Florent Le Ven

Institut Universitaire de Cardiologie et de Pneumologie de Québec (Hôpital Laval), Québec, Quebec, Canada

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Publications (18)51.61 Total impact

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    ABSTRACT: The transthoracic echocardiographic (TTE) evaluation of the severity of residual aortic regurgitation (AR) following transcatheter aortic valve implantation (TAVI) has been controversial and lacks validation.
    Heart (British Cardiac Society) 08/2014; · 5.01 Impact Factor
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    ABSTRACT: Little is known about the usefulness of evaluating cardiac neurohormones in patients undergoing transcatheter aortic valve implantation (TAVI). The objectives of this study were to evaluate the baseline values and serial changes of N-terminal prohormone B-type natriuretic peptide (NT-proBNP) after TAVI, its related factors, and prognostic value. A total of 333 consecutive patients were included, and baseline, procedural, and follow-up (median 20 months, interquartile range 9 to 36) data were prospectively collected. Systematic NT-proBNP measurements were performed at baseline, hospital discharge, 1, 6, and 12 months, and yearly thereafter. Baseline NT-proBNP values were elevated in 86% of the patients (median 1,692 pg/ml); lower left ventricular ejection fraction and stroke volume index, greater left ventricular mass, and renal dysfunction were associated with greater baseline values (p <0.01 for all). Higher NT-proBNP levels were independently associated with increased long-term overall and cardiovascular mortalities (p <0.001 for both), with a baseline cut-off level of ∼2,000 pg/ml best predicting worse outcomes (p <0.001). At 6- to 12-month follow-up, NT-proBNP levels had decreased (p <0.001) by 23% and remained stable up to 4-year follow-up. In 39% of the patients, however, there was a lack of NT-proBNP improvement, mainly related to preprocedural chronic atrial fibrillation, lower mean transaortic gradient, and moderate-to-severe mitral regurgitation (p <0.01 for all). In conclusion, most patients undergoing TAVI presented high NT-proBNP levels, and a lack of improvement was observed in >1/3 of the patients after TAVI. Also, higher NT-proBNP levels predicted greater overall and cardiac mortalities at a median follow-up of 2 years. These findings support the implementation of NT-proBNP measurements for the clinical decision-making process and follow-up of patients undergoing TAVI.
    The American journal of cardiology 03/2014; 113(5):851-9. · 3.58 Impact Factor
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    ABSTRACT: Early detection and accurate estimation of aortic stenosis (AS) severity are the most important predictors of successful long-term outcomes in patients. Current clinical parameters used for evaluation of the AS severity have several limitations including flow dependency. Estimation of AS severity is specifically challenging in patients with low-flow and low transvalvular pressure gradient conditions. A proper diagnosis in these patients needs a comprehensive evaluation of the left ventricle (LV) hemodynamic loads. This study has two objectives: (1) developing a lumped-parameter model to describe the ventricular-valvular-arterial interaction and to estimate the LV stroke work (SW); (2) introducing and validating a new index, the normalized stroke work (N-SW), to assess the global hemodynamic load imposed on the LV. N-SW represents the global hemodynamic load that the LV faces for each unit volume of blood ejected. The model uses a limited number of parameters which all can be measured non-invasively using current clinical imaging modalities. The model was first validated by comparing its calculated flow waveforms with the ones measured using Cardiovascular Magnetic Resonance (CMR) in 49 patients and 8 controls. A very good correlation and concordance were found throughout the cycle (median root mean square: 12.21 mL/s) and between the peak values (r = 0.98; SEE = 0.001, p<0.001). The model was then used to determine SW using the parameters measured with transthoracic Doppler-echocardiography (TTE) and CMR. N-SW showed very good correlations with a previously-validated index of global hemodynamic load, the valvular arterial impedance ([Formula: see text]), using data from both imaging modalities (TTE: r = 0.82, SEE = 0.01, p<0.001; CMR: r = 0.74, SEE = 0.01, p<0.001). Furthermore, unlike , N-SW was almost independent from variations in the flow rate. This study suggests that considering N-SW may provide incremental diagnostic and prognostic information, beyond what standard indices of stenosis severity and provide, particularly in patients with low LV outflow.
    PLoS ONE 01/2014; 9(1):e86793. · 3.73 Impact Factor
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    ABSTRACT: Increased myocardial trabeculations define non-compaction cardiomyopathy (NCC). Imaging advancements have led to increasingly common identification of prominent trabeculations with unknown implications. We quantified and determined the impact of trabeculations’ burden on cardiac function and stretch in a population of healthy young adults. One hundred adults aged 18-35 (28±4 years, 55% women) without known cardiovascular disease were prospectively studied by cardiovascular magnetic resonance (CMR). Left ventricular (LV) volumes, segmental function, and ejection fraction (EF), and left atrial (LA) volumes were determined. Thickness and area of trabeculated (T) and dense (D) myocardium were measured for each standardized LV segment. N-terminal pro-brain natriuretic peptide (Nt-pro-BNP) was measured. Eighteen % of individuals had ≥1 positive traditional criteria for NCC and 11% meet new proposed NCC CMR criteria. T/D ratios were uniformly greater at end-diastole vs. end-systole (0.90±0.25 vs. 0.42 ±0.13, p<0.0001), in women vs. men (0.85±0.24 vs. 0.72±0.19, p=0.006), at anterior vs. non-anterior segments (1.41±0.59 vs. 0.88±0.35, p<0.0001), and at apical vs. non-apical segments (1.31±0.56 vs. 0.87±0.38, p<0.0001). The largest T/D ratios were associated with lower LVEF (57.0±5.3 vs. 62±5.5, p=0.0001) and greater Nt-pro-BNP (203±98 vs. 155±103, p=0.04). Multivariable regression identified greater end-systolic T/D ratios as the strongest independent predictor of lower LVEF, beyond age and gender, LA or LV volumes, and Nt-pro-BNP (β=-9.9, 95% CI -15-4.9, p<0.001). In conclusion, healthy adults possess variable amounts of trabeculations that regularly meet criteria for NCC. Greater trabeculations are associated with decreased LV function. Apparently healthy young adults with increased trabecular burden possess evidence of mildly impaired cardiac function.
    The American Journal of Cardiology. 01/2014;
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    ABSTRACT: Background Recent studies have reported that obesity, metabolic syndrome, and diabetes are associated with LV hypertrophy (LVH) and dysfunction in aortic stenosis (AS) patients. The purpose of this study was to examine the association between amount and distribution of body fat and LVH and systolic dysfunction in AS patients. Methods 124 patients with AS were prospectively recruited in the PROGRESSA study and underwent Doppler-echocardiography and computed tomography (CT). Presence and severity of LVH was assessed by LV mass indexed for height2.7 (LVMi) and LV dysfunction by global longitudinal strain (GLS). CT was used to quantify abdominal visceral (VAT) and subcutaneous (SAT) adipose tissue, and total adipose tissue (TAT). Results Body mass index (BMI) correlated strongly with TAT (r=0.85), moderately with VAT (r=0.70), and SAT (r=0.69), and weakly with the proportion of VAT (VAT/TAT ratio: r=0.19). In univariate analysis, higher BMI, TAT, VAT, SAT, and VAT/TAT were associated with increased LVMi whereas higher VAT and VAT/TAT ratio were associated with reduced GLS. Multivariate analysis revealed that larger BMI (p<0.0001) and higher VAT/TAT ratio (p=0.01) were independently associated with greater LVH, whereas only the VAT/TAT ratio (p=0.03) was independently associated with reduced GLS. Conclusion This study suggests that both total and visceral adiposity are independently associated with LVH in AS patients. Furthermore, impairment of LV systolic function does not appear to be influenced by total obesity but is rather related to excess visceral adiposity. These findings provide impetus for elaboration of interventional studies aiming at visceral adiposity in AS population.
    The Canadian journal of cardiology 01/2014; · 3.12 Impact Factor
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    ABSTRACT: Valve effective orifice area EOA and transvalvular mean pressure gradient (MPG) are the most frequently used parameters to assess aortic stenosis (AS) severity. However, MPG measured by cardiovascular magnetic resonance (CMR) may differ from the one measured by transthoracic Doppler-echocardiography (TTE). The objectives of this study were: 1) to identify the factors responsible for the MPG measurement discrepancies by CMR versus TTE in AS patients; 2) to investigate the effect of flow vorticity on AS severity assessment by CMR; and 3) to evaluate two models reconciling MPG discrepancies between CMR/TTE measurements. Eight healthy subjects and 60 patients with AS underwent TTE and CMR. Strouhal number (St), energy loss (EL), and vorticity were computed from CMR. Two correction models were evaluated: 1) based on the Gorlin equation (MPGCMR-Gorlin); 2) based on a multivariate regression model (MPGCMR-Predicted). MPGCMR underestimated MPGTTE (bias = -6.5 mmHg, limits of agreement from -18.3 to 5.2 mmHg). On multivariate regression analysis, St (p = 0.002), EL (p = 0.001), and mean systolic vorticity (p < 0.001) were independently associated with larger MPG discrepancies between CMR and TTE. MPGCMR-Gorlin and MPGTTE correlation and agreement were r = 0.7; bias = -2.8 mmHg, limits of agreement from -18.4 to 12.9 mmHg. MPGCMR-Predicted model showed better correlation and agreement with MPGTTE (r = 0.82; bias = 0.5 mmHg, limits of agreement from -9.1 to 10.2 mmHg) than measured MPGCMR and MPGCMR-Gorlin. Flow vorticity is one of the main factors responsible for MPG discrepancies between CMR and TTE.
    Journal of Cardiovascular Magnetic Resonance 09/2013; 15(1):84. · 4.44 Impact Factor
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    ABSTRACT: OBJECTIVES: We aimed to assess the impact of baseline LV outflow, LV ejection fraction (LVEF) and transvalvular gradient on outcomes following transcatheter aortic valve replacement (TAVR) in patients with severe aortic stenosis. BACKGROUND: Low flow, i.e. reduced stroke volume index (SVi), can occur with both reduced and preserved LVEF. Low flow is often associated with low gradient despite severe stenosis and with worse outcomes following surgical aortic valve replacement. However, there is few data about the impact of low flow on outcomes following TAVR. METHOD: We retrospectively analyzed the clinical, Doppler-echocardiographic and outcome data prospectively collected in 639 patients who underwent TAVR for symptomatic severe AS in two Canadian centers. RESULTS: In this cohort, 334 (52.3 %) patients had a low flow (SVi<35ml/m(2)) and these patients had increased 30-day mortality (11.4 vs. 5.9 %, p=0.01), 2-year all-cause mortality (35.3 vs. 30.9 %, p=0.005) and 2-year cardiovascular mortality (25.7 vs. 16.8 %, p=0.01) compared to patients with normal flow. Reduced flow was an independent predictor of 30-day mortality (Odd Ratio: 1.94, p=0.026), cumulative all-cause mortality (Hazard ratio [HR]: 1.27 per 10ml/m² SVi decrease, p=0.016) and cumulative cardiovascular mortality (HR: 1.29 per 10ml/m² decrease, p=0.04). Despite significant association in univariable analyses, low LVEF and low mean gradient were not found to be independent predictors of outcomes in multivariable analyses. CONCLUSION: Low flow but not low LVEF or low gradient is an independent predictor of early and late mortality following TAVR in high-risk patients with severe AS. SVi should be integrated in the risk stratification process of these patients.
    Journal of the American College of Cardiology 06/2013; · 14.09 Impact Factor
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    ABSTRACT: AIMS: The aims of this study were : (i) to determine the feasibility and reproducibility of the measurement of valve kinetic parameters by cardiovascular magnetic resonance (CMR) and (ii) to examine the association between these parameters and markers of a poor prognosis in patients with aortic stenosis (AS). METHODS AND RESULTS: Eight healthy control subjects and 71 patients with AS (0.60 cm(2) ≤ EOA ≤ 1.90 cm(2)) underwent transthoracic echocardiography (TTE) and CMR. The valve opening slope (OS) and closing slope (CS) were calculated from instantaneous effective orifice area (EOA) curves obtained by CMR. Intra- and inter-observer variability were 4.8 ± 3.9 and 5.0 ± 4.1%, respectively, for OS, 3.8 ± 2.9 and 4.0 ± 3.1% for CS. OS was significantly related to the plasma level of NT-pro-brain natriuretic peptide (BNP) (r = -0.36, P = 0.002), whereas the EOA or gradient were not. CONCLUSION: This study demonstrates the excellent feasibility and reproducibility of CMR for the measurement of valve kinetic parameters in patients with AS. Larger studies are needed to confirm the incremental prognostic value of these new CMR parameters of aortic valve kinetics in patients with severe AS.
    European heart journal cardiovascular Imaging. 01/2013;
  • Médecine Nucléaire. 04/2012; 36(4):176.
  • Thrombosis and Haemostasis 03/2012; 107(5):1005-7. · 6.09 Impact Factor
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    ABSTRACT: Introduction Venous thromboembolism (VTE) is a common disease. The incidence rises markedly with increasing age; over the age of 75, the annual incidence reaches 1 per 100. Background Besides major risk factors (surgery, trauma and acute medical illness), four risk factors have to be taken into account in the management of VTE: increasing age, cancer, previous history of VTE and pregnancy. To date, with the exception of the antiphospholipid syndrome and antithrombin deficiency, “thrombophilias” do not appear to change the management of VTE. Viewpoints “Thrombophilias” are useful tools for understanding the pathophysiology of VTE. Therefore, further studies are needed to identify new biological anomalies and their impact on the risk of VTE. Recently, links between VTE and atherosclerosis have been demonstrated, leading to new concept of pan-vascular disease and prevention. Conclusions VTE is a major public health problem. The knowledge of VTE risk factors is of major importance in identifying high-risk patients and in reducing the incidence and mortality of VTE.
    Revue des Maladies Respiratoires. 02/2012; 29(2):254–266.
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    ABSTRACT: Venous thromboembolism (VTE) is a common disease. The incidence rises markedly with increasing age; over the age of 75, the annual incidence reaches 1 per 100. Besides major risk factors (surgery, trauma and acute medical illness), four risk factors have to be taken into account in the management of VTE: increasing age, cancer, previous history of VTE and pregnancy. To date, with the exception of the antiphospholipid syndrome and antithrombin deficiency, "thrombophilias" do not appear to change the management of VTE. "Thrombophilias" are useful tools for understanding the pathophysiology of VTE. Therefore, further studies are needed to identify new biological anomalies and their impact on the risk of VTE. Recently, links between VTE and atherosclerosis have been demonstrated, leading to new concept of pan-vascular disease and prevention. VTE is a major public health problem. The knowledge of VTE risk factors is of major importance in identifying high-risk patients and in reducing the incidence and mortality of VTE.
    Revue des Maladies Respiratoires 02/2012; 29(2):254-66. · 0.50 Impact Factor
  • International journal of cardiology 07/2011; 151(2):252. · 6.18 Impact Factor
  • International journal of cardiology 02/2011; 146(3):475-9. · 6.18 Impact Factor
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    ABSTRACT: Extracranial internal carotid artery stenosis is a risk factor for perioperative stroke in patients undergoing coronary artery bypass surgery (CAB). Although selective and non-selective methods of preoperative carotid screening have been advocated, it remains unclear if this screening is clinically relevant. To test whether selective carotid screening is as effective as non-selective screening in detecting significant carotid disease. The case records of patients consecutively undergoing CAB were reviewed. Patients were stratified retrospectively into high- or low-risk groups according to risk factors for significant carotid stenosis and perioperative stroke: peripheral vascular disease (PVD), carotid bruit, diabetes mellitus, age >70 years and/or history of cerebrovascular disease. Prevalence of carotid stenosis detected by ultrasonography, surgical management and perioperative stroke rates were determined in each group. Overall, 205 consecutive patients underwent preoperative carotid screening. The prevalence of significant carotid stenosis was 5.8%. Univariate analysis confirmed that PVD (P=0.005), carotid bruit (P=0.003) and diabetes mellitus (P=0.05) were significant risk factors for stenosis. Carotid stenosis was a risk factor for stroke (P=0.03). Prevalence of carotid stenosis was higher in the high-risk group (9.1%) than the low-risk group (1.2%) (P<0.05). All concomitant or staged carotid endarterectomies/CAB (5/205) and all patients who had perioperative strokes (5/205) were in the high-risk group (P=0.01). In our cohort, selective screening of patients aged >70 years, with carotid bruit, a history of cerebrovascular disease, diabetes mellitus or PVD would have reduced the screening load by 40%, with trivial impact on surgical management or neurological outcomes.
    Archives of cardiovascular diseases 02/2011; 104(2):77-83. · 0.66 Impact Factor
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    ABSTRACT: Background Extracranial internal carotid artery stenosis is a risk factor for perioperative stroke in patients undergoing coronary artery bypass (CAB) surgery. Although both selective and nonselective methods of preoperative carotid screening have been advocated, it remains unclear if this screening is clinically relevant. Methods Files of patients consecutively undergoing CAB were reviewed. Patients were retrospectively stratified into high- or low-risk groups according to risk factors for significant carotid stenosis and perioperative stroke identified in the literature: presence of peripheral vascular disease, carotid bruit, diabetes mellitus, age over 70 years and/or previous history of cerebrovascular disease. Prevalence of carotid stenosis detected by ultrasonography, surgical management, and perioperative stroke rates were determined in each group. Results 205 consecutive patients underwent preoperative carotid screening. The prevalence of significant carotid stenosis detected by ultrasonography was 5.8%. Univariate analysis confirmed that peripheral vascular disease (p = 0.005), carotid bruit (p = 0.003) and diabetes mellitus (p = 0.05) were significant risk factors for stenosis. Carotid stenosis was a risk factor for stroke (p = 0.03). Prevalence of carotid stenosis was higher in high-risk group than in low-risk group (9.1% vs 1.2%; p<0.05). All concomitant or staged carotid endarterectomies/CAB (5/205) and all patients who suffered perioperative strokes (5/205) were in the high-risk group (p = 0.01). Conclusion In our cohort, selective screening of patients with either an age over 70, a carotid bruit, a history of cerebrovascular disease, a diabete mellitus or a peripheral vascular disease would have reduced the screening load by 40% with trivial impact on surgical management or neurologic outcomes.
    Archives of Cardiovascular Diseases Supplements 01/2011; 3(1):21-22.
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    ABSTRACT: The aim of this paper is to report clinical characteristics, consequences, echocardiographic features, and pathological findings encountered in patients suffering from valvular disease associated with benfluorex exposure in a multicentre French registry. Forty patients suffering from unexplained restrictive valvular disease with a previous exposition to benfluorex, a fenfluramine derivative, were identified from eight French university hospitals. Patients were mostly women (87.5%) with a mean age of 57 ± 9 years and high body mass index of 30 ± 7 kg/m²; 37.5% of them presented with severe heart failure symptoms (NYHA class III and IV). Benfluorex mean daily dose was 415 ± 131 mg with total therapy duration of 72 ± 53 months. Resulting cumulative dose was 910 ± 675 g. Common echocardiographic findings were leaflets and sub-valvular apparatus thickening and retraction. Aortic and mitral valve regurgitations resulting from leaflets loss of coaptation were the most frequent findings (87.5 and 82.5%) and were severe in 29 patients (72.5%). Multiple valve involvements were present in 31 cases (77.5%). Pulmonary arterial hypertension was identified in 20 cases (50%). Histopathological examination demonstrated abundant extra cellular matrix encasing the leaflets without modification of valve architecture. Fifteen patients (37.5%) underwent valvular surgery. Benfluorex-related valvulopathy shares numerous characteristics with other drug-induced valvular disease. Clinical consequences may be serious with severe heart failure symptoms that may lead to surgical treatment.
    European Heart Journal – Cardiovascular Imaging 12/2010; 12(4):265-71. · 2.39 Impact Factor
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    Florent Le Ven, Erwan Orhan, Yannick Jobic
    Archives of cardiovascular diseases 10/2010; 103(10):559-60. · 0.66 Impact Factor

Publication Stats

77 Citations
51.61 Total Impact Points

Institutions

  • 2014
    • Institut Universitaire de Cardiologie et de Pneumologie de Québec (Hôpital Laval)
      Québec, Quebec, Canada
  • 2013
    • Institut universitaire de cardiologie et de pneumologie de Québec
      Québec, Quebec, Canada
    • Laval University
      • Department of Surgery
      Québec, Quebec, Canada
  • 2010–2011
    • Centre Hospitalier Universitaire de Brest
      Brest, Brittany, France