Personne : Hachicha, Zeineb
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Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval
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- PublicationRestreintB-type natriuretic peptide in low-flow, low-gradient aortic stenosis : relationship to hemodynamics and clinical outcome : results from the Multicenter Truly or Pseudo-Severe Aortic Stenosis (TOPAS) study.(American Heart Association, 2007-06-05) Bergler-Klein, Jutta; Fuchs, Christina; Mundigler, Gerald; Mohty, Dania; Hachicha, Zeineb; Burwash, Ian G.; Blais, Claudia; Pibarot, Philippe; Dumesnil, Jean G.; Beanlands, Robert S. B.; Walter-Publig, Nicole; Rader, Florian; Baumgartner, HelmutBACKGROUND: The prognostic value of B-type natriuretic peptide (BNP) is unknown in low-flow, low-gradient aortic stenosis (AS). We sought to evaluate the relationship between AS and rest, stress hemodynamics, and clinical outcome. METHODS AND RESULTS: BNP was measured in 69 patients with low-flow AS (indexed effective orifice area < 0.6 cm2/m2, mean gradient < or = 40 mm Hg, left ventricular ejection fraction < or = 40%). All patients underwent dobutamine stress echocardiography and were classified as truly severe or pseudosevere AS by their projected effective orifice area at normal flow rate of 250 mL/s (effective orifice area < or = 1.0 cm2 or > 1.0 cm2). BNP was inversely related to ejection fraction at rest (Spearman correlation coefficient r(s)=-0.59, P<0.0001) and at peak stress (r(s)=-0.51, P<0.0001), effective orifice area at rest (r(s)=-0.50, P<0.0001) and at peak stress (r(s)=-0.46, P=0.0002), and mean transvalvular flow (r(s)=-0.31, P=0.01). BNP was directly related to valvular resistance (r(s)=0.42, P=0.0006) and wall motion score index (r(s)=0.36, P=0.004). BNP was higher in 29 patients with truly severe AS versus 40 with pseudosevere AS (median, 743 pg/mL [Q1, 471; Q3, 1356] versus 394 pg/mL [Q1, 191 to Q3, 906], P=0.012). BNP was a strong predictor of outcome. In the total cohort, cumulative 1-year survival of patients with BNP > or = 550 pg/mL was only 47+/-9% versus 97+/-3% with BNP < 550 (P<0.0001). In 29 patients who underwent valve replacement, postoperative 1-year survival was also markedly lower in patients with BNP > or = 550 pg/mL (53+/-13% versus 92+/-7%). CONCLUSIONS: BNP is significantly higher in truly severe than pseudosevere low-gradient AS and predicts survival of the whole cohort and in patients undergoing valve replacement.
- PublicationRestreintPreoperative posterior leaflet angle accurately predicts outcome after restrictive mitral valve annuloplasty for ischemic mitral regurgitation(American Heart Association, 2007-02-13) Sénéchal, Mario; Magne, Julien; Hachicha, Zeineb; Pibarot, Philippe; Dumesnil, Jean G.; Dagenais, FrançoisBACKGROUND: Ischemic mitral regurgitation (MR) often persists after restrictive mitral valve annuloplasty, in which case it is associated with worse clinical outcomes. The goal of the present study was to determine whether persistence of MR and/or clinical outcome could be predicted from preoperative analysis of mitral valve configuration METHODS AND RESULTS : In 51 consecutive patients undergoing restrictive annuloplasty for ischemic MR, posterior leaflet (PL) angle, anterior leaflet angle, coaptation distance, and tenting area were quantified by echocardiography before surgery (6+/-3 days), and MR severity was assessed before and early after surgery (9+/-4 days). Postoperatively, persistence of mild to moderate MR (vena contracta > 3 mm) was observed in 11 (22%) of the patients. The best predictor of postoperative persistence of MR was a PL angle > or = 45 degrees (sensitivity 100%, specificity 97%, positive predictive value 92%, negative predictive value 100%). Patients with persistent MR had markedly lower 3-year event-free survival (26+/-20%) compared with those with nonpersistent MR (75+/-12%, P=0.01). Preoperative presence of a PL angle > or = 45 degrees also was associated with a markedly lower 3-year event-free survival (22+/-17% versus 76+/-12%; P<0.001). CONCLUSIONS: In patients undergoing restrictive annuloplasty for ischemic MR, persistence of MR and 3-year event-free survival can accurately be predicted by preoperative analysis of mitral valve configuration. Patients with a PL angle > or = 45 degrees (ie, with high PL restriction) should thus be considered poor candidates for this procedure, and concomitant or alternative procedures should be contemplated.
- PublicationRestreintParadoxical low-flow, low-gradient severe aortic stenosis despite preserved ejection fraction is associated with higher afterload and reduced survival.(American Heart Association, etc., 2007-06-05) Hachicha, Zeineb; Bogaty, Peter; Pibarot, Philippe; Dumesnil, Jean G.Background— Recent studies and current clinical observations suggest that some patients with severe aortic stenosis on the basis of aortic valve area may paradoxically have a relatively low gradient despite the presence of a preserved left ventricular (LV) ejection fraction. The objective of the present study was to document the prevalence, potential mechanisms, and clinical relevance of this phenomenon. Methods and Results— We retrospectively studied the clinical and Doppler echocardiographic data of 512 consecutive patients with severe aortic stenosis (indexed aortic valve area 0.6 cm2 m 2) and preserved LV ejection fraction ( 50%). Of these patients, 331 (65%) had normal LV flow output defined as a stroke volume index 35 mL m2, and 181 (35%) had paradoxically low-flow output defined as stroke volume index 35 mL m 2. When compared with normal flow patients, low-flow patients had a higher prevalence of female gender (P 0.05), a lower transvalvular gradient (32 17 versus 40 15 mm Hg; P 0.001), a lower LV diastolic volume index (52 12 versus 59 13 mL m 2; P 0.001), lower LV ejection fraction (62 8% versus 68 7%; P 0.001), a higher level of LV global afterload reflected by a higher valvulo-arterial impedance (5.3 1.3 versus 4.1 0.7 mm Hg · mL 1 · m 2; P 0.001) and a lower overall 3-year survival (76% versus 86%; P 0.006). Only age (hazard ratio, 1.04; 95% CI, 1.01 to 1.08; P 0.025), valvulo-arterial impedance 5.5 mm Hg · mL 1 · m 2 (hazard ratio, 2.6; 95% CI, 1.2 to 5.7; P 0.017), and medical treatment (hazard ratio, 3.3; 95% CI, 1.8 to 6.7; P 0.0003) were independently associated with increased mortality. Conclusion— Patients with severe aortic stenosis may have low transvalvular flow and low gradients despite normal LV ejection fraction. A comprehensive evaluation shows that this pattern is in fact consistent with a more advanced stage of the disease and has a poorer prognosis. Such findings are clinically relevant because this condition may often be misdiagnosed, which leads to a neglect and/or an underestimation of symptoms and an inappropriate delay of aortic valve replacement surgery.
- PublicationRestreintUsefulness of exercise-stress echocardiography for risk stratification of true asymptomatic patients with aortic valve stenosis(European Society of Cardiology, 2010-03-21) Maréchaux, Sylvestre; Blais, Agnès; Bergeron, Sébastien; Bellouin, Annaïk; Hachicha, Zeineb; Pibarot, Philippe; Meimoun, Patrick; Dumesnil, Jean G.; Arsenault, Marie; Le Tourneau, Thierry; Ennezat, Pierre-VladimirAims : Abnormal exercise test defined as the occurrence of exercise limiting symptoms, fall in blood pressure below baseline, or complex ventricular arrhythmias is useful to predict clinical events in asymptomatic patients with aortic stenosis (AS). The purpose of this study was to determine whether exercise-stress echocardiography (ESE) adds any incremental prognostic value to resting echocardiography in patients with AS having a normal exercise response. Methods and results : One hundred and eighty-six asymptomatic patients with at least moderate AS and preserved LV ejection fraction (=50%) were assessed by Doppler-echocardiography at rest and during a maximum ramp semi-supine bicycle exercise test. Fifty-one (27%) patients had an abnormal exercise test and were excluded from the present analysis. Among the 135 patients with normal exercise test, 67 had an event (aortic valve replacement motivated by symptoms or cardiovascular death) at a mean follow-up of 20+14 months. The variables independently associated with events were: age =65 years [hazard ratio (HR) ¼ 1.96; 95% confidence interval (CI): 1.15–3.47; P ¼ 0.01], diabetes, (HR ¼ 3.20; 95% CI: 1.33–6.87; P ¼ 0.01), LV hypertrophy (HR ¼ 1.96; 95% CI: 1.17–3.27; P ¼ 0.01), resting mean gradient .35 mmHg (HR ¼ 3.60; 95% CI: 2.11–6.37; P , 0.0001), and exercise-induced increase in mean gradient .20 mmHg (HR ¼ 3.83; 95% CI: 2.16–6.67; P , 0.0001). Conclusion : The exercise-induced increase in transvalvular gradient may be helpful to improve risk stratification in asymptomatic AS patients with normal exercise response. These results thus suggest that ESE may provide additional prognostic information over that obtained from standard exercise testing and resting echocardiography.
- PublicationRestreintUsefulness of the valvuloarterial impedance to predict adverse outcome in asymptomatic aortic stenosis(Elsevier Biomedical, 2009-09-08) Hachicha, Zeineb; Pibarot, Philippe; Dumesnil, Jean G.Objectives: This study was designed to examine the prognostic value of valvuloarterial impedance (Z(va)) in patients with aortic stenosis (AS). Background: We previously showed that the Z(va) is superior to standard indexes of AS severity in estimating the global hemodynamic load faced by the left ventricle (LV) and predicting the occurrence of LV dysfunction. This index is calculated by dividing the estimated LV systolic pressure (systolic arterial pressure + mean transvalvular gradient) by the stroke volume indexed for the body surface area. Methods: We retrospectively analyzed the clinical and echocardiographic data of 544 consecutive patients having at least moderate AS (aortic jet velocity > or =2.5 m.s(-1)) and no symptoms at baseline. The primary end point for this study was the overall mortality regardless of the realization of aortic valve replacement (AVR). Results: Four-year survival was significantly (p < 0.001) lower in the patients with a baseline Z(va) > or =4.5 mm Hg x ml(-1) x m(2) (65 +/- 5%) compared with those with Z(va) between 3.5 and 4.5 mm Hg x ml(-1) x m(2) (78 +/- 4%) and those with Z(va) < or =3.5 mm Hg x ml(-1) x m(2) (88 +/- 3%). The risk of mortality was increased by 2.76-fold in patients with Z(va) > or =4.5 mm Hg x ml(-1) x m(2) and by 2.30-fold in those with a Z(va) between 3.5 and 4.5 mm Hg x ml(-1) x m(2) after adjusting for other risk factors and type of treatment (surgical vs. medical). Conclusions: Increased Z(va) is a marker of excessive LV hemodynamic load, and a value >3.5 successfully identifies patients with a poor outcome. These findings suggest that beyond standard indexes of stenosis severity, the consideration of Z(va) may be useful to improve risk stratification and clinical decision making in patients with AS.