Urinary Marker Profiles in Heart Failure with Reduced Versus Preserved Ejection Fraction.

BACKGROUND: Recent data suggest different causes of renal dysfunction between heart failure with reduced (HFrEF) versus preserved ejection fraction (HFpEF). We therefore studied a wide range of urinary markers reflecting different nephron segments in heart failure patients. METHODS: In 2070, in chronic heart failure patients, we measured several established and upcoming urinary markers reflecting different nephron segments. RESULTS: Mean age was 70 ± 12 years, 74% was male and 81% (n = 1677) had HFrEF. Mean estimated glomerular filtration rate (eGFR) was lower in patients with HFpEF (56 ± 23 versus 63 ± 23 ml/min/1.73 m2, P = 0.001). Patients with HFpEF had significantly higher values of NGAL (58.1 [24.0-124.8] versus 28.1 [14.6-66.9] µg/gCr, P < 0.001) and KIM-1 (2.28 [1.49-4.37] versus 1.79 [0.85-3.49] µg/gCr, P = 0.001). These differences were more pronounced in patients with an eGFR > 60 ml/min/1.73m2. CONCLUSIONS: HFpEF patients showed more evidence of tubular damage and/or dysfunction compared with HFrEF patients, in particular when glomerular function was preserved.

Differential biomarker expression in heart failure patients with and without mitral regurgitation: Insights from BIOSTAT-CHF.

BACKGROUND: Mitral regurgitation (MR) frequently coexists with heart failure (HF). OBJECTIVES: To better understand potential pathophysiological differences between patients with HF with or without moderate-severe MR, we compared differentially expressed circulating biomarkers between these two groups. METHODS: The Olink Proteomics® Multiplex Cardiovascular (CVD) -II, CVD-III, Immune Response and Oncology-II panels of 363 unique proteins from different pathophysiological domains were used to investigate the biomarker profiles of HF patients from index and validation cohorts of the BIOSTAT-CHF study stratified according to the presence of moderate-to-severe MR or no-mild MR. RESULTS: The index cohort included 888 patients (46%) with moderate-to-severe MR and 1029 (54%) with no-mild MR at baseline. The validation cohort included 522 patients (33%) with moderate-to-severe MR and 1076 (66%) with no-mild MR at baseline. Compared to patients with no-mild MR, those with moderate-to-severe MR had lower body mass index, higher comorbidity burden, signs and symptoms of more severe HF, lower systolic blood pressure, and larger left atrial and ventricular dimensions, in both cohorts. NT-proBNP, CA125, fibroblast growth factor 23 (FGF23) and growth hormone 1 (GH1) were up-regulated, whereas leptin (LEP) was down-regulated in patients with moderate-severe MR versus no-mild MR, in both index and validation cohorts. CONCLUSION: Circulating biomarkers differently expressed in HF patients with moderate-severe MR versus no-mild MR were related to congestion, lipid and mineral metabolism and oxidative stress. These findings may be of value for the development of novel treatment targets in HF patients with MR.

Multiomics Analysis Provides Novel Pathways Related to Progression of Heart Failure.

BACKGROUND: Despite major advances in pharmacological treatment for patients with heart failure, residual mortality remains high. This suggests that important pathways are not yet targeted by current heart failure therapies. OBJECTIVES: We sought integration of genetic, transcriptomic, and proteomic data in a large cohort of patients with heart failure to detect major pathways related to progression of heart failure leading to death. METHODS: We used machine learning methodology based on stacked generalization framework and gradient boosting algorithms, using 54 clinical phenotypes, 403 circulating plasma proteins, 36,046 transcript expression levels in whole blood, and 6 million genomic markers to model all-cause mortality in 2,516 patients with heart failure from the BIOSTAT-CHF (Systems BIOlogy Study to TAilored Treatment in Chronic Heart Failure) study. Results were validated in an independent cohort of 1,738 patients. RESULTS: The mean age of the patients was 70 years (Q1-Q3: 61-78 years), 27% were female, median N-terminal pro-B-type natriuretic peptide was 4,275 ng/L (Q1-Q3: 2,360-8,486 ng/L), and 7% had heart failure with preserved ejection fraction. During a median follow-up of 21 months, 657 (26%) of patients died. The 4 major pathways with a significant association to all-cause mortality were: 1) the PI3K/Akt pathway; 2) the MAPK pathway; 3) the Ras signaling pathway; and 4) epidermal growth factor receptor tyrosine kinase inhibitor resistance. Results were validated in an independent cohort of 1,738 patients. CONCLUSIONS: A systems biology approach integrating genomic, transcriptomic, and proteomic data identified 4 major pathways related to mortality. These pathways are related to decreased activation of the cardioprotective ERBB2 receptor, which can be modified by neuregulin.

Biomarker signature and pathophysiological pathways in patients with chronic heart failure and metabolic syndrome.

AIM: The comorbidities that collectively define metabolic syndrome are common in patients with heart failure. However, the role of metabolic syndrome in the pathophysiology of heart failure is not well understood. We therefore investigated the clinical and biomarker correlates of metabolic syndrome in patients with heart failure. METHODS AND RESULTS: In 1103 patients with heart failure, we compared the biomarker expression using a panel of 363 biomarkers among patients with (n = 468 [42%]) and without (n = 635 [58%]) metabolic syndrome. Subsequently, a pathway overrepresentation analysis was performed to identify key biological pathways. Findings were validated in an independent cohort of 1433 patients with heart failure of whom 615 (43%) had metabolic syndrome. Metabolic syndrome was defined as the presence of three or more of five criteria, including central obesity, elevated serum triglycerides, reduced high-density lipoprotein cholesterol, insulin resistance and hypertension. The most significantly elevated biomarkers in patients with metabolic syndrome were leptin (log2 fold change 0.92, p = 5.85 × 10-21 ), fatty acid-binding protein 4 (log2 fold change 0.61, p = 1.21 × 10-11 ), interleukin-1 receptor antagonist (log2 fold change 0.47, p = 1.95 × 10-13 ), tumour necrosis factor receptor superfamily member 11a (log2 fold change 0.35, p = 4.16 × 10-9 ), and proto-oncogene tyrosine-protein kinase receptor Ret (log2 fold change 0.31, p = 4.87 × 10-9 ). Network analysis identified 10 pathways in the index cohort and 6 in the validation cohort, all related to inflammation. The primary overlapping pathway in both the index and validation cohorts was up-regulation of the natural killer cell-mediated cytotoxicity pathway. CONCLUSION: Metabolic syndrome is highly prevalent in heart failure and is associated with biomarkers and pathways relating to obesity, lipid metabolism and immune responses underlying chronic inflammation.

Operation Moonshot: rapid translation of a SARS-CoV-2 targeted peptide immunoaffinity liquid chromatography-tandem mass spectrometry test from research into routine clinical use.

OBJECTIVES: During 2020, the UK's Department of Health and Social Care (DHSC) established the Moonshot programme to fund various diagnostic approaches for the detection of SARS-CoV-2, the pathogen behind the COVID-19 pandemic. Mass spectrometry was one of the technologies proposed to increase testing capacity. METHODS: Moonshot funded a multi-phase development programme, bringing together experts from academia, industry and the NHS to develop a state-of-the-art targeted protein assay utilising enrichment and liquid chromatography tandem mass spectrometry (LC-MS/MS) to capture and detect low levels of tryptic peptides derived from SARS-CoV-2 virus. The assay relies on detection of target peptides, ADETQALPQRK (ADE) and AYNVTQAFGR (AYN), derived from the nucleocapsid protein of SARS-CoV-2, measurement of which allowed the specific, sensitive, and robust detection of the virus from nasopharyngeal (NP) swabs. The diagnostic sensitivity and specificity of LC-MS/MS was compared with reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) via a prospective study. RESULTS: Analysis of NP swabs (n=361) with a median RT-qPCR quantification cycle (Cq) of 27 (range 16.7-39.1) demonstrated diagnostic sensitivity of 92.4% (87.4-95.5), specificity of 97.4% (94.0-98.9) and near total concordance with RT-qPCR (Cohen's Kappa 0.90). Excluding Cq>32 samples, sensitivity was 97.9% (94.1-99.3), specificity 97.4% (94.0-98.9) and Cohen's Kappa 0.95. CONCLUSIONS: This unique collaboration between academia, industry and the NHS enabled development, translation, and validation of a SARS-CoV-2 method in NP swabs to be achieved in 5 months. This pilot provides a model and pipeline for future accelerated development and implementation of LC-MS/MS protein/peptide assays into the routine clinical laboratory.

Pathophysiologic Processes and Novel Biomarkers Associated With Congestion in Heart Failure.

BACKGROUND: Congestion is the main driver behind symptoms of heart failure (HF), but pathophysiology related to congestion remains poorly understood. OBJECTIVES: Using pathway and differential expression analyses, the authors aim to identify biological processes and biomarkers associated with congestion in HF. METHODS: A congestion score (sum of jugular venous pressure, orthopnea, and peripheral edema) was calculated in 1,245 BIOSTAT-CHF patients with acute or worsening HF. Patients with a score ranking in the bottom or top categories of congestion were deemed noncongested (n = 408) and severely congested (n = 142), respectively. Plasma concentrations of 363 unique proteins (Olink Proteomics Multiplex CVD-II, CVD-III, Immune Response and Oncology II panels) were compared between noncongested and severely congested patients. Results were validated in an independent validation cohort of 1,342 HF patients (436 noncongested and 232 severely congested). RESULTS: Differential protein expression analysis showed 107/363 up-regulated and 6/363 down-regulated proteins in patients with congestion compared with those without. FGF-23, FGF-21, CA-125, soluble ST2, GDF-15, FABP4, IL-6, and BNP were the strongest up-regulated proteins (fold change [FC] >1.30, false discovery rate [FDR], P < 0.05). KITLG, EGF, and PON3 were the strongest down-regulated proteins (FC <-1.30, FDR P < 0.05). Pathways most prominently involved in congestion were related to inflammation, endothelial activation, and response to mechanical stimulus. The validation cohort yielded similar findings. CONCLUSIONS: Severe congestion in HF is mainly associated with inflammation, endothelial activation, and mechanical stress. Whether these pathways play a causal role in the onset or progression of congestion remains to be established. The identified biomarkers may become useful for diagnosing and monitoring congestion status.

Clinical implications of low estimated protein intake in patients with heart failure.

BACKGROUND: A higher protein intake has been associated with a higher muscle mass and lower mortality rates in the general population, but data about protein intake and survival in patients with heart failure (HF) are lacking. METHODS: We studied the prevalence, predictors, and clinical outcome of estimated protein intake in 2516 patients from the BIOlogy Study to TAilored Treatment in Chronic Heart Failure (BIOSTAT-CHF) index cohort. Protein intake was calculated in spot urine samples using a validated formula [13.9 + 0.907 * body mass index (BMI) (kg/m2 ) + 0.0305 * urinary urea nitrogen level (mg/dL)]. Association with mortality was assessed using multivariable Cox regression models. All findings were validated in an independent cohort. RESULTS: We included 2282 HF patients (mean age 68 ± 12 years and 27% female). Lower estimated protein intake in HF patients was associated with a lower BMI, but with more signs of congestion. Mortality rate in the lowest quartile was 32%, compared with 18% in the highest quartile (P < 0.001). In a multivariable model, lower estimated protein intake was associated with a higher risk of death compared with the highest quartile [hazard ratio (HR) 1.50; 95% confidence interval (CI) 1.03-2.18, P = 0.036 for the lowest quartile and HR 1.46; 95% CI 1.00-2.18, P = 0.049 for the second quartile]. CONCLUSIONS: An estimated lower protein intake was associated with a lower BMI, but signs of congestion were more prevalent. A lower estimated protein intake was independently associated with a higher mortality risk.

Pathophysiological pathways related to high plasma growth differentiation factor 15 concentrations in patients with heart failure.

AIMS: Elevated concentrations of growth differentiation factor 15 (GDF-15) in patients with heart failure (HF) have been consistently associated with worse clinical outcomes, but what disease mechanisms high GDF-15 concentrations represent remains unclear. Here, we aim to identify activated pathophysiological pathways related to elevated GDF-15 expression in patients with HF. METHODS AND RESULTS: In 2279 patients with HF, we measured circulating levels of 363 biomarkers. Then, we performed a pathway over-representation analysis to identify key biological pathways between patients in the highest and lowest GDF-15 concentration quartiles. Data were validated in an independent cohort of 1705 patients with HF. In both cohorts, the strongest up-regulated biomarkers in those with high GDF-15 were fibroblast growth factor 23 (FGF-23), death receptor 5 (TRAIL-R2), WNT1-inducible signalling pathway protein 1 (WISP-1), tumour necrosis factor receptor superfamily member 11a (TNFRSF11A), leucocyte immunoglobulin-like receptor subfamily B member 4 (LILRB4), and trefoil factor 3 (TFF3). Pathway over-representation analysis revealed that high GDF-15 patients had increased activity of pathways related to inflammatory processes, notably positive regulation of chemokine production; response to interleukin-6; tumour necrosis factor and death receptor activity; and positive regulation of T-cell differentiation and inflammatory response. Furthermore, we found pathways involved in regulation of insulin-like growth factor (IGF) receptor signalling and regulatory pathways of tissue, bones, and branching structures. GDF-15 quartiles significantly predicted all-cause mortality and HF hospitalization. CONCLUSION: Patients with HF and high plasma concentrations of GDF-15 are characterized by increased activation of inflammatory pathways and pathways related to IGF-1 regulation and bone/tissue remodelling.

Determination of N7-glycidamide guanine adducts in human blood DNA following exposure to dietary acrylamide using liquid chromatography/tandem mass spectrometry.

RATIONALE: Acrylamide is classified as a probable human carcinogen that is metabolised to glycidamide, which can covalently bind to DNA. The aim of this study was to investigate the formation of N7-glycidamide guanine (N7-GA-Gua) adducts in human blood DNA following exposure to acrylamide present in carbohydrate-rich foods as part of the normal human diet. METHODS: Lymphocyte DNA was extracted from blood samples obtained from healthy human volunteers. Following thermal depurination of the DNA samples, N7-GA-Gua adducts were quantified using a validated liquid chromatography/tandem mass spectrometry (LC/MS/MS) method incorporating a stable isotope labelled internal standard. Estimated dietary acrylamide intake was recorded by completion of food frequency questionnaires for the 24 hours prior to volunteer blood donation. RESULTS: An LC/MS/MS method was validated with a limit of detection of 0.25 fmol and a lower limit of quantitation of 0.50 fmol on column. N7-GA-Gua adducts were detected in human blood DNA with the levels ranging between 0.3 to 6.3 adducts per 108 nucleotides. The acrylamide intake was calculated from the food frequency questionnaires ranging between 20.0 and 78.6 µg. CONCLUSIONS: Identification and quantification of N7-GA-Gua adducts in the blood DNA of healthy volunteers suggests that dietary acrylamide exposure may lead to the formation of DNA adducts. This important finding warrants further investigation to ascertain a correlation between environmental/dietary acrylamide exposure and levels of DNA adducts.

Additional burden of iron deficiency in heart failure patients beyond the cardio-renal anaemia syndrome: findings from the BIOSTAT-CHF study.

AIMS: Whereas the combination of anaemia and chronic kidney disease (CKD) has been extensively studied in patients with heart failure (HF), the contribution of iron deficiency (ID) to this dysfunctional interplay is unknown. We aimed to assess clinical associates and pathophysiological pathways related to ID in this multimorbid syndrome. METHODS AND RESULTS: We studied 2151 patients with HF from the BIOSTAT-CHF cohort. Patients were stratified based on ID (transferrin saturation <20%), anaemia (World Health Organization definition) and/or CKD (estimated glomerular filtration rate <60 ml/min/1.73 m2 ). Patients were mainly men (73.3%), with a median age of 70.5 (interquartile range 61.4-78.1). ID was more prevalent than CKD and anaemia (63.3%, 47.2% and 35.6% respectively), with highest prevalence in those with concomitant CKD and anaemia (77.5% vs. 59.3%; p < 0.001). There was a considerable overlap in biomarkers and pathways between patients with isolated ID, anaemia or CKD, or in combination, with processes related to immunity, inflammation, cell survival and cancer amongst the common pathways. Key biomarkers shared between syndromes with ID included transferrin receptor, interleukin-6, fibroblast growth factor-23, and bone morphogenetic protein 6. Having ID, either alone or on top of anaemia and/or CKD, was associated with a lower overall summary Kansas City Cardiomyopathy Questionnaire score, an impaired 6-min walk test and increased incidence of hospitalizations and/or mortality in multivariable analyses (all p < 0.05). CONCLUSION: Iron deficiency, CKD and/or anaemia in patients with HF have great overlap in biomarker profiles, suggesting common pathways associated with these syndromes. ID either alone or on top of CKD and anaemia is associated with worse quality of life, exercise capacity and prognosis of patients with worsening HF.

Mass spectrometric detection of KRAS protein mutations using molecular imprinting.

Cancer is a disease of cellular evolution where single base changes in the genetic code can have significant impact on the translation of proteins and their activity. Thus, in cancer research there is significant interest in methods that can determine mutations and identify the significant binding sites (epitopes) of antibodies to proteins in order to develop novel therapies. Nano molecularly imprinted polymers (nanoMIPs) provide an alternative to antibodies as reagents capable of specifically capturing target molecules depending on their structure. In this study, we used nanoMIPs to capture KRAS, a critical oncogene, to identify mutations which when present are indicative of oncological progress. Herein, coupling nanoMIPs (capture) and liquid chromatography-mass spectrometry (detection), LC-MS has allowed us to investigate mutational assignment and epitope discovery. Specifically, we have shown epitope discovery by generating nanoMIPs to a recombinant KRAS protein and identifying three regions of the protein which have been previously assigned as epitopes using much more time-consuming protocols. The mutation status of the released tryptic peptide was identified by LC-MS following capture of the conserved region of KRAS using nanoMIPS, which were tryptically digested, thus releasing the sequence of a non-conserved (mutated) region. This approach was tested in cell lines where we showed the effective genotyping of a KRAS cell line and in the plasma of cancer patients, thus demonstrating its ability to diagnose precisely the mutational status of a patient. This work provides a clear line-of-sight for the use of nanoMIPs to its translation from research into diagnostic and clinical utility.

Plasma P-selectin is a predictor of mortality in heart failure with preserved ejection fraction.

AIMS: The aim of the study was to assess the association of P-selectin with outcomes in heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: This is a prospective, observational study of 130 HFpEF patients who underwent clinical profiling, blood sampling, 6 min walk testing, Minnesota Living with Heart Failure Questionnaire evaluation, echocardiography, cardiovascular magnetic resonance imaging, calculation of the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) risk scores, and blinded plasma P-selectin measurement. Patients were followed up for the endpoint of all-cause mortality. The HFpEF subgroup with higher P-selectin levels [overall median 26 372, inter-quartile range (19 360-34 889) pg/mL] was associated with lower age, higher heart rate, less prevalent atrial fibrillation, more frequent current smoking status, and lower right ventricular end-diastolic volumes. During follow-up (median 1428 days), there were 38 deaths. Following maximal sensitivity and specificity receiver operating characteristic curve analysis, P-selectin levels above 35 506 pg/mL were associated with greater risk of all-cause mortality [hazard ratio (HR) 2.700; 95% confidence interval (CI) 1.416-5.146; log-rank P = 0.002]. Following multivariable Cox proportional hazards regression analysis and when added to MAGGIC scores, only P-selectin (adjusted HR 1.707; 95% CI 1.099-2.650; P < 0.017) and myocardial infarction detected by cardiovascular magnetic resonance imaging (HR 2.377; 95% CI 1.114-5.075; P < 0.025) remained significant predictors. In a final model comprising all three parameters, only P-selectin (HR 1.447; 95% CI 1.130-1.853; P < 0.003) and MAGGIC scores (HR 1.555; 95% CI 1.136-2.129; P < 0.006) remained independent predictors of death. Adding P-selectin (0.618, P = 0.035) improved the area under the receiver operating characteristic curve for mortality prediction for MAGGIC scores (0.647, P = 0.009) to 0.710, P < 0.0001. CONCLUSIONS: Plasma P-selectin is an independent predictor of mortality and provides incremental prognostic information beyond MAGGIC scores in HFpEF.

Association of gut-related metabolites with outcome in acute heart failure.

BACKGROUND: Trimethylamine N-oxide (TMAO), a gut-related metabolite, is associated with heart failure (HF) outcomes. However, TMAO is the final product of a complex metabolic pathway (ie, choline/carnitine) that has never been entirely investigated in HF. The present study investigates a panel of metabolites involved in the TMAO-choline/carnitine metabolic pathway for their associations with outcome in acute HF patients. METHODS: In total, 806 plasma samples from acute HF patients were analyzed for TMAO, trimethyllysine, L-carnitine, acetyl-L-carnitine, γ-butyrobetaine, crotonobetaine, trimethylamine, betaine aldehyde, choline, and betaine using a developed liquid chromatography-tandem mass spectrometry method. Associations with outcome of all-cause mortality (death) and a composite of all-cause mortality and/or rehospitalization caused by HF (death/HF) at 30 days and 1 year were investigated. RESULTS: TMAO, trimethyllysine, L-carnitine, acetyl-L-carnitine, and γ-butyrobetaine were associated with death and death/HF at 30 days (short term; hazard ratio 1.30-1.49, P≤ .021) and at 1 year (long term; hazard ratio 1.15-1.25, P≤ .026) when adjusted for cardiac risk factors. L-carnitine and acetyl-L-carnitine were superior for short-term outcomes whereas TMAO was the superior metabolite for association with long-term outcomes. Furthermore, acetyl-L-carnitine and L-carnitine were superior for in-hospital mortality and improved risk stratification when combined with current clinical risk scores (ie, Acute Decompensated HEart Failure National REgistry, Organized Program To Initiate Lifesaving Treatment In Hospitalized Patients With Heart Failure, and Get With The Guidelines-Heart Failure; odds ratio (OR) ≥ 1.52, P≤ .020). CONCLUSIONS: Carnitine-related metabolites show associations with adverse outcomes in acute HF, in particular L-carnitine and acetyl-L-carnitine for short-term outcomes, and TMAO for long-term outcomes. Further studies are warranted to investigate the role and implications of carnitine metabolites including intervention in the pathogenesis of HF.

Proteomic Characterization of Circulating Molecular Perturbations Associated With Pancreatic Adenocarcinoma Following Intravenous ω-3 Fatty Acid and Gemcitabine Administration: A Pilot Study.

BACKGROUND: Administration of intravenous ω-3 fatty acid (ω-3FA) in advanced pancreatic adenocarcinoma patients receiving gemcitabine chemotherapy shows disease stabilization and improved progression-free survival. Using high-definition plasma proteomics, the underlying biological mechanisms responsible for these clinical effects are investigated. METHODS AND RESULTS: A pilot study involving plasma that was collected at baseline from 13 patients with histologically confirmed, unresectable pancreatic adenocarcinoma (baseline group) after 1-month treatment with intravenous gemcitabine and ω-3FA (treatment group) and intravenous gemcitabine only (control group) and was prepared for proteomic analysis. A 2-arm study comparing baseline vs treatment and treatment vs control was performed. Proteins were isolated from plasma with extensive immunodepletion, then digested and labeled with isobaric tandem mass tag peptide tags. Samples were then combined, fractionated, and injected into a QExactive-Orbitrap Mass-Spectrometer and analyzed on Proteome Discoverer and Scaffold with ensuing bioinformatics analysis. Selective reaction monitoring analysis was performed for verification. In total, 3476 proteins were identified. Anti-inflammatory markers (C-reactive protein, haptoglobin, and serum amyloid-A1) were reduced in the treatment group. Enrichment analysis showed angiogenesis downregulation, complement immune systems upregulation, and epigenetic modifications on histones. Pathway analysis identified direct action via the Pi3K-AKT pathway. Serum amyloid-A1 significantly reduced (P < .001) as a potential biomarker of efficacy for ω-3FA. CONCLUSIONS: This pilot study demonstrates administration of ω-3FA has potential anti-inflammatory, antiangiogenic, and proapoptotic effects via direct interaction with cancer-signaling pathways in patients with advanced pancreatic adenocarcinoma. Further studies in a larger sample size is required to validate the clinical correlation found in this preliminary study.

Short-term adverse remodeling progression in asymptomatic aortic stenosis.

OBJECTIVES: Aortic stenosis (AS) is characterised by a long and variable asymptomatic course. Our objective was to use cardiovascular magnetic resonance imaging (MRI) to assess progression of adverse remodeling in asymptomatic AS. METHODS: Participants from the PRIMID-AS study, a prospective, multi-centre observational study of asymptomatic patients with moderate to severe AS, who remained asymptomatic at 12 months, were invited to undergo a repeat cardiac MRI. RESULTS: Forty-three participants with moderate-severe AS (mean age 64.4 ± 14.8 years, 83.4% male, aortic valve area index 0.54 ± 0.15 cm2/m2) were included. There was small but significant increase in indexed left ventricular (LV) (90.7 ± 22.0 to 94.5 ± 23.1 ml/m2, p = 0.007) and left atrial volumes (52.9 ± 11.3 to 58.6 ± 13.6 ml/m2, p < 0.001), with a decrease in systolic (LV ejection fraction 57.9 ± 4.6 to 55.6 ± 4.1%, p = 0.001) and diastolic (longitudinal diastolic strain rate 1.06 ± 0.2 to 0.99 ± 0.2 1/s, p = 0.026) function, but no overall change in LV mass or mass/volume. Late gadolinium enhancement increased (2.02 to 4.26 g, p < 0.001) but markers of diffuse interstitial fibrosis did not change significantly (extracellular volume index 12.9 [11.4, 17.0] ml/m2 to 13.3 [11.1, 15.1] ml/m2, p = 0.689). There was also a significant increase in the levels of NT-proBNP (43.6 [13.45, 137.08] pg/ml to 53.4 [19.14, 202.20] pg/ml, p = 0.001). CONCLUSIONS: There is progression in cardiac remodeling with increasing scar burden even in asymptomatic AS. Given the lack of reversibility of LGE post-AVR and its association with long-term mortality post-AVR, this suggests the potential need for earlier intervention, before the accumulation of LGE, to improve the long-term outcomes in AS. KEY POINTS: • Current guidelines recommend waiting until symptom onset before valve replacement in severe AS. • MRI showed clear progression in cardiac remodeling over 12 months in asymptomatic patients with AS, with near doubling in LGE. • This highlights the need for potentially earlier intervention or better risk stratification in AS.

Differences in biomarkers and molecular pathways according to age for patients with HFrEF.

AIMS: Elderly patients with heart failure with reduced ejection fraction (HFrEF) have worse prognosis and less often receive guideline-recommended therapies. We aim to better understand the underlying pathophysiological processes associated with ageing in HFrEF potentially leading to targeted therapies in this vulnerable population. METHODS AND RESULTS: From a panel of 363 cardiovascular biomarkers available in 1611 patients with HFrEF in the BIOSTAT-CHF index cohort and cross-validated in 823 patients in the BIOSTAT-CHF validation cohort, we tested which biomarkers were dysregulated in patients aged >75 vs. <65 years. Second, pathway overrepresentation analyses were performed to identify biological pathways linked to higher plasma concentrations of biomarkers in elderly vs. younger patients. After adjustment, multiple test correction [false discovery rate (FDR) 1%], and cross-validation, 27/363 biomarkers were associated with older age, 22 positively and 5 negatively. The biomarkers that were positively associated with older age were associated with tumour cell regulation, extra-cellular matrix organization, and inflammatory processes, whereas biomarkers negatively associated with older age were associated with pathways that may point to cell proliferation and tumourigenesis. Among the 27 biomarkers, WFDC2 (WAP four-disulphide core domain protein 2)-that broadly functions as a protease inhibitor-was associated with older age and had the strongest association with all outcomes. No protein-by-sex interaction was observed. CONCLUSIONS: In elderly HFrEF patients, pathways associated with extra-cellular matrix organization, inflammatory processes, and tumour cell regulation were activated, while pathways associated with tumour proliferation functions were down-regulated. These findings may help in a better understanding of the ageing processes in HFrEF and identify potential therapeutic targets.

Plasma Tenascin-C: a prognostic biomarker in heart failure with preserved ejection fraction.

INTRODUCTION: Tenascin-C is a marker of interstitial fibrosis. We assessed whether plasma Tenascin-C differed between heart failure with preserved ejection fraction (HFpEF) and asymptomatic controls and related to clinical outcomes. MATERIALS AND METHODS: Prospective, observational study of 172 age- and sex-matched subjects (HFpEF n = 130; controls n = 42, age 73 ± 9, males 50%) who underwent phenotyping with 20 plasma biomarkers, echocardiography, cardiac MRI and 6-minute-walk-testing. The primary endpoint was the composite of all-cause death/HF hospitalisation. RESULTS: Tenascin-C was higher in HFpEF compared to controls (13.7 [10.8-17.3] vs (11.1 [8.9-12.9] ng/ml, p < 0.0001). Tenascin-C correlated positively with markers of clinical severity (NYHA, E/E', BNP) and plasma biomarkers reflecting interstitial fibrosis (ST-2, Galectin-3, GDF-15, TIMP-1, TIMP-4, MMP-2, MMP-3, MMP-7, MMP-8), cardiomyocyte stress (BNP, NTpro-ANP), inflammation (MPO, hs-CRP, TNFR-1, IL6) and renal dysfunction (urea, cystatin-C, NGAL); p < 0.05 for all. During follow-up (median 1428 days), there were 61 composite events (21 deaths, 40 HF hospitalizations). In multivariable Cox regression analysis, Tenascin-C (adjusted hazard ratio [HR] 1.755, 95% confidence interval [CI] 1.305-2.360; p < 0.0001) and indexed extracellular volume (HR 1.465, CI 1.019-2.106; p = 0.039) were independently associated with adverse outcomes. CONCLUSIONS: In HFpEF, plasma Tenascin-C is higher compared to age- and sex-matched controls and a strong predictor of adverse outcomes. Trial registration: ClinicalTrials.gov: NCT03050593.

Concentric vs. eccentric remodelling in heart failure with reduced ejection fraction: clinical characteristics, pathophysiology and response to treatment.

AIMS: Heart failure is traditionally classified by left ventricular ejection fraction (LVEF), rather than by left ventricular (LV) geometry, with guideline-recommended therapies in heart failure with reduced ejection fraction (HFrEF) but not heart failure with preserved ejection fraction (HFpEF). Most patients with HFrEF have eccentric LV hypertrophy, but some have concentric LV hypertrophy. We aimed to compare clinical characteristics, biomarker patterns, and response to treatment of patients with HFrEF and eccentric vs. concentric LV hypertrophy. METHODS AND RESULTS: We performed a retrospective post-hoc analysis including 1015 patients with HFrEF (LVEF <40%) from the multinational observational BIOSTAT-CHF study. LV geometry was classified using two-dimensional echocardiography. Network analysis of 92 biomarkers was used to investigate pathophysiologic pathways. Concentric LV hypertrophy was present in 142 (14%) patients, who were on average older and more likely hypertensive compared to those with eccentric LV hypertrophy. Network analysis revealed that N-terminal pro-B-type natriuretic peptide was an important hub in eccentric hypertrophy, whereas in concentric hypertrophy, tumour necrosis factor receptor 1, urokinase plasminogen activator surface receptor, paraoxonase and P-selectin were central hubs. Up-titration of beta-blockers was associated with a mortality benefit in HFrEF with eccentric but not concentric LV hypertrophy (P-value for interaction ≤0.001). For angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, the hazard ratio for mortality was higher in concentric hypertrophy, but the interaction was not significant. CONCLUSION: Patients with HFrEF with concentric hypertrophy have a clinical and biomarker phenotype that is distinctly different from those with eccentric hypertrophy. Patients with concentric hypertrophy may not experience similar benefit from up.-titration of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and beta-blockers compared to patients with eccentric hypertrophy.

The measurement of KRAS G12 mutants using multiplexed selected reaction monitoring and ion mobility mass spectrometry.

RATIONALE: There is a considerable clinical demand to determine key mutations in genes involved with cancer which necessitates the deployment of highly specific and robust analytical methods. Multiplex liquid chromatography with selected reaction monitoring (LC/SRM) assays offer the ability to achieve quantitation down to levels expected to be present in clinical samples. Ion mobility mass spectrometry (IMS/MS) assays can provide increased peak capacity and hence separation in an extremely short time frame, and in addition provide physicochemical data regarding the collision cross-section of an analyte which can be used in conjunction with the m/z value of an ion to increase detection specificity. METHODS: For LC/SRM, unlabelled peptides and corresponding stable-isotope-labelled standards were spiked into digested human plasma and analysed using ultrahigh-performance liquid chromatography (UHPLC) coupled to a triple quadrupole mass spectrometer to enable the generation of analyte-specific calibration lines. Synthetic unlabelled peptides were infused into a Synapt G2 mass spectrometer for travelling wave ion mobility separation and TW CCSN2 values were derived from comparison with previously generated TW CCSN2 calibration values. RESULTS: Linear calibration lines (0.125 to 25 fmol/µL) were established for each of the KRAS peptides. UHPLC separated the peptides and hence enabled them to be split into different retention time functions/windows. This separation enabled detection of three or four transitions for each light and heavy peptide with at least 10 points per peak for accurate quantitation. All six KRAS G12 peptides were separated using IMS/MS, enabling precise TW CCSN2 values to be determined. Although some of the G12 peptides chromatographically co-eluted, all the peptides were distinguished by m/z, retention time and/or drift time. CONCLUSIONS: This study advocates that LC/SRM and IMS/MS could both be used to identify single amino acid substitutions in KRAS as an alternative to commonly used methods such as circulating tumour DNA analysis.