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

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

Unveiling cardiac amyloidosis, its characteristics and outcomes among patients with mitral regurgitation undergoing transcatheter edge-to-edge mitral valve repair

Background

Mitral regurgitation (MR) and cardiac amyloidosis (CA) both primarily affect older patients. Data on co-existence and prognostic implications of MR and CA are currently lacking.

Purpose

We aimed to identify prevalence, clinical characteristics and outcomes of MR-CA compared to lone MR.

Methods

Consecutive patients undergoing transcatheter edge-to-edge repair (TEER) for MR were screened for concomitant CA at two Austrian centers using a multi-parametric approach including core-lab 99mTc-DPD bone scintigraphy and echocardiography, and immunoglobulin light-chain assessment. Transthyretin-CA (ATTR) was diagnosed by DPD (Perugini Grade-1: early infiltration; Grades-2/3: clinical CA) and absence of monoclonal protein, and light-chain-(AL)-CA via tissue biopsy. Mass spectroscopy was performed in case of conflicting immunohistochemical results. All-cause mortality and hospitalization for heart failure (HHF) served as composite endpoint.

Results

In total, 120 patients (76.9±8.1 years, 55.8% male) were recruited. Clinical CA was diagnosed in n=14 (11.7%; 12 ATTR, 1 AL, 1 combined ATTR/AL), and early amyloid infiltration in n=9 (7.5%). MR-CA had higher troponin levels, thicker left ventricular walls, and a higher prevalence of carpal tunnel syndrome and left anterior fascicular block compared to lone MR (all p<0.05). Independent predictors of MR-CA were increased posterior wall thickness, and presence of left anterior fascicular block on ECG. Procedural success (MR reduction ≥1 grade) and periprocedural complications of TEER were similar in MR-CA and lone MR (p for all=n.s.).

After a median of 1.7 years, 25.8% had experienced death and/or HHF. MR-CA had worse outcomes compared to lone MR with regard to the composite endpoint (HR 2.2, 95% confidence interval [95% CI] 1.0–4.7, p=0.039), driven by a 2.5-fold higher risk for HHF (HR 2.5, 95% CI 1.1–5.9), but comparable mortality (HR 1.6, 95% CI 0.4–6.1; Graphical abstract).

Conclusions

Dual pathology of MR-CA is common in elderly MR patients undergoing TEER, and has worse post-interventional outcomes compared to lone MR. Given technical feasibility of TEER in MR-CA, valvular repair should be considered as an option to improve forward volume in a state with typically low output. Future studies should evaluate the prognostic benefits of TEER and CA-specific treatment in MR-CA.

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

Myocardial work – new insights from deformation imaging in patients with advanced heart failure

Background

The evaluation of myocardial contractility appears to be a major determinant for the prognosis and allocation of treatment strategies in advanced systolic heart failure (HFrEF). Non-invasive measurement of myocardial work is currently emerging as a new promising method for the assessment of myocardial contractility, as it additionally accounts for hemodynamic loading conditions of the ventricle.

Objectives

This study sought to assess the prognostic impact of myocardial work in patients with advanced heart failure and to compare it with routinely used deformation imaging parameters.

Methods

We included 234 patients with HFrEF under guideline directed therapy and comprehensively assessed myocardial work, as well as global longitudinal strain (GLS) by speckle tracking echocardiography. The primary endpoint was all-cause mortality.

Results

Median age of the patients was 68 years (IQR 60–75) and 78% were male. Over a 5-year follow-up period, 107 patients died. Median GWI was 526 mmHg% (IQR 366–779) and median GCW was 730 mmHg% (IQR 523–988). Parameters of myocardial work displayed a strong and independent association with long-term mortality, even after careful adjustment for clinical and echocardiographic confounders (Table 1). Additionally, we observed a significantly better calibration towards long-term mortality for GCW compared to GLS as the current golden standard for myocardial deformation imaging (AUC 0.63 vs. 0.60; P=0.007).

Conclusion

This is the first study to comprehensively assess global myocardial work in patients with advanced heart failure. Important treatment decisions rely on the assessment of myocardial contractility and risk stratification, specifically in late stages of the disease where exact guiding of treatment success and timely allocation of more aggressive treatment strategies are warranted. By incorporating loading conditions, myocardial work seems to be able to sensitively detect changes in myocardial contractility thath predict a dismal course of the disease. Furthermore, our data suggests that global constructive work is a more sensitive parameter to predict long-term outcome compared to the currently used echocardiographic deformation imaging parameters (i.e. GLS).

Funding Acknowledgement

Type of funding source: None

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.

P1580 Global regurgitant volume - approaching the critical mass in valvular-driven heart failure

Aims

Recent progress in the diagnosis of functional valve regurgitation forms a coherent perception of severity thresholds by quantitative assessment. However, thresholds focused on either valve in isolation -not accounting for the global hemodynamic burden arising from concomitant functional regurgitation of the mitral and tricuspid valves. We sought to determine whether the global regurgitant volume is associated with adverse cardiac remodeling and mortality.

Methods and results

This long-term observational study included 414 patients on guideline-directed medical therapy. Baseline global regurgitant load defined as the sum of mitral and tricuspid regurgitant volume was assessed by the proximal flow convergence method. All-cause mortality during five years follow-up served as the primary endpoint. The median global regurgitant load was 30ml (IQR 15-49) with 67% accounting for mitral and 33% accounting for tricuspid regurgitant volume. The global regurgitant load had significant impact on outcome with a crude HR of 1.46 (1.28-1.66; P < 0.001) for a 1-SD increase in global regurgitant volume, results that remained virtually unchanged after bootstrap or clinical confounder-based adjustment (P < 0.001 for adjusted models). Spline curve analysis showed a linearly increasing risk with a threshold of 50ml and sustained increasing risk thereafter.

Conclusions

The present study demonstrates the detrimental effect of the global regurgitant load in patients with HFrEF. The threshold where heart failure is driven by the valve lesions is a global regurgitant volume of 50ml with continuously increasing risk beyond that threshold. Future studies need to address whether an attempt to reduce the global regurgitant volume can improve outcome.

Abstract P1580 Figure 1 - Global RegVol

P1764 A unifying concept for the quantitative definition of functional mitral regurgitation

Background

Diverging guideline definitions for the quantitative assessment of severe secondary mitral regurgitation (sMR) reflect the lacking link of the sMR spectrum to mortality and has introduced a source of uncertainty and continuing debate.

Objectives

The current study aimed to define improved risk-thresholds specifically tailored to the complex nature of sMR that provide a unifying solution to the ongoing guideline-controversy.

Methods

We enrolled 423 heart failure patients under guideline directed medical therapy and assessed sMR by effective regurgitant orifice area (EROA), regurgitant volume (RegVol) and regurgitant fraction (RegFrac).

Results

Measures of sMR severity were consistently associated with 5-year mortality with a HR for a 1-SD increase of 1.42 (95%CI 1.25-1.63, P < 0.001) for EROA, 1.37 (95%CI 1.20-1.56, P < 0.001) for RegVol and 1.50 (95%CI 1.30-1.73, P < 0.001) for RegFrac. Results remained statistically significant after bootstrap- or clinical confounder-based adjustment. Spline-curve analyses (Figure 1A-C) showed a linearly increasing risk enabling to stratify in low-risk (EROA < 20mm2 and RegVol < 30ml), intermediate-risk (EROA 20-30mm2 and RegVol 30-45ml) and, high-risk (EROA≥30mm2 and RegVol≥45ml). In the intermediate-risk group, a RegFrac ≥50% as indicator for hemodynamic severe sMR was associated with poor outcome (P = 0.017). A unifying concept based on combined assessment of the EROA, the RegVol, and the RegFrac (Figure 1D) showed a significantly better discrimination compared to the currently established algorithms (Table 1).

Conclusions

Risk-based thresholds tailored to the pathophysiological concept of sMR provide a unifying solution to the ongoing guideline controversy. An algorithm based on the combined assessment of the unifying cut-offs for EROA, RegVol and RegFrac improves risk prediction compared to currently established grading.

Table 1 Definition of severe sMR Cox regression analysis ROC analysis IDI analysis HR (95%CI) P-Value ROC P-Value-for-comparison IDI P-Value Unifying concept 3.76 (2.71-5.23) <0.001 0.63 –- –- –- ACC/AHA definition 3.20 (2.14-4.78) <0.001 0.57 <0.001 0.06 <0.001 ESC/EACTS definition 1.52 (1.10-2.09) 0.01 0.55 <0.001 0.13 <0.001 ACC/ASE expert consensus 1.89 (1.40-2.56) <0.001 0.59 0.04 0.08 <0.001 Comparison of the unifying concept with the ACC/AHA, ESC/EACTS and ACC/ASE expert consensus definitions of sMR by Cox regression, ROC, and IDI demonstrated the most powerfull prediction by the unifying concept with significantly higher ROC area under the curve and better discriminatory power by IDI.

Abstract P1764 Figure 1 A-D

5943Mechanistic insights of papillary muscle dyssynchrony mediated function mitral regurgitation and modulation by cardiac resynchronization

Background

Mechanistic features of functional mitral regurgitation (FMR) include papillary muscle displacement due to left ventricular remodeling. Intraventricular conduction delay might further augment this condition by introducing interpapillary muscle dyssynchrony.

Objectives

To define this mechanism as a major contributing factor in FMR and prove the reversibility of FMR by interpapillary muscle resynchronization.

Methods

We enrolled 269 chronic HFrEF patients with conduction delay and comprehensively assessed dyssynchrony by complementary echocardiographic techniques. Opposing wall delay, calculated by speckle tracking, was determined as the time difference between peak longitudinal strain of the mid-anterior and inferior wall from a 2-chamber view. Furthermore, opposing wall delay was assessed as the time difference between peak strain values from tissue Doppler velocity-coded data of the mid-inferior septal and mid-lateral wall segments.

Results

Patients with severe FMR had markedly increased interpapillary longitudinal dyssynchrony (160ms [IQR 120–200]) compared to those with moderate (70ms [IQR 40–110]), no, or mild FMR (60ms [IQR 30–100]; P<0.001). Increased interpapillary muscle dyssynchrony was correlated with effective regurgitant orifice area (P<0.001; Figure A), regurgitant volume (P<0.001, Figure B) and vena contracta width (P<0.001, Figure C). Restoration of longitudinal papillary muscle synchronicity by cardiac resynchronization therapy (CRT) was correlated with FMR regression, as reflected by the reduction in regurgitant volume (P<0.001) and vena contracta width (P<0.001). Conversely, the improvement of FMR was associated with improved interpapillary radial (P=0.006) and longitudinal (P<0.001) dyssynchrony. The improvement of dyssynchrony-mediated FMR signified a better prognosis compared to no improvement in FMR during the 8-year follow-up period even after comprehensive adjustment by a bootstrap-selected confounder model (adj. HR of 0.41; 95% CI 0.18–0.91; P=0.028; Figure D). The results remained virtually unchanged after adjustment for left bundle branch block.

Figure 1. Dyssynchrony-FMR-CRT

Conclusion

Intraventricular dyssynchrony introduces unequal contraction by papillary muscle bearing walls, which has an adverse effect on FMR. CRT can effectively restore interpapillary balance and thus create a less tented leaflet configuration, resulting in a clinically meaningful reduction of FMR. The restoration of papillary muscle synchronicity in dyssynchrony-mediated FMR translates into a significantly better prognosis.

P6492Quantitative definition of severe functional mitral regurgitation - A matter of intercontinental debate

Background

Recent divergence between AHA/ACC and ESC/EACTS guidelines of the quantitative definition for severe functional mitral regurgitation (sFMR) introduced uncertainty, inconsistency and continuing debate. The relation of each threshold with long-term outcome, in patients under guideline directed therapy (GDT) remains however uncertain.

Methods

We enrolled 269 heart failure patients with reduced ejection fraction (HFrEF) and graded sFMR according to both guideline-recommendations [AHA/ACC: effective regurgitant orifice area (EROA) ≥40mm2 or regurgitant volume (RegVol) ≥60ml/beat and ESC/EACTS: EROA ≥20mm2 or RegVol ≥30ml/beat]. All-cause mortality was defined as the primary endpoint.

Result

According to AHA/ACC guidelines sFMR occurred in 17% by EROA with a median EROA of 0.5mm2 (IQR 0.4–0.6) and in 13% by RegVol with a median RegVol of 76ml/beat (IQR 69–101). According to ESC/EACTS guidelines sFMR occurred in 53% by EROA with a median EROA of 0.4mm2 (IQR 0.2–0.4)and 40% according to RegVol with a median RegVol of 51ml/beat (IQR 37–69). During 8-years follow-up, 165 patients died. We observed a significant association with outcome for sFMR according to AHA/ACC guidelines quantified by EROA (HR 1.66, 95% CI 1.13–2.43, P=0.009; Figure 1A) as well as RegVol (HR 2.02, 95% CI 1.34–3.05, P=0.001; Figure 1A). In contrast, the ESC/EACTS definition of sFMR was related with outcome exclusively if quantified by RegVol (HR 1.46, 95% CI 1.05–2.05, P=0.026; Figure 1B) but not for EROA (HR 1.30, 95% CI 0.91–1.86, P=0.15; Figure 1B).

Figue 1

Conclusion

In this contemporary HFrEF cohort under GDT there is significant association of the ACC/AHA proposed cut-off for severe FMR and long-term mortality. The ESC/EACTS definitions are associated with mortality exclusively for the RegVol. The lack of association between sFMR based on ESC/EACTS EROA cut-offs with mortality potentially results from incorporating patients where the regurgitant burden may still be compensated and has not yet become a driving force of disease progression. Contemporary definition of sFMR entails decision making for surgical/transcatheter repair. Cut-offs need to account for the competing risks of the procedure versus the potential benefit of reducing mortality. Lower thresholds may expose a significant proportion of patients to unnecessary risk of futile procedures and higher thresholds may withhold potentially life-extending therapies. The disagreement between the two guidelines does not only convey a source of uncertainty for treating physicians but also lead to inconsistent treatment allocation thereby hindering comprehensive and comparable research. Future studies need to approximate to the true nature of severe functional mitral valve disease in an attempt to facilitate a unifying definition of sFMR.

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.