Personne : Briand, Martin.
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Faculté de médecine, Université Laval
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- PublicationRestreintMetabolic syndrome negatively influences disease progression and prognosis in aortic stenosis(Elsevier, 2006-06-06) Briand, Martin.; Couët, Jacques; Cartier, Amélie.; Pibarot, Philippe; Dumesnil, Jean G.; Després, Jean-Pierre; Mathieu, Patrick; Lemieux, Isabelle.; Arsenault, MarieObjectives: This study sought to examine the association between the metabolic syndrome (MS) and the progression of aortic stenosis (AS). Background It has been suggested that aortic valve sclerosis and its progression to AS are caused by an atherosclerotic process. Metabolic syndrome is associated with a higher risk of vascular atherosclerosis. Thus, we hypothesized that the atherogenic features of MS could negatively influence disease progression and prognosis in patients with AS. Methods: We retrospectively analyzed the data of 105 consecutive patients (age 69 ± 12 years, 64 men) with at least moderate AS. Of these patients, 40 (38%) had MS identified according to the modified clinical criteria proposed by the National Cholesterol Education Program-Adult Treatment Panel III. The hemodynamic progression of AS was assessed by the measurement of the annualized decrease in valve area during the follow-up period of the study, which averaged 28 ± 13 months. Event-free survival was defined as the absence of death or aortic valve replacement during follow-up. Results: The hemodynamic progression of the stenosis was twice as fast (-0.14 ± 0.13 cm2/year vs. -0.08 ± 0.08 cm2/year, p = 0.008) and the three-year event-free survival was markedly lower (44 ± 8% vs. 69 ± 6%, p = 0.002) among patients with MS. In multivariate analysis, MS was found to be a strong independent predictor of both stenosis progression (p = 0.006) and event-free survival (odds ratio 3.85, 95% CI 1.96 to 7.58, p < 0.001). Conclusions: The present study is the first to report that MS is associated with a faster disease progression and worse outcome in patients with AS. Such findings open new avenues of research and provide a strong impetus for the elaboration of additional prospective studies focusing on this association.
- PublicationRestreintHemodynamic performance during maximum exercise in adult patients with the ross operation and comparison with normal controls and patients with aortic bioprostheses(Elsevier, 2000-10-24) Briand, Martin.; Laforest, Isabelle; Cartier, Paul C.; Pibarot, Philippe; Dumesnil, Jean G.This study examines the resting and exercise hemodynamic performance of the pulmonary autografts in the aortic position as well as of the homografts used for right ventricular outflow reconstruction in patients undergoing the Ross operation. Previous studies have reported excellent resting hemodynamics in patients who underwent aortic valve replacement with a pulmonary autograft. However, there are very few studies of their hemodynamic performance during exercise. Twenty adult subjects who underwent the Ross operation and 12 normal control subjects were submitted to maximum ramp bicycle exercise. The valve effective orifice areas and transvalvular gradients of both aortic (autograft) and pulmonary (homograft) valves were measured at rest and at peak of maximum exercise using Doppler echocardiography. Valve areas were indexed for body surface area. The hemodynamics of the aortic valve were very similar in Ross subjects and in control subjects at rest and during exercise. However, the indexed valve area of the pulmonary valve at rest was significantly (p <0.001) lower in the Ross subjects (1.10 ± 0.46 cm 2 /m 2 ) than in the control subjects (1.95 ± 0.41 cm 2 /m 2 ), resulting in higher (p = 0.004) mean gradients at rest (Ross: 9 ± 7 mm Hg vs control: 2 ± 1 mm Hg) and at peak exercise (Ross: 21 ± 14 mm Hg vs control: 7 ± 2 mm Hg). The pulmonary autograft provided excellent hemodynamics in the aortic position either at rest or during maximum exercise, whereas moderately high gradients were found during exercise across the homograft implanted in the pulmonary valve position. Future improvement of the Ross procedure should be oriented toward the search of new methods to prevent the deterioration of the homografts
- PublicationRestreintReduced systemic arterial compliance impacts significantly on left ventricular afterload and function in aortic stenosis : implications for diagnosis and treatment(American College of Cardiology, 2005-06-17) Briand, Martin.; Kadem, Lyes; Pibarot, Philippe; Gervais Tongué, Antonio; Dumesnil, Jean G.; Rieu, Régis; Garcia, DamienObjectives: We sought to determine to what extent systemic arterial compliance (SAC) might impact on afterload and left ventricular (LV) function in patients with aortic stenosis (AS). Background: Although AS and reduced SAC may often coexist in the same patient, their relative impact on LV function is not well understood. Methods: Systemic arterial compliance was calculated as the ratio of stroke volume index to arterial pulse pressure in 208 patients with at least moderate AS. As a measure of global afterload, we calculated the valvulo-arterial impedance (Zva), which theoretically accounts for the effects of both AS and SAC. Results: Patients were divided into four groups: group 1, moderate AS and normal SAC (n = 77; 37%); group 2, moderate AS and low SAC (n = 50; 24%); group 3, severe AS and normal SAC (n = 45; 22%); and group 4, severe AS and low SAC (n = 36; 17%). The prevalences of LV diastolic and systolic dysfunction were 60% and 6% in group 1, 86% and 12% in group 2, 82% and 16% in group 3, and 94% and 31% in group 4. In multivariate analysis excluding Zva, energy loss index and SAC were both independent predictors of LV dysfunction, but when Zva was entered into the analyses, it became the only hemodynamic variable to be independently associated with LV dysfunction. Conclusions: Reduced SAC is a frequent occurrence in elderly patients with AS, where it independently contributes to increased afterload and decreased LV function. Systemic arterial compliance should be taken into consideration when evaluating these patients with regard to diagnosis and treatment.
- PublicationRestreintHemodynamic performance at rest and during exercise after aortic valve replacement : comparison of pulmonary autografts versus aortic homografts.(American Heart Association, 2002-09-24) Briand, Martin.; Laforest, Isabelle; Cartier, Paul C.; Pibarot, Philippe; Dumesnil, Jean G.Background : The Ross procedure and aortic homografts have both been shown to have superior hemodynamic performance after valve replacement, but there have been few comparisons. Methods : Sequential Doppler echocardiograms were performed up to 5 years after aortic valve replacement in 132 patients with the Ross procedure and 111 patients with an aortic homograft (AH). Measurements included assessment of valvular regurgitation and calculations of valve effective orifice area (EOA) and mean transvalvular gradients; the same measurements were also performed at the level of the pulmonary homograft in the Ross patients as well as during maximum exercise in 20 Ross patients and 14 AH patients. Results : Aortic valve hemodynamics were stable during follow-up for both procedures and values at 1 year showed larger indexed EOAs (1.77±0.45 versus 1.42±0.35 cm2/m2, P<0.001) and lower gradients (2±3 versus 4±3 mm Hg) for the Ross procedure; similar findings were also observed during exercise (1.99±0.44 versus 1.36±0.39 cm2/m2, P<0.001 and 7±3 versus 17±11 mm Hg). Prevalence and severity of aortic regurgitation were low in both groups, although 4 patients (1 Ross, 3 AH) underwent a second operation for this reason. Also, various degrees of pulmonary homograft stenosis were found in 20% of Ross patients, 4 of which underwent a second operation. Conclusion : Both procedures provide continued excellent hemodynamics of the aortic valve. The Ross procedure has a slight advantage, but this is somewhat counterbalanced by the deterioration of the pulmonary homograft in up to 20% of patients. Further studies aimed at clarifying longer-term outcomes as well as preventing pulmonary homograft stenosis with the Ross operation are clearly needed.
- PublicationRestreintMetabolic syndrome is associated with faster degeneration of bioprosthetic valves(American Heart Association, 2006-07-04) Briand, Martin.; Voisine, Pierre; Pibarot, Philippe; Dumesnil, Jean G.; Dagenais, François.; Després, Jean-Pierre; Mathieu, PatrickBACKGROUND: Several studies have reported similarities between calcification of the native aortic valve and atherosclerosis. Recent studies also suggested that hypercholesterolemia may be a risk factor for calcific degeneration of bioprosthetic valves. The metabolic syndrome (MS) is associated with a higher risk of vascular atherosclerosis. We thus hypothesized that the atherogenic features of MS could accelerate bioprosthetic valve degeneration. METHODS AND RESULTS: We included 217 patients who underwent aortic valve replacement with a bioprosthetic valve in the study. Of these patients, 71 patients (33%) had MS defined according to the modified criteria proposed by the National Cholesterol Education Program Adult Treatment Panel III. The annualized increase in mean transprosthetic gradient and the worsening of transprosthetic regurgitation measured by Doppler echocardiography were used to assess the deterioration of valve hemodynamic function. Patients with MS had higher progression of gradient (+4+/-5 mm Hg/year versus +2+/-2 mm Hg/year, P<0.001), higher proportion of > or = 1/3 degree worsening of regurgitation (25% versus 12%, P=0.02), and higher proportion of valve function deterioration defined as regurgitation worsening and/or > or = 3 mm Hg/year increase in gradient (41% versus 25%, P=0.02) when compared with patients without MS. On multivariate analysis, MS was an independent predictor of gradient progression (P=0.01), regurgitation worsening (P=0.02), and valve function deterioration (P=0.02). The other independent predictors were diabetes, renal insufficiency, and higher mean gradient at baseline. CONCLUSIONS: This is the first study to report that the MS is independently associated with faster bioprosthetic valve degeneration. This study could pave the way for the development of a new medical therapy able to significantly reduce the structural valve deterioration of bioprostheses
- PublicationRestreintMidterm echocardiographic follow-up after Ross operation(American Heart Association, 2000-11-07) Briand, Martin.; Cartier, Paul C.; Pibarot, Philippe; Dumesnil, Jean G.Background— The pulmonary autograft (Ross) operation is an attractive treatment for aortic valve disease, but hemodynamic follow-up is not well defined. Methods and Results— One hundred thirty-two consecutive patients (62% male, mean age 40±11 years) were followed up to 5 years after the Ross operation. Echocardiography was performed early (within 30 days), 3 to 6 months, and yearly after surgery. The valve effective orifice area (EOA) and mean transvalvular gradient of both aortic and pulmonary valves were measured, and transvalvular regurgitation was assessed by using color Doppler echocardiography. EOA was indexed for body surface area. The hemodynamic performance was excellent for both the aortic and pulmonary valves early after surgery (gradient, 3±4 and 3±4 mm Hg, respectively). It remained stable thereafter for the aortic valve, whereas there was a significant deterioration of the EOA (-0.74±0.82 cm2) and gradient (+6±8 mm Hg) for the pulmonary valve, which occurred mostly during the first 6 months after surgery. This hemodynamic deterioration resulted in suboptimal (defined as an EOA index <0.85 cm2/m2) hemodynamics in 19.3% of the patients, to the extent that 3 (2%) of the 132 patients eventually had to be subjected to further surgery for severe pulmonary valve stenosis. Conclusions— The pulmonary autograft provides continued excellent hemodynamics in the aortic position, whereas moderately high gradients can be found across the pulmonary homograft in some patients. Further studies are necessary to identify the factors responsible for the deterioration of the hemodynamic performance of the homograft in the pulmonary position and to determine its impact on right ventricular function and clinical status.