A streamlined, machine learning-derived approach to risk-stratification in heart failure patients with secondary tricuspid regurgitation

Background

Secondary tricuspid regurgitation (sTR) is the most frequent valvular heart disease and has significant impact on mortality. A high burden of comorbidities often worsens the already dismal prognosis of sTR, while tricuspid interventions remain underused and initiated too late.

Objectives

To examine the most powerful predictors of all-cause mortality in moderate and severe sTR using machine learning techniques and to provide a streamlined approach to risk-stratification using readily available clinical, echocardiographic and laboratory parameters.

Methods

This large-scale, long-term observational study included 3359 moderate and 1509 severe sTR patients encompassing the entire heart failure spectrum (preserved, mid-range and reduced ejection fraction). A random survival forest was applied to investigate the most important predictors and group patients according to their number of adverse features (Figure 1).

Results

The identified predictors and thresholds, that were associated with significantly worse mortality were higher age (≥75 in moderate and ≥70 years in moderate and severe sTR respectively), higher NT-proBNP (≥4000 pg/ml), increased high sensitivity C-reactive protein (≥1.0 mg/dl), serum albumin <40 g/L and hemoglobin <13 g/dL. Additionally, grouping patients according to the number of adverse features yielded important prognostic information, as patients with 4 or 5 adverse features had a sevenfold risk increase in moderate sTR (7.11 [2.27–4.30] HR 95% CI, P<0.001) and fivefold risk increase in severe sTR (5.08 [3.13–8.24] HR 95% CI, P<0.001) (Figure 2: A moderate sTR derivation, B moderate sTR validation, C severe sTR derivation, D severe sTR validation).

Conclusion

This study presents a streamlined, machine learning-derived and internally validated approach to risk-stratification in patients with moderate and severe sTR, that adds important prognostic information to aid clinical decision-making.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Austrian Science Fund

Life expectancy and early to mid-term dysfunction of transcatheter aortic prostheses: incidence, modes, correlates, and outcome

Backgrounds

Bioprosthetic valve dysfunction (BVD) is a major concern regarding transcatheter aortic valve implantation (TAVI) in low-risk patients.

Aims

To assess incidence, determinants, modes, and outcome of early to mid-term BVD after TAVI in relation with life expectancy.

Methods

Consecutive TAVI recipients (2007–2020) with a post-interventional follow-up ≥1-year were prospectively included. BVD components and bioprosthetic valve failure (BVF) were assessed according to updated Valve-Academic-Research-Consortium-3 criteria. Echocardiographic and laboratory follow-up was performed prior to discharge, at 3- and 12-months, and yearly thereafter. BVD/BVF and all-cause death served as endpoints. Average life expectancy was calculated from National Open Health Data and patients were stratified according to tertiles (1st: <6.85y, 2nd: 6.85–9.7y, 3rd: >9.7y).

Results

Of 1047 patients (81.6±6.8 y/o, 52.7% female, EuroSCORE II 4.5±2.5), ≥2 follow-ups were available from 622 (serial echo cohort). After a median echo follow-up of 12.2 months, incidence rates of BVD and BVF were 8.4% [95% confidence interval 6.7–10.3], and 3.5% [2.5–4.9] per valve-year, respectively, without differences between life expectancy tertiles (Figure 1). BVD incidence was double within the first year of implant (9.9% [7.7–12.6] per valve-year; mostly non-structural VD) vs. beyond (4.8% [3.1–7.2] per valve-year; structural and non-structural VD). Valve-in-valve procedure, and stenosis severity (both p<0.05), but not age/life expectancy (p>0.5) predisposed for BVD.

After 4.4±3.0 years, mortality was 36.7%. Time-dependent BVD/BVF were independently associated with outcome for patients in the first (adjusted hazard ratio [AHR] 1.72 [1.06–2.88]/ 2.97 [1.72–6.22]) and second (AHR 1.96 [1.02–3.73]/ 2.31 [1.00–5.30]), but not the third tertile of life expectancy (AHR 1.42 [0.66–3.12]/ 1.84 [0.71–4.79]; Figure 1).

Conclusions

In this large prospective observational cohort, early to mid-term BVD after TAVI occurred at the same rate across the spectrum of life expectancy and was not prognostic among those with the longest life expectancy.

Funding Acknowledgement

Type of funding sources: None.

Supervised learning-derived tailored risk-stratification in patients with severe secondary mitral regurgitation

Background

Mitral regurgitation secondary to heart failure (sMR) has considerable impact on quality of life, heart failure (HF) rehospitalizations and mortality. A diverse burden of comorbidities suggests multifaceted aspects of individual risks. This risk-spectrum has never been studied but is essential to understand disease trajectories.

Objectives

To provide a comprehensive and structured decision-tree-like approach to risk-stratification in patients with severe sMR.

Methods

This large-scale, long-term observational study included 1317 patients with severe sMR from the entire HF spectrum (preserved, mid-range and reduced ejection fraction). Primary endpoint was all-cause mortality and survival tree analysis, a supervised learning technique, was applied to identify patient subgroups with excessive risk of mortality (Figure 1).

Results

Eight distinct subgroups that differed significantly in long-term survival were identified (Figure 2). Subgroup 7, characterized by younger age (≤66), higher hemoglobin (>12.7 g/dl) and higher albumin levels (>40.6 g/l) had the best survival. In contrast, subgroup 5 displayed a 20-fold risk of mortality (HR 95% CI: 20.38 ([0.78–38.52]), P<0.001) and presented with older age (>68 years) and low serum albumin (≤40.6 g/l) and higher NT-proBNP levels (≥9750 pg/ml). Results were consistent in internal and temporal validation.

Conclusion

Supervised machine learning reveals an unexpected heterogeneity in the sMR risk-spectrum, indicating the clinical challenges tied to severe sMR. A decision-tree-like model can guide through the risk spectrum and provide tailored risk-stratification. This structured approach provides the foundation to generate hypotheses towards improved therapeutic strategies and optimized patient care.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Austrian Science Fund

Neurofilaments in heart failure-depicting the brain-heart axis

Introduction

Experimental studies have fueled theoretical concerns about neurocognitive side effects of the angiotensin-receptor-neprilysin-inhibitor (ARNi) sacubitril/valsartan as neprilysin is not only involved in the degradation of vasoactive peptides, but also in the degradation of amyloid-β in the brain. To date, no study could demonstrate cognition- and dementia-related adverse effects following neprilysin-inhibition. Recent advances in blood-based tests made it feasible to precisely measure the concentration of neurofilament light chain in plasma (sNfL).sNfl has been found to be altered in neurodegenerative disease, making it a potential biomarker for screening and early detection of cognitive impairment. This study investigated the association of sNfL levels with the severity of disease and prognosis in heart failure with reduced ejection fraction (HFrEF) and explored the response of sNfL levels to the initiation of ARNi.

Methods

HFrEF patients were prospectively enrolled and clinically followed-up.sNfL levels were measured by a single-molecule array assay. The association of sNfL with heart failure (HF) severity and outcome was assessed. The discriminatory power of sNFL was assessed using Harrell's C-statistic and was compared to NT-proBNP. In a subset of 47 patients, sNfL levels were determined before the initiation of ARNi (baseline), 3±2 months (short-term) and 12±3 months (long-term) after.

Results

A total of 177 HFrEF patients were included into the study. Median age was 61 years (IQR: 51–72) and 75% of patients were male. Median sNfL levels were 26.2 pg/ml (IQR: 14.1–43.8).sNfL concentration was significantly associated with HF severity reflected by NT-proBNP (rs=0.361, p<0.001) and NYHA class (p<0.001) (Figure 1A). Thirty-one (17.5%) patients died during a median follow-up time of 2.8 years (IQR: 2.3–3.3). Increased sNfL concentration was indicative for worse overall survival even after adjustment for age, sex, kidney function and NT-proBNP [adj. HR for ln[sNfL]: 1.78 (95% CI: 1.13–2.80, p=0.012] (Figure 1B). In terms of discriminatory accuracy, sNfl was comparable with NT-proBNP (C-index: 0.75 [CI: 0.67–0.83] vs. 0.71 [CI: 0.63–0.80], p=0.299). Regarding the effect of ARNi-therapy no significant change in sNfL was observed at short- and long-term follow-up (26.0 pg/ml [IQR: 15.1–51.4] vs. 31.5 pg/ml [IQR: 15.8–51.3]; vs. 31.3 pg/ml [IQR: 15.5–54.0], p>0.05 for all) (Figure 2).

Conclusions

This study suggests that sNFL is a high performing marker to predict outcome in HFrEF independent of NT-proBNP. NEP-inhibition by ARNi does not seem to reasonably influence sNfL levels. The nature of sNfL release is uncertain. As sNfL is assumed to be specific for axonal injury, sNfL increase in HFrEF may be driven by hypoperfusion due to fixed peripheral vasoconstriction characteristic for more severe disease states. Whether sNfL levels are able to aid screening and early therapy of neurocognitive decline in HFrEF has to be elucidated in further studies.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Austrian Society of Cardiology - Research Grant

Right ventricular longitudinal strain on cardiovascular magnetic resonance imaging predicts outcome in patients undergoing transcatheter mitral valve repair

Background

The prognostic value of left and right ventricular global longitudinal strain (LV and RV GLS) derived from cardiovascular magnetic resonance (CMR) feature tracking in patients with severe mitral regurgitation (MR) undergoing transcatheter mitral valve repair (TMVR) is unknown.

Methods

Consecutive patients scheduled for TMVR underwent pre-procedural and follow-up CMR imaging including feature tracking strain analysis. Kaplan-Meier estimates and multivariate Cox-regression analyses were used to identify the prognostic impact of LV and RV GLS on CMR using a composite of heart failure hospitalization and death.

Results

A total of 62 patients (78.3±7.0y/o, 45% female, EuroSCORE II: 9.7±7.2%) with severe MR underwent CMR prior to TMVR. 23 (37%) patients presented with right ventricular dysfunction (RVD) defined by RV GLS >−20% on CMR. At baseline, RVD was associated with NT-proBNP levels (9510 vs. 4064pg/mL, p=0.030). On CMR, RVD was associated with reduced left and RV ejection fraction (LVEF: 39.2 vs. 48.7%, p=0.011, RVEF: 35.1 vs. 46.7%, p<0.001), as well as increased LV GLS (−14.0 vs. −19.5%, p=0.003).

A total of 18 events (12 deaths, 6 hospitalizations for heart failure) occurred during follow-up (mean 11.4±9.1months). While LV GLS was not significantly associated with outcome (HR 0.95, 95% CI: 0.90–1.01, p=0.082), RV GLS showed a strong and independent association with event-free survival by multivariate Cox-regression analysis (adj.HR 0.91, 95% CI: 0.83–0.99, p=0.033) after adjustment for relevant baseline and procedural data (EuroSCORE II, post-procedural residual MR), imaging parameters (TAPSE, LV and RVEF on CMR), and cardiac biomarkers (NT-proBNP). When compared with the “gold standard” RVEF on CMR (RVEF <45%: adj.HR 0.86, 95% CI: 0.23–3.20, p=0.825) and TAPSE on echo (TAPSE <17mm: adj.HR: 2.77, 95% CI: 0.72–10.70, p=0.140), only RVD (RV GLS >−20%: adj.HR 5.05, 95% CI: 1.23–20.63, p=0.024) was significantly associated with the composite endpoint (Figure 1). Follow-up CMR was performed in 21 (34%) patients. RV GLS significantly improved after TMVR (−20.6 to −25.2%, p=0.016, Figure 2).

Conclusions

RV rather than LV GLS, as determined on CMR, is an important predictor of outcome in patients undergoing TMVR. At 1 year follow-up, RV function significantly improved, and thus might add useful prognostic information on top of established risk factors.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Transcatheter versus surgical valve repair in patients with severe mitral regurgitation

Background

Transcatheter edge-to-edge mitral valve repair (TMVR) is increasingly performed, however, its efficacy in comparison with surgical MV treatment (SMV) is unknown.

Methods

Consecutive patients with severe mitral regurgitation (MR) undergoing TMVR (68% functional, 32% degenerative) or SMV (9% functional, 91% degenerative; 23% MV replacement) were enrolled. To account for differences in baseline characteristics, propensity score-matching including age, EuroSCORE-II, left ventricular ejection fraction, and NT-proBNP was performed. A composite of heart failure (HF) hospitalization/death was defined as primary endpoint. Kaplan-Meier curves and Cox-regression analyses were used to investigate associations between baseline, imaging, and procedural parameters and outcome.

Results

Between July 2017 and April 2020, 245 patients were enrolled, of which 102 patients could be adequately matched (73y/o, 61% females, EuroSCORE-II: 5.7%, p>0.05 for all). Despite matching, TMVR patients were sicker at baseline (higher rates of prior myocardial infarction, coronary revascularization, pacemakers/defibrillators, and diabetes mellitus, p<0.009 for all).

Patients were followed for 28.3±27.2 months, during which 27 events (17 deaths, 10 HF hospitalizations) occurred.Postprocedural MR reduction (MR grade <2: TMVR vs. SMV: 88% vs. 94%, p=0.487) and freedom from HF hospitalization/death (log-rank: p=0.221) were similar at two years. By multivariable Cox analyses, EuroSCORE-II (adj.HR 1.07 [95% CI: 1.00–1.13], p=0.027) and postprocedural MR severity (adj.HR 1.85 [95% CI: 1.17–2.92], p=0.009) emerged as independent predictors of outcome.

Conclusions

In this propensity matched, all-comers cohort, 2-year outcomes after TMVR versus SMV were similar. Given the reported favorable long-term durability of TMVR, the interventional approach emerges as valuable alternative for a substantial number of patients with functional and degenerative MR at high/prohibitive surgical risk.

Funding Acknowledgement

Type of funding sources: None.

Imaging and circulating biomarkers: a united approach for secondary tricuspid regurgitation

Background

Secondary tricuspid regurgitation (STR) is frequent among patients with heart failure with reduced ejection fraction (HFrEF), however inheres considerable diagnostic challenges. The assessment of circulating biomarkers reflecting neurohumoral activation may constitute a valuable supplement to the currently imaging-based diagnostic process. This study therefore sought to investigate (i) the expression of a set of complementary biomarkers in STR, (ii) to evaluate their association with STR severity, and (iii) to analyse whether the combination of neurohormone measurement and echocardiographic grading improves the individual patient risk assessment.

Methods

We included 576 HFrEF patients under guideline-directed therapy recording functional, echocardiographic, invasive hemodynamic and biochemical measurements, i.e. N-terminal pro-B-type natriuretic peptide, mid-regional pro-atrial natriuretic peptide (MR-proANP), mid-regional pro-adrenomedullin, C-terminal pro-endothelin-1 (CT-pro-ET1) and copeptin.

Results

Plasma levels of aforementioned neurohormones were significantly rising with increasing STR severity (for all P<0.001). Among all measured biomarkers, CT-pro-ET1 and MR-proANP were closest related to severe STR, even after multivariate adjustment for established clinical confounders (adj. OR 1.46; 95% CI 1.11–1.91, P=0.006 and adj. OR 1.45, 95% CI 1.13–1.87, P=0.004, respectively). By means of individual outcome in patients with moderate to severe STR, adding the selected biomarkers (i.e. CT-pro-ET1 and MR-proANP) resulted in a substantial improvement in the discriminatory power regarding long-term mortality (C-statistic: 0.54 vs. 0.65, P<0.001; continuous NRI 57%, P<0.001).

Conclusions

Circulating biomarkers closely relate to STR severity and correlate with hemodynamic and morphologic mechanisms of STR. Specifically, MR-proANP and CT-pro-ET1 are closely linked to the presence of severe STR and a combined assessment with the guideline recommended echocardiographic grading leads to a significant improvement of individual risk stratification.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): FWF - Austrian Science Fund Graphical AbstractNeurohumoral profiles of STR

Principal morphomic components of secondary mitral regurgitation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Austrian Science Fund (FWF – identification number: KLI-818B).

Background

Secondary mitral regurgitation in patients with heart failure and reduced ejection fraction (sMR) results from distortion of the physiologic cardiac architecture. Underlying morphological components might account for the clinical impact of sMR but have not yet been assessed systematically or related to outcome. 

Objectives

To investigate the morphologic features of sMR and their prognostic impact on outcome. 

Methods

This study used morphomic network profiling in patients with stable heart failure under guideline directed medical therapy. Principal component analysis was applied and three factors extracted, of which Factor 1 and 2 were strongly related to sMR and outcome. Based on the factors, four morphologically distinct clusters were derived. 

Results

Morphomic data from 383 patients were profiled. Factor 1 consists of high loadings of left atrial morphological information, factor 2 high loadings of left ventricular morphology. Cluster analysis revealed four morphologically distinct phenotypes. sMR was most prominent in cluster 3 and 4. The morphological difference was left ventricular size (enddiastolic volume 188ml (160-224) versus 315ml (264-408), P < 0.001). Clusters were associated with mortality (P < 0.001), however, sMR remained independently associated with mortality after adjusting for the clusters (adj.HR 1.42, 95% CI 1.14–1.77; P < 0.01) (Figure 1/ Panel B). The detrimental association of sMR with mortality was mainly driven by cluster 3 (HR 2.18, 95% CI 1.32-3.60; P = 0.002), the "small LV cavity" phenotype (Figure 1/ Panel A).

Conclusions

These results challenge the current perception of sMR resulting exclusively from global or local LV remodeling and, supported by previous concepts, emphasize the role of the atrial component as a pathophysiologic mechanism. The association of sMR with mortality cannot be purely attributed to cardiac morphology alone. Additionally, other key aspects such as balance of closing and tethering forces contribute to mitral valve closure. The association of sMR with mortality mainly driven by the small LV cavity phenotype refines the prognostic impact of sMR in relation to the underlying anatomic variability.

Abstract Figure. Survival for clusters and adj. sMR

552 Natural history of bivalvular functional regurgitation

Introduction

Bivalvular functional regurgitation (BVFR) defined as concomitant mitral and tricuspid insufficiency has not been described or systematically assessed before. The present study therefore sought to define incidence, impact and natural history of BVFR in heart failure with reduced ejection fraction (HFrEF) to provide the foundation for risk assessment and directions for potential treatment strategies.

Methods

We enrolled 1021 consecutive patients with HFrEF under guideline-directed medical therapy and performed comprehensive echocardiographic and neurohumoral profiling. Mitral and tricuspid regurgitation was quantified by an integrated approach comprising valve morphology, width of the proximal regurgitant jet, proximal flow convergence, and pulmonary venous flow. All-cause mortality during a five-year follow up served as the primary endpoint.

Results

Thirty percent of patients suffered from moderate or severe BVFR. Long-term mortality increased with the presence and severity of FR with severe BVFR representing the highest risk-subset (P < 0.001). Severe BVFR patients were more symptomatic and displayed an adverse remodeling and neurohumoral activation pattern (all P < 0.05). Severe BVFR was associated with excess mortality (Figurel 1, Panel A) independently of clinical (adj.HR 1.52, 95%CI 1.39-1.84;P < 0.001) and echocardiographic (adj.HR 1.31, 95%CI 1.11-1.54;P = 0.001) confounders, guideline-directed medical therapy (adj. HR 1.55, 95%CI 1.35-1.79;P < 0.001) and neurohumoral activation (adj.HR 1.31, 95%CI 1.07-1.59;P = 0.009). Moderate BVFR (n = 99) comprised equal baseline characteristics and similar risk as isolated severe FR. (Figure 1, Panel B) (HR 0.95, 95%CI 0.69-1.30;P = 0.73).

Conclusion

This long-term outcome study shows the multi-faceted nature of FR and defines BVFR as an important clinical entity associated with impaired functional class, adverse cardiac remodeling and excess risk of mortality. Moderate BVFR conveys similar risk as isolated severe FR reflecting the deleterious impact of the global regurgitant load on the failing heart and the need of an integrated understanding for risk-assessment.

Abstract 552 Figure 1 (Panel A and B)

P1763 Impact of disproportionate functional mitral regurgitation

Background

Application of the effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) is potentially limited as such lesion-focused metrics inevitably lack flexibility to account for the heterogeneity of left ventricular size and function. A recently proposed conceptual framework seeks to rearrange EROA and RegVol cut-offs according to left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF), introducing the novel term "disproportionate FMR" to describe clinically meaningful FMR.

Methods

To test the impact of disproportionate FMR, we embedded data of 291 heart failure patients with reduced ejection fraction (HFrEF) under guideline directed therapy (GDT) into this framework. Regurgitant Volume and EROA were plotted against LVEDV using bubble plots that also account for the heterogeneity of EF (Figure 1 A and C). The black lines depict a regurgitant fraction (RegFrac) of 50% at the median EF (25%) or Vmax (4.3m/s) of the study population. Thus, above individual center lines (illustrated by different bubble sizes) FMR severity is disproportionate, within the area of measurement uncertainty it is proportionate to LV dilation and below, it is likely non-severe. The degree of uncertainty of proportionate FMR is determined by the imprecision of the measurements defined as 2SDs of regurgitant fraction (±6.6%) per Bland-Altmann analysis.

Results

During a median follow-up of 84 months (IQR 84-136), 166 patients died. Disproportionate FMR was associated with excess mortality (RegVol: HR 1.97, 95%CI 1.38-2.81, P < 0.001; EROA: HR 2.22, 95%CI 1.52-3.22), whereas proportionate FMR was not associated with increased long-term mortality (RegVol: HR 1.04, 95%CI 0.71-1.53, P = 0.83; EROA: HR 1.06, 95%CI 0.71-1.58, P = 0.79; Figure 1B&D).

Conclusions

In this contemporary HFrEF cohort every fifth patient has disproportionate FMR which conveys a two-fold increased risk of mortality which provides evidence for the validity of the conceptual framework. Advancement of the proposed framework to clinical practice has several implications: 1)EROA and RegVol are metrics that do not account for the contextual variability of LVEDV and EF. 2)The RegFrac -not incorporated in ESC guidelines but integrated in AHA/ACC definitions- provides a metric proportionated to left ventricular size and function supporting its use to define relevant FMR. However, technical limits suggest its complementary use on top of more robust metrics such as EROA and RegVol. Future studies need to clarify whether disproportionate FMR reflects the subgroup of patients that benefit from mitral valve repair, and provide a robust algorithm that integrates the metrics of FMR severity in a complementary manner.

Abstract P1763 Figure.

P1832 T1 mapping and echo-global longitudinal strain are early markers of cardiac involvement in patients with fabry disease

OnBehalf

Constantin Gatterer

Introduction

Fabry disease (FD) is one of the most common lysosomal storage diseases caused by deficiency of Alpha-Galactosidase A and accumulation of glycosphingolipids in all cells containing lysosomes. Cardiac involvement is characterized by left ventricular hypertrophy, conduction abnormalities and myocardial fibrosis with consecutive cardiomyopathy in late stages.

Purpose

As the detection of early signs of cardiac involvement is crucial for the initiation of enzyme replacement therapy (ERT) or Chaperon therapy, we intended to find early imaging markers.

Methods

Cardiac MRI (CMR) including Late Gadolinium Enhancement (LGE), representing fibrosis, and T1-mapping as well as echocardiography with measurement of global longitudinal strain (GLS) were done as part of the regular check-ups for patients with FD.

Results

The study cohort of 30 FD patients (20-69 years, 53% women) in different stages of disease showed low GLS values already at the time of baseline echocardiography (mean: -17,22%), correlating with the amount of LGE (r = 0,73; p = 0,003) and ejection fraction measured by CMR (CMR-EF; r=-0,74; p = 0,002).

After an average follow-up of 39 months (STD 18), GLS values were significantly declined (-15,51 %; p = 0,009) and correlated with T1 times (r = 0,7; p = 0,04), while LGE and CMR-EF did not significantly change compared to baseline.

Baseline T1 times correlated negatively with the reduction of GLS (r=-0,7; p = 0,003), while LGE and CMR-EF showed no correlation with the course of GLS. ERT appeared to have no influence on the extend of GLS reduction.

Conclusion

Low native CMR T1 times, indicating sphingolipid accumulation in the myocardium, seem to represent the beginning of cardiac involvement in FD and might predict the course of GLS. GLS is a sensitive parameter for early detection of cardiac manifestation and disease progression, while LGE and CMR-EF could not recognize slight deterioration of left ventricular function.

P1634Comparison of inflammation based prognostic scores in patients with stable heart failure with reduced ejection fraction

Background

Elevated inflammatory markers and malnutrition are characteristic for heart failure with reduced ejection fraction (HFrEF) correlating with disease severity and prognosis. Nutritional decline is closely linked to inflammation. Evidence emerges that heart failure can be triggered by inflammation directly, meaning that progression of HF is a function of individual inflammatory host response. We aimed to investigate and compare the impact of well-established inflammation based scores and inflammation-related nutritional scores on survival in HFrEF.

Methods

Stable HFrEF-patients undergoing routine ambulatory care between 2011 and 2017 have been identified from a prospective registry. Comorbidities and laboratory data at baseline were assessed. All-cause mortality was defined the primary endpoint. The modified Glasgow Prognostic Score (mGPS: 0/1/2 based on CRP and albumin), the neutrophil-to-lymphocyte ratio (NLR), the monocyte-to-lymphocyte ratio (MLR), the platelet-to-lymphocyte ratio (PLR) as well as the Nutritional Risk Index (NRI = (1.519 × serum albumin, g/dL) + (41.7 × present weight (kg)/ideal body weight (kg)) and the Prognostic Nutritional Index (PNI = albumin (g l–1) × total lymphocyte count × 109 l–1) were calculated. The association of the scores with HF severity and impact on overall survival were determined.

Results

Data of 443 patients receiving well titrated guideline directed HF therapy have been analyzed. Median age was 64 years (IQR 53–72), 73% were male. Median body mass index (BMI) was 26.6kg/m2 (IQR 23.8–30.2), median NT-proBNP was 2053pg/ml (IQR 842–4345) with most patients presenting in NYHA class II (178, 40%) and III (173, 39%). The mGPS was 0 for 352 (80%), 1 for 76 (17%) and 2 for 14 (3%) patients, respectively. All scores correlated with HF severity reflected by NT-proBNP [p<0.001 for mGPS, r=−0.48; p<0.001 for PNI] and NYHA class [p<0.001 for mGPS and PNI]. All scores were associated with all-cause mortality in univariate analysis. After adjustment for age, gender and kidney function only mGPS, PLR, NRI and PNI remained significantly associated with outcome. Out of these the ROC were highest for PNI and mGPS [0.674 and 0.652 respectively] and solely these scores remained significantly associated with mortality after including NT-proBNP in the multivariate model [adj.HR 1.87 (95% CI: 1.20–2.91), p=0.006 for mGPS; 0.62 (95% CI: 0.40–0.96), p=0.032 for PNI]. Kaplan Meier analysis confirmed the discriminatory power of mGPS and PNI (Figure 1).

Conclusions

Enhanced inflammation and malnutrition are more common in advanced heart failure. Among established inflammation and nutritional scores merely mGPS and PNI are associated with survival in HFrEF patients independently of NT-proBNP. This relationship emphasizes the significance of the individual proinflammatory response on prognosis.This easily available score may help clinicians to identify HFrEF patients with worse prognosis with urgent need for intensified therapy and/or alternate treatment options.

6097Aminoterminal proB-type natriuretic peptide: a key parameter to optimise therapeutic management of low-flow, low-gradient aortic stenosis

Background

B-type natriuretic peptide (BNP) and aminoterminal-proBNP (NT-proBNP) are well established surrogates of LV function impairment. However, data are scarce regarding their prognostic value to risk-stratify patients with classical low-flow, low-gradient aortic stenosis (LFLG-AS, with low left ventricular [LV] ejection fraction).

Methods

The TOPAS study is a prospective observational cohort of 240 patients with aortic valve area <0.6 cm2/m2, mean gradient<40 mmHg and LVEF<50%. True severe AS was adjudicated using flow independent grading schemes.

Results

BNP significantly predicted one-year (area under the receiver operating-characteristic curve [AUC]) 0.62±0.04, p=0.026) but not three-year mortality. After adjustment for the severity of AS, initial treatment (aortic valve replacement [AVR] vs. conservative management [ConsRx]), age, sex and the EuroSCORE (Model#1), BNP-ratio>550 pg/ml had a trend to predict time to death (HR=2.14 [1.00–4.58], p=0.05). In contrast, NT-proBNP ratio significantly predicted both one and three-year mortality (AUC=0.67±0.04 and 0.66±0.05, both p=0.001), and independently predicted time to death (HR=1.39 per 1 unit of Log transformed NT-proBNP [1.11–1.74], p=0.004). In a head-to-head comparison (108 patients with both biomarkers), the AUCs to predict one and thre-year mortality were significantly higher with NT-proBNP versus BNP (p<0.009). NT-proBNP but not BNP independently predicted mortality and significantly improved Model#1 (Likelihood ratio test Chi2=15.95, p<0.001). The category-free net reclassification index of NT-proBNP was 0.71 (p=0.008) versus 0.38 (p=0.15) for BNP. Furthermore, there was a marked survival benefit associated with AVR in patients with NT-proBNP ≥1700 pg/ml (adjusted hazard ratio (aHR) associated to AVR vs conservative management=0.52 [0.31–0.85], p=0.009), while those<1700 pg/ml had excellent one-year survival under ConsRx (only one death [4.5±4.4%] at one year as compared to 23 [37±6.2%] for ConsRx-NTproBNP>1700, aHR=0.11 [0.01–0.83], p=0.033). The survival benefit associated with AVR interacted with NT-proBNP (p<0.001) but not with true or pseudosevere AS (p=0.53 for interaction), suggesting that NT-proBNP might identify moderate AS patients but sufficiently severe valvulo-ventricular disease to justify AVR.

Survival according to NT-proBNP and AVR

Conclusion

NT-proBNP appears to be an excellent biomarker for the clinical purpose of risk-stratifying classical LFLG-AS. A threshold of 1700 pg/ml i.e. close to the diagnostic threshold for heart failure in acute dyspnea, was a strong independent determinant of the survival benefit associated with aortic valve replacement. Our findings suggest that NT-proBNP should be preferred over BNP.

Acknowledgement/Funding

Canadian Institute of Health Research

P1620Association of granulocyte neprilysin (CD10) expression with prognosis in heart failure with reduced ejection fraction

Background

The exact mechanism of action of neprilysin inhibition (NEPi) is still a subject of debate. The soluble form of the enzyme (sNEP), detectable in plasma, is discussed controversially as a potential biomarker in heart failure with reduced ejection fraction (HFrEF). NEP is present on solid tissues but identically to CD10, expressed on the surface of leukocytes under physiological conditions. The possible impact of NEP expression on peripheral leukocytes on prognosis and its association with sNEP levels have not been investigated yet.

Methods

99 stable HFrEF patients were prospectively enrolled and clinically followed-up. Laboratory markers including NT-proBNP were assessed. NEP (CD10) expression on peripheral blood cells were measured by flow cytometry using a combination of six antibodies with fluorescence minus one samples as control [CD3 (#555339), CD19 (#555413), CD56 (#335826), CD16 (#561306), CD14 (#562692), +/−CD10 (#332777); BD Biosciences,USA]. sNEP levels were determined by a specific ELISA [SEB785Hu, USCN, China].Associations between NEP expression and heart failure severity, sNEP levels and all-cause mortality were determined.

Results

Median age was 65 years (IQR: 55–73), 75% were male. Median NT-proBNP level was 1700pg/ml (IQR: 794–4009).NEP was expressed on granulocytes with 94.8% (IQR: 90.5–97.4) of CD10+ cells and measurable on B-cells and monocytes with 8.5% (IQR: 5.3–13.5) and 0.8% (IQR: 0.4–1.5) of CD10+ cells of the respective leukocyte subtype. NEP expression on T-cells was not detectable. The mean fluorescence intensity (MFI) of CD10+ cells was 5461 (IQR: 4028–6904) for granulocytes, 640 (IQR: 535–740) for B-cells and 1589 (IQR: 1395–1975) for monocytes. Granulocyte NEP expression, but not NEP expression on B-cells or monocytes, correlated inversely with heart failure severity reflected by NT-proBNP level (r=−0.46, p<0.001) and NYHA class (p=0.013) (Figure A). sNEP concentrations correlated weakly with NEP expression on granulocytes (r=0.22, p=0.030) as well as the MFI of CD10+ granulocytes (r=0.31, p=0.003). 15% of the patients died during a median FUP of 24 (IQR: 23–28) months. Increased NEP expression on granulocytes was indicative for better overall survival even after adjustment for age and kidney function [adj. HR per 1-IQR increase of MFI 0.41 (95% CI: 0.18–0.94), p=0.035]. Kaplan-Meier analysis illustrates the impact of granulocyte NEP expression on outcome graphically (Figure B).

Figure 1

Conclusions

Albeit beneficial effects of NEPi by ARNI therapy, NEP expression on granulocytes is inversely correlated with heart failure severity and mortality. The results support the inverse relationship between BNP and plasma NEP activity reported for a mixed population of heart failure patients. The positive correlation of granulocyte NEP expression and sNEP indicates a possible contribution of shed membrane NEP molecules to plasma NEP levels as a surrogate marker. The utility of granulocyte NEP expression or sNEP as biomarkers in HFrEF have to be further evaluated.

P5448Enzymatic regulation of the myocardial tissue renin-angiotensin-system of the failing heart

Background

In heart failure with reduced ejection fraction (HFrEF) the renin-angiotensin-system (RAS) is dysregulated and serves as therapeutic target. Research has been focusing on plasma RAS. Information on tissue RAS is scarce although assumedly more crucial for myocardial function. Among known angiotensins, only AngII and AngIII are detectable in the failing heart. Plasma samples in HFrEF show high AngI and AngII levels with clearly distinguishable AngI/AngII ratios for different RAS-inhibitors. AngII and AngIII levels in the myocardium were comparable for different RAS-inhibitors, i.e. no RAS-blocker, ACE-inhibitor, ARB or angiotensin-receptor neprilysin-inhibitor (ARNI). Here we aimed to elucidate the metabolic regulation of tissue RAS enzymes for these four different modalities of RAS-inhibition.

Methods

Enzyme regulation and metabolic activities were investigated in myocardial samples of end-stage HFrEF patients undergoing heart transplantation with a mass-spectrometry based method. Concentrations of respective angiotensin metabolites AngI, AngII, Ang1–7, AngIII, Ang1–5 and AngIV (RAS-fingerprints) were investigated after adding AngI or AngII and incubation to display metabolic patterns of the main plasma angiotensins. Metabolic activities of distinct enzymes have been assessed for the no therapy and ACE-I subgroups. Patients were stratified according to background therapy with RAS-inhibitors.

Results

A total of 30 patients were included (n=6 without RAS-blockade, n=16 with ACE-I, n=6 with ARB, n=2 with ARNI). Median age was 55 (IQR 45–63) years, 87%were male. Etiology of HF was ischemic in 40%, median NT-proBNP levels were 3498pg/ml (IQR 1761–8400). Patterns for tissue RAS metabolism of AngI and AngII was visually similar for all groups, indicating comparable regulation of tissue RAS enzymes independent from therapy (Figure 1). The formation of AngII from AngI was mainly chymase dependent with conversion rates of 99.4 (IQR 77.0–254.1) (pg/μg protein)/h for ACE-I and 141.8 (IQR 67.9–369.2) (pg/μg protein)/h for no RAS-blockade, whereas ACE-related generation of AngII was under the detection limit. The formation of Ang1–7 from AngI was mediated by NEP and PEP. The contribution of NEP was significantly higher [5022 (IQR 5002–5286) (pg/μg)/h vs 3555 (IQR 3351–3849) (pg/μg)/h, p=0.005 for the ACE-I group and 4729 (IQR 4438–6135) (pg/μg)/h vs 3601 (IQR 3052–4182) (pg/μg)/h, p=0.012 for no RAS-blockade]. No differences in tissue enzymatic activities between ACE-I and no therapy, as already indicated by the metabolization patterns occurred.

Figure 1

Conclusions

Enzymatic tissue RAS regulation in end-stage HF seems to be independent from the mode of established RAS-inhibitor therapy.In contrast to plasma, AngII formation of the tissue is mainly chymase dependent, whereas ACE seems to play an unsignificant role. NEP has a substantial role in generating beneficial Ang1–7 from AngI. The impact of NEP inhibition by ARNI on tissue RAS and mechanism of action have to be further investigated.

6099Impact of aortic valve replacement on outcomes of patients with low-flow, low-gradient moderate aortic stenosis

Background

Aortic valve replacement (AVR) is recommended for patients with low-flow, low-gradient (LFLG) and true-severe aortic stenosis (TSAS). However, there is very few data on the potential benefit of AVR in patients with LFLG pseudo-severe (i.e. moderate) AS (PSAS).

Methods

Consecutive patients with aortic valve area ≤0.6 cm2/m2, mean gradient <40 mmHg were prospectively recruited in a multicenter observational cohort study. The patients were categorized in TSAS vs. PSAS using previously reported thresholds of flow-independent parameters of AS severity (projected valve area at normal flow rate ≤1.0 cm2 and/or aortic valve calcium score by CT >1200 AU in women and >2000 AU in men). To account for between-treatment-group differences, inverse probability-of-treatment weighting was combined to Cox proportional hazards regression.

Results

Among the 430 patients included in this study, 297 (69%) were classified as TSAS and 274 (57%) underwent AVR. Of note, 21% of the patients treated by AVR were classified as PSAS. In patients managed conservatively (ConsRx), 52% had PSAS and 48% TSAS. During a median follow-up of 28 months [8–60], 198 patients died. The adjusted weighted hazard ratio (awHR) of death associated with AVR as compared to ConsRx was 0.42 [0.24–0.73] (p<0.0001, Figure1-Panel-A). This survival benefit associated with AVR was observed not only in patients with TSAS but also in those with PSAS (awHR: 0.29 [0.12–0.70]; p=0.006, Figure1-Panel-B).

Figure 1

Conclusion

The results of this study suggest that AVR is associated with a survival benefit not only in LFLG patients with TSAS but also in those with PSAS. Randomized trials are needed to confirm the benefit of AVR in patients with moderate AS and depressed LV systolic function.

Acknowledgement/Funding

Canadian Institute of Health Research

P5449Neurohumoral regulation of the low-, medium- and high-renin HFrEF phenotypes

Background

Previous investigations of plasma Renin-Angiotensin-System (RAS) fingerprints of patients with heart failure with reduced ejection fraction (HFrEF) revealed the existence of low, medium and high renin phenotypes independently of disease severity. Plasma renin serves as an excellent surrogate for angiotensin levels. The different renin phenotypes could not only hypothetically respond differently to RAS blockade but associated alterations of other vasoactive peptide systems could elucidate disease mechanisms and novel targets for heart failure therapy. The study aimed to investigate the relation between RAS regulation and pathophysiologically relevant vasoactive peptide systems based on different renin phenotypes.

Methods

We prospectively enrolled 369 patients with stable HFrEF. Laboratory markers including NT-proBNP and active renin concentration (ARC) were assessed. Plasma NEP levels (sNEP), bioactive adrenomedullin (bio-ADM) and big-endothelin1 (bigET-1) were measured by ELISA (R&D systems, UK; Sphingotec GmbH, Germany and Eagle Biosciences, Austria). NEP activity was determined by a fluorimetric peptide cleavage assay. The correlation between biomarkers and association with all-cause mortality was assessed. sNEP, bio-ADM and bigET-1 levels as well as NEP activity between the different renin phenotypes (i.e. <15. percentile, 15.-85. percentile and >85. percentile of ARC) was compared.

Results

Median age was 65 (IQR 53–73) years, 75% of patients were male. Median NT-proBNP levels were 1936 (IQR 855–4126) pg/mL. Median ARC was 155 (29–569) μIE/mL, the low, medium and high renin HFrEF phenotypes showed median ARC levels of 4.2μIE/mL (IQR 2.0–7.8), 155.1μIE/mL (IQR 43.3–353.5) and 2360μIE/mL (IQR 1483–3250) μIE/mL. Median bigET-1 was 0.62pmol/L (IQR 0.42–1.10), bio-ADM 26.0pg/mL (IQR 16.1–46.7), sNEP 413pg/mL (IQR 0–4111) and NEP activity 2.36nmol/mL/min (IQR 1.16–4.59). There was no correlation between sNEP and NEP activity [r=0.09, p=0.088]. ARC did not show a meaningful correlation with any of the four biomarkers [p=ns for sNEP, NEP activity and bigET-1; r=0.13, p=0.018 for bio-ADM]. In the univariate analysis ARC, bigET-1, bio-ADM but not sNEP and NEP activity, were associated with outcome. This association remained significant after adjustment for age, gender and kidney function for all three markers and for ARC after adding NT-proBNP [adj. HR per 1-IQR increase of ARC 1.27 (95% CI 1.04–1.22), p=0.003]. There were no differences in bigET-1, bio-ADM and sNEP or NEP activity stratified by the different renin phenotypes (Figure1).

Figure 1

Conclusions

ARC is a risk factor for mortality in HFrEF patients, independently of NT-proBNP. Plasma NEP levels and activity neither correlated with each other nor were associated with outcome. Bio-ADM and bigET-1 were strong risk factors for all-cause mortality. Interestingly, neither NEP nor bio-ADM or bigET-1 were related to RAS-activation, suggesting that there is no direct relationship with RAS regulation.

P5573Disproportionate functional mitral regurgitation: advancing a conceptual framework from bench to bedside

Introduction

A recently proposed conceptual framework seeks to rearrange the effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) cut-offs according to left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) in functional mitral regurgitation introducing “disproportionate FMR” to describe clinically meaningful FMR. The conceptual framework, however, remains hypothetical.

Purpose

To test the significance of disproportionate FMR.

Methods

Data of 291 heart failure patients with reduced ejection fraction (HFrEF) under guideline directed therapy were embedded into this conceptual framework (Figure 1A). The black line represents the relationship when the degree of FMR is proportionate to LVEDV with a regurgitant fraction of (RegFrac) of 50%. The dashed lines represent the degree of uncertainty determined by the imprecision inherent to the measurement of RegFrac defined as 2SD for inter- and intraobserver variability by Bland-Altmann analysis (equals ±6.6%). Cox-regression and Kaplan-Meier analysis were applied to assess the association between FMR proportionality and mortality.

Results

Median age was 68 years (IQR 61–75), 77% were male. Median LVEF was 25% (IQR 18–33) and LVEDV was 214ml (IQR 165–267). Disproportionate FMR was present in 71 patients (24%) (red dots Figure 1A) with a median EROA of 0.26cm2 (IQR 0.18–0.34) and a median RegVol of 42ml (IQR 28–52), proportionate FMR (yellow dots Figure 1 A) in 81 patients (28%) with a median EROA of 0.12cm2 (IQR 0.09–0.17) and a median RegVol of 18ml (IQR 14–27). During 7-years follow-up, 166 patients died. Disproportionate FMR was associated with excess mortality compared to patients with non-severe FMR (HR 1.97, 95% CI 1.04–0.71, P<0.001), whereas proportionate FMR was not associated with increased long-term mortality (HR 1.04, 95% CI −1.53–0.71, P=0.83, Figure 1B).

Figure 1. Panel A and B

Conclusion

Every fifth patient suffers from disproportionate FMR which conveys a two-fold increased risk of mortality. Disproprtionate FMR corresponds to an EROA of roughly 0.3cm2 and a RegVol of 45ml – the unifying intersection between ESC and ACC/AHA guidelines to define severe FMR. The RegFrac provides a measure proportionated to left ventricular size and function supporting its use to define clinically relevant FMR. However, RegFrac is subject to compound error due to imputation of multiple measurements limiting its use as the leading contender for FMR grading. Regardless of the term used to describe clinically significant FMR, the conceptual framework emphasizes the unmet clinical need for recalibrated cut-offs for FMR severity condensed to an algorithm that combines the strengths of several measurements of FMR severity in an integrated manner.

5937Natural history of functional tricuspid regurgitation: implications of quantitative doppler assessment

Objectives

To establish the prognostic value of quantitative measures of functional tricuspid regurgitation (TR) severity i.e. effective regurgitant orifice area (EROA) and regurgitant volume.

Methods

382 patients with HFrEF on guideline-directed medical therapy were enrolled and TR EROA as well as regurgitant volume by Doppler/2D-echocardiography were assessed. All-cause mortality was defined as the primary study endpoint.

Results

Quantitative metrics of TR severity were consistently associated with mortality with a HR of 1.27 (95% CI 1.13–1.42, P<0.001) for the EROA and of 1.29 (95% CI 1.14–1.45, P<0.001) for the regurgitant volume (Figure 1, Panels A and B). Results remained unchanged after bootstrap- or clinical confounder-based adjustment. A spline curve pattern illustrates the association with mortality with thresholds for the EROA≥0.2cm2, and the regurgitant volume≥20ml with sustained excess mortality thereafter (Figure 1 Panels C-D).

Figure 1. Panels A–D

Conclusions

This large-scale study demonstrates the prognostic value of quantitative measures of TR severity in HFrEF. Thresholds for EROA and TR regurgitant volume associated with mortality fall within current ranges defining non-severe TR. This may potentially impact therapeutic decision making particularly timing of intervention.

Speckle-Tracking-Based Evaluation of Vascular Strain at Different Sites of the Arterial Tree in Healthy Adults

Purpose: Vascular ultrasound (US) allows the analysis of vascular strain by speckle-tracking. This study sought to assess the extent to which vas cular strain varies between different segments of the arterial tree. Furthermore, this study aimed to investigate the reproducibility of vascular strain determination as well as of the components that contribute to the variance of vascular strain measurements in different vascular beds. Materials and Methods: Speckle-tracking was used to determine the vascular strain of the abdominal aorta (AA), the common carotid artery (CCA), the common femoral (CFA) and the popliteal artery (PA) of healthy adults. Intra- and interday reproducibility and the components of variance of vascular strain of the respective arteries were determined. Results: A total of 589 US clips obtained in 10 healthy adults (7 males, 28.3 ± 3.2 years) were analyzable. Vascular strain was 7.2 ± 3.0 % in the AA, 5.7 ± 2.1 % in the CCA, 2.1 ± 1.1 % in the CFA and 1.9 ± 1.1 % in the PA. The intraday coefficients of variation of vascular strain were 6.2 % (AA), 3.9 % (CCA), 3.3 % (CFA) and 6.1 % (PA), and the interday coefficients of variation were 5.9 % (AA), 8.4 % (CCA), 10 % (CFA) and 4.6 % (PA). The variance of vascular strain mainly depended on the investigated vessel and subject. Individual DUS clips, the day of examination and the (right/left) body side (in paired arteries) had no impact on the variance of vascular strain. Conclusion: Vascular strain substantially varies between different sites of the arterial tree. Speckle-tracking by DUS allows the reliable determination of vascular strain at different arterial sites.