULTS

Among 1,278 patients (age 60.1 ± 12.1 years, 82% men, left ventricular ejection fraction [LVEF] 34% ± 14%), median concentrations of MR-proANP were 990 pg/mL (Q1-Q3: 557-1,563 pg/mL), NT-proBNP 1,648 pg/mL (Q1-Q3: 652-3,960 pg/mL), and BNP 291 pg/mL (Q1-Q3: 103-777 pg/mL). No subpopulation with inappropriately low MR-proANP (relative to BNP/NT-proBNP) was observed. Clinical event rates were similar for biomarker tertiles. Increments in MR-proANP exhibited steeper associations with concurrent shifts in left ventricular size, diastolic indexes and LVEF than BNP/NT-proBNP at baseline and serially (P < 0.05), and lower odds of beneficial left ventricular reverse remodeling: OR: 0.35 (95% CI: 0.18-0.70). In single-biomarker models, MR-proANP(log10) was associated with the highest hazard (4 to 6 times) for each outcome. In multimarker models, independent associations were observed for the primary outcome (MR-proANP and NT-proBNP), HF-hospitalization and cardiovascular admission (MR-proANP only), and all-cause mortality (NT-proBNP only) (P < 0.05). The discriminative value of MR-proANP was superior to BNP/NT-proBNP (HF-hospitalization) and BNP (primary outcome) (P < 0.05).

CONCLUSIONS

MR-proANP was not inappropriately low relative to concurrent BNP/NT-proBNP values. Proportional increments in MR-proANP were more pronounced than for B-peptides for given decrements in cardiac structure/function. MR-proANP offered greater independent predictive power overall.

Remote intensive management to improve antiplatelet adherence in acute myocardial infarction: a secondary analysis of the randomized controlled IMMACULATE trial

This study aim to investigate if remote intensive coaching for the first 6 months post-AMI will improve adherence to the twice-a-day antiplatelet medication, ticagrelor. Between July 8, 2015, to March 29, 2019, AMI patients were randomly assigned to remote intensive management (RIM) or standard care (SC). RIM participants underwent 6 months of weekly then two-weekly consultations to review medication side effects and medication adherence coaching by a centralized nurse practitioner team, whereas SC participants received usual cardiologist face-to-face consultations. Adherence to ticagrelor were determined using pill counting and serial platelet reactivity measurements for 12 months. A total of 149 (49.5%) of participants were randomized to RIM and 152 (50.5%) to SC. Adherence to ticagrelor was similar between RIM and SC group at 1 month (94.4 ± 0.7% vs. 93.6±14.7%, p = 0.537), 6 months (91.0±14.6% vs. 90.6±14.8%, p = 0.832) and 12 months (87.4±17.0% vs. 89.8±12.5%, p = 0.688). There was also no significant difference in platelet reactivity between the RIM and SC groups at 1 month (251AU*min [212-328] vs. 267AU*min [208-351], p = 0.399), 6 months (239AU*min [165-308] vs. 235AU*min [171-346], p = 0.610) and 12 months (249AU*min [177-432] vs. 259AU*min [182-360], p = 0.678). Sensitivity analysis did not demonstrate any association of ticagrelor adherence with bleeding events and major adverse cardiovascular events. RIM, comprising 6 months of intensive coaching by nurse practitioners, did not improve adherence to the twice-a-day medication ticagrelor compared with SC among patients with AMI. A gradual decline in ticagrelor adherence over 12 months was observed despite 6 months of intensive coaching.

Distinguishing heart failure with reduced ejection fraction from heart failure with preserved ejection fraction: A phenomics approach

AIM

Pathophysiological differences between patients with heart failure with preserved (HFpEF) and reduced (HFrEF) ejection fraction (EF) remain unclear. Therefore we used a phenomics approach, integrating selected proteomics data with patient characteristics and cardiac structural and functional parameters, to get insight into differential pathophysiological mechanisms and identify potential treatment targets.

METHODS AND RESULTS

We report data from a representative subcohort of the prospective Singapore Heart Failure Outcomes and Phenotypes (SHOP), including patients with HFrEF (EF <40%, n = 217), HFpEF (EF ≥50%, n = 213), and age- and sex-matched controls without HF (n = 216). We measured 92 biomarkers using a proximity extension assay and assessed cardiac structure and function in all participants using echocardiography. We used multi-block projection to latent structure analysis to integrate clinical, echocardiographic, and biomarker variables. Candidate biomarker targets were cross-referenced with small-molecule and drug databases. The total cohort had a median age of 65 years (interquartile range 60-71), and 50% were women. Protein profiles strongly discriminated patients with HFrEF (area under the curve [AUC] = 0.89) and HFpEF (AUC = 0.94) from controls. Phenomics analyses identified unique druggable inflammatory markers in HFpEF from the tumour necrosis factor receptor superfamily (TNFRSF), which were positively associated with hypertension, diabetes, and increased posterior and relative wall thickness. In HFrEF, interleukin (IL)-8 and IL-6 were possible targets related to lower EF and worsening renal function.

CONCLUSION

We identified pathophysiological mechanisms related to increased cardiac wall thickness parameters and potentially druggable inflammatory markers from the TNFRSF in HFpEF.

Proteomic Associations of NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) in Heart Failure With Preserved Ejection Fraction

BACKGROUND

NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels are variably elevated in heart failure with preserved ejection fraction (HFpEF), even in the presence of increased left ventricular filling pressures. NT-proBNP levels are prognostic in HFpEF and have been used as an inclusion criterion for several recent randomized clinical trials. However, the underlying biologic differences between HFpEF participants with high and low NT-proBNP levels remain to be fully understood.

METHODS

We measured 4928 proteins using an aptamer-based proteomic assay (SOMAScan) in available plasma samples from 2 cohorts: (1) Participants with HFpEF enrolled in the PHFS (Penn Heart Failure Study; n=253); (2) TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist Trial) participants in the Americas (n=218). We assessed the relationship between SOMAScan-derived plasma NT-proBNP and levels of other proteins available in the SOMAScan assay version 4 using robust linear regression, with correction for multiple comparisons, followed by pathway analysis.

RESULTS

NT-proBNP levels exhibited prominent proteome-wide associations in PHFS and TOPCAT cohorts. Proteins most strongly associated with NT-proBNP in both cohorts included SVEP1 (sushi, von Willebrand factor type-A, epidermal growth factor, and pentraxin domain containing 1; βTOPCAT=0.539; P<0.0001; βPHFS=0.516; P<0.0001) and ANGPT2 (angiopoietin 2; βTOPCAT=0.571; P<0.0001; βPHFS=0.459; P<0.0001). Canonical pathway analysis demonstrated consistent associations with multiple pathways related to fibrosis and inflammation. These included hepatic fibrosis and inhibition of matrix metalloproteases. Analyses using cut points corresponding to estimated quantitative concentrations of 360 pg/mL (and 480 pg/mL in atrial fibrillation) revealed similar proteomic associations.

CONCLUSIONS

Circulating NT-proBNP levels exhibit prominent proteomic associations in HFpEF. Our findings suggest that higher NT-proBNP levels in HFpEF are a marker of fibrosis and inflammation. These findings will aid the interpretation of NT-proBNP levels in HFpEF and may guide the selection of participants in future HFpEF clinical trials.

Multiple circulating forms of neprilysin detected with novel epitope-directed monoclonal antibodies

Neprilysin (NEP) is an emerging biomarker for various diseases including heart failure (HF). However, major inter-assay inconsistency in the reported concentrations of circulating NEP and uncertainty with respect to its correlations with type and severity of disease are in part attributed to poorly characterized antibodies supplied in commercial ELISA kits. Validated antibodies with well-defined binding footprints are critical for understanding the biological and clinical context of NEP immunoassay data. To achieve this, we applied in silico epitope prediction and rational peptide selection to generate monoclonal antibodies (mAbs) against spatially distant sites on NEP. One of the selected epitopes contained published N-linked glycosylation sites at N285 and N294. The best antibody pair, mAb 17E11 and 31E1 (glycosylation-sensitive), were characterized by surface plasmon resonance, isotyping, epitope mapping, and western blotting. A validated two-site sandwich NEP ELISA with a limit of detection of 2.15 pg/ml and working range of 13.1-8000 pg/ml was developed with these mAbs. Western analysis using a validated commercial polyclonal antibody (PE pAb) and our mAbs revealed that non-HF and HF plasma NEP circulates as a heterogenous mix of moieties that possibly reflect proteolytic processing, post-translational modifications and homo-dimerization. Both our mAbs detected a ~ 33 kDa NEP fragment which was not apparent with PE pAb, as well as a common ~ 57-60 kDa moiety. These antibodies exhibit different affinities for the various NEP targets. Immunoassay results are dependent on NEP epitopes variably detected by the antibody pairs used, explaining the current discordant NEP measurements derived from different ELISA kits.

Circulating erythroferrone has diagnostic utility for acute decompensated heart failure in patients presenting with acute or worsening dyspnea

Objectives

In dyspneic patients with atrial fibrillation (AF) or obesity, the diagnostic performance of NT-proBNP for acute heart failure is reduced. We evaluated the erythroblast derived protein erythroferrone (ERFE) as an ancillary biomarker for the diagnosis of acute decompensated heart failure (ADHF) in these comorbid subgroups in both Western and Asian populations.

Methods

The diagnostic performance of ERFE (Intrinsic Lifesciences) and NT-proBNP (Roche Cobas e411) for ADHF was assessed in 479 New Zealand (NZ) and 475 Singapore (SG) patients presenting with breathlessness.

Results

Plasma ERFE was higher in ADHF, compared with breathlessness from other causes, in both countries (NZ; 4.9 vs. 1.4 ng/ml, p < 0.001) and (SG; 4.2 vs. 0.4 ng/ml, p = 0.021). The receiver operating characteristic (ROC) areas under the curve (AUCs) for discrimination of ADHF were reduced in the NZ cohort compared to SG for ERFE (0.75 and 0.84, p = 0.007) and NT-proBNP (0.86 and 0.92, p = 0.004). Optimal cut-off points for ERFE yielded comparable sensitivity and positive predictive values in both cohorts, but slightly better specificity, negative predictive values and accuracy in SG compared with NZ. In patients with AF, the AUC decreased for ERFE in each cohort (NZ: 0.71, n = 105, SG: 0.61, n = 44) but increased in patients with obesity (NZ: 0.79, n = 150, SG: 0.87, n = 164).

Conclusions

Circulating ERFE is higher in patients with ADHF than in other causes of new onset breathlessness with fair diagnostic utility, performing better in Asian than in Western patients. The diagnostic performance of ERFE is impaired in patients with AF but not patients with obesity.

Combined Inhibition of Phosphodiesterase-5 and -9 in Experimental Heart Failure

BACKGROUND

Intracellular second messenger cyclic guanosine monophosphate (cGMP) mediates bioactivity of the natriuretic peptides and nitric oxide, and is key to circulatory homeostasis and protection against cardiovascular disease. Inhibition of cGMP-degrading phosphodiesterases (PDEs) PDE5 and PDE9 are emerging as pharmacological targets in heart failure (HF).

OBJECTIVES

The present study investigated dual enhancement of cGMP in experimental HF by combining inhibition of PDE-5 (P5-I) and PDE-9 (P9-I).

METHODS

Eight sheep with pacing-induced HF received on separate days intravenous P5-I (sildenafil), P9-I (PF-04749982), P5-I+P9-I, and vehicle control, in counterbalanced order.

RESULTS

Compared with control, separate P5-I and P9-I significantly increased circulating cGMP concentrations in association with reductions in mean arterial pressure (MAP), left atrial pressure (LAP), and pulmonary arterial pressure (PAP), with effects of P5-I on cGMP, MAP, and PAP greater than those of P9-I. Only P5-I decreased pulmonary vascular resistance. Combination P5-I+P9-I further reduced MAP, LAP, and PAP relative to inhibition of either phosphodiesterase alone. P9-I and, especially, P5-I elevated urinary cGMP levels relative to control. However, whereas inhibition of either enzyme increased urine creatinine excretion and clearance, only P9-I induced a significant diuresis and natriuresis. Combined P5-I+P9-I further elevated urine cGMP with concomitant increases in urine volume, sodium and creatinine excretion, and clearance similar to P9-I alone, despite the greater MAP reductions induced by combination treatment.

CONCLUSIONS

Combined P5-I+P9-I amalgamated the superior renal effects of P9-I and pulmonary effects of P5-1, while concurrently further reducing cardiac preload and afterload. These findings support combination P5-I+P9-I as a therapeutic strategy in HF.

Immunotherapy targeting isoDGR-protein damage extends lifespan in a mouse model of protein deamidation

Aging results from the accumulation of molecular damage that impairs normal biochemical processes. We previously reported that age-linked damage to amino acid sequence NGR (Asn-Gly-Arg) results in "gain-of-function" conformational switching to isoDGR (isoAsp-Gly-Arg). This integrin-binding motif activates leukocytes and promotes chronic inflammation, which are characteristic features of age-linked cardiovascular disorders. We now report that anti-isoDGR immunotherapy mitigates lifespan reduction of Pcmt1-/- mouse. We observed extensive accumulation of isoDGR and inflammatory cytokine expression in multiple tissues from Pcmt1-/- and naturally aged WT animals, which could also be induced via injection of isoDGR-modified plasma proteins or synthetic peptides into young WT animals. However, weekly injection of anti-isoDGR mAb (1 mg/kg) was sufficient to significantly reduce isoDGR-protein levels in body tissues, decreased pro-inflammatory cytokine concentrations in blood plasma, improved cognition/coordination metrics, and extended the average lifespan of Pcmt1-/- mice. Mechanistically, isoDGR-mAb mediated immune clearance of damaged isoDGR-proteins via antibody-dependent cellular phagocytosis (ADCP). These results indicate that immunotherapy targeting age-linked protein damage may represent an effective intervention strategy in a range of human degenerative disorders.

Personalized diagnosis in suspected myocardial infarction

BACKGROUND

In suspected myocardial infarction (MI), guidelines recommend using high-sensitivity cardiac troponin (hs-cTn)-based approaches. These require fixed assay-specific thresholds and timepoints, without directly integrating clinical information. Using machine-learning techniques including hs-cTn and clinical routine variables, we aimed to build a digital tool to directly estimate the individual probability of MI, allowing for numerous hs-cTn assays.

METHODS

In 2,575 patients presenting to the emergency department with suspected MI, two ensembles of machine-learning models using single or serial concentrations of six different hs-cTn assays were derived to estimate the individual MI probability (ARTEMIS model). Discriminative performance of the models was assessed using area under the receiver operating characteristic curve (AUC) and logLoss. Model performance was validated in an external cohort with 1688 patients and tested for global generalizability in 13 international cohorts with 23,411 patients.

RESULTS

Eleven routinely available variables including age, sex, cardiovascular risk factors, electrocardiography, and hs-cTn were included in the ARTEMIS models. In the validation and generalization cohorts, excellent discriminative performance was confirmed, superior to hs-cTn only. For the serial hs-cTn measurement model, AUC ranged from 0.92 to 0.98. Good calibration was observed. Using a single hs-cTn measurement, the ARTEMIS model allowed direct rule-out of MI with very high and similar safety but up to tripled efficiency compared to the guideline-recommended strategy.

CONCLUSION

We developed and validated diagnostic models to accurately estimate the individual probability of MI, which allow for variable hs-cTn use and flexible timing of resampling. Their digital application may provide rapid, safe and efficient personalized patient care.

TRIAL REGISTRATION NUMBERS

Data of following cohorts were used for this project: BACC ( www.

CLINICALTRIALS

gov ; NCT02355457), stenoCardia ( www.

CLINICALTRIALS

gov ; NCT03227159), ADAPT-BSN ( www.australianclinicaltrials.gov.au ; ACTRN12611001069943), IMPACT ( www.australianclinicaltrials.gov.au , ACTRN12611000206921), ADAPT-RCT ( www.anzctr.org.au ; ANZCTR12610000766011), EDACS-RCT ( www.anzctr.org.au ; ANZCTR12613000745741); DROP-ACS ( https://www.umin.ac.jp , UMIN000030668); High-STEACS ( www.

CLINICALTRIALS

gov ; NCT01852123), LUND ( www.

CLINICALTRIALS

gov ; NCT05484544), RAPID-CPU ( www.

CLINICALTRIALS

gov ; NCT03111862), ROMI ( www.

CLINICALTRIALS

gov ; NCT01994577), SAMIE ( https://anzctr.org.au ; ACTRN12621000053820), SEIGE and SAFETY ( www.

CLINICALTRIALS

gov ; NCT04772157), STOP-CP ( www.

CLINICALTRIALS

gov ; NCT02984436), UTROPIA ( www.

CLINICALTRIALS

gov ; NCT02060760).

Sacubitril/valsartan versus valsartan in regressing myocardial fibrosis in hypertension: a prospective, randomized, open-label, blinded endpoint clinical trial protocol

Background

Diffuse interstitial myocardial fibrosis is a key common pathological manifestation in hypertensive heart disease (HHD) progressing to heart failure (HF). Angiotensin receptor-neprilysin inhibitors (ARNi), now a front-line treatment for HF, confer benefits independent of blood pressure, signifying a multifactorial mode of action beyond hemodynamic regulation. We aim to test the hypothesis that compared with angiotensin II receptor blockade (ARB) alone, ARNi is more effective in regressing diffuse interstitial myocardial fibrosis in HHD.

Methods

Role of ARNi in Ventricular Remodeling in Hypertensive LVH (REVERSE-LVH) is a prospective, randomized, open-label, blinded endpoint (PROBE) clinical trial. Adults with hypertension and left ventricular hypertrophy (LVH) according to Asian sex- and age-specific thresholds on cardiovascular magnetic resonance (CMR) imaging are randomized to treatment with either sacubitril/valsartan (an ARNi) or valsartan (an ARB) in 1:1 ratio for a duration of 52 weeks, at the end of which a repeat CMR is performed to assess differential changes from baseline between the two groups. The primary endpoint is the change in CMR-derived diffuse interstitial fibrosis volume. Secondary endpoints include changes in CMR-derived left ventricular mass, volumes, and functional parameters. Serum samples are collected and stored to assess the effects of ARNi, compared with ARB, on circulating biomarkers of cardiac remodeling. The endpoints will be analyzed with reference to the corresponding baseline parameters to evaluate the therapeutic effect of sacubitril/valsartan vs. valsartan.

Discussion

REVERSE-LVH will examine the anti-fibrotic potential of sacubitril/valsartan and will offer mechanistic insights into the clinical benefits of sacubitril/valsartan in hypertension in relation to cardiac remodeling. Advancing the knowledge of the pathophysiology of HHD will consolidate effective risk stratification and personalized treatment through a multimodal manner integrating complementary CMR and biomarkers into the conventional care approach.Clinical Trial Registration: ClinicalTrials.gov, identifier, NCT03553810.

Injectable liposomal docosahexaenoic acid alleviates atherosclerosis progression and enhances plaque stability

Atherosclerosis is a chronic inflammatory vascular disease that is characterized by the accumulation of lipids and immune cells in plaques built up inside artery walls. Docosahexaenoic acid (DHA, 22:6n-3), an omega-3 polyunsaturated fatty acid (PUFA), which exerts anti-inflammatory and antioxidant properties, has long been purported to be of therapeutic benefit to atherosclerosis patients. However, large clinical trials have yielded inconsistent data, likely due to variations in the formulation, dosage, and bioavailability of DHA following oral intake. To fully exploit its potential therapeutic effects, we have developed an injectable liposomal DHA formulation intended for intravenous administration as a plaque-targeted nanomedicine. The liposomal formulation protects DHA against chemical degradation and increases its local concentration within atherosclerotic lesions. Mechanistically, DHA liposomes are readily phagocytosed by activated macrophages, exert potent anti-inflammatory and antioxidant effects, and inhibit foam cell formation. Upon intravenous administration, DHA liposomes accumulate preferentially in atherosclerotic lesional macrophages and promote polarization of macrophages towards an anti-inflammatory M2 phenotype, resulting in attenuation of atherosclerosis progression in both ApoE-/- and Ldlr-/- experimental models. Plaque composition analysis demonstrates that liposomal DHA inhibits macrophage infiltration, reduces lipid deposition, and increases collagen content, thus improving the stability of atherosclerotic plaques against rupture. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) further reveals that DHA liposomes can partly restore the complex lipid profile of the plaques to that of early-stage plaques. In conclusion, DHA liposomes offer a promising approach for applying DHA to stabilize atherosclerotic plaques and attenuate atherosclerosis progression, thereby preventing atherosclerosis-related cardiovascular events.

Association Between Diabetes, Chronic Kidney Disease, and Outcomes in People With Heart Failure From Asia

Background

Diabetes mellitus (DM), chronic kidney disease (CKD), and heart failure (HF) are pathophysiologically linked and increasing in prevalence in Asian populations, but little is known about the interplay of DM and CKD on outcomes in HF.

Objectives

This study sought to investigate outcomes in patients with heart failure with preserved ejection fraction (HFpEF) vs heart failure with reduced ejection fraction (HFrEF) in relation to the presence of DM and CKD.

Methods

Using the multinational ASIAN-HF registry, we investigated associations between DM only, CKD only, and DM+CKD with: 1) composite of 1-year mortality or HF hospitalization; and 2) Kansas City Cardiomyopathy Questionnaire scores, according to HF subtype.

Results

In 5,239 patients with HF (74.6% HFrEF, 25.4% HFpEF; mean age 63 years; 29.1% female), 1,107 (21.1%) had DM only, 1,087 (20.7%) had CKD only, and 1,400 (26.7%) had DM+CKD. Compared with patients without DM nor CKD, DM+CKD was associated with 1-year all-cause mortality or HF hospitalization in HFrEF (adjusted HR: 2.07; 95% CI: 1.68-2.55) and HFpEF (HR: 2.37; 95% CI: 1.40-4.02). In HFrEF, DM only and CKD only were associated with 1-year all-cause mortality or HF hospitalization (both HRs: 1.43; 95% CI: 1.14-1.80), while in HFpEF, CKD only (HR: 2.54; 95% CI: 1.46-4.41) but not DM only (HR: 1.01; 95% CI: 0.52-1.95) was associated with increased risk (interaction P < 0.01). Adjusted Kansas City Cardiomyopathy Questionnaire scores were lower in patients with DM+CKD (HFrEF: mean 60.50, SEM 0.77, HFpEF: mean 70.10, SEM 1.06; P < 0.001) than with no DM or CKD (HFrEF: mean 66.00, SEM 0.65; and HFpEF: mean 75.80, SEM 0.99).

Conclusions

Combined DM and CKD adversely effected outcomes independently of HF subtype, with CKD a consistent predictor of worse outcomes. Strategies to prevent and treat DM and CKD in HF are urgently required.

Impact of Diabetes on Myocardial Fibrosis in Patients With Hypertension: The REMODEL Study

BACKGROUND

Compared with patients with hypertension only, those with hypertension and diabetes (HTN/DM) have worse prognosis. We aimed to characterize morphological differences between hypertension and HTN/DM using cardiovascular magnetic resonance; and compare differentially expressed proteins associated with myocardial fibrosis using high throughput multiplex assays.

METHODS

Asymptomatic patients underwent cardiovascular magnetic resonance: 438 patients with hypertension (60±8 years; 59% males) and 167 age- and sex-matched patients with HTN/DM (60±10 years; 64% males). Replacement myocardial fibrosis was defined as nonischemic late gadolinium enhancement on cardiovascular magnetic resonance. Extracellular volume fraction was used as a marker of diffuse myocardial fibrosis. A total of 184 serum proteins (Olink Target Cardiovascular Disease II and III panels) were measured to identify unique signatures associated with myocardial fibrosis in all patients.

RESULTS

Despite similar left ventricular mass (P=0.344) and systolic blood pressure (P=0.086), patients with HTN/DM had increased concentricity and worse multidirectional strain (P<0.001 for comparison of all strain measures) compared to hypertension only. Replacement myocardial fibrosis was present in 28% of patients with HTN/DM compared to 16% of those with hypertension (P<0.001). NT-proBNP (N-terminal pro-B-type natriuretic peptide) was the only protein differentially upregulated in hypertension patients with replacement myocardial fibrosis and independently associated with extracellular volume. In patients with HTN/DM, GDF-15 (growth differentiation factor 15) was independently associated with replacement myocardial fibrosis and extracellular volume. Ingenuity Pathway Analysis demonstrated a strong association between increased inflammatory response/immune cell trafficking and myocardial fibrosis in patients with HTN/DM.

CONCLUSIONS

Adverse cardiac remodeling was observed in patients with HTN/DM. The novel proteomic signatures and associated biological activities of increased immune and inflammatory response may partly explain these observations.

Regional Handling and Prognostic Performance of Circulating Insulin-Like Growth Factor Binding Protein-7 in Heart Failure

BACKGROUND

Regional handling and the prognostic performance of insulin-like growth factor binding protein (IGFBP)-7, in contrast or in combination with other candidate biomarkers, in chronic heart failure (CHF) remain uncertain.

OBJECTIVES

The authors investigated the regional handling of plasma IGFBP-7 and its association with long-term outcomes in CHF in comparison with selected circulating biomarkers.

METHODS

Plasma concentrations of IGFBP-7, N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin-T, growth differentiation factor-15, and high-sensitivity C-reactive protein were measured prospectively in a cohort with CHF (n = 863). The primary outcome was the composite of heart failure (HF) hospitalization or all-cause mortality. In a separate non-HF cohort (n = 66) undergoing cardiac catheterization, transorgan gradients of plasma IGFBP-7 concentrations were evaluated.

RESULTS

Among 863 patients (age 69 ± 14 years, 30% female, 36% HF with preserved ejection fraction), IGFBP-7 (median: 121 [IQR: 99-156] ng/mL) related inversely to left ventricular volumes but directly to diastolic function. Above the optimal cutoff, IGFBP-7 ≥110 ng/mL was independently associated with 32% increased hazard of the primary outcome: 1.32 (95% CI: 1.06-1.64). Among the 5 markers, IGFBP-7 had the highest hazard for a proportional increment in plasma concentrations independent of HF phenotype in single- and double-biomarker models, and provided incremental prognostic value beyond clinical predictors plus NT-proBNP, high-sensitivity troponin-T, and high-sensitivity C-reactive protein (P < 0.05). Assessment of regional concentrations indicated renal secretion of IGFBP-7 in contrast to renal extraction of NT-proBNP, possible cardiac extraction of IGFBP-7 in contrast to secretion of NT-proBNP, and common hepatic extraction of both peptides.

CONCLUSIONS

Transorgan regulation of IGFBP-7 is distinct from NT-proBNP. Circulating IGFBP-7 independently predicts adverse outcomes in CHF with a strong prognostic performance when compared with other well-recognized cardiac-specific or noncardiac prognostic markers.

Myeloperoxidase Inhibition Reverses Biomarker Profiles Associated With Clinical Outcomes in HFpEF

BACKGROUND

Systemic microvascular dysfunction and inflammation are postulated to play a pathophysiologic role in heart failure with preserved ejection fraction (HFpEF).

OBJECTIVES

This study aimed to identify biomarker profiles associated with clinical outcomes in HFpEF and investigate how inhibition of the neutrophil-derived reactive oxygen species-producing enzyme, myeloperoxidase, affects these biomarkers.

METHODS

Using supervised principal component analyses, the investigators assessed the associations between baseline plasma proteomic Olink biomarkers and clinical outcomes in 3 independent observational HFpEF cohorts (n = 86, n = 216, and n = 242). These profiles were then compared with the biomarker profiles discriminating patients treated with active drug vs placebo in SATELLITE (Safety and Tolerability Study of AZD4831 in Patients With Heart Failure), a double-blind randomized 3-month trial evaluating safety and tolerability of the myeloperoxidase inhibitor AZD4831 in HFpEF (n = 41). Pathophysiological pathways were inferred from the biomarker profiles by interrogation of the Ingenuity Knowledge database.

RESULTS

TNF-R1, TRAIL-R2, GDF15, U-PAR, and ADM were the top individual biomarkers associated with heart failure hospitalization or death, and FABP4, HGF, RARRES2, CSTB, and FGF23 were associated with lower functional capacity and poorer quality of life. AZD4831 downregulated many markers (most significantly CDCP1, PRELP, CX3CL1, LIFR, VSIG2). There was remarkable consistency among pathways associated with clinical outcomes in the observational HFpEF cohorts, the top canonical pathways being associated with tumor microenvironments, wound healing signaling, and cardiac hypertrophy signaling. These pathways were predicted to be downregulated in AZD4831 relative to placebo-treated patients.

CONCLUSIONS

Biomarker pathways that were most strongly associated with clinical outcomes were also the ones reduced by AZD4831. These results support the further investigation of myeloperoxidase inhibition in HFpEF.

Hepatic steatosis and advanced hepatic fibrosis are independent predictors of long-term mortality in acute myocardial infarction

AIM

To examine the prevalence and prognosis of hepatic steatosis and fibrosis in post-acute myocardial infarction (AMI) patients.

METHODS

Patients presenting with AMI to a tertiary hospital were examined from 2014 to 2021. Hepatic steatosis and advanced hepatic fibrosis were determined using the Hepatic Steatosis Index and fibrosis-4 index, respectively. The primary outcome was all-cause mortality. Cox regression models identified determinants of mortality after adjustments and Kaplan-Meier curves were constructed for all-cause mortality, stratified by hepatic steatosis and advanced fibrosis.

RESULTS

Of 5765 patients included, 24.8% had hepatic steatosis, of whom 41.7% were diagnosed with advanced fibrosis. The median follow-up duration was 2.7 years. Patients with hepatic steatosis tended to be younger, female, with elevated body mass index and an increased metabolic burden of diabetes, hypertension and hyperlipidaemia. Patients with hepatic steatosis (24.6% vs. 20.9% mortality, P < .001) and advanced fibrosis (45.6% vs. 32.9% mortality, P < .001) had higher all-cause mortality rates compared with their respective counterparts. Hepatic steatosis (adjusted hazard ratio 1.364, 95% CI 1.145-1.625, P = .001) was associated with all-cause mortality after adjustment for confounders. Survival curves showed excess mortality in patients with hepatic steatosis compared with those without (P = .002).

CONCLUSIONS

Hepatic steatosis and advanced fibrosis have a substantial prevalence among patients with AMI. Both are associated with mortality, with an incrementally higher risk when advanced fibrosis ensues. Hepatic steatosis and fibrosis could help risk stratification of AMI patients beyond conventional risk factors.

Comparison of SPEED, S-Trap, and In-Solution-Based Sample Preparation Methods for Mass Spectrometry in Kidney Tissue and Plasma

Mass spectrometry is a powerful technique for investigating renal pathologies and identifying biomarkers, and efficient protein extraction from kidney tissue is essential for bottom-up proteomic analyses. Detergent-based strategies aid cell lysis and protein solubilization but are poorly compatible with downstream protein digestion and liquid chromatography-coupled mass spectrometry, requiring additional purification and buffer-exchange steps. This study compares two well-established detergent-based methods for protein extraction (in-solution sodium deoxycholate (SDC); suspension trapping (S-Trap)) with the recently developed sample preparation by easy extraction and digestion (SPEED) method, which uses strong acid for denaturation. We compared the quantitative performance of each method using label-free mass spectrometry in both sheep kidney cortical tissue and plasma. In kidney tissue, SPEED quantified the most unique proteins (SPEED 1250; S-Trap 1202; SDC 1197). In plasma, S-Trap produced the most unique protein quantifications (S-Trap 150; SDC 148; SPEED 137). Protein quantifications were reproducible across biological replicates in both tissue (R2 = 0.85–0.90) and plasma (SPEED R2 = 0.84; SDC R2 = 0.76, S-Trap R2 = 0.65). Our data suggest SPEED as the optimal method for proteomic preparation in kidney tissue and S-Trap or SPEED as the optimal method for plasma, depending on whether a higher number of protein quantifications or greater reproducibility is desired.

Endothelial Damage Arising From High Salt Hypertension Is Elucidated by Vascular Bed Systematic Profiling

BACKGROUND

Considerable evidence links dietary salt intake with the development of hypertension, left ventricular hypertrophy, and increased risk of stroke and coronary heart disease. Despite extensive epidemiological and basic science interrogation of the relationship between high salt (HS) intake and blood pressure, it remains unclear how HS impacts endothelial cell (EC) and vascular structure in vivo. This study aims to elucidate HS-induced vascular pathology using a differential systemic decellularization in vivo approach.

METHODS

We performed systematic molecular characterization of the endothelial glycocalyx and EC proteomes in mice with HS (8%) diet-induced hypertension versus healthy control animals. Isolation of eGC and EC compartments was achieved using differential systemic decellularization in vivo methodology. Altered protein expression in hypertensive compared to normal mice was characterized by liquid chromatography tandem mass spectrometry. Proteomic results were validated using functional assays, microscopic imaging, and histopathologic evaluation.

RESULTS

Proteomic analysis revealed a significant downregulation of eGC and associated proteins in HS diet-induced hypertensive mice (among 1696 proteins identified in this group, 723 were markedly decreased in abundance, while only 168 were increased in abundance. Bioinformatic analysis indicated substantial derangement of the eGC layer, which was subsequently confirmed by fluorescent and electron microscopy assessment of vessel damage ex vivo. In the EC fraction, HS-induced hypertension significantly altered protein mediators of contractility, metabolism, mechanotransduction, renal function, and the coagulation cascade. In particular, we observed dysregulation of integrin subunits α2, α2b, and α5, which was associated with arterial wall inflammation and substantial infiltration of CD68+ monocyte-macrophages. Consequently, HS-induced hypertensive mice also displayed reduced vascular integrity of multiple organs including lungs, kidneys, and heart.

CONCLUSIONS

These findings provide novel molecular insight into HS-induced structural changes in eGC and EC composition that may increase cardiovascular risk and potentially guide the development of new diagnostics and therapeutic interventions.

Prognostic modelling of clinical outcomes after first-time acute coronary syndrome in New Zealand

OBJECTIVE

The Multi-Ethnic New Zealand Study of Acute Coronary Syndromes (MENZACS) was established to investigate the drivers of secondary events after first-time acute coronary syndrome (ACS), including addressing inequitable outcomes by ethnicity. Herein, the first clinical outcomes and prognostic modelling approach are reported.

METHODS

First, in 28 176 New Zealanders with first-time ACS from a national registry, a clinical summary score for predicting 1-year death/cardiovascular readmission was created using Cox regression of 20 clinical variables. This score was then calculated in the 2015 participant MENZACS study to represent clinical risk. In MENZACS, Cox regression was used to assess N-terminal pro-B-type natriuretic peptide (NT-proBNP) as a prognostic marker for death/cardiovascular readmission in four models, adjusting for (1) age and sex; (2) age, sex, ethnicity; (3) clinical summary score; (4) clinical summary score and ethnicity.

RESULTS

Of the 2015 MENZACS participants (mean age 61 years, 79% male, 73% European, 14% Māori, 5% Pacific people), 2003 were alive at discharge. Of the 2003, 416 (20.8%) experienced all-cause death/cardiovascular readmission over a median of 3.5 years. In a simple model, age, male sex, Māori ethnicity and NT-proBNP levels were significant predictors of outcome. After adjustment for the clinical summary score, which includes age and sex, NT-proBNP and ethnicity were no longer statistically significant: log₂(NT-proBNP) hazard ratio (HR) 1.03, 95% confidence interval (95% CI) 0.98 to 1.08, p=0.305; Māori ethnicity HR 1.26, 95% CI 0.97 to 1.62, p=0.084.

CONCLUSIONS

In 2015 patients with first-time ACS, recurrent events were common (20.8%). Increasing NT-proBNP levels and Māori ethnicity were predictors of death/cardiovascular readmission, but not after adjustment for the 20 clinical risk factors represented by the clinical summary score.

TRIAL REGISTRATION NUMBER

ACTRN12615000676516.

Titration of medications and outcomes in multi-ethnic heart failure cohorts (with reduced ejection fraction) from Singapore and New Zealand

AIMS

We investigated titration patterns of angiotensin-converting enzyme inhibitors (ACEis)/angiotensin receptor blockers (ARBs) and beta-blockers, quality of life (QoL) over 6 months, and associated 1 year outcome [all-cause mortality/heart failure (HF) hospitalization] in a real-world population with HF with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Participants with HFrEF (left ventricular ejection fraction <40%) from a prospective multi-centre study were examined for use and dose [relative to guideline-recommended maintenance dose (GRD)] of ACEis/ARBs and beta-blockers at baseline and 6 months. 'Stay low' was defined as <50% GRD at both time points, 'stay high' as ≥50% GRD, and 'up-titrate' and 'down-titrate' as dose trajectories. Among 1110 patients (mean age 63 ± 13 years, 16% women, 26% New York Heart Association Class III/IV), 714 (64%) were multi-ethnic Asians from Singapore and 396 were from New Zealand (mainly European ethnicity). Baseline use of either ACEis/ARBs or beta-blockers was high (87%). Loop diuretic was prescribed in >80% of patients, mineralocorticoid receptor antagonist in about half of patients, and statins in >90% of patients. At baseline, only 11% and 9% received 100% GRD for each drug class, respectively, with about half (47%) achieving ≥50% GRD for ACEis/ARBs or beta-blockers. At 6 months, a large majority remained in the 'stay low' category, one third remained in 'stay high', whereas 10-16% up-titrated and 4-6% down-titrated. Patients with lower (vs. higher) N-terminal pro-beta-type natriuretic peptide levels were more likely to be up-titrated or be in 'stay high' for ACEis/ARBs and beta-blockers (P = 0.002). Ischaemic aetiology, prior HF hospitalization, and enrolment in Singapore (vs. New Zealand) were independently associated with higher odds of 'staying low' (all P < 0.005) for prescribed doses of ACEis/ARBs and beta-blockers. Adjusted for inverse probability weighting, ≥100% GRD for ACEis/ARBs [hazard ratio (HR) = 0.42; 95% confidence interval (CI) 0.24-0.73] and ≥50% GRD for beta-blockers (HR = 0.58; 95% CI 0.37-0.90) (vs. Nil) were associated with lower hazards for 1 year composite outcome. Country of enrolment did not modify the associations of dose categories with 1 year composite outcome. Higher medication doses were associated with greater improvements in QoL.

CONCLUSIONS

Although HF medication use at baseline was high, most patients did not have these medications up-titrated over 6 months. Multiple clinical factors were associated with changes in medication dosages. Further research is urgently needed to investigate the causes of lack of up-titration of HF therapy (and its frequency), which could inform strategies for timely up-titration of HF therapy based on clinical and biochemical parameters.

Pathophysiologic mechanism for MYOcarditis in COVID-19 VAccinations ("MYOVAx" Study)

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NMRC COVID-19 Research Fund

Objective

This is the first prospective cohort study in Singapore to investigate the COVID-19 vaccine-associated myocarditis to understand its pathophysiology.

Introduction

Acute myocarditis and other cardiovascular symptoms have been observed to be associated with the two mRNA-based coronavirus disease 2019 (COVID-19) vaccines—namely Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273)—currently in-use in Singapore. The mechanisms through which myocarditis occurs are unknown, hence our study aims to understand the pathophysiology of myocarditis associated with COVID-19 vaccines.

Methods

Patients with onset of cardiac manifestations were recruited from multiple hospital outpatient clinics between November 2021 and September 2022. Clinical history and physical examination data was collected with blood sample collection, echocardiography, 12-lead electrocardiogram (ECG), coronary angiography and magnetic resonance imaging (MRI) at recruitment and 6-month follow-up. Analysis of biomarkers, genetic, serological and MRI data was conducted.

Results

As of 6 September 2022, a total of 5 patients have been enrolled (4 males, 1 female). The most commonly reported symptoms across all patients were chest pain/discomfort (80%), followed by palpitations (40%). MRI evidence of myocarditis has been detected in 2 (50%) of the male patients, of which both reported two or more symptoms occurring 1-2 days post-vaccination. Both patients have each received at least two doses of either the Pfizer-BioNTech BNT162b2 vaccine or Moderna mRNA-1273 vaccine. Their MRI findings were consistent with myocarditis. On late gadolinium enhancement (LGE) imaging, epicardial enhancement at the basal inferolateral segment and mid-wall enhancement at the apical anterior, lateral and inferior walls were observed in one patient. Patchy, mid-wall LGE in the basal inferior/inferolateral wall was observed in the other patient. No MRI evidence of myocarditis was available for the sole female patient.

Conclusion

While more data is needed to definitively prove the association of the two mRNA-based Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273 COVID-19 vaccines with post-vaccination myocarditis, we believe our findings may support further investigations to enable risk stratification for vaccine-associated myocarditis and identify potential preventative strategies accordingly.

An integrated signature of extracellular matrix proteins and a diastolic function imaging parameter predicts post-MI long-term outcomes

Background

Patients suffering from acute myocardial infarction (AMI) are at risk of secondary outcomes including major adverse cardiovascular events (MACE) and heart failure (HF). Comprehensive molecular phenotyping and cardiac imaging during the post-discharge time window may provide cues for risk stratification for the outcomes.

Materials and methods

In a prospective AMI cohort in New Zealand (N = 464), we measured plasma proteins and lipids 30 days after hospital discharge and inferred a unified partial correlation network with echocardiographic variables and established clinical biomarkers (creatinine, c-reactive protein, cardiac troponin I and natriuretic peptides). Using a network-based data integration approach (iOmicsPASS+), we identified predictive signatures of long-term secondary outcomes based on plasma protein, lipid, imaging markers and clinical biomarkers and assessed the prognostic potential in an independent cohort from Singapore (N = 190).

Results

The post-discharge levels of plasma proteins and lipids showed strong correlations within each molecular type, reflecting concerted homeostatic regulation after primary MI events. However, the two molecular types were largely independent with distinct correlation structures with established prognostic imaging parameters and clinical biomarkers. To deal with massively correlated predictive features, we used iOmicsPASS + to identify subnetwork signatures of 211 and 189 data features (nodes) predictive of MACE and HF events, respectively (160 overlapping). The predictive features were primarily imaging parameters, including left ventricular and atrial parameters, tissue Doppler parameters, and proteins involved in extracellular matrix (ECM) organization, cell differentiation, chemotaxis, and inflammation. The network signatures contained plasma protein pairs with area-under-the-curve (AUC) values up to 0.74 for HF prediction in the validation cohort, but the pair of NT-proBNP and fibulin-3 (EFEMP1) was the best predictor (AUC = 0.80). This suggests that there were a handful of plasma proteins with mechanistic and functional roles in predisposing patients to the secondary outcomes, although they may be weaker prognostic markers than natriuretic peptides individually. Among those, the diastolic function parameter (E/e' - an indicator of left ventricular filling pressure) and two ECM proteins, EFEMP1 and follistatin-like 3 (FSTL3) showed comparable performance to NT-proBNP and outperformed left ventricular measures as benchmark prognostic factors for post-MI HF.

Conclusion

Post-discharge levels of E/e', EFEMP1 and FSTL3 are promising complementary markers of secondary adverse outcomes in AMI patients.

Review A State of Natriuretic Peptide Deficiency

Measurement of natriuretic peptides (NPs) has proven its clinical value as biomarker, especially in the context of heart failure (HF). In contrast, a state partial NP deficiency appears integral to several conditions in which lower NP concentrations in plasma presage overt cardiometabolic disease. Here, obesity and type 2 diabetes have attracted considerable attention. Other factors - including age, sex, race, genetics, and diurnal regulation - affect the NP "armory" and may leave some individuals more prone to development of cardiovascular disease. The molecular maturation of NPs has also proven complex with highly variable O-glycosylation within the biosynthetic precursors. The relevance of this regulatory step in post-translational propeptide maturation has recently become recognized in biomarker measurement/interpretation and cardiovascular pathophysiology. An important proportion of people appear to have reduced effective net NP bioactivity in terms of receptor activation and physiological effects. The state of NP deficiency, then, both entails a potential for further biomarker development and could also offer novel pharmacological possibilities. Alleviating the state of NP deficiency before development of overt cardiometabolic disease in selected patients could be a future path for improving precision medicine.

Diagnostic and prognostic performance of the ratio between high-sensitivity cardiac troponin I and troponin T in patients with chest pain

Background

Elevations of high-sensitivity cardiac troponin (hs-cTn) concentrations not related to type 1 myocardial infarction are common in chest pain patients presenting to emergency departments. The discrimination of these patients from those with type 1 myocardial infarction (MI) is challenging and resource-consuming. We aimed to investigate whether the hs-cTn I/T ratio might provide diagnostic and prognostic increment in this context.

Methods

We calculated the hs-cTn I/T ratio in 888 chest pain patients having hs-cTnI (Abbott Laboratories) or hs-cTnT (Roche Diagnostics) concentrations above the respective 99^th percentile at 2 hours from presentation. All patients were followed for one year regarding mortality.

Results

The median hs-cTn I/T ratio was 3.45 (25^th, 75^th percentiles 1.80–6.59) in type 1 MI patients (n = 408 ☯46.0%]), 1.18 (0.81–1.90) in type 2 MI patients (n = 56 ☯6.3%]) and 0.67 (0.39–1.12) in patients without MI. The hs-cTn I/T ratio provided good discrimination of type 1 MI from no type 1 MI (area under the receiver-operator characteristic curve 0.89 ☯95% confidence interval 0.86–0.91]), of type 1 MI from type 2 MI (area under the curve 0.81 ☯95% confidence interval 0.74–0.87]), and was associated with type 1 MI in adjusted analyses. The hs-cTn I/T ratio provided no consistent prognostic value.

Conclusions

The hs-cTn I/T ratio appears to be useful for early diagnosis of type 1 MI and its discrimination from type 2 MI in chest pain patients presenting with elevated hs-cTn. Differences in hs-cTn I/T ratio values may reflect variations in hs-cTn release mechanisms in response to different types of myocardial injury.

Material property alterations for phenotypes of heart failure with preserved ejection fraction: A numerical study of subject-specific porcine models

A substantial proportion of heart failure patients have a preserved left ventricular (LV) ejection fraction (HFpEF). This condition carries a high burden of morbidity and mortality and has limited therapeutic options. left ventricular pressure overload leads to an increase in myocardial collagen content, causing left ventricular stiffening that contributes to the development of heart failure patients have a preserved left ventricular ejection fraction. Although several heart failure patients have a preserved left ventricular ejection fraction models have been developed in recent years to aid the investigation of mechanical alterations, none has investigated different phenotypes of the disease and evaluated the alterations in material properties. In this study, two similar healthy swine were subjected to progressive and prolonged pressure overload to induce diastolic heart failure characteristics, providing a preclinical model of heart failure patients have a preserved left ventricular ejection fraction. Cardiac magnetic resonance imaging (cMRI) scans and intracardiac pressures were recorded before and after induction. In both healthy and disease states, a corresponding finite element (FE) cardiac model was developed via mesh morphing of the Living Heart Porcine model. The material properties were derived by calibrating to its passive and active behavior. The change in the passive behavior was predominantly isotropic when comparing the geometries before and after induction. Myocardial thickening allowed for a steady transition in the passive properties while maintaining tissue incompressibility. This study highlights the importance of hypertrophy as an initial compensatory response and might also pave the way for assessing disease severity.

Identifying Candidate Circulating RNA Markers for Coronary Artery Disease by Deep RNA-Sequencing in Human Plasma

Advances in RNA sequencing (RNA-Seq) have facilitated transcriptomic analysis of plasma for the discovery of new diagnostic and prognostic markers for disease. We aimed to develop a short-read RNA-Seq protocol to detect mRNAs, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in plasma for the discovery of novel markers for coronary artery disease (CAD) and heart failure (HF). Circulating cell-free RNA from 59 patients with stable CAD (half of whom developed HF within 3 years) and 30 controls was sequenced to a median depth of 108 paired reads per sample. We identified fragments from 3986 messenger RNAs (mRNAs), 164 long non-coding RNAs (lncRNAs), 405 putative novel lncRNAs and 227 circular RNAs in plasma. Circulating levels of 160 mRNAs, 10 lncRNAs and 2 putative novel lncRNAs were altered in patients compared with controls (absolute fold change >1.2, p < 0.01 adjusted for multiple comparisons). The most differentially abundant transcripts were enriched in mRNAs encoded by the mitochondrial genome. We did not detect any differences in the plasma RNA profile between patients who developed HF compared with those who did not. In summary, we show that mRNAs, lncRNAs and circular RNAs can be reliably detected in plasma by deep RNA-Seq. Multiple coding and non-coding transcripts were altered in association with CAD, including several mitochondrial mRNAs, which may indicate underlying myocardial ischaemia and oxidative stress. If validated, circulating levels of these transcripts could potentially be used to help identify asymptomatic individuals with established CAD prior to an acute coronary event.

Comparative performances of soluble urokinase plasminogen activator receptor and Mid-regional proADM to predict composite death and new heart failure rehospitalisation in acutely breathless patients

Background

Soluble urokinase plasminogen activator receptor (suPAR) is a pleotropic receptor, capable of orchestrating plaque vulnerability and vascular immune dysfunction. Mid-regional pro-adrenomedullin (MR-proADM) is the stable peptide precursor of adrenomedullin, with concentrations reflective of vasodilation and cardiac remodelling. We compared the prognostic performances of suPAR and MR-proADM for the composite clinical endpoint of death and new heart failure (HF) in patients with undifferentiated breathlessness.

Methods

Patients presenting to hospital with the primary complaint of acute dyspnoea were recruited in New Zealand (n=612) and in Singapore (n=483)]. Baseline plasma measurements were undertaken for suPAR (ViroGates) and MR-proADM (Thermo Scientific). Cardiac biomarker levels of NT-proBNP (Roche) was available on all patients. Statistical assessment was made using SPSS v28 (IBM), with all biomarkers treated as continuous variables and presented as median [interquartile range (IQR)]. Prognostic performance of suPAR, MR-proADM and NT-proBNP to predict the composite clinical endpoint of death/new HF at 90-days and 1-yr were assessed using receiver operator curve (ROC) area under the curve (AUC) analysis (Z-scores) and Cox hazard regression analysis (per doubling of biomarker concentrations) after adjustment for traditional risk factors. P-value &lt;0.05 was considered statistically significant.

Results

In the entire acutely breathless cohort [median age: 65 years (IQR: 52.9–76.0), 63.1% males], 343/1095 of patients had the final adjudication of ADHF. suPAR and MR-proADM concentrations were higher with increasing age (Spearmans rho, r&gt;0.46, P&lt;0.0001), lower eGFR (r&gt;0.58, P&lt;0.0001) and in those with ADHF (r&gt;0.40, P&lt;0.0001). During the follow-up period, 122 patients were categorised with death/new HF by 90-days, rising to 281 at 1-year. suPAR and MR-proADM were able to predict death/new HF at 90-days (both ROC-AUC &gt;0.77) and at 1-year (both ROC-AUC ≥0.78) (Table 1). All markers were however less accurate in predicting this endpoint in the presence of ADHF (ROC-AUC &lt;0.71). After adjustment in Cox-regression modelling, suPAR obtained HR &gt;1.35 per doubling of suPAR concentrations (P=0.001) for outcomes at 90-days and at 1-year (Table 2), achieving the highest prognostic performance for this clinical endpoint, followed by NT-proBNP (HR &gt;1.29) (Table 2), whilst MR-proADM was not an independent predictor of death/HF in this cohort. suPAR was also an independent predictor of death/HF for patients with ADHF, obtaining HR &gt;1.35 per doubling of concentrations. Above a cut-off concentration of 3.6 ng/mL, suPAR was associated with a HR of 2.1 (95% CI: 1.55–2.91) for death/HF at 1-year for acutely dyspnoeic patients.

Conclusion

suPAR concentrations is superior than MR-proADM in predicting the clinical end-point of death/HF at 1-year in this cohort. It may aid in risk-stratification strategies for the management of acutely breathless patients.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): National Heart Foundation of New ZealandHealth Research Council of New Zealand

Congestion in heart failure: a circulating biomarker-based perspective. A review from the Biomarkers Working Group of the Heart Failure Association, European Society of Cardiology

Congestion is a cardinal sign of heart failure (HF). In the past, it was seen as a homogeneous epiphenomenon that identified patients with advanced HF. However, current evidence shows that congestion in HF varies in quantity and distribution. This updated view advocates for a congestive-driven classification of HF according to onset (acute vs. chronic), regional distribution (systemic vs. pulmonary), compartment of distribution (intravascular vs. extravascular), and clinical vs. subclinical. Thus, this review will focus on the utility of circulating biomarkers for assessing and managing the different fluid overload phenotypes. This discussion focused on the clinical utility of the natriuretic peptides, carbohydrate antigen 125 (also called mucin 16), bio-adrenomedullin and mid-regional pro-adrenomedullin, ST2 (also known as interleukin-1 receptor-like 1), cluster of differentiation 146, troponin, C-terminal pro-endothelin-1, and parameters of haemoconcentration. The utility of circulation biomarkers on top of clinical evaluation, haemodynamics, and imaging needs to be better determined by dedicated studies. Some multiparametric frameworks in which these tools contribute to management are proposed.

Endotrophin, a Collagen VI Formation-Derived Peptide, in Heart Failure

BACKGROUND

Endotrophin, a collagen type VI-derived peptide, mediates metabolic dysregulation, inflammation, and fibrosis in animal models, but has not been studied in human heart failure (HF).

METHODS

We examined the association between circulating endotrophin and outcomes in participants suffering from HF with preserved ejection fraction (HFpEF) enrolled in the TOPCAT trial (n=205). Associations were validated in a participant-level meta-analysis (n=810) that included participants with HFpEF from the PHFS study (United States; n=174), PEOPLE cohort (New Zealand; n=168), a randomized trial of vasodilator therapy (United States; n=45), a cohort from Donostia University Hospital and University of Navarra (Spain; n=171), and the TRAINING-HF trial (Spain; n=47). We also assessed associations in HF with reduced ejection fraction in PHFS (n=1,642).

RESULTS

Plasma endotrophin levels at baseline were associated with risk of future death (standardized hazard ratio [HR] = 1.74; 95% confidence interval [CI]=1.36-2.24; P<0.001) and death or HF-related hospital admission (DHFA; standardized HR=2.11; 95% CI= 1.67-2.67; P<0.001) in TOPCAT. Endotrophin improved reclassification and discrimination for these outcomes beyond the MAGGIC risk score and NT-proBNP (N-terminal pro b-type natriuretic peptide). Findings were confirmed in the participant-level meta-analysis. In participants with HF with reduced ejection fraction in PHFS, endotrophin levels were associated with death (standardized HR=1.82; 95% CI=1.66-2.00; P<0.001) and DHFA (standardized HR=1.40; 95% CI=1.31-1.50; P<0.001), but the strength of the latter association was substantially lower than for the MAGGIC risk score (standardized HR=1.93; 95% CI=1.76-2.12) and BNP (standardized HR=1.78; 95% CI=1.66-1.92).

CONCLUSIONS

Circulating endotrophin levels are independently associated with future poor outcomes in patients with HF, particularly in HFpEF. (Funded by Bristol Myers Squibb; Instituto de Salud Carlos III [Spain] and European Regional Development Fund; European Commission CRUCIAL project; and the U.S. National Institutes of Health National Heart, Lung, and Blood Institute.).

Proteomic Analysis of Effects of Spironolactone in Heart Failure With Preserved Ejection Fraction

BACKGROUND

The TOPCAT trial (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist Trial) suggested clinical benefits of spironolactone treatment among patients with heart failure with preserved ejection fraction enrolled in the Americas. However, a comprehensive assessment of biologic pathways impacted by spironolactone therapy in heart failure with preserved ejection fraction has not been performed.

METHODS

We conducted aptamer-based proteomic analysis utilizing 5284 modified aptamers to 4928 unique proteins on plasma samples from TOPCAT participants from the Americas (n=164 subjects with paired samples at baseline and 1 year) to identify proteins and pathways impacted by spironolactone therapy in heart failure with preserved ejection fraction. Mean percentage change from baseline was calculated for each protein. Additionally, we conducted pathway analysis of proteins altered by spironolactone.

RESULTS

Spironolactone therapy was associated with proteome-wide significant changes in 7 proteins. Among these, CARD18 (caspase recruitment domain-containing protein 18), PKD2 (polycystin 2), and PSG2 (pregnancy-specific glycoprotein 2) were upregulated, whereas HGF (hepatic growth factor), PLTP (phospholipid transfer protein), IGF2R (insulin growth factor 2 receptor), and SWP70 (switch-associated protein 70) were downregulated. CARD18, a caspase-1 inhibitor, was the most upregulated protein by spironolactone (-0.5% with placebo versus +66.5% with spironolactone, P<0.0001). The top canonical pathways that were significantly associated with spironolactone were apelin signaling, stellate cell activation, glycoprotein 6 signaling, atherosclerosis signaling, liver X receptor activation, and farnesoid X receptor activation. Among the top pathways, collagens were a consistent theme that increased in patients receiving placebo but decreased in patients randomized to spironolactone.

CONCLUSIONS

Proteomic analysis in the TOPCAT trial revealed proteins and pathways altered by spironolactone, including the caspase inhibitor CARD18 and multiple pathways that involved collagens. In addition to effects on fibrosis, our studies suggest potential antiapoptotic effects of spironolactone in heart failure with preserved ejection fraction, a hypothesis that merits further exploration.

Assays Specific for BNP1-32 and NT-proBNP Exhibit a Similar Performance to Two Widely Used Assays in the Diagnosis of Heart Failure

BACKGROUND

Secretion of cardioprotective B-type natriuretic peptide 1-32 (BNP1-32) is increased proportionately with cardiac dysfunction, but its measurement in plasma is difficult. Therefore, less specific BNP and amino-terminal proBNP (NT-proBNP) assays that detect the precursor molecule proBNP alongside BNP or NT-proBNP metabolites were developed to reflect BNP1-32 secretion and are now mandated in the diagnosis of heart failure (HF). We compared the diagnostic performance of 2 widely used clinical assays: the Roche proBNPII assay, and Abbott BNP assay, against our recently developed in-house assays that measure either intact BNP1-32 or NT-proBNP.

METHODS

EDTA plasma samples obtained from patients presenting with breathlessness (n = 195, 60 [31%] with clinically adjudicated HF) were assayed using the Roche NT-proBNP and our specific in-house BNP1-32 and NTBNP assays. A subset (n = 75) were also assessed with the Abbott BNP assay.

RESULTS

Roche NT-proBNP was highly correlated with BNP1-32 and NTBNP (Spearman rho = 0.92 and 0.90, respectively, both Ps < 0.001), and all 3 assays similarly discriminated acute HF from other causes of breathlessness (ROC analysis areas under the curve 0.85-0.89). The Abbott BNP assay performed similarly to the other assays. Roche NT-proBNP and BNP1-32 assays had similar sensitivity (83% and 80%), specificity (83% and 84%), positive (70% and 71%) and negative (91% and 90%) predictive values, and accuracy (both 83%) at their optimal cutoffs of 1536 and 12 ng/L, respectively.

CONCLUSIONS

Since all assays exhibited similar performance in the diagnosis of HF, currently mandated assays provide a reliable proxy for circulating concentrations of active BNP1-32 in HF diagnosis.

Circulating cardiac biomarkers improve risk stratification for incident cardiovascular disease in community dwelling populations

Background

Plasma cardiac markers may assist in prediction of incident cardiovascular disease.

Methods

The incremental value of cardiac Troponins (T and I) and NT-proBNP added to risk factors in the PREDICT score for incident cardiovascular disease (CVD) in primary care, was assessed in 4102 asymptomatic participants in a randomised controlled trial of Vitamin D (ViDA). Findings were corroborated in 2528 participants in a separate community-based observational registry of CVD-free volunteers (HVOLS).

Findings

Hazard ratios for first cardiovascular events adjusted for PREDICT risk factors, comparing fifth to first quintiles of marker plasma concentrations, were 2.57 (95% CI 1.47-4.49); 3.01 (1.66-5.48) and 3.38 (2.04-5.60) for hs-cTnI, hs-cTnT and NT-proBNP respectively. The C statistic for discrimination of the primary endpoint increased from 0.755 to 0.771 (+0.016, p = 0.01). Cardiac marker data correctly reclassified risk upwards in 6.7% of patients and downwards in 3.3%. These findings were corroborated by results from HVOLS.

Interpretation

Increments in plasma cardiac biomarkers robustly and reproducibly predicted increased hazard of incident CVD, independent of established risk factors, in two community-dwelling populations. Cardiac markers may augment risk assessment for onset of CVD in primary care.

Funding

ViDA was funded by the Health Research Council of New Zealand (grant 10/400) and the Accident Compensation Corporation. HVOLS was funded by the Health Research Council of NZ Programme Grants (grants 02/152 and 08/070) and by grants from the Heart Foundation of NZ and the Christchurch Heart Institute Trust. Roche Diagnostics provided in-kind support for NT-proBNP and hs-cTnT assays and Abbott Laboratories for hs-cTnI assays.

Effects of Hypertrophic and Dilated Cardiac Geometric Remodeling on Ejection Fraction

Background: Both heart failure (HF) with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) can present a wide variety of cardiac morphologies consequent to cardiac remodeling. We sought to study if geometric changes to the heart during such remodeling will adversely affect the ejection fraction (EF) parameter’s ability to serve as an indicator of heart function, and to identify the mechanism for it.

Methods and Results: A numerical model that simulated the conversion of myocardial strain to stroke volume was developed from two porcine animal models of heart failure. Hypertrophic wall thickening was found to elevate EF, while left ventricle (LV) dilation was found to depress EF when myocardial strain was kept constant, causing EF to inaccurately represent the overall strain function. This was caused by EF being calculated using the endocardial boundary rather than the mid-wall layer. Radial displacement of the endocardial boundary resulted in endocardial strain deviating from the overall LV strain, and this deviation varied with LV geometric changes. This suggested that using the epi- or endo-boundaries to calculate functional parameters was not effective, and explained why EF could be adversely affected by geometric changes. Further, when EF was modified by calculating it at the mid-wall layer instead of at the endocardium, this shortcoming was resolved, and the mid-wall EF could differentiate between healthy and HFpEF subjects in our animal models, while the traditional EF could not.

Conclusion: We presented the mechanism to explain why EF can no longer effectively indicate cardiac function during cardiac geometric changes relevant to HF remodeling, losing the ability to distinguish between hypertrophic diseased hearts from healthy hearts. Measuring EF at the mid-wall location rather than endocardium can avoid the shortcoming and better represent the cardiac strain function.

Development and validation of a decision support tool for the diagnosis of acute heart failure: systematic review, meta-analysis, and modelling study

OBJECTIVES

To evaluate the diagnostic performance of N-terminal pro-B-type natriuretic peptide (NT-proBNP) thresholds for acute heart failure and to develop and validate a decision support tool that combines NT-proBNP concentrations with clinical characteristics.

DESIGN

Individual patient level data meta-analysis and modelling study.

SETTING

Fourteen studies from 13 countries, including randomised controlled trials and prospective observational studies.

PARTICIPANTS

Individual patient level data for 10 369 patients with suspected acute heart failure were pooled for the meta-analysis to evaluate NT-proBNP thresholds. A decision support tool (Collaboration for the Diagnosis and Evaluation of Heart Failure (CoDE-HF)) that combines NT-proBNP with clinical variables to report the probability of acute heart failure for an individual patient was developed and validated.

MAIN OUTCOME MEASURE

Adjudicated diagnosis of acute heart failure.

RESULTS

Overall, 43.9% (4549/10 369) of patients had an adjudicated diagnosis of acute heart failure (73.3% (2286/3119) and 29.0% (1802/6208) in those with and without previous heart failure, respectively). The negative predictive value of the guideline recommended rule-out threshold of 300 pg/mL was 94.6% (95% confidence interval 91.9% to 96.4%); despite use of age specific rule-in thresholds, the positive predictive value varied at 61.0% (55.3% to 66.4%), 73.5% (62.3% to 82.3%), and 80.2% (70.9% to 87.1%), in patients aged <50 years, 50-75 years, and >75 years, respectively. Performance varied in most subgroups, particularly patients with obesity, renal impairment, or previous heart failure. CoDE-HF was well calibrated, with excellent discrimination in patients with and without previous heart failure (area under the receiver operator curve 0.846 (0.830 to 0.862) and 0.925 (0.919 to 0.932) and Brier scores of 0.130 and 0.099, respectively). In patients without previous heart failure, the diagnostic performance was consistent across all subgroups, with 40.3% (2502/6208) identified at low probability (negative predictive value of 98.6%, 97.8% to 99.1%) and 28.0% (1737/6208) at high probability (positive predictive value of 75.0%, 65.7% to 82.5%) of having acute heart failure.

CONCLUSIONS

In an international, collaborative evaluation of the diagnostic performance of NT-proBNP, guideline recommended thresholds to diagnose acute heart failure varied substantially in important patient subgroups. The CoDE-HF decision support tool incorporating NT-proBNP as a continuous measure and other clinical variables provides a more consistent, accurate, and individualised approach.

STUDY REGISTRATION

PROSPERO CRD42019159407.

Effect of monthly vitamin D supplementation on cardiac biomarkers: A post-hoc analysis of a randomized controlled trial

The effects of vitamin D supplementation on cardiovascular diseases are controversial. Data on effects of vitamin D upon cardiac biomarkers, as surrogate endpoints of cardiovascular diseases, are limited and inconclusive. Therefore, we carried out a post-hoc analysis of sub-samples of a randomized, double-blinded, placebo-controlled trial with community-based older adults who were randomized to receive monthly 100,000-IU vitamin D or placebo, to determine effect of monthly vitamin D supplementation on high-sensitivity cardiac troponin I (hs-cTnI), troponin T (hs-cTnT) and N-terminal-pro-B-type natriuretic peptide (NT-proBNP). Adjusted relative difference (aRD) of follow-up geometric mean of biomarkers and adjusted relative risk (aRR) of elevated biomarkers between two groups were calculated. A total of 779 participants aged 50-84 y, randomized to vitamin D (n = 395) or placebo (n = 384) groups underwent sampling for measurement of plasma biomarkers at baseline and after one or two years treatment. Over a mean follow-up of 1.6 years, we did not find significant relative difference of geometric mean levels of three biomarkers at follow-up between vitamin D and placebo groups: hs-cTnI (aRD=1.03, 95%CI=0.97-1.09), hs-cTnT (aRD=0.99, 95%CI=0.95-1.04), and NT-proBNP (aRD=1.01, 95%CI=0.92-1.10). No significant differences were found in likelihood of clinically elevated biomarkers between two groups: hs-cTnI (aRR=0.92, 95%CI=0.51-1.69), hs-cTnT (aRR=1.11, 95%CI=0.86-1.42), and NT-proBNP (aRR=1.03,95%CI=0.89-1.20). However, among participants with initial low vitamin D status (<50 nmol/L, n = 200), follow-up NT-proBNP were significantly lower in the vitamin D group compared to placebo (geometric mean 75.9 vs 94.5 pg/mL, respectively; aRD=0.84, 95%CI=0.71-<1.00). The same results were observed for the NT-proBNP levels change from baseline between two groups. Overall, in older adults, monthly vitamin D supplementation did not reduce concentrations of hs-cTnI, hs-cTnT, and NT-proBNP. In those with low vitamin D status, vitamin D treatment was associated, on follow up and change from baseline, with lower plasma NT-proBNP compared with placebo. This potentially signals reduced risk of subsequent heart failure within this sub-group. However, we acknowledge that these findings need to be considered exploratory. Further research is required to replicate them.