Grading mitral regurgitation using 4D flow CMR: comparison to transthoracic echocardiography

Abstract Funding Acknowledgements Type of funding sources: None. BACKGROUND Mitral Regurgitation (MR) is currently primarily assessed using multiple transthoracic echocardiography (TTE) parameters. Two-dimensional Cardiac Magnetic Resonance (CMR) can be used in difficult cases but has limited agreement with TTE for quantifying MR. We hypothesized that 4D Flow CMR may help to quantify MR. OBJECTIVES To determine the 4D Flow CMR thresholds that achieve the best agreement with TTE for grading MR. METHODS We conducted a single-center prospective study of patients evaluated for chronic primary MR in 2016-2020. MR was evaluated blindly by TTE and 4D Flow CMR respectively by two cardiologists and two radiologists with decades of experience. MR was graded with both methods as mild, moderate or severe. 4D Flow CMR measurements included MR regurgitant volume per beat (RV) and mitral anterograde flow per beat (MF). RF was obtained as the ratio RV/MF. Additionally, MF was compared to left ventricular stroke volume (LVSV) by cine-CMR. RESULTS We included 33 patients in the initial cohort and 33 in the validation cohort. Inter-observer agreement was good for TTE and excellent for 4D Flow CMR. Agreement between MF and LVSV was excellent. Using recommended TTE thresholds (30 mL, 60 mL, 30%, 50%), agreement was moderate for RV and RF. The best agreement between 4D Flow CMR and TTE was obtained with CMR thresholds of 20 mL and 40 mL for RV (κ=0.93; 95%CI, 0.8-1) and 20% and 37% for RF (κ=0.90; 95%CI, 0.7-0.9). In the validation cohort, agreement between TTE and 4D Flow CMR was good with the optimal thresholds (κ= 0.78; 95%CI, 0.61-0.94). CONCLUSION We propose CMR thresholds that provide a good agreement between TTE and CMR for grading MR. Further studies are needed to fully validate 4D-Flow CMR accuracy for primary MR quantification.

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Grading mitral regurgitation using 4D flow CMR: comparison to transthoracic echocardiography

European Heart Journal ◽

10.1093/eurheartj/ehab724.0174 ◽

2021 ◽

Vol 42 (Supplement_1) ◽

Author(s):

S Ribeyrolles ◽

J L Monin ◽

A Rohnean ◽

C Diakov ◽

C Caussin ◽

...

Keyword(s):

Mitral Regurgitation ◽

Transthoracic Echocardiography ◽

Validation Cohort ◽

Left Ventricular ◽

Observer Agreement ◽

4D Flow ◽

Funding Sources ◽

4D Flow Cmr ◽

Optimal Thresholds ◽

Initial Cohort

Abstract Background Mitral Regurgitation (MR) is currently primarily assessed using multiple transthoracic echocardiography (TTE) parameters. Two-dimensional Cardiac Magnetic Resonance (CMR) can be used in difficult cases but has limited agreement with TTE for quantifying MR. We hypothesized that 4D Flow CMR may help to quantify MR. Purpose To determine the 4D Flow CMR thresholds that achieve the best agreement with TTE for grading MR. Methods We conducted a single-center prospective study of patients evaluated for chronic primary MR in 2016–2020. MR was evaluated blindly by TTE and 4D Flow CMR respectively by two cardiologists and two radiologists with decades of experience. MR was graded with both methods as mild, moderate or severe. 4D Flow CMR measurements included MR regurgitant volume per beat (RV) and mitral anterograde flow per beat (MF). RF was obtained as the ratio RV/MF. Additionally, MF was compared to left ventricular stroke volume (LVSV) by cine-CMR. Results We included 33 patients in the initial cohort and 33 in the validation cohort. Inter-observer agreement was good for TTE and excellent for 4D Flow CMR. Agreement between MF and LVSV was excellent. Using recommended TTE thresholds (30 mL, 60 mL, 30%, 50%), agreement was moderate for RV and RF. The best agreement between 4D Flow CMR and TTE was obtained with CMR thresholds of 20 mL and 40 mL for RV (κ=0.93; 95% CI, 0.8–1) and 20% and 37% for RF (κ=0.90; 95% CI, 0.7–0.9). In the validation cohort, agreement between TTE and 4D Flow CMR was good with the optimal thresholds (κ= 0.78; 95% CI, 0.61–0.94). Conclusion We propose CMR thresholds that provide a good agreement between TTE and CMR for grading MR. Further studies are needed to fully validate 4D-Flow CMR accuracy for primary MR quantification. FUNDunding Acknowledgement Type of funding sources: None. Quantification of MR using 4D Flow CMR

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Direct mitral regurgitation quantification in hypertrophic cardiomyopathy using 4D flow CMR jet tracking: evaluation in comparison to conventional CMR

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/s12968-021-00828-y ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Aakash N. Gupta ◽

Ryan Avery ◽

Gilles Soulat ◽

Bradley D. Allen ◽

Jeremy D. Collins ◽

...

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Mitral Regurgitation ◽

Intraclass Correlation ◽

Left Ventricular ◽

Volumetric Method ◽

Fair Agreement ◽

Observer Agreement ◽

4D Flow ◽

Systolic Volume ◽

4D Flow Cmr

Abstract Background Quantitative evaluation of mitral regurgitation (MR) in hypertrophic cardiomyopathy (HCM) by cardiovascular magnetic resonance (CMR) relies on an indirect volumetric calculation. The aim of this study was to directly assess and quantify MR jets in patients with HCM using 4D flow CMR jet tracking in comparison to standard-of-care CMR indirect volumetric method. Methods This retrospective study included patients with HCM undergoing 4D flow CMR. By the indirect volumetric method from CMR, MR volume was quantified as left ventricular stroke volume minus forward aortic volume. By 4D flow CMR direct jet tracking, multiplanar reformatted planes were positioned in the peak velocity of the MR jet during systole to calculate through-plane regurgitant flow. MR severity was collected for agreement analysis from a clinical echocardiograms performed within 1 month of CMR. Inter-method and inter-observer agreement were assessed by intraclass correlation coefficient (ICC), Bland–Altman analysis, and Cohen’s kappa. Results Thirty-seven patients with HCM were included. Direct jet tracking demonstrated good inter-method agreement of MR volume compared to the indirect volumetric method (ICC = 0.80, p = 0.004) and fair agreement of MR severity (kappa = 0.27, p = 0.03). Direct jet tracking showed higher agreement with echocardiography (kappa = 0.35, p = 0.04) than indirect volumetric method (kappa = 0.16, p = 0.35). Inter-observer reproducibility of indirect volumetric method components revealed the lowest reproducibility in end-systolic volume (ICC = 0.69, p = 0.15). Indirect volumetric method showed good agreement of MR volume (ICC = 0.80, p = 0.003) and fair agreement of MR severity (kappa = 0.38, p < 0.001). Direct jet tracking demonstrated (1) excellent inter-observer reproducibility of MR volume (ICC = 0.97, p < 0.001) and MR severity (kappa = 0.84, p < 0.001) and (2) excellent intra-observer reproducibility of MR volume (ICC = 0.98, p < 0.001) and MR severity (kappa = 0.88, p < 0.001). Conclusions Quantifying MR and assessing MR severity by indirect volumetric method in HCM patients has limited inter-observer reproducibility. 4D flow CMR jet tracking is a potential alternative technique to directly quantify and assess MR severity with excellent inter- and intra-observer reproducibility and higher agreement with echocardiography in this population.

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Grading mitral regurgitation using 4D-Flow CMR: Comparison to transthoracic echocardiography

Archives of Cardiovascular Diseases Supplements ◽

10.1016/j.acvdsp.2021.04.031 ◽

2021 ◽

Vol 13 (3) ◽

pp. 251-252

Author(s):

S. Ribeyrolles ◽

J.L. Monin ◽

A. Rohnean ◽

C. Diakov ◽

C. Caussin ◽

...

Keyword(s):

Mitral Regurgitation ◽

Transthoracic Echocardiography ◽

4D Flow ◽

4D Flow Cmr

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Stent interventions for pulmonary artery stenosis improve bi-ventricular flow efficiency in a swine model

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/s12968-021-00709-4 ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Ryan J. Pewowaruk ◽

Gregory P. Barton ◽

Cody Johnson ◽

J. Carter Ralphe ◽

Christopher J. Francois ◽

...

Keyword(s):

Ejection Fraction ◽

Pulmonary Artery ◽

Ventricular Function ◽

Intervention Group ◽

Left Ventricular ◽

Pulmonary Artery Stenosis ◽

Swine Model ◽

4D Flow ◽

4D Flow Cmr ◽

The Impact

Abstract Background Branch pulmonary artery (PA) stenosis (PAS) commonly occurs in patients with congenital heart disease (CHD). Prior studies have documented technical success and clinical outcomes of PA stent interventions for PAS but the impact of PA stent interventions on ventricular function is unknown. The objective of this study was to utilize 4D flow cardiovascular magnetic resonance (CMR) to better understand the impact of PAS and PA stenting on ventricular contraction and ventricular flow in a swine model of unilateral branch PA stenosis. Methods 18 swine (4 sham, 4 untreated left PAS, 10 PAS stent intervention) underwent right heart catheterization and CMR at 20 weeks age (55 kg). CMR included ventricular strain analysis and 4D flow CMR. Results 4D flow CMR measured inefficient right ventricular (RV) and left ventricular (LV) flow patterns in the PAS group (RV non-dimensional (n.d.) vorticity: sham 82 ± 47, PAS 120 ± 47; LV n.d. vorticity: sham 57 ± 5, PAS 78 ± 15 p < 0.01) despite the PAS group having normal heart rate, ejection fraction and end-diastolic volume. The intervention group demonstrated increased ejection fraction that resulted in more efficient ventricular flow compared to untreated PAS (RV n.d. vorticity: 59 ± 12 p < 0.01; LV n.d. vorticity: 41 ± 7 p < 0.001). Conclusion These results describe previously unknown consequences of PAS on ventricular function in an animal model of unilateral PA stenosis and show that PA stent interventions improve ventricular flow efficiency. This study also highlights the sensitivity of 4D flow CMR biomarkers to detect earlier ventricular dysfunction assisting in identification of patients who may benefit from PAS interventions.

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Longitudinal change in left ventricular 4D flow kinetic energy after myocardial infarction

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.282 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

H Ben-Arzi ◽

A Das ◽

C Kelly ◽

RJ Van Der Geest ◽

A Chowdhary ◽

...

Keyword(s):

Myocardial Infarction ◽

Kinetic Energy ◽

Left Ventricular ◽

Three Dimensions ◽

Longitudinal Change ◽

P Value ◽

4D Flow ◽

Longitudinal Changes ◽

Funding Sources ◽

End Diastolic Volume

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation HRUK Background. Four-dimensional flow (4D flow) cardiovascular magnetic resonance (CMR) imaging provides quantification of intra-cavity left ventricular (LV) flow kinetic energy (KE) parameters in three dimensions. Myocardial infarction (MI) is known to cause acute alterations in intra-cardiac blood flow but assessments of longitudinal changes are lacking. Purpose. Assess longitudinal changes in LV flow post ST-elevation myocardial infarction (STEMI). Method. Twenty acutely reperfused STEMI patients (13 men, 7 women, mean age 54 ± 9 years) underwent 3T CMR acutely (within 5-7 days) and 3 months post-MI. CMR protocol included functional imaging, late gadolinium enhancement and 4D flow. Using Q-MASS, LV KE parameters were derived and indexed to LV end-diastolic volume (LVKEiEDV). Based on acute ejection fraction (EF), patients were grouped as follows: preserved (pEF) EF >50%, reduced (rEF) EF <50% including mild (rEF= 40-49%), moderate to severe (EF <40%) impairment. Results. Out of 20 patients, 13 had rEF acutely (7 mild rEF, 6 moderate to severe rEF). Acute LVKEiEDV parameters varied significantly between pEF and rEF (Table). At 3 months, pEF and mild rEF patients showed a significant (P < 0.05) reduction in average, systolic and peak-A wave LVKEiEDV. Mild rEF patients also had significant (P < 0.05) reduction in minimal and peak-E wave LVKEiEDV. However in patients with moderate to severe rEF in the acute scan, there were no significant change by 3 months (Figure). Conclusion. Following MI, 4D flow LVKE derived biomarkers significantly decreased over time in pEF and mild rEF groups but not in moderate to severe rEF group. 4D flow assessment might provide incremental prognostic value beyond EF assessment alone. Table pEF (n = 7) rEF (n = 13) V1 V2 P-value V1 V2 P-value EF(%) 56 ± 5 55 ± 4 0.40 41 ± 7 47 ± 9 0.01 Infarct Size(%) 31 ± 20 15 ± 9 0.04 18 ± 13† 16 ± 11 0.41 LV KEiEDV parameters Average(µJ/ml) 9 ± 2 7 ± 2 0.02 10 ± 3† 8 ± 3 0.01 Minimal(µJ/ml) 1 ± 0.6 1 ± 0.5 0.46 1.3 ± 0.5 1 ± 0.6 0.03 Systolic(µJ/ml) 10 ± 4 7 ± 2 <0.01 12 ± 4† 7 ± 3 <0.01 Diastolic(µJ/ml) 8 ± 3 7 ± 2 0.13 9 ± 3 8 ± 3 0.09 Peak-E wave(µJ/ml) 22 ± 9 23 ± 8 0.44 20 ± 7 18 ± 10 0.23 Peak-A wave(µJ/ml) 18 ± 10 11 ± 4 0.04 17 ± 9 14 ± 7 0.02 †P < 0.05 V1 comparison between pEF and rEF Abstract Figure

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P5874D Flow cardiac magnetic resonance quantification of mitral regurgitation, comparison with transthoracic echocardiography

European Heart Journal ◽

10.1093/eurheartj/ehz747.0196 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

S Ribeyrolles ◽

J L Monin ◽

A Rohnean ◽

C Diakov ◽

C Caussin ◽

...

Keyword(s):

Cardiac Magnetic Resonance ◽

Magnetic Resonance ◽

Stroke Volume ◽

Left Ventricular ◽

Left Ventricular Stroke Volume ◽

4D Flow ◽

Mitral Flow ◽

4D Flow Cmr ◽

Mr Quantification ◽

Cine Cmr

Abstract Background Mitral valve regurgitation (MR) is currently primarily assessed by a multiparametric approach with transthoracic echocardiography (TTE) that can be further completed by 2D Cardiac Magnetic Resonance (2D CMR) in case of doubt or poor acoustic window. TTE and 2D CMR have nevertheless imperfect agreement in terms of MR quantification. Time-resolved phase-contrast cardiac magnetic resonance imaging with flow-encoding in three spatial directions (4D Flow CMR) could help in MR quantification. Purpose Compare 4D Flow CMR quantification of MR with TTE using a multiparametric approach. Methods We conducted a monocentric, prospective study at the Institut Mutualiste Montsouris in Paris between November 2016 and 2017 including patients with chronic primitive MR. MR was evaluated with a multiparametric approach by two cardiologists with TTE and quantitatively by two radiologists with 4D Flow CMR. MR was classified as mild, moderate or severe and evaluated blindly with consensus in case of disagreement. 4D Flow CMR measurements consisted in quantifying MR regurgitant volume (RV) and MR regurgitant fraction (RF). 4D anterograde mitral flow was compared to left ventricular stroke volume using 2D-cine CMR. Results 33 patients were included. Inter-observer agreement was good in TTE (kappa= 0.75 95% CI [0.57- 0.92]) and excellent in 4D Flow CMR (ICC= 0.94 95% CI [0.79–0.95]). Agreement with TTE was excellent using optimized thresholds (Mild: RV≤20mL RF≤20%, Moderate: RV=21–39mL RF=21–36%, Severe: RV≥40mL RF≥37%): kappa= 0.93 95% CI [0.8–1] for RV and kappa= 0.90 95% CI [0.7–0.9] for RF. A validation cohort confirmed that the 4D flow thresholds as determined were accurate for MR grading. Agreement between 4D anterograde mitral flow and 2D-cine CMR left ventricular stroke volume was also excellent (ICC= 0.92 95% CI [0.85–0.96]). Conclusion 4D Flow CMR is a reliable tool for MR quantification. It provides direct quantitative evaluation of MR with low inter-observer variability. It may therefore be used as a gatekeeper before therapeutic decisions such as surgery.

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4D Flow cardiac magnetic resonance quantification of mitral regurgitation, comparison with transthoracic echocardiography

Archives of Cardiovascular Diseases Supplements ◽

10.1016/j.acvdsp.2019.09.117 ◽

2020 ◽

Vol 12 (1) ◽

pp. 54

Author(s):

S. Ribeyrolles ◽

J.L. Monin ◽

A. Rohnean ◽

C. Diakov ◽

C. Caussin ◽

...

Keyword(s):

Cardiac Magnetic Resonance ◽

Magnetic Resonance ◽

Mitral Regurgitation ◽

Transthoracic Echocardiography ◽

4D Flow

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P1481 Embolic infarct in a known coronary artery disease patient

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez319.906 ◽

2020 ◽

Vol 21 (Supplement_1) ◽

Author(s):

A H Ali ◽

U Alnuaimi ◽

S I Lacau ◽

C Badiu ◽

A C Popescu

Keyword(s):

Myocardial Infarction ◽

Mitral Regurgitation ◽

Transthoracic Echocardiography ◽

Disease Patient ◽

Mitral Annulus ◽

Left Ventricular ◽

Inferior Wall ◽

Mitral Leaflet ◽

St Segment ◽

Posterior Mitral Leaflet

Abstract A 60 y/o diabetic and hypertensive lady with previous anterior infarction treated by primary PCI with stenting of the proximal LAD (2011) and CABG for stent thrombosis, presented for chest pain. Admission ECG showed ST segment elevation in II, III aVF, ST segment depression in V1-V2 (A). Urgent coronary angiography was performed. It showed non-significant lesions on RCA and LCX, occlusion of the proximal LAD stent, patent LIMA to LAD and first diagonal with non-significant stenosis of the distal anastomosis (B). Transthoracic echocardiography (C) showed calcific mass involving the mitral annulus and posterior mitral leaflet, moderate mitral regurgitation, hipokinesia of the basal segment of the inferior wall with preserved LV ejection fraction. Transesophageal echocardiography (D) confirmed the calcified mass involving the mitral annulus and the posterior mitral leaflet. There was no significant mitral stenosis, and mitral regurgitation was moderate. Thoracic CT showed massive mitral calcification and a possible thrombus attached to it. (E) Myocardial infarction was confirmed by troponin rise and fall. The patient was discharged on dual antiplatelet therapy, ACE-I, betablocker and statin. At one month follow-up transthoracic echocardiography the central area of the mitral mass became hypoechogenic, and a bilobated hypermobile structure was seen attached to the ventricular side of the mass (F). Blood cultures were negative and there was no inflammatory syndrome. Cardiac magnetic resonance (H) confirmed myocardial infarction and showed massive calcification of the posterior mitral annulus. TEE performed after another month showed a very long hypermobile structure attached to the mitral annulus calcification, which was entering the left ventricular outflow tract reaching the plane of the aortic valve (G). The patient underwent surgical mitral valve replacement and redo CABG and the mass was excised. The pathologic aspect of the excised material was cazeous and friable (I). The initial presentation was presumably an embolic infarct with cazeous material. Abstract P1481 Figure.

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