Aptamer proteomics for biomarker discovery in heart failure with reduced ejection fraction

Background

Though current heart failure (HF) biomarkers are highly prognostic, systematically characterizing associations between circulating proteins and risk of subsequent events may improve clinical risk prediction and illuminate new biological pathways. Large-scale assays measuring thousands of proteins now enable unbiased proteomic investigation in clinical trials.

Purpose

To identify and replicate serum proteins associated with HF events in patients with chronic HF with reduced ejection fraction (HFrEF), and to develop and validate a proteomic risk score.

Methods

Serum levels of 4076 proteins were measured at baseline in the ATMOSPHERE (n=1261, 487 events over 6 years) and PARADIGM-HF (n=1257, 287 events over 4 years) trials of chronic HFrEF using a modified aptamer-based proteomics assay. Proteins associated with the primary endpoint, HF hospitalization or cardiovascular death, were identified in the ATMOSPHERE discovery cohort (false discovery rate<0.05) by Cox regression adjusted for age, sex, treatment arm, and anticoagulant use, and replicated in PARADIGM-HF (Bonferroni-corrected p<0.05). A proteomic risk score was derived in ATMOSPHERE using Cox LASSO penalized regression and evaluated in PARADIGM-HF compared to the MAGGIC clinical risk score and N-terminal pro-B-type natriuretic peptide (NT-proBNP). For proteins associated with the primary endpoint, pathway analysis was conducted using Ingenuity Pathway analysis and an exploratory two-sample Mendelian randomization was performed using genetic and outcome data from both trials and protein quantitative trait loci from deCODE to infer which identified proteins contribute to HF prognosis.

Results

We identified 377 serum proteins associated with the primary endpoint in ATMOSPHERE and replicated 167 in PARADIGM-HF. Prognostic proteins included known HF biomarkers Growth Differentiation Factor 15, NT-proBNP, and Angiopoietin-2, and also a previously unrecognized HF biomarker: Sushi, Von Willebrand Factor Type A, EGF And Pentraxin Domain Containing 1 (SVEP1) (HR 1.60 [95% CI 1.44–1.79] per standard deviation [SD], p=2x10–17) (Table 1). Proteins related to hepatic fibrosis, granulocyte adhesion, and inhibition of matrix metalloproteinases were over-represented. A 64-protein risk score derived in ATMOSPHERE predicted clinical events in PARADIGM-HF with greater discrimination (c-statistic 0.70) than the MAGGIC clinical score (c-statistic 0.61), NT-proBNP (c-statistic 0.65), or both (c-statistic 0.66) (Figure 1). Genetically predicted levels of NT-proBNP, WISP2, FSTL1, and CTSS were associated with the primary endpoint by Mendelian randomization.

Conclusions

We identify SVEP1, an extracellular matrix protein known to cause inflammation in vascular smooth muscle cells, as a previously unrecognized HF biomarker. A 64-protein score improved risk discrimination compared with NT-proBNP and may assist in identifying high-risk patients for clinical trials or disease management programs.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The ATMOSPHERE and PARADIGM-HF trials were sponsored by Novartis

Elevated markers of liver function are associated with poorer outcomes in HFREF: an analysis of DAPA-HF

Background

Abnormalities of liver tests in patients with heart failure with reduced ejection fraction (HFrEF) is a well-recognised phenomenon. We examined the prognostic value of measures of liver function in a large contemporary cohort of patients with HFrEF enrolled in the Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure (DAPA-HF) trial

Methods

In this post-hoc analysis of the DAPA-HF trial we studied 4625 patients with liver function tests available at baseline. Cox proportional hazards models were used to assess the association between liver tests (total bilirubin, alkaline phosphatase [ALP], alanine transaminase [ALT], aspartate transaminase [AST]) and the Model for End-stage Liver Disease excluding INR (MELD-XI) score (calculated as 5.11 Ln [total bilirubin as mg/dL] + 11.76 Ln [creatinine as mg/dL] + 9.44), and the risk of the primary composite endpoint (hospitalisation or urgent visit for heart failure or cardiovascular death). Models were adjusted for age, sex, race, region, systolic blood pressure, heart rate, LVEF, eGFR, log-transformed NT-proBNP, NYHA class, history of hypertension, stroke, myocardial infarction, atrial fibrillation, heart failure aetiology and randomized treatment to dapagliflozin and stratified by diabetic status at baseline. An interaction term between each measure and the effect of treatment on the primary composite outcome was tested as a fractional polynomial.

Results

Total bilirubin, ALP, and MELD-XI score were associated with a higher risk of all the primary outcome (Figure 1) but not ALT or AST. These relationships persisted after adjustment: total bilirubin per log unit increase (HR=1.46; 95% CI 1.28 – 1.67, p<0.001), ALP per log unit increase (HR=1.39; 95% CI 1.15 – 1.66, p<0.001), MELD-XI per 1 SD increase (HR 1.27; 95% CI 1.13 – 1.42, p<0.001). The effect of dapagliflozin on the primary outcome was not modified by the baseline levels of either total bilirubin, ALP or MELD-XI score (Figure 2)

Conclusions

Higher total bilirubin, ALP and MELD-XI score were independently associated with a higher risk of cardiovascular death or worsening HF and may be useful routinely available biomarkers to assess prognosis. The efficacy of dapagliflozin was the not modified by baseline levels of any of these markers.

Funding Acknowledgement

Type of funding sources: None. Figure 2

Global differences in heart failure with preserved ejection fraction: the paragon-hf trial

Background

Heart failure with preserved ejection fraction (HFpEF) is a global public health problem with important regional differences. We investigated these differences in the PARAGON-HF trial, the largest, most inclusive global HFpEF trial.

Methods

We studied differences in clinical characteristics, outcomes and regional treatment effects of Sacubitril/Valsartan in 4796 patients with HFpEF from the PARAGON-HF trial, grouped according to geographic region.

Results

Regional differences in patient characteristics and comorbidities were observed (Figure 1): patients from Western Europe were oldest (75±7 years) with the highest prevalence of atrial fibrillation (36%); Central/Eastern European patients were youngest (71±8 years) with the highest prevalence of coronary artery disease (CAD, 49%); North American patients had the highest prevalence of obesity (64%) with metabolic syndrome; Latin American patients were youngest and had a high prevalence of obesity (53%); Asia-Pacific patients had a high prevalence of diabetes (44%) despite low prevalence of obesity (26%). Rates of the primary composite endpoint of total hospitalizations for HF and death from cardiovascular causes was lowest in patients from Central Europe (9 per 100 patient years) and highest in patients from North America (28 per 100 patient years), which was primarily driven by a greater number of total hospitalizations for HF and independent of confounders. In the total population, sacubitril–valsartan did not result in a significantly lower rate of total hospitalizations for heart failure and death from cardiovascular causes with no significant heterogeneity in treatment response to sacubitril-valsartan across regions.

Conclusion

This first report on regional differences in the largest prospective global trial in HFpEF suggests substantial regional heterogeneity with respect to phenotype, outcomes and quality of life.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Study funded by Novartis

Effect of socioeconomic deprivation on the population risk of incident heart failure hospitalisation: an analysis of the Renfrew/Paisley Study

BACKGROUND

There are few data describing the effect of socioeconomic deprivation on the risk of developing heart failure (HF).

AIMS

To examine the relationship between socioeconomic deprivation and hospitalisation with HF over 20 years.

METHODS

Between 1972 and 1976, 15,402 individuals, aged 45-64 years, residing in two towns in Scotland, underwent cardiovascular screening. We report hospitalisations with HF over the subsequent 20 years according to Carstairs deprivation category and Social Class.

RESULTS

Following screening, 628 men and women (4.1%) were hospitalised with a primary diagnosis of HF. There was a gradient in the risk of HF hospitalisation with increasing socioeconomic deprivation (P=0.003). Of the most deprived individuals, 6.4% were hospitalised for HF compared to 3.5% of the most affluent group. Cox-proportional Hazard models showed that independent of age, sex and baseline risk factors for cardio-respiratory status, greater socioeconomic deprivation increased the risk of HF admission (P<0.001, overall). The adjusted risk of admission for HF was 39% greater in the most versus least deprived subjects (RR 1.39 95% CI 1.04-2.01; P=0.04).

CONCLUSION

These data show a link between social deprivation and the risk of developing HF, irrespective of baseline cardio-respiratory status and cardiovascular risk factors.