1337Myocardial extracellular volume in patients with aortic stenosis undergoing valve intervention - A multicentre T1 mapping study

Abstract Background The development of myocardial fibrosis is a key mechanism in the transition from compensated hypertrophy to heart failure in aortic stenosis (AS). Focal and diffuse fibrosis can be quantified using cardiac magnetic resonance (CMR) imaging late gadolinium-enhanced (LGE) and T1 mapping techniques. Purpose To assess T1 mapping measures of fibrosis in patients with severe AS referred for aortic valve intervention, and determine their associations with clinical characteristics, disease severity and long-term clinical outcome. Methods In this international prospective cohort study, patients with severe AS underwent contrast enhanced CMR with T1 mapping and LGE prior to aortic valve intervention. Image analysis was performed by a single core laboratory and the extracellular volume fraction [ECV%] calculated from T1 mapping images. The presence of LGE was determined visually and quantified using the full-width-at-half-maximum technique. Results Four-hundred and forty patients (70±10 years, 59% male) from ten international centres were enrolled. Aortic valve intervention was performed 15 [4 to 58] days following CMR. Within a follow-up of 3.8 [2.8 to 4.6] years, 52 patients died. ECV% (mean 27.7±3.6%) correlated with increasing age, Society of Thoracic Surgeons Predicted Risk of Mortality score, known coronary artery disease, lower peak aortic-jet velocity, larger left ventricular (LV) mass, lower LV ejection fraction, and presence of LGE (P<0.05 for all). Following adjustment for all demographic and clinical variables, ECV% remained associated with age (P=0.028), LV ejection fraction (P<0.001) and presence of LGE (P=0.035). Univariable predictors of all-cause mortality included age, male sex, impaired LV ejection fraction and presence of LGE (all P<0.05). A progressive increase in all-cause mortality was seen across tertiles of ECV% (17.3, 31.6 and 52.7 deaths per 1000 patient-years; log-rank test, P=0.009). ECV% was independently associated with all-cause mortality following adjustment for age, sex, impaired LV ejection fraction and presence of LGE (HR per unit increase in ECV: 1.10, 95%, (1.02–1.19), P=0.013). ECV440 abstract iamge Conclusion In patients with severe aortic stenosis scheduled for aortic valve intervention, extracellular volume-based T1 mapping correlates with LV decompensation. ECV% is a strong independent predictor of late all-cause mortality and is a potential therapeutic target.

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T1 Mapping for Noninvasively Detecting Diffuse Fibrosis in Severe Aortic Stenosis

Journal of Medical Imaging and Health Informatics ◽

10.1166/jmihi.2020.3076 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1534-1539

Author(s):

Jiajun Xie ◽

Xuhua Jian ◽

Qiyang Lu ◽

Jinxiu Meng ◽

Yu-Hsiang Juan ◽

...

Keyword(s):

Aortic Stenosis ◽

Cardiac Mri ◽

T1 Mapping ◽

Volume Fraction ◽

Severe Aortic Stenosis ◽

Extracellular Volume ◽

Extracellular Volume Fraction ◽

Left Ventricular ◽

Diffuse Fibrosis ◽

Mapping Technique

Purpose: To evaluate myocardial diffuse fibrosis in severe aortic stenosis (SAS) with cardiac magnetic resonance imaging (MRI) T1 mapping technique. Methods: Twenty-seven SAS patients and 15 controls were enrolled and performed cardiac MRI. Left ventricular (LV) structure, function and T1-derived parameters were measured to compare between SAS group and the controls. Correlation between T1-derived parameters and the extent of histologic fibrosis was performed in 15 patients who underwent aortic valve replacement surgery and myocardial biopsy. Results: The SAS group had LV remodeling with ventricular dilatation, hypertrophy, and contractile dysfunction. The native T1 (1336.2±62.5 ms vs. 1277.6±40.7 ms, p = 0.002) and extracellular volume fraction (ECV%) (26.7±2.2% vs. 24.9±2.2%, p = 0.018) were elevated in the SAS in comparison to the controls. Only ECV and λ correlated with the extent of fibrosis as measured by histology. Conclusion: Cardiac MRI with T1 mapping provides a noninvasive approach to evaluate LV myocardial diffuse fibrosis in SAS.

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First-phase ejection fraction by cardiovascular magnetic resonance predicts outcomes in aortic stenosis

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/s12968-021-00756-x ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Haotian Gu ◽

Rong Bing ◽

Calvin Chin ◽

Lingyun Fang ◽

Audrey C. White ◽

...

Keyword(s):

Cardiovascular Magnetic Resonance ◽

Magnetic Resonance ◽

Aortic Valve ◽

Aortic Stenosis ◽

Ejection Fraction ◽

Proportional Hazards ◽

Function Analysis ◽

Extracellular Volume ◽

Left Ventricular ◽

Cox Proportional Hazards

Abstract Background First-phase ejection fraction (EF1; the ejection fraction measured during active systole up to the time of maximal aortic flow) measured by transthoracic echocardiography (TTE) is a powerful predictor of outcomes in patients with aortic stenosis. We aimed to assess whether cardiovascular magnetic resonance (CMR) might provide more precise measurements of EF1 than TTE and to examine the correlation of CMR EF1 with measures of fibrosis. Methods In 141 patients with at least mild aortic stenosis, we measured CMR EF1 from a short-axis 3D stack and compared its variability with TTE EF1, and its associations with myocardial fibrosis and clinical outcome (aortic valve replacement (AVR) or death). Results Intra- and inter-observer variation of CMR EF1 (standard deviations of differences within and between observers of 2.3% and 2.5% units respectively) was approximately 50% that of TTE EF1. CMR EF1 was strongly predictive of AVR or death. On multivariable Cox proportional hazards analysis, the hazard ratio for CMR EF1 was 0.93 (95% confidence interval 0.89–0.97, p = 0.001) per % change in EF1 and, apart from aortic valve gradient, CMR EF1 was the only imaging or biochemical measure independently predictive of outcome. Indexed extracellular volume was associated with AVR or death, but not after adjusting for EF1. Conclusions EF1 is a simple robust marker of early left ventricular impairment that can be precisely measured by CMR and predicts outcome in aortic stenosis. Its measurement by CMR is more reproducible than that by TTE and may facilitate left ventricular structure–function analysis.

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Abstract 2066: Does Mitral Regurgitation Regress After Aortic Valve Replacement For Aortic Stenosis ? A Prospective Multicenter Study

Circulation ◽

10.1161/circ.116.suppl_16.ii_447-c ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Philippe Unger ◽

Danièle Plein ◽

Bernard Cosyns ◽

Guy Van Camp ◽

Olivier Xhaët ◽

...

Keyword(s):

Aortic Valve ◽

Mitral Regurgitation ◽

Aortic Stenosis ◽

Ejection Fraction ◽

Aortic Valve Replacement ◽

Valve Replacement ◽

Left Ventricular ◽

Aortic Valve Area ◽

Regurgitant Volume ◽

Lv Ejection Fraction

Background: Mitral regurgitation (MR) is common in patients undergoing aortic valve replacement (AVR) for aortic stenosis (AS). Whether its severity may decrease after AVR remains controversial. Previous studies were mainly retrospective and the degree of MR was assessed at best semi-quantitatively. This study sought to prospectively and quantitatively assess how AVR may affect MR severity. Methods: Patients with AS scheduled for isolated AVR and presenting holosystolic MR which was not considered for replacement or repair were included. Previous mitral valve surgery; severe aortic regurgitation and poor acoustic windows were excluded. Thirty-five patients (mean age 77±7 years) were studied before (median 1, range 1– 41 days) and after AVR (median 7, range 4 –19 days). All patients underwent a comprehensive echocardiographic examination; MR was assessed by Doppler echocardiography using color flow mapping of the regurgitant jet and the PISA method. No patient had prolapsed or flail mitral leaflet as mechanism of MR. Results: Preoperative maximal and mean transaortic pressure gradients and aortic valve area were 74±26 mmHg, 44±16 mmHg, and 0.57±0.18 cm 2 , respectively. Left ventricular (LV) ejection fraction increased from 49±16 % to 55±15 % after AVR (p<0.001). LV end-diastolic volume decreased from 91±32 ml to 77±30 ml (p<0.001).The ratio of MR jet to left atrial area decreased from 30±16% to 20±14% (p<0.001). MR effective regurgitant orifice (ERO) and regurgitant volume decreased from 10±5 mm 2 to 8±6 mm 2 (p=0.015) and from 19±10 ml to 11±9 ml (p<0.0001). The decrease in ERO and in regurgitant volume was similar in patients with preserved or depressed LV ejection fraction (≤45 %) (2±3 vs 3±6 mm 2 and 7±9 vs 8±7 ml; p=NS, respectively). Conclusions: AVR is associated with an early postoperative reduction of the quantified degree of MR. This mainly results from a decrease in regurgitant volume and only modestly from a reduction in ERO, emphasizing the contributing role of the decrease in driving pressure accross the mitral regurgitant orifice.

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621 Anemia and its impact on clinical, echocardiographic parameters and prognosis in patients with severe aortic stenosis and normal left ventricular ejection fraction

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez319.307 ◽

2020 ◽

Vol 21 (Supplement_1) ◽

Author(s):

C Beladan ◽

A Calin ◽

A D Mateescu ◽

M Rosca ◽

R Enache ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Stenosis ◽

Ejection Fraction ◽

Severe Aortic Stenosis ◽

Nyha Class ◽

Left Ventricular ◽

Volume Index ◽

All Cause Mortality ◽

Echocardiographic Parameters ◽

Study Population

Abstract Background Anemia is common in patients (pts) with severe aortic stenosis (AS). Untreated anemia and severe AS are individually associated with the development of heart failure, however data regarding the potential detrimental effect of anemia on left ventricular (LV) function and prognosis in pts with severe AS are controversial. Aim To investigate the impact of anemia on clinical status, echocardiographic parameters and prognosis in pts with severe AS and preserved LV ejection fraction (LVEF). Methods Consecutive patients with severe AS (aortic valve area [AVA] index ≤ 0.6 cm2/m2) and preserved LVEF (>50%) referred to our echocardiography laboratory were prospectively screened. All patients underwent complete clinical examination and comprehensive echocardiography, including speckle tracking-derived measurements of LV and left atrial (LA) strain. Baseline clinical variables included NYHA class, cardiac risk factors, haemoglobin (Hb) level and glomerular filtration rates (GFR, by MDRD formula). The definition of anemia was based on gender-specific cut-off values, as recommended by the WHO (Hb <13.0 g/dL for men, <12.0 g/dL for women). Patients with more than mild aortic regurgitation or mitral valve disease, atrial fibrillation or cardiac pacemakers were excluded. Results The study population included 264 patients (pts) (66 ± 11 yrs, 147 men). Anemia was present in 64 pts (24%). Aortic valve replacement (AVR) was performed in 151 pts. Dividing the study population into 2 groups, according to the presence/absence of anemia, no significant differences were found between groups regarding: age (p = 0.09), body surface area (p = 0.6), LVEF (62 ± 7 vs 63 ± 6%, p = 0.2), LV Global Longitudinal Strain (-15.2 ± 4 vs -14.7 ± 3 %, p = 0.4), LV mass index (p = 0.9), mean aortic gradient (p = 0.2) and indexed AVA (0.40 ± 0.09 vs 0.39 ± 0.09 cm2/m2, p = 0.6), or presence of significant coronary artery disease (p = 0.9). Compared to pts with normal Hb level, in pts with anemia NYHA class (p = 0.03), brain natriuretic peptide values (p = 0.004), lateral E/e’(16.2 ± 6.9 vs 13.7 ± 6.3, p = 0.01) and average E/e" ratio (15.9 ± 5.9 vs 14.1 ± 5.3, p = 0.03), LA volume index (54.3 ± 16.9 vs 45.0 ± 12.1 ml/m2, p < 0.001), and systolic pulmonary artery pressure (38 ± 13 vs 33 ± 8, p = 0.009) were all significantly higher. During a 3–years follow-up 47 pts died. Age, NYHA class, BNP serum level, baseline anemia, LA volume index and systolic pulmonary pressure were associated with all-cause mortality in the whole study group (p < 0.03 for all). In the group of pts who underwent AVR, NYHA class was the only independent predictor of all-cause mortality. Conclusions In our study including pts with severe AS and preserved LVEF, patients with baseline anemia presented worse functional status and LV diastolic dysfunction and increased 3-year all-cause mortality compared to those with normal Hb levels. However, in pts who underwent surgical AVR, there was no impact of baseline anemia on 3-year survival.

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Clinical and echocardiographic outcomes of patients with moderate to severe aortic stenosis and preserved, mid-range and reduced ejection fraction

European Heart Journal ◽

10.1093/ehjci/ehaa946.1982 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

N Chew ◽

N Ngiam ◽

B.Y.Q Tan ◽

C.H Sia ◽

H.W Sim ◽

...

Keyword(s):

Heart Failure ◽

Aortic Valve ◽

Aortic Stenosis ◽

Ejection Fraction ◽

Severe Aortic Stenosis ◽

Left Ventricular ◽

Left Ventricular Ejection ◽

Aortic Valve Area ◽

Ventricular Ejection Fraction ◽

All Cause Mortality

Abstract Background Left ventricular ejection fraction (EF) plays an important role in risk stratifying and guiding therapy for patients with aortic stenosis (AS). This study aims to describe the clinical and echocardiographic outcomes of AS patients with preserved (ASpEF), mid-range (ASmrEF) and reduced (ASrEF) EF. Methods 713 consecutive patients with index echocardiographic diagnosis of moderate-severe AS (aortic valve area <1.5cm2) were allocated according to the EF into three groups: ASrEF (EF<40%), ASmrEF (EF 40–50%), and ASpEF (EF>50%). The study outcomes were defined as 5-year all-cause mortality, heart failure admissions, and aortic valve replacement (AVR). Results In comparison to patients with ASpEF, those with ASrEF were more frequently male, and systolic blood pressure was significantly lower on enrolment (p<0.001). Diabetes, ischemic heart disease and atrial fibrillation were more commonly seen in the ASrEF and ASmrEF groups, compared to ASpEF group. All-cause mortality rates were 30.5% for ASpEF, 50.8% for ASmrEF, 55.0% for ASrEF groups (p<0.001). Increased rates of heart failure admissions were seen in the ASmrEF and ASrEF groups (30.5% and 33.9%, respectively, vs. 14.9% in ASpEF group). Patients with ASrEF had significantly higher rates of AVR as compared to those in the ASmrEF and ASpEF groups (p=0.032). Conclusion Echocardiographic and clinical outcomes of ASmrEF patients resembled those of ASrEF more closely than the ASpEF patients. Stratifying AS patients according to the different EF groups may improve risk assessment and treatment strategies. Figure 1 Funding Acknowledgement Type of funding source: None

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Risk prediction in patients with low-flow, low-gradient aortic stenosis and reduced ejection fraction undergoing TAVI

Open Heart ◽

10.1136/openhrt-2021-001912 ◽

2022 ◽

Vol 9 (1) ◽

pp. e001912

Author(s):

Sebastian Ludwig ◽

Alina Goßling ◽

Moritz Seiffert ◽

Dirk Westermann ◽

Jan-Malte Sinning ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Stenosis ◽

Ejection Fraction ◽

Risk Prediction ◽

Left Ventricular ◽

Low Flow ◽

Volume Index ◽

Left Ventricular Ejection ◽

Score System ◽

All Cause Mortality

ObjectivePatients with low-flow, low-gradient aortic stenosis (LFLG AS) and reduced left ventricular ejection fraction (LVEF) are known to suffer from poor prognosis after transcatheter aortic valve implantation (TAVI). This study aimed to develop a simple score system for risk prediction in this vulnerable subset of patients.MethodsAll patients with LFLG AS with reduced EF and sufficient CT data for aortic valve calcification (AVC) quantification, who underwent TAVI at five German centres, were retrospectively included. The Risk prEdiction in patients with Low Ejection Fraction low gradient aortic stenosis undergoing TAVI (RELiEF TAVI) score was developed based on multivariable Cox regression for all-cause mortality.ResultsAmong all included patients (n=718), RELiEF TAVI score variables were defined as independent predictors of mortality: male sex (HR 1.34 (1.06, 1.68), p=0.013), underweight (HR 3.10 (1.50, 6.40), p=0.0022), chronic obstructive pulmonary disease (HR 1.55 (1.21, 1.99), p=0.001), pulmonary hypertension (HR 1.51 (1.17, 1.94), p=0.0015), atrial fibrillation (HR 1.28 (1.03, 1.60), p=0.028), stroke volume index (HR 0.96 (0.95, 0.98), p<0.001), non-transfemoral access (HR 1.36 (1.05, 1.76), p=0.021) and low AVC density (HR 1.44 (1.15, 1.79), p=0.0012). A score system was developed ranging from 0 to 12 points (risk of 1-year mortality: 13%–99%). Kaplan-Meier analysis for low (0–1 points), moderate (2–4 points) and high RELiEF TAVI score (>4 points) demonstrated rates of 18.0%, 29.0% and 46.1% (p<0.001) for all-cause mortality and 23.8%, 35.9% and 53.4% (p<0.001) for the combined endpoint of all-cause mortality or heart failure rehospitalisation after 1 year, respectively.ConclusionsThe RELiEF TAVI score is based on simple clinical, echocardiographic and CT parameters and might serve as a helpful tool for risk prediction in patients with LFLG AS and reduced LVEF scheduled for TAVI.

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Abstract 18343: B-type Natriuretic Peptide (BNP) Levels Correlate With Indices of Left Ventricular Function and Predict Outcomes Following Transcatheter Aortic Valve Implantation (TAVI): A Cardiovascular Magnetic Resonance Imaging Study

Circulation ◽

10.1161/circ.132.suppl_3.18343 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Alistair C Lindsay ◽

Ritesh Kanyal ◽

Paramvir Sawhney ◽

Helen Broadhurst ◽

Katie Harron ◽

...

Keyword(s):

Aortic Valve ◽

Ejection Fraction ◽

Severe Aortic Stenosis ◽

Left Ventricular ◽

Resonance Imaging ◽

Transcatheter Aortic Valve ◽

All Cause Mortality ◽

The Mean ◽

Lv Ejection Fraction ◽

Valve Implantation

Background: High levels of B-type natriuretic peptide (BNP) have been shown to predict outcomes following transcatheter aortic valve implantation (TAVI). However, the relationship between pre-procedural BNP levels and magnetic resonance imaging (MRI) parameters of cardiac function has not previously been described in patients with severe aortic stenosis undergoing TAVI. Methods: 108 patients underwent cardiac MRI and had measurements of BNP taken prior to TAVI. MRI was performed using a 1.5T scanner; steady-state free precession sequences were used for aortic valve planimetry and to assess ventricular volumes and mass. Gadolinium enhancement was assessed after injection of 0.1 mmol/kg of gadolinium contrast agent. Semi-automated image analysis was performed by two specialist reviewers blinded to patient treatment. Results: The mean age of the population studied was 79 years (IQR 74-85); mean follow-up was 805 days (IQR 368-1025). The mean BNP level was 698 ng/l (range 14-6048); univariate linear regression showed significant relationships between BNP and left ventricular (LV) ejection fraction (p<0.0001), end diastolic volume (p=0.001), end systolic volume (p<0.0001), and indexed mass (p=0.012). Median BNP levels were lower in patients who survived than in those who died (287ng/l vs. 560ng/l; p=0.099); ROC curve analysis found a BNP level of >170ng/l to be the optimal cutoff for the prediction of all-cause mortality. Survival curve analysis showed a significantly increased risk of all-cause mortality in patients with BNP>170ng/l and MRI LV ejection fraction <50% (Hazard ratio 5.72, p=0.015; Figure). Conclusions: In patients with severe aortic stenosis undergoing TAVI, BNP levels are closely correlated with LV function, indexed LV mass, and both end-systolic and end-diastolic volumes, as measured by MRI. Patients with BNP>170ng/l and MRI LV ejection fraction<50% are at significantly higher risk of death following TAVI.

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Abstract 12459: Is Ejection Fraction <50% the Optimal Threshold for Referral for Valve Replacement in Patients With Severe Aortic Stenosis? Impact of Ejection Fraction on Post-Operative Outcome

Circulation ◽

10.1161/circ.130.suppl_2.12459 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Jordi S Dahl ◽

Mackram F Eleid ◽

Hector Michelena ◽

Christopher Scott ◽

Rakesh Suri ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Stenosis ◽

Ejection Fraction ◽

Valve Replacement ◽

Severe Aortic Stenosis ◽

Left Ventricular ◽

Optimal Threshold ◽

Volume Index ◽

Asymptomatic Patients ◽

All Cause Mortality

Introduction: In asymptomatic patients with severe aortic stenosis (SAS), left ventricular (LV) ejection fraction (EF) <50% is generally considered to be the threshold for referral for aortic valve replacement (AVR). Hypothesis: We investigated the importance of LVEF on long-term outcome after AVR in symptomatic and asymptomatic SAS patients and studied whether LVEF < 50% is the optimal threshold for referral for AVR. Methods and Results: We retrospectively identified 2017 patients with SAS (aortic valve area (AVA)<1cm2, mean aortic valve gradient ≥40 mm Hg, or indexed AVA <0.6 cm2/m2) who underwent surgical AVR from January 1995 to June 2009 at our institution. Patients were divided into 4 groups depending on preoperative LVEF (<50% in 300 (15%) patients, 50-59% in 331 (17%), 60-69% in 908 (45%), and ≥70% in 478 (24%)). The primary end-point was all-cause mortality. During follow-up of 5.3±4.4 years, 1056 (52%) died. Five-year mortality rate increased with decreasing LVEF (41% (n=106), LVEF<50%); 35% (n=98), LVEF 50-59%; 26% (n=192), LVEF 60-69%; 22% (n=90), LVEF≥70%, p<0.0001). Compared to patients with LVEF≥60%, patients with LVEF 50-59% had increased mortality (HR 1.58, p<0.001), with a similar risk increase in both symptomatic (HR=1.56, p<0.001) and asymptomatic patients (HR 1.58, p=0.006, Figure). In a Cox regression analysis corrected for standard risk factors, LV mass index, AVA, and stroke volume index, LVEF was predictive of all-cause mortality (HR=0.89 per 10%, p<0.001). When this multivariable analysis was repeated in the subset of 1333 patients with no history of coronary artery disease, LVEF was still associated with all-cause mortality (HR=0.90 per 10%, p=0.009). Conclusion: In patients with SAS undergoing AVR, patients with LVEF 50-59% have also increased mortality compared to patients with LVEF>60%, suggesting that a different LVEF threshold should be used when referring for AVR.

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Abstract 18283: Left Ventricular STIFFness vs. Fibrosis Quantification by T1 MAPping in Heart Failure With Preserved Ejection Fraction - STIFFMAP-HFpEF

Circulation ◽

10.1161/circ.132.suppl_3.18283 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Karl-Philipp Rommel ◽

Max von Roeder ◽

Thomas Stiermaier ◽

Konrad Latuscynski ◽

Christian Oberueck ◽

...

Keyword(s):

Heart Failure ◽

Ejection Fraction ◽

Myocardial Fibrosis ◽

T1 Mapping ◽

Volume Fraction ◽

Extracellular Volume ◽

Left Ventricular ◽

Diffuse Myocardial Fibrosis ◽

Preserved Ejection Fraction ◽

Stiffness Constant

Introduction: Heart Failure with Preserved Ejection Fraction (HFpEF) is an increasing public health problem. To tailor successful treatment strategies it is essential to identify patients’ individual pathologies contributing to HFpEF. Cardiac magnetic resonance (CMR) derived T1-Mapping has been suggested as non-invasive tool to quantify diffuse myocardial fibrosis. Invasive tracings of pressure-volume relations represent the gold-standard for assessing load-independent mechanical diastolic properties of the left ventricle. Hypothesis: Aim of this study was therefore to elucidate the diagnostic performance of T1-Mapping in HFpEF patients by examining the relationship between the extracellular volume fraction (ECV) and invasively measured parameters of diastolic function and to study the potential of ECV to differentiate between different pathomechanisms in HFPEF. Methods: We performed CMR T1-Mapping in 21 patients with HFpEF and 11 patients without heart failure symptoms (further referred to as controls). Pressure volume loops were obtained with a conductance catheter during basal conditions and handgrip exercise. Transient preload reduction was used to extrapolate the diastolic stiffness constant. Results: Patients with HFpEF showed a higher extra cellular volume fraction (p=0.001), an elevated load-independent passive LV stiffness constant - ß (p<0.001) and a longer time constant of active LV-relaxation Tau (p=0.04). ECV correlated well with ß (r =0.75, p <0.001). After multivariate analysis, ECV remained the only independent predictor of ß. Within the HFpEF cohort, patients with ECV over median showed higher left ventricular masses (p=0.04) and a higher LV stiffness (p=0.05). ECV < median identified patients with a prolonged active LV relaxation (p=0.008) and a marked hypertensive reaction to exercise due to a pathologic arterial elastance (p=0.05). Conclusions: Diffuse myocardial fibrosis, assessed by CMR derived T1-Mapping independently predicts invasively measured LV stiffness in HFpEF. In addition, ECV helps to non-invasively distinguish the role of impaired active relaxation and passive stiffness and refines characterization of patients, which represents a prerequisite for any successful therapy in the future.

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Valvulo-Arterial Impedance and Dimensionless Index for Risk Stratifying Patients With Severe Aortic Stenosis

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.742297 ◽

2021 ◽

Vol 8 ◽

Author(s):

Yogamaya Mantha ◽

Shutaro Futami ◽

Shohei Moriyama ◽

Michinari Hieda

Keyword(s):

Aortic Valve ◽

Aortic Stenosis ◽

Ejection Fraction ◽

Continuous Wave ◽

Left Ventricular ◽

Low Flow ◽

Aortic Valve Area ◽

Arterial Impedance ◽

Stenosis Severity ◽

Lv Ejection Fraction

The hemodynamic effects of aortic stenosis (AS) consist of increased left ventricular (LV) afterload, reduced myocardial compliance, and increased myocardial workload. The LV in AS patients faces a double load: valvular and arterial loads. As such, the presence of symptoms and occurrence of adverse events in AS should better correlate with calculating the global burden faced by the LV in addition to the transvalvular gradient and aortic valve area (AVA). The valvulo-arterial impedance (Zva) is a useful parameter providing an estimate of the global LV hemodynamic load that results from the summation of the valvular and vascular loads. In addition to calculating the global LV afterload, it is paramount to estimate the stenosis severity accurately. In clinical practice, the management of low-flow low-gradient (LF-LG) severe AS with preserved LV ejection fraction requires careful confirmation of stenosis severity. In addition to the Zva, the dimensionless index (DI) is a very useful parameter to express the size of the effective valvular area as a proportion of the cross-section area of the left ventricular outlet tract velocity-time integral (LVOT-VTI) to that of the aortic valve jet (dimensionless velocity ratio). The DI is calculated by a ratio of the sub-valvular velocity obtained by pulsed-wave Doppler (LVOT-VTI) divided by the maximum velocity obtained by continuous-wave Doppler across the aortic valve (AV-VTI). In contrast to AVA measurement, the DI does not require the calculation of LVOT cross-sectional area, a major cause of erroneous assessment and underestimation of AVA. Hence, among patients with LG severe AS and preserved LV ejection fraction, calculation of DI in routine echocardiographic practice may be useful to identify a subgroup of patients at higher risk of mortality who may derive benefit from aortic valve replacement. This article aims to elucidate the Zva and DI in different clinical situations, correlate with the standard indexes of AS severity, LV geometry, and function, and thus prove to improve risk stratification and clinical decision making in patients with severe AS.

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